2007-2018
Fall Semester 2022
Chemical Inventory Management: S&T Chemtrack System
Office Staff, Environmental Health and Safety, Missouri S&T
- General Information
- Introduce Environmental Health and Safety
- Show online General Laboratory Safety Training system
- Hazardous Material Safety and Management
- Chemtrack System
- Keeping an accurate chemical inventor
New Methods for C–N and C–C Bond Formation Based on Unique Reactivity in Iron Complexes
Dr. Jamie Neely, Professor, Dept. of Chem., St. Louis University, St. Louis
For more information, click here.
Abstract: First row transition metals present opportunities for the discovery of novel catalytic transformations enabled by their distinct reactivity. Iron complexes are especially attractive as transition metal catalysts given that iron is generally nontoxic and is the most abundant d-block metal in the Earth’s crust. Research in the Neely focuses on the development of new C–N and C–C bond-forming methods based on reactivity that is specific to iron. We take advantage of insights from stoichiometric studies to probe reaction mechanisms and optimize catalytic conditions. We are currently using this approach to explore iron-catalyzed methods for alkyne carboamination and linear trimerization.
Click to view Dr. Neely's Seminar Flyer.
Environmental Compliance: Hazardous Material and Chemical Waste Management
Office Staff, Environmental Health and Safety, Missouri S&T
- Hazardous Waste Management
- Federal Regulations
- Chemical Waste – proper storage and labeling
- Chemical Waste – pick-up request
- Biological Waste
- Universal Waste
- Spill Response
Chirality Determination and Enhancement of Carvone Using Microwave Three-Wave Mixing Spectroscopy
Nicole Moon, Graduate Student, Chemistry, Missouri S&T
Abstract: Building off the previous works of Schnell, Patterson, and Pate, a microwave three-wave mixing (M3WM) spectrometer has recently been constructed and demonstrated at Missouri University of Science and Technology for the use in chirality determination. Unique to this spectrometer is the use of multiple arbitrary waveform generators synchronized to one another to simultaneously generate the orthogonal microwave pulses needed for M3WM. The first molecule studied with this instrument was carvone, whose traditional microwave spectrum is dominated by internal rotation splittings caused by two non-equivalent methyl rotors. In addition to demonstrating the spectrometer’s capabilities, this experiment marked the first time a M3WM experiment was completely operable in the 6-18 GHz frequency region of the electromagnetic spectrum. Since the success of this initial experiment, preliminary work has begun on enhancing the chiral signal via a process known as chiral coherent quantum control. Recently acquired data shows much promise in this methodology. Within this seminar, the design, construction, and demonstration of the M3WM instrument’s capabilities using the enantiomers of carvone will be discussed along with a brief venture into the reinvestigation into the pure rotational spectrum of R-carvone.
High-spin quasiparticles in solid states
Dr. Hyunsoo Kim, Professor, Physics, Missouri S&T
Abstract: Quasiparticles with total angular momentum greater than j=1/2 can emerge in a solid state with strong spin-orbit interaction. Whilethe existence of such high-spin quasiparticles has been known for decades, their implication has been largely overlooked. The possibility of superconductivity beyond spin-triplet in such solid states attracted
substantial attention. In this talk, I will talk about unconventional quantum oscillations and superfluid response in half-Heusler YPtBi which is a topological semimetal with j=3/2 quasiparticles. The angledependent quantum oscillation exhibits striking anisotropy, and the London penetration depth varies as almost temperature-linear, both of which are not easily expected in a compound with cubic symmetry. These anomalous behaviors can be explained within j=3/2 Fermi surface and high-spin superconductivity.
Click to view Dr. Kim's Seminar Flyer.
Epitaxial Electrodeposition of Wide Bandgap Cuprous Bromides
Bin Luo, Graduate Student, Chemistry, Missouri S&T
Abstract: Cuprous halides are an important class of wide bandgap p-type semiconductors used in opto-electronics. Cuprous bromide (CuBr) shows potential for short-wavelength devices due to a large exciton binding energy (108 meV) and near-ultraviolet bandgap (3.1 eV). However, the growth of high-quality epitaxial CuBr films by electrodeposition has remained a challenge. Here, we introduce a low-cost electrochemical procedure for producing epitaxial CuBr(111) on a Ag(111) substrate by a [111]-oriented silver bromide (AgBr) buffer layer. The AgBr buffer layer forms during the electrodeposition of the CuBr. The mismatch between CuBr(111) and AgBr(111) is -1.3%. CuBr(100) is also produced on a Ag(100) surface by a AgBr(100) buffer layer that is rotated in-plane 45° relative to the Ag(100) surface.
Epitaxial Single-Domain Metal-Organic Framework Cu-BTC(111) Films by Electrochemical Conversion from Cu2O(111)
Xiaoting Zhang, Graduate Student, Chemistry, Missouri S&T
Abstract: Metal-organic frameworks (MOFs) are an important class of highly porous materials with extensive chemical and structural merits. However, the fabrication of MOF thin films orientated along all crystallographic axes remains a challenge. Here, we achieved highly crystalline single-domain MOF thin films with out-of-plane {111} crystal family by electrochemical conversion from cuprous oxide. Copper(II)-benzene-1,3,5-tricarboxylate, Cu3(BTC)2 (referred to as Cu-BTC) is a well-known metal-organic open framework material with a cubic crystal system. Highly ordered Cu-BTC(111) continuous thin films were produced by electrochemical oxidation using electrodeposited epitaxial Cu2O(111) films as substrate/precursor. In addition, free-standing Cu-BTC(111) membranes were obtained by epitaxial lift-off following the electrochemical etching of the residual Cu2O underneath Cu-BTC.
Developing a Community-of-Scholars Atmosphere in General Chemistry Courses
Dr. Steven W. Keller, Professor, Chemistry, University of Missouri, Columbia
Abstract: General Chemistry is often perceived (maybe even correctly) as a ”weed-out” class, a pair of courses literally designed to derail student goals and aspirations. Even in the absence of malicious intent, the combination of mathematical exactness and conceptual abstractness makes these courses difficult. While in no way am I advocating for us to shy away from challenging material, we will talk about ways of giving students a greater sense of ownership and inclusion even in a large lecture course. Individually designed research projects, small group activities (both in lab and in lecture) and a cooperative (as opposed to competitive) grading scheme are some ways I’ve been attempting to change the culture of the class.
Click to view Dr. Keller Seminar Flyer
Chasing Tack in Polymer (Gels)
Dr. Thomas Schuman, Professor, Chemistry, Missouri S&T
Abstract: Polymer gels are utilized for many applications: fuel cell membranes, ion exchange resins, super absorbent baby diapers, and, in our research, conformance control of eroded or fractured petroleum wells. Polymer gels are insoluble, crosslinked structures that can reduce permeability of otherwise open flow passages and, by disallowing water from flowing through the lease-resistance path, increases oil production by making water floods push oil rather than merely flow through unobstructed paths. The ability to redirect water to push oil is known as conformance control. Gels are made in water solution as bulk gels, resulting in a huge mass of water-swollen, crosslinked polymer. The bulk gel is dried and particulated to specific size distribution to produce what is known as preformed particle gels (PPG). These are redispersed into water and pumped into petroleum wells. The particles swell and their swollen mass sticks in pore channels, which reduces flow of that channel. Our recent developments have resulted in 6 patent/patent applications associated with compositions of polymer gels for conformance control purposes. In particular, the gel designs cause the swollen particle to display tack such that the particles can reassemble from PPG back into a bulk gel structure. A self-healing, auto-adherent aspect better occludes water channels and improves conformance control and oil recovery efficiency/reducing water cut of recovered fluid. The issue we have been chasing with respect to polymer gels is what enables self-healing, i.e., tack, and how do we design gels of different composition to possess tack? Tack is a polymer property where the polymer material is sticky and polymer chains can entangle in a structural way to develop strength. Plasticization is where polymers are swollen and have mobility and can entangle but not in a structural way; no strength is developed. Our first successful gel utilized a zirconium salt additive that provided tack, reassembly, and a strong bulk-gel-like material. A newly funded project is developing high temperature (300°C) PPG for sealing of geothermal well leakage. I will describe some of our developmental and initial work into the science of tack in polymer gels.
Click to view Dr. Thomas Schuman Flyer
Catalyst Design: Transition Metal Mixed Anionic Chalcogenides in Electrocatalytic Water Splitting and CO2 Reduction Applications
Ibrahim Abdullahi, Graduate Student, Chemistry, Missouri S&T
Abstract: While there is increasing depletion of the world’s fossil fuels, CO2 emissions from fossil fuels is rapidly increasing worldwide, and strategies are direly needed to prevent further increase in atmospheric CO2 levels. Electrochemical water splitting to generate O2 and H2 as zero emission energy source along with direct conversion of CO2 into value-added chemicals are viable approaches proposed to address this issue. Transition metal chalcogenides have been recognized as one of the most promising class of compounds that showed huge potential for both water splitting and CO2 reduction reaction (CO2RR). Our work focuses on catalyst design, via systematic and exploratory approaches to understand inherent property of catalyst from its isolated core metal complexes with M-En central core (M = metal; E = S, Se, and Te), and how it compares with a bulk nanostructured solid with similar M-En bonding nature, and their effect towards OER and CO2RR. This gives a good understanding of the active site chemistry, predict activity and trends as well as leads to a fundamental knowledge about better catalyst choice for OER and CO2RR. Various systematically designed electrocatalytic systems: tetrahedral bis(diselenoimidodiphosphinato) cobalt [Co{(SePiPr2)2N}2] and decacarbonyltrichromium diselenide [(CO)10Se2Cr3)]2- complex, metal embedded graphitic carbon aerogel from polyacrylonitrile, ternary metal based mixed anionic (telluro)-selenide and ceria-based fluorites series will be discussed, their syntheses, characterizations, and electrochemical studies towards OER and CO2RR will be presented.
Vibronic coupling in N-methylpyrrole
Alexander Davies, Post-doctoral fellow, Chemistry, Missouri S&T
Addressing diffusion in the solid photo- and photoeletrocatalysts
Pravas Deria, Associate professor, School of Chemical & Biomolecular Science, Southern Illinois University-Carbondale
Metal-Free Photoredox Catalysis for the S-Trifluoromethylation of Heteroaromatic Thiols
Raheemat Rafiu, Graduate Student, Chemistry, Missouri S&T
Evaluation of N-acetylcysteine Amide as a Potential treatment option for Traumatic Brain Injury using tandem LC-MS
Olajide Adetunji, Graduate Student, Chemistry, Missouri S&T
Development of Catalytic Membranes and Composites for Energy Storage Devices and Nonenzymatic Biosensors
Harish Singh, Graduate Student, Chemistry, Missouri S&T
Synthesis, Development and Applications of Novel Transition Metal Complexes
Meenakshi Sharma, Graduate Student, Chemistry, Missouri S&T
Accessing anionic and cationic redox in metal chalcogenides through building block approach
Santhoshkumar Sundaramoorthy, Graduate Student, Chemistry, Missouri S&T
Harnessing the chemistry of cementitious materials towards the next-generation eco-efficient concretes
Monday Okoronkwo, Assistant professor, Chemical and Biochemical Engineering, Missouri S&T
Exploring the Application of DNA Nanostructures in the Electrochemical Biosensors and Microbial Fuel Cells
Krishna Thapa, Graduate Student, Chemistry, Missouri S&T
Abstract: With the extraordinary biocompatibility and programmability to accurately organize nanoscale materials, DNA nanostructures have been extensively explored for various of applications, such as biosensing, imaging, drug delivery, and stimuli-responsive devices. In the past decades, DNA-based electrochemical biosensor has attracted broad scientific and clinical interests due to its unique hybridization specificity, fast response time, and potential for miniaturization. Here, a novel 3D DNA origami-based ultrasensitive electrochemical biosensor for detection of let-7i miRNA, a biomarker for Traumatic Brain Injury (TBI) will be presented. In addition, with its ability to self-assemble into diverse multidimensional structures, DNA origami nanostructure has shown great promise as a carrier for small organic molecules, such as chemotherapy drugs and fluorescent dyes. For the first time, a three-dimensional DNA origami nanostructure serving as electron mediator-methylene blue carriers was employed to enhance the electron production and transfer in E. Coli system-based Microbial Fuel Cells.
Introducing polybenzodiazine aerogels as all nitrogen analogs of polybenzoxazines; synthesis, characterization, and their application in CO2 capture
Vaibhav Edlabadkar, Graduate Student, Chemistry, Missouri S&T
Abstract: Tetrahydroquinazoline (THQ) was designed as an all-nitrogen analogue of main-stream benzoxazine monomers. THQ solutions in DMF gelled at 100 oC via HCl-catalyzed ring opening polymerization to polybenzodiazine (PBDAZ) wet gels, which were dried in an autoclave with supercritical fluid CO2 to nanoporous solids classified as aerogels. Such aerogels are referred to as PBDAZ-100 and undergo ring-fusion aromatization at 240 oC under O2 to PBDAZ-240. Chemical identification of PBDAZ-100 and PBDAZ-240 relied on consideration of all nine possible polymerization pathways, in combination with elemental analysis, infrared and solid-state 13C NMR spectroscopy, and 15N NMR spectroscopy of aerogels from selectively 15N-enriched THQ monomer. Subsequently, fully oxidized PBDAZ-240 aerogels were carbonized at 800 oC under Ar to carbon aerogels. The resulting C-PBDAZ-800 carbon aerogels were further etched chemically under flowing CO2 at 1000 oC. PBDAZ-derived carbons and etched carbons were evaluated for their CO2 adsorption capacity and selectivity towards other gases. CO2-etched carbon aerogels showed very high CO2 uptake (11.2 ± 0.9 mmol g−1 at 273 K, 1 bar). The high selectivity of CO2 versus H2 in the range of (407 ± 104) is attractive for pre-combustion capture of CO2 and the high selectivity of CO2 versus N2 in the range of (52 ± 18) is attractive for post-combustion CO2 capture from flue gases.
Development and Analysis of Ringdown-Free T1 Relaxation Methods
Zachary Mayes, Graduate Student, Chemistry, Missouri S&T
Abstract: Longitudinal nuclear-spin relaxation (T1 relaxation) has long been used to gain information about the immediate molecular vicinity of NMR-active nuclear spins. While the chemical shift offers information about the magnetic field at the location of an investigated nucleus and, thus, the electronic structure of a molecule, information gained from T1 relaxation relates to the mobility and vicinity of a molecule. The mobility of molecules is influenced by its rigidity, the temperature of the environment and, in case of porous media, by the pore size and molecule-surface interactions. Two new NMR relaxation techniques are introduced making it possible to accurately determine T1 times under specific conditions that would be considered unfavorable for NMR measurements. First, a pulse-ringdown-free Freeman-Hill-inspired experiment is presented, which is particularly useful when metal pressure probes are used for NMR investigations, such as the toroid cavity probe. Further developments of the ringdown-free T1 experiment are the RAPTOR (Rapid Acquisition Pulse Train to Observe Relaxation) method and its frequency-selective extension RAPTOR-S. Both RAPTOR sequences were developed to drastically reduce experimental time for T1 time determinations. The accuracy of the ringdown-free techniques including RAPTOR and RAPTOR-S are tested and compared with standard T1 methods.
Nitrene Transfer Chemistry Mediated via Transition Metal (M = Cu, Mn, Fe and Co) Coordination Reagents
Suraj Sahoo, Graduate Student, Chemistry, Missouri S&T
Abstract: A family of cationic divalent and monovalent metal complexes (M = Mn, Fe, Co, Cu) using tris[(tetramethylguanidino)phenyl]amine and corresponding bipodal congener (N-methyl-bis[(tetramethylguanidino)phenyl]amine) were synthesized. The tripodal complexes were obtained from the reaction of the corresponding ligand and [M(NCMe)6(PF6)2 precursors. Alternatively, the bipodal complexes were prepared via a two-step process, initially with the reaction between the ligands and metal chlorides (MnCl2, FeCl2 and CoCl2) followed by a substitution reaction with TlPF6 to afford bipodal metal complex analogues (with acetonitrile coordination) with the exception of copper, where in [Cu(NCMe)4][PF6]2 was used directly as the precursor. The characterization of this family of cationic complexes exhibited stoichiometric variations and structural complexities with the expected result that the bipodal analogues offered additional coordination sites for catalytic studies as compared to the tripodal complexes. An extensive comparative study was then carried out in terms of nitrene transfer chemistry towards aziridination of olefins with certain metal complexes showing additional activity towards formation of five membered heterocycles (pyrrolidines and imidazolines) in presence of excess olefins or acetonitrile. The catalytic reactions were then judiciously optimized with the most productive iron reagents, and mechanistic studies uncovered the dual role of the metal as a nitrene-transfer agent and a Lewis acid.
Development of Rapid and Sensitive Methods for Trace Analysis of Phytohormones and Lipid Peroxidation Products in Corn Seeds
Sargun Kaur, Graduate Student, Chemistry, Missouri S&T
Abstract: Plant seed germination, growth, and response to biotic and abiotic stresses are regulated by plant hormones (phytohormones). Various phytohormones have synergistic or antagonistic functions during the germination and growth stages. Stored seeds can deteriorate and become susceptible to various environmental stresses and diseases. Therefore, the measurement of phytohormone and other metabolite levels can provide an insight into seed germination, viability, and vigor. Simultaneous screening of different classes of phytohormones and lipid-peroxidation products was accomplished with a newly developed liquid chromatography – tandem mass spectrometry (LC-MS/MS) method using rapid non-derivatized sample preparation. The types and levels of volatile compounds emitted from seeds can also be a quantitative indicator of the seed germination potential and vigor. Low molecular weight volatile compounds such as short-chain aldehydes, alcohols and carboxylic acids may be used as chemical markers for assessing the seed quality since they are produced from the lipid peroxidation initiated by autooxidation or enzymatic oxidation of unsaturated fatty acids during the seed storage and aging period. Therefore, a headspace – solid-phase microextraction – gas chromatography/mass spectrometry (HS-SPME-GC/MS) method was developed and validated for analyzing these volatile organic compounds in corn (Zea mays) seeds.
Spring Semester 2022
Career Opportunities and Employer Relations: Student Services
Hannah Ramsey-Standage, Student Service Coordinator, COER, Missouri S&T
Description: Career Opportunities and Employer Relations (COER) is located on the 3rd floor of Norwood Hall. COER is dedicated to helping Missouri S&T students and alumni pursue their career goals assisting in all stages from summer internships, to co-ops and full-time employment. Services include student advising, LinkedIn reviews, professional development workshops, career fairs and more!
Designing complex chalcogenides using building block approach for energy storage and energy conversion applications
Srikanth Balijapelly, Graduate Student, Dept. of Chem., Missouri S&T
Abstract: Solid-state chalcogenides have been the foundation of electronics industry and many emerging technologies such as batteries, thermoelectric, spintronics and non-linear optics. Therefore, new materials discovery with enhanced properties has been an attractive and modern area of research in the current decade. Chalcogenides are compounds of metal with sulfur, selenium, and tellurium. Semiconducting to metallic nature induced by lower electronegativity of S, Se, and Te makes this class of compounds scientifically interesting for diverse applications. However, a large class of complex chalcogenides are still undiscovered due to the lack of predictive tools in high temperature exploratory solid-state reactions. In this work, we present a new synthetic methodology called ‘Building Block Approach’ which takes advantage of the preformed main group molecular building units as reaction precursors with metal chloride salts. Employing this approach, a library of materials from layered to three-dimensional crystal structures have been discovered. The in situ synchrotron powder X-ray diffraction studies are employed to understand the reaction mechanism and product formation, which unveiled that product formation takes place within a second at a particular temperature through a solid-state diffusion. Magnetism, linear and nonlinear optical properties, ionic conductivity, and electrochemical properties of the synthesized materials will be presented.
Rapid synthesis of primary amines by radical C-H amination
Dr. Robert J. Comito, Dept. of Chem., University of Houston, Houston, TX
For more information, visit the webpage here.
Abstract: Simple amination of sp3 C-H bonds to primary amines (RNH2) would rapidly accelerate the synthesis of bioactive alkaloids and the postsynthetic modification of polymers. Yet this transformation remains highly limited in comparison to simple hydroxylation and halogenation, reactions fundamental both to both biosynthesis and industrial organic chemistry. This talk discusses my laboratory’s development of an intermolecular sp3 C-H amination protocol that delivers primary ammonium salts (R-NH3Cl) in one pot upon aqueous workup. Mild conditions, good site selectivity, and reactivity on unactivated sp3 C-H bonds distinguish our method from other radical CH amination reactions. We have further characterized a unique mechanism involving hydrogen-atom transfer to iminyl radicals that will inform the development of CH activation chemistry. I discuss out ongoing application of this method to material synthesis and our strategies to control site selectivity by electronic tuning.
About the Speaker: Robert Comito is a synthetic organic chemist who studies new reactions and catalysts for small molecule and polymer synthesis. Robert completed a BA in chemistry and mathematics at Rutgers University in New Jersey, the state where Robert grew up. While at Rutgers, Robert studied medicinal chemistry with Prof. Spencer Knapp and at the Merck Future Talent Program. Robert then completed his PhD in 2014 at Princeton University with future Nobel Prize winner David MacMillan. His thesis focused on asymmetric alkylation reactions using organocatalysis and the total synthesis of polypyrrolindoline natural products. Robert then pursued postdoctoral studies at Massachusetts Institute of Technology under Mircea Dinca, where he studied olefin upgrading and polymer synthesis with metal-organic frameworks. In 2018, Robert joined the faculty at the University of Houston as the Herman and Joan Suit Professor of Polymer Chemistry. His research is supported by the ACS Petroleum Research Fund and the Welch Foundation. Robert currently leads a team of 8 graduate students, one postdoc, and four undergraduates. Robert also serves on the UH Chemistry department's graduate admissions committee and is a good person to contact about graduate opportunities at UH.
The informational flyer can be downloaded here: Feb. 7 Flyer (Dr. Robert Comito)
Synthesis of Tetraaza and Tetraamido Macrocyclic Ligands and their Metal Complexes: Potential Catalysts in Nitrene Transfer Chemistry
Himanshu Bhatia, Graduate Student, Dept. of Chem., Missouri S&T
Abstract: Atom/group-transfer chemistry along with direct and selective functionalization of C-H and C=C bonds has a great potential towards generating a plethora of high value chemical compounds. Our work seeks to produce and expand a library of catalysts used for carbon or nitrogen group insertion chemistry by utilizing earth-abundant transition metals. Macrocyclic ligand metal complexes have been targeted for their potential as catalysts, as they are thermodynamically more stable and oxidatively robust. Recent work has involved frameworks with the end goal of N4 coordination of the desired transition metals. Tetraaza macrocyclic chiral solvating agents (TAMCSA) have been synthesized and are currently being further explored as chelating agents of metal catalysts for nitrene- and carbene- transfer chemistry vis-à-vis C–H and C=C bonds. A series of tetraamido and tetraaza macrocyclic ligands have been synthesized and metallated with suitable Cu, Fe and Co precursors, and further employed for the aziridination of olefins and amination of C–H bonds.
Fiber-Optic Raman Sensor in Material Science and Biochemical Application
Bohong Zhang, Graduate Student, Electrical Engineering, Missouri S&T
Abtract: In the past few decades, Raman spectroscopy has had undergone growth as a great molecular analysis technique. When light interacts with molecules in the sample, most photons are dispersed or scattered at equal electricity as they are incident. However, a very small number of photons appeared at energy levels to form inelastic scattering, which is detected by the spectrometer as the Raman spectrum. Due to the different molecules constituting the material, the energy transferred by the scattered light through molecular vibration varies greatly. Then, Raman spectroscopy has been considered a fingerprint technique to identify and distinguish molecules in materials. Compared with the traditional Raman spectroscopy system, the fiber-optic Raman sensor has unique advantages such as small size, lightweight, low cost, and high precision. Fiber-optic Raman sensor has been found in various sensing and measurement applications. Based on the micro-material properties, the fiber-optic Raman probe is widely used in the research of material science and biomedical. In this seminar, several fiber-optic Raman probes such as the High-Temperature Raman probe, Miniaturized Raman probe, and surface-enhanced Raman probe will be introduced with different applications.
Computational Study of Rotation-Inversion Isomerization of N-Ethyl-N-(2,2,2-trifluoroethyl) Methyl Carbamate
Brian Jameson, Graduate Student, Dept. of Chem., Missouri S&T
Abstract: While developing a synthetic route for fluoro-functionalized lysine derivatives, we observed the presence of two quartets in the 13C NMR spectra corresponding to the -CF3 group of amine containing intermediates with a tert-butyl carbamate (Boc) protecting group. The presence of the second set of peaks occurred only in Boc protected species, and we hypothesized that two isomers of the carbamate intermediates were present in solution. Based on extensive computational studies of the conformational space, we can confidently assign the two sets of -CF3 quartets to two rotational isomers (rotamers) about the N-CO2R carbamate bond. Here, we report the results of computational studies for the model system N-ethyl-N-(2,2,2-trifluoroethyl) methyl carbamate which explain the presence of two rotamers. The CN rotational profiles were investigated by coupled rotation-inversion mapping, indicating eight distinct transition state structures between four minima. The computed 13C NMR chemical shifts and 13C-19F J-coupling constants of the most stable rotamers are in good agreement with the experimental spectra.
Figure 1. Rotation-inversion surfaces E(ρ,π) for E/Z-isomerizations E-1 ⇌ Z-2 via TS structures 3b.
Weyl semimetals: the case of CeAlGe
Dr. Halyna Hodovanets, Assistant Professor, Physics, Missouri S&T
Abstract: Single crystals have played an important role in technological advances. One notable example is silicon which is widely used nowadays in transistors, solar cells, semiconductor detectors, and most importantly integrated circuits (chips) used in the computer. Up until now, the scaled size, capacity, and speed of those chips have progressed immensely due to technological advances and have been roughly following Moore’s law. In order to achieve a further continued technology scaling of integrated circuits or replace them with new devices, new materials are necessary. New materials are especially important for the next generation of computers-quantum computers.
Weyl semimetals are among the materials proposed to have significant potential in informational technologies [1] and to harbor the necessary elements for quantum computing [2]. They host Weyl nodes at specific points in their Brillouin zone, a pair of relativistic fermions with different chirality, Weyl fermions. The nontrivial momentum-space topology due to the Weyl nodes leads to various fascinating phenomena, such as the chiral anomaly, chiral magnetic effect, anomalous magnetoresistance and Hall effect, [3,4] large nonsaturating thermopower [6] and ultrafast photocurrents [7] just to name a few. The essential ingredients for the realization of the Weyl semimetal are the absence of inversion symmetry and or time-reversal symmetry. The RAlX (where R = Rare Earth and X = Ge, Si) family has been recently identified as a large class of Weyl semimetal based on systematic first-principles band structure calculations.[8] In this respect, I will present details and importance of crystal growth of non-centrosymmetric CeAlGe single crystals, their physical properties, anomalous magnetotransport, and discuss the future implications of our findings and the tunability of RAlGe and RAlSi families.
[1] B. Zhao et al., Phys. Rev. Research 2, 013286 (2020).
[2] N. P. Armitage, E. J. Mele, and A. Vishwanath, Rev. Mod. Phys. 90, 015001 (2018).
[3] L. Wollmann, A. K. Nayak, S.S.P Parkin, and C. Felser, Book Series: Annual Review of Materials Research 47, 247 (2017).
[4] D. Li et al., Nature 572, 624 (2019).
[5] B. Skinner et al., Sci. Adv. 4, 1 (2019).
[6] N. Sirica et al., Phys. Rev. Lett. 122, 197401 (2019).
[7] G. Chang et al., Phys. Rev. B 97, 041104 (2018).
For more information, see the seminar flyer for Dr. Halyna Hodovanets.
Epitaxial electrodeposition of transparent hole conductors and lift-off of ordered foils for flexible electronics
Bin Luo, Graduate Student, Dept. of Chem., Missouri S&T
Abstract: Epitaxial electrodeposition is a simple, low-cost technology to produce highly ordered materials on single-crystal surfaces. Epitaxial lift-off of films can produce free-standing ordered foils for flexible electronics. In this talk, we will discuss the epitaxial electrodeposition of materials and lift-off flexible foils. Firstly, an epitaxial Cu(111) film was electrodeposited on a self-assembled monolayer (SAM) of the amino acid L-cysteine on Au(111). Direct epitaxial lift-off of the Cu film without etching gives a single-crystal-like Cu(111) foil which could be utilized as flexible substrate for further growing other ordered materials. Secondly, epitaxial hole conductor CuSCN nanorods were electrodeposited onto Au(111). Highly-ordered CuSCN could provide a low density of defect sites and grain boundaries, suppressing charge recombination probabilities and facilitating efficient charge transport in opto-electronic devices such as perovskite solar cells. An ordered and transparent CuSCN foil was produced by epitaxial lift-off following a triiodide etch of the thin Au substrate. In addition, preliminary results will be presented on the low-mismatch CuCl(111)//Si(111) epitaxial systems.
Publications:
1. Luo, B.; Banik, A.; Bohannan, E. W.; Switzer, J. A. Epitaxial Electrodeposition of Cu (111) onto an l-Cysteine Self-Assembled Monolayer on Au (111) and Epitaxial Lift-Off of Single-Crystal-like Cu Foils for Flexible Electronics. J. Phys. Chem. C 2020, 124, 21426-21434.
2. Banik, A.; Tubbesing, J. Z.; Luo, B.; Zhang, X.; Switzer, J. A. Epitaxial Electrodeposition of Optically Transparent Hole-Conducting CuI on n-Si (111). Chem. Mater. 2021, 33, 3220-3227.
3. Luo, B.; Banik, A.; Bohannan, E. W.; Switzer, J. A. Epitaxial Electrodeposition of Hole-Transport β-CuSCN Nanorods on Au(111) at the Wafer Scale and Lift-off to Produce Flexible and Transparent Foils. Chem. Mater. 2022, 34, 970-978.
Molecular Engineering and Three-Dimensional Mapping of Interfaces at the Nanoscale
Dr. Shan Zhou (faculty candidate), Department of Materials Science and Engineering. University of Illinois at Urbana-Champaign
Abstract: I will discuss my work and vision on the foundational role of nanomaterial interfaces to address pressing needs in applications related tomaterial cytotoxicity, chiral metamaterials, energy storage and biomedicines. The first part of the talk will focus on molecular engineering of nanoparticles, including a “uphill” ligand exchange strategy that enables a complete replacement of strongly-bound surface species with weakly-bound biocompatible ligands on gold nanoparticles to reduce their cytotoxicity, a
regioselective strategy to decorate macromolecules precisely on designated sites of gold nanoparticles for their promises in biomedicines and selfassemblies, and an unprecedented demonstration on largescale selfassembled chiral superlattices achieved by tuning interparticle interactions via surface modifications. In the second part of my talk, I will discuss my efforts to understand the interfacial structures at the underexplored nanoscale by direct imaging. I will describe our recent development of electrochemical-3D-atomic force microscopy, a new tool with a high spatial resolution (sub-10 pm) and unique capabilities of characterizing soft interfacial structures at a solid-liquid interface, and showcase its capability in molecular mapping to establish the structure-property relationship in energy storage. These new advancements in surface chemistry and interface science are paving the way for the rational development of nanomaterials sought in energy and biomedical research.
Advanced Analytical Instrument Methods for Structure Determination
Dr. Li Li, Center for Alzheimer’s and Neurodegenerative Diseases, University of Texas Southwestern Medical Center
Abstract: The advances of modern analytical instruments have greatly extended our detection limit and improved resolution for structure determination, not only for small molecules but also for big complexes of proteins. Mass spectrometry and cryo-electron spectroscopy are among the most powerful analytical tools for life science studies. In this talk, I will discuss three associated projects. 1. Development of a novel ionization method named Continuous Flow Desorption Ionization (CF_EDESI) for mass spectrometry. This ionization method improves on traditional electrospray ionization (ESI) by conserving protein tertiary structure, reducing signal from undesired lipid adducts, and affording direct coupling with normal phase chiral separation. 2. Development of covalent and non-covalent “shift reagents” for improved separation of mono- and disaccharides in ion mobility mass spectrometry. 3. Application of cryo-electron microscopy and other structure biology methods to determine the 3D structures of fibrils formed from acetylated protein Tau peptides. I will also briefly discuss mass spectrometry tools for identifying microorganisms (Shimadzu MALDI_iD plus or Bruker MALDI Biotyper), imaging tissues (Bruker
Tissuetyper), and identifying protein-protein interactions (crosslinking mass spectrometry).
Enhanced Separation of Rare Earth Elements (REEs) using Novel Ionic Liquids
Dr. Lana Z. Alagha, Dept. of Mining and Nuclear Engineering, Missouri S&T
Abstract: Owing to their crucial importance, increasing demands, and monopolistic supply, the development of novel technologies for the recovery of critical metals is of considerable significance. Ionic liquids are currently applied as alternatives to conventional solvents and extractants that are used in the solvent extraction process, which plays a major role in the hydrometallurgical separation of critical metals, due to their higher selectivity and physiochemical flexibility. This research developed a new type of ammonium-based functionalized ionic liquids (FILs) for improved extraction and separation of rare earth elements (REEs). Both anions and cations of synthesized FILs are composed of only C, H, O, and N atoms, which are incinerable and therefore would help to reduce the amounts of solid wastes produced by the extraction process. The developed FILs shows high extraction efficiency, improved loading capacity, fast kinetics, and enhanced selectivity towards heavy REEs. Moreover, back-extraction studies revealed that the synthesized FILs can be recycled and effectively reused in the extraction process.
Novel Synthetic methods for the Trifluoromethylation of Aldehyde Derived Hydrazones
Puspa Aryal, Graduate Student, Dept. of Chem., Missouri S&T
Abstract:
Part 1: Cu-Catalyzed C(sp2–H)-Trifluoromethylation of Aldehyde Hydrazones with Langlois Reagent
The C(sp2)-H trifluoromethylation of hydrazones would give access to the a-trifluoromethylated hydrazones that can serve as intermediates in the synthesis of pharmaceutically interesting, fluorinated compounds. Here, we demonstrate the Cu-Catalyzed C(sp2)-H trifluoromethylation of the aldehyde hydrazones under environmentally benign conditions using the readily available and cost effective Langlois reagent (sodium trifluoromethanesulfinate). This reaction is broadly applicable to a series of aromatic aldehyde N-amino morpholine hydrazones to give the corresponding C(sp2)-trifluoromethyl hydrazones in moderate to high yields. The reaction generally tolerates a series of electron-releasing as well as electron-withdrawing substituents on the aromatic ring.
Part 2: Acetic Acid-Promoted Transition Metal-Free, Photo redox Catalyzed Trifluoromethylation of Aldehyde Hydrazones
Radical C(sp2)-H trifluoromethylation of aromatic aldehyde hydrazones is achieved in moderate to high yields under oxidative photo redox catalysis conditions, using inexpensive, bench-stable sodium trifluoromethanesulfinate (Langlois reagent), and Rose Bengal (RB) as the photocatalyst in the presence of acetic acid as the promoter. Acetic acid accelerates the rates of trifluoromethylation reactions and substantially eliminates the formation of the adventitious byproducts.
Metal Sulfides as Emerging Paradigm for the Sequestration of Toxic Heavy Metals and Radionuclides
Dr. Saiful M. Islam, Dept. of Chem., Jackson State University, Jackson, MS
For more information, visit the webpage here.
Abstract: Efficient treatment of wastewater such as industrial and nuclear waste effluents is one of the major concerns for countries all over the world. The design of an efficient and cost-effective adsorbent of toxic ions is of great interest to the scientific community. Metal sulfide is a remarkable class of materials that can lay out highly ordered crystalline and disordered amorphous solids with diverse structural features. Among these, the crystalline materials with molecular anionic features or open frameworks three- and two-dimensional structures display a rich abundance of sulfide that are exposed on building units. Similar exposure of sulfides is also observed in the meso to microporous amorphous metal sulfides. An integrated feature of the building motifs, surface-exposed basic frameworks and the strong Lewis acid-base interactions of the soft polarizable Lewis basic sulfides and Lewis acidic metal ions synergistically display an exceptional efficiency, selectivity, sorption kinetics for soft or relatively soft metal ions. Here, this research talk will focus on the rational design and the synthesis of metal sulfides with targeted sorption properties, structural features, and their applications in the sequestrations of chemically soft heavy metal and radioactive ions, as well as toxic gaseous species.
Click to view Dr. Islam's Seminar Flyer.
Fall Semester 2021
Hazardous Material and Chemical Waste Management
Office Staff, Environmental Health and Safety, Missouri S&T
Abstract:
Hazardous Waste Management
- Federal Regulations
- Chemical Waste - proper storage and labeling
- Chemical Waste - pick-up request
- Biological Waste
- Universal Waste
- Spill Response
S&T Chemtrack System
Office Staff, Environmental Health and Safety, Missouri S&T
Abstract:
- General Information
- Introduce Environmental Health and Safety
- Show online General Laboratory Safety Training system
- Hazardous Material Safety and Management
- Chemtrack System
- Keeping an accurate chemical inventory
Explosives education and research opportunities at Missouri S&T
Dr. Kwame Awuah-Offei, Interim Director Mining Eng., Professor, Mining & Nuc. Eng., Missouri S&T
Abstract: Missouri S&T has a long history of education and research relating to explosives and energetic materials. Our explosives engineering MS and PhD programs are unique in the US and offer a variety of courses and research opportunities for students and faculty. The current research initiatives include traumatic brain injury, mine safety, structural response, and industrial and other applications of explosives. This presentation provides an overview of the educational and research opportunities available through the Explosives Engineering program. The presentation emphasizes the role chemistry can play in advancing S&T’s research and educational mission in energetic materials and explosives.
For more information, see the flyer here.
Accessing Mitochondrial Targets for Therapeutic Gain in Major Diseases
Dr. Shanta Dhar, Biochem. and Molecular Bio., Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine
Abstract: Noncommunicable and infectious diseases need innovative ways for treatment and prevention. For example, tumor cells adapt to diverge survival strategies defying traditional cancer therapies and challenge us to pursue new mechanistic and multimodal approaches. Our community needs to be well-equipped to handle emerging and re-emerging pathogens through rapid intervention, prevention, and treatment. Similarly, atherosclerosis and other hypercholesterolemia-related conditions pose a unique threat. Addressing resistant cancers, viral diseases, and cardiovascular diseases in general population as well as in pregnant women comes with significant barriers to effective treatment. In this presentation, I will discuss some of our recent developments on platform nanotechnologies which can utilize intracellular targeting strategies, use of prodrugs, and selective biological membrane crossing abilities to bring therapeutic gain in major diseases such as resistant cancers, atherosclerosis, and viral diseases such as HIV.
View the informational flyer here.
Chemical Education and Outreach beyond Broader Impacts
Dr. Nancy Ruzycki, Mat. Sci. and Eng., University of Florida
Abstract: Academics often engage in broader impact efforts related to their research work designed to excite K12 students about science, but these efforts rarely result in any academic benefit for the student or teachers in the immediate community. How can graduate students and academic faculty design broader impact activities which benefit students and teachers and help to build your profile for authentic broader impact?
Being able to align authentic broader impact to research goals requires development of a logic model and use of system thinking practices to ensure there are measurable outcomes for activities at the student and teacher level in addition to having meaningful alignment to research projects. This talk will showcase the landscape of K12 opportunities and how you can create a logic model which addresses and aligns activities and outcomes. These logic models are also appropriate for use in NSF proposals.
For more information, see the flyer here.
Electron (De)Localization in f-Element Systems: From Fundamental Questions to QIS Design Principles
Dr. Henry S. La Pierre, Dept. of Chem., Georgia Institute of Technology
Abstract: The La Pierre group studies how collective magnetic, physical, and chemical properties arise from electron (de)localization phenomena in f-element systems. Our studies include the development of solid-state and solution methodologies for the synthesis of novel lanthanide and actinide (Th – Pu) materials and complexes. These synthetic efforts are paired with synchrotron and neutron spectroscopies and physical property studies to break down the challenge of understanding the electronic structure of f-element systems. Particularly in solid-state systems, the f-elements present unique valence electronic structures due the near degeneracies engendered in these systems and strong electron correlation. Our efforts to-date have focused on the synthesis and analysis of systems governed by one of three phenomena: magnetic super-exchange (i.e. exchange coupled systems), multi-configurational electronic structures (ground state degeneracy including hybridization with ligand/band states), and mixed-valence metal ions (i.e. mixed f/d occupancy and mixed-oxidation states). Understanding and controlling the manifestation of these phenomena in molecular systems is crucial for understanding the interplay of these phenomena underpinning topological insulators such as SmB6 and PuB6 and superconductors such as CeCoIn5 and PuCoGa5. In turn, the group has employed this expanded fundamental understanding of f-element electronic structure to construct components of quantum information technologies (e.g. qubits, single-molecule magnets).
See the flyer here.
Designer Nanoparticles to Overcome Therapeutic Resistance in Cancer
Dr. Raghuraman Kannan, Dept. of Radiology and Dept. of Bioeng., University of Missouri-Columbia
Abstract: Lung cancer is the number one cause of cancer-related deaths in men and women, with an 8-10 month post-treatment median survival time. Non-Small Cell Lung Cancer (NSCLC) accounts for 80 % of lung cancers. The treatment plan for NSCLC patients is determined based on the active mutations (EGFR, ALK/ROS, and KRAS) present in the tumor. For example, if the patient bears mutations in the EGFR region, the treatment plan involves tyrosine kinase inhibitors (TKI) such as Osimertinib or Erlotinib. The initial treatment eliminates the tumor from the patient, but the cancer returns after 12-14 months. But, this time, the TKIs fail to control the tumor growth, finding an alternative pathway to survive. Our team elucidated the mechanism of drug resistance and identified the alternative biomarker pathway. Based on the data, we developed an RNAi -nanoparticle, which can reduce the tumor's biomarkers (or protein) levels. The reduction in protein levels reverses the drug resistance in cancer and sensitizes it to TKI. Furthermore, we demonstrated that this nanoparticle could control tumor growth in several animal studies. In the talk, I will present the synthesis of the designer RNAi nanoparticle and results from cell and animal studies.
For more information, see the flyer here.
Strong-field spectroscopies with ultrafast laser pulses
Dr. Anh-Thu Le, Dept. of Physics, University of Connecticut
Abstract: Recent progress in laser technology has led to new coherent light sources that can be used to investigate ultrafast processes in matter. To take advantage of these new light sources, different experimental techniques have been developed to reveal the inner-workings of coupled electron-nuclear dynamics in molecules. Our group has developed theoretical and computational tools to understand and decode hidden information from the experimental measurements. In this talk, I will present our group’s recent progress in understanding ultrafast intense laser-matter interactions using some of the most promising techniques such as laser-induced electron diffraction, high-harmonic generation spectroscopy, and attosecond transient absorption spectroscopy. Throughout the talk, I will also address the challenges and opportunities for practical realization of molecular "movies" with atomic resolution in space and time that can provide new insights into fundamental chemical reactions.
O2 Complexes
Amanda J. Duerden, Graduate Student, Dept. of Chem., Missouri S&T
Abstract: Fundamental knowledge about Van der Waals (VDW) complexes (provided by the acquisition and interpretation of laboratory data in conjunction with theoretical and computational results), provides critical information for our understanding of chemical compositions, interactions, and reactions within our atmosphere, and throughout the universe. Despite the relevance, and longstanding interest, complexes involving molecular oxygen are still shrouded in mystery due to the incredible difficulty in nearly every aspect of their study. This talk centers around invoking a 3-fold intertwined approach blending improving experimental data acquisition, fitting, and potential energy surfaces to explore of a family of small molecule O2-complexes. Resulting serendipitous discoveries will also be discussed.
Evaluation of N-Acetylcysteine Amide as a Therapeutic for Traumatic Brain Injury Using LC-MS/MS
Olajide Adetunji, Graduate Student, Dept. of Chem., Missouri S&T
Abstract: Head insult through forceful contact or explosion are the major causes of traumatic brain injury (TBI). The long-term TBI effects may be the result of oxidative stress, which arises from increased reactive oxygen species after physical disruption of neurons and glial cells. Emphasis has been placed on diagnosis, but an effective treatment remains lacking for this disease. In our study, N-acetylcysteine amide (NACA), an antioxidant prodrug with good bioavailability was evaluated for preventive and therapeutic efficacy for TBI-related oxidative damage. To induce mild to severe TBI, Rats were exposed to open-field blasts designed to mimic real-life explosion effects. Rats were administered NACA at varying concentrations and times to optimize the dosing conditions for this study. At the treatment-period end, blood, urine, and brain tissue samples were collected from the test animals. Rigorous sample preparation was conducted prior to the liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis to determine the levels of potential TBI biomarkers. LC-MS/MS methods were developed in both positive and negative electrospray ionization modes which yielded excellent sensitivity, linearity, recovery, and reproducibility for the investigated analytes. Oxidative stress biomarkers such as reduced/oxidized glutathione, N-acetylaspartic acid, 5-hydroxyindoleacetic acid, 8-isoprostaglandin and 4-hydroxynonenal were measured to evaluate the antioxidant treatment efficacy.
Metal-Free Photoredox-Catalysis for the S Trifluoromethylation (S–CF3) of Thiols
Raheemat Rafiu, Graduate Student, Dept. of Chem., Missouri S&T
Abstract: The S-Trifluoromethylation of Thiols provides access to pharmaceutically interesting compounds. The current synthetic methods for this trifluoromethylation reaction involve the use of either expensive noble-metal-based organometallic catalysts and expensive or toxic reagents. We have demonstrated a convenient visible-light photoredox catalyzed S-trifluoromethylation of various thiols under metal-free conditions, using the cost-effective sodium trifluoromethanesulfinate (Langlois regent) as the trifluoromethylating agent and diacetyl as the photocatalyst. This novel organocatalysis-based synthetic method provides a convenient and cost-effective alternative to the transition-metal-catalyzed photoredox reactions.
Monitoring pteridine levels in a progressive breast cancer cell model using HPLC-MS/MS
Lindsey K. Rasmussen, Graduate Student, Dept. of Chem., Missouri S&T
Abstract: Pteridines include folate-derived metabolites that have been associated with certain cancers in clinical studies. However, their biological significance in cancer metabolism remains poorly understood. The purpose of this study was to examine the effects of tumorigenicity on pteridine metabolism by studying a panel of 15 pteridine derivatives using a progressive, isogenic human breast cell line model with and without folic acid dosing. Non-tumorigenic MCF10A, pre-malignant MCF10AT, and tumorigenic MCF10CA1a cells were dosed with folic acid and cultured. Pteridines were then analyzed in both intracellular and extracellular contexts using an improved HPLC-MS/MS method. Folic acid dosing resulted in increased extracellular levels of several pteridines in a dose-dependent manner. Extracellular pterin and 6-hydroxylumazine further correlated with tumorigenicity upon folic acid dosing, providing in vitro evidence in support of their development as novel cancer biomarkers. The pathway and metabolism of these pteridine breast cancer biomarkers derived from folic acid were further investigated. To the best of our knowledge, this study presents the first use of an isogenic cancer cell model to investigate the effects of tumorigenicity on pteridine metabolism. This unique methodology may be extended to other metabolites and diseases to better understand the role of metabolites in disease etiology and progression.
Morphology-dependent mechanical properties of shape memory poly(isocyanurate-urethane) (PIR-PUR) aerogels
A B M Shaheen ud Doulah, Graduate Student, Dept. of Chem., Missouri S&T
Abstract: The catalytic activity of a large number of metal ions is compared with a well-known catalyst, dibutyltin dilaurate, in the formation of shape memory poly(isocyanurate-urethane) (PIR-PUR) aerogels. In turn, the catalytic activity, and thereby the gelation time, was correlated with the nanomorphology and the mechanical properties of the resulting materials. Fourth-period salts from FeCl3 to GaCl3 as well as InCl3 and SnCl4 catalyze formation of PIR-PUR aerogels. 119Sn NMR, indicates complex formation of the metal ion with TEG followed by reaction with the isocyanate. The gelation rate was found to increase from Fe to Cu and decline from Cu to Ga. As the gelation time decreased, the morphology of PIR-PUR aerogels changed from bicontinuous to spheroidal. For equal gelation times, the skeletal structural features were similar, irrespective of catalyst. Aerogels with bicontinuous frameworks were stiffer than those with spheroidal frameworks, and those consisting of smaller spheres were stiffer than those with larger spheres. Next, through structural design at the macro (bulk) scale, the shape-memory response of the stiffer version of these PIR-PUR aerogels (e.g., those with bicontinuous nanomorphologies), was augmented with an auxetic effect manifested by a negative Poisson’s ratio of approximately −0.8 at 15% compressive strain.
Multinary Sulfides with Potential Applications in Infrared Nonlinear Optical Devices
Dr. Jennifer Aitken, Chem. and Biochem., Duquesne University, Pittsburgh, PA
Abstract: Currently the only way to access the mid-IR spectral region using all solid-state laser (SSL) technology is with the use of down-conversion processes, such as second harmonic generation (SHG), implementing nonlinear optical (NLO) crystals. Yet, the current commercially-available IR NLO crystals have several shortcomings, including multiphoton absorption effects and low laser-induced damage thresholds (LIDTs) that limit the wavelength range and power output of the devices. Several groups are searching for new IR NLO materials implementing different strategies with hopes to access noncentrosymmetric (NCS) materials, because the lack of an inversion center is the first criterion for an SHG crystal. Our group has chosen to pursue the family of quaternary diamond-like semiconductors because their compositions are predictable based on valence electron rules and their structures are inherently noncentrosymmetric. Recently, we have identified several outstanding quaternary diamond-like semiconductor chalcogenides with strong SHG, impressive LIDTs and phase-matchability over a wide region. This seminar will discuss those results and outline future steps to elevate these materials to next-generation candidacy.
For more information, see the flyer here.
Quantitation of Urinary and Serum Metabolites for Clinical Assessment of Traumatic Brain Injury
Austin Sigler, Graduate Student, Dept. of Chem., Missouri S&T
Abstract: Traumatic brain injuries (TBI) induce complex neurometabolic changes rich with potential molecular biomarkers for injury characterization and severity assessment. Moreover, repetitive exposure to low-level blasts can produce progressive clinical and biological manifestations similar to mild TBIs. The detection of such subclinical injuries represents an unmet medical need. In response, an analytical workflow, consisting of four high-performance liquid chromatography – tandem mass spectrometry (HPLC-MS/MS) methods, was developed to screen a panel of 22 metabolites putatively associated with TBI in serum and urine. In this study, a longitudinal study was conducted at the Urban Mobility Breacher Course at Fort Leonard Wood in which urinary and serum metabolites from 27 military personnel were compared before and during breacher training. The Wilcoxon Signed Rank test was used to find significant differences between the pre-blast and post-blast samples. Significant differences were observed allowing rejection of the null hypothesis and confirming the utility of several molecular biomarkers in the study. Additional statistical analysis was also performed and will be presented in detail. This project was supported by the Leonard Wood Institute through a Cooperative Agreement with the United States Army Research Laboratory (W911NF-14-2-0034).
Spring Semester 2021
Intellectual Property, Here and Elsewhere
John Woodson, Interim Director, Technology Transfer & Economic Development, Missouri S&T
Abstract: For over 150 years now, advancing science and scientific discovery been a cornerstone of education at Missouri University of Science & Technology. In fact, the University of Missouri System’s mission states that we are to “achieve excellence in the discovery, dissemination, preservation and application of knowledge”. The Technology Transfer & Economic Development Office plays an important role at Missouri S&T in the preservation (through patents and copyrights), dissemination (through licensing), and application (through finding commercial partners) of the university’s scientific discoveries. Many of the tasks performed by the TTED Office could apply for any or our students or even help them choose a career path or employer. This talk will explore the different types of intellectual property and how they fit in at the University and elsewhere.
Multifunctional Dendrimers For Drug and Gene Delivery
Dr. Hu Yang, Dept. of Chemical and Biological Engineering, Missouri S&T
Abstract: With collaboration with researchers with expertise in pharmaceutics and medicine, Dr. Yang’s laboratory is conducting cutting-edge research to improve therapeutic index & drug properties, achieve controlled release, enable non-invasive alternative administration and improve patient compliance; and foster translational and convergence research and education. He has been actively developing novel polymers, polymer-drug coupling chemistries, and creative approaches and models to address various challenges facing drug delivery in medication management and therapy. His ongoing projects are focused on the development and translational applications of efficient drug and gene delivery systems and formulations for cancer, ocular and cardiovascular diseases as well as exploration of non-invasive routs of administration for chronic disease medication management such as diabetes. In this talk, he will present the latest work on the development and translational application of the advanced drug and gene delivery systems for improved therapy of cancer, glaucoma, and atherosclerosis.
Bioanalyte Sensing with ZnO Carbon Nanotube and Silicon Nanowire Electrocatalysts
Dr. Charles Chusuei, Dept. of Chem., Middle Tennessee State University, Murfreesboro, TN
Abstract: The morphology and size of ZnO nanostructures were controlled using hydrothermal synthesis, varying the hydrothermal treatment temperature, before attachment to COOH-functionalized multi-walled carbon nanotubes. High activity for H2O2 reduction was achieved when nanocomposite precursors with a roughly semi-spherical morphology (no needle-like particles present) formed at 90°C. A 2.4-fold increase in cyclic voltammetry (CV) current accompanied by a decrease in overpotential from the composites made from the nanosized, needle-like-free ZnO shapes were shown compared to those produced from needle-like ZnO structures. Electrocatalytic activity varied with pH, maximizing at pH 7.4. A stable, linear response for H2O2 in the 1-20 mM range was observed.
Acetaminophen (APAP) is an antipyretic, analgesic agent, the overdose of which poses a risk for liver failure. An APAP sensor was made by depositing silicon nanowires (SiNWs) onto glassy carbon electrodes (GCEs). The electrocatalytic activity of the SiNW/GCE sensors was monitored under varying pH and concentrations using CV and chronoamperometry (CA). CVs using SiNWs at 0.5-13 mM APAP was used to detect the redox potentials of APAP. The selective detection of APAP was then demonstrated using CA at +0.568 V vs Ag/AgCl, where APAP is fully oxidized. SiNWs have promising use for APAP toxicity monitoring.
Unprecedented Response Times in Photorefractive Composites
Dr. Jeff Winiarz, Dept. of Chem., Missouri S&T
Abstract: The photorefractive effect involves the creation of a reversible hologram generated through the intersection of two coherent beams in an appropriate medium and can be realized in polymeric composites which simultaneously exhibit photoconductive and electro-optic properties. Especially promising in this field are nanocomposites of polymers and inorganic semiconductor nanocrystals, commonly known as quantum dots. Initial experiments focused on the use of Q-dots as photosensitizers and the ability to easily control the magnitude of the bandgap through quantum confinement. The broad tunability of the spectral response and increased photo-charge generation efficiency were particularly attractive. More recently, however, time-of-flight experiments have revealed that the inclusion of Q-dots significantly enhances the mobility of charge carriers in polymeric composites. This enhanced mobility translates into an improved response time; an issue which has plagued this class of materials since their inception and has precluded their use in many practical applications. This seminar will present data confirming that through judicious selection of an appropriate semiconductor material, an enhanced charge-carrier mobility attributable to the nanocrystals can be realized, leading to improved response times.
A facile method to enable phosphoinositides cell-permeable and photoactivatable
Dr. Manish Singh, Dept. of Chem., Lincoln University, Jefferson City, MO
Abstract: Phosphoinositides (PIPs) are a diverse class of lipid signaling molecules implicated in nearly all facets of cell signaling including migration, proliferation, and apoptosis. Mutations in numerous PIP modifying enzymes occur frequently in human disease, especially cancers, though the effects of these mutations on the global metabolic system have been poorly defined. Likewise, heterogeneous protein expression and undefined feedback loops further complicate obtaining a global view of metabolism and understanding the PIP metabolic pathway’s role in disease. Current approaches have been unsuccessful in obtaining a systems-wide analysis due to various technical challenges including low sensitivity, use of indirect measurements of activity, and a lack of validated reporters and delivery methods. To achieve our goal of systematic analysis of PIPs cellular metabolism, we developed a simple photocaging technique for cellular delivery of fluorescent PIPs. This general photocaging method can be used to generate a variety of photolabile probes in a short span of time.
Nanoscale imaging of electrochemical energy conversion and storage systems
Dr. Justin Sambar, Dept. of Chem., Colorado State University, Fort Collins, CO
Abstract: Nanostructured materials are poised to play an important role in clean and renewable energy. However, nanomaterials are chemically and structurally heterogeneous in size, shape, and surface structural features. We strive to understand the correlation between nanoparticle chemistry/structure and functional properties. The first part of my talk will focus on elucidating charge storage mechanisms in nanoscale materials related to electrochemical technologies such as batteries and smart windows. I will discuss our high-throughput electro-optical imaging method that measures the battery-like and capacitive-like (i.e., pseudocapacitive) charge storage contributions in single metal oxide nanoparticles. I will present our recent single particle-level measurements that show (1) individual particles exhibit different charge storage mechanisms at the same applied potential and (2) particle size-dependent pseudocapacitive charge storage properties. The second part of my talk will focus on solar energy conversion using ultrathin semiconductors such as monolayer-thick (ML) two-dimensional (2D) materials such as MoS2 and WS2. We developed a correlated laser reflection and scanning photocurrent microscopy approach to study how layer thickness and surface structural features (edges versus basal planes) influence solar energy conversion efficiency. I will highlight our photocurrent microscopy study that revealed how layer stacking order in heterojunction photoelectrodes influences charge separation, transport, and recombination pathways.
For more information, view the flyer here.
Mixed Anionic Transition Metal Chalcogenides for High-efficiency Electrocatalytic Water Splitting
Ibrahim Abdullahi, Dept. of Chem., Missouri S&T
Abstract: Many transition metal chalcogenides-based materials have been reported for water splitting as OER, HER and bifunctional electrocatalyst. It is understood that decreasing the electronegativity of chalcogens in transition metal chalcogenide, increases covalency in the transition metal-chalcogen bond, altering the electronic band structure of the material and subsequently lowering the oxidation potential. However, the stability of the catalyst is compromised. Also, doping at transition metal sites have also been suggested to redistribute charge density around catalytically active sites therefore affecting their catalytic properties.
To provide more insight into the chemistry of these materials, from synthesis to structure-property relationship, the effect of mixed anion chalcogenides was investigated, by gradually replacing some portion of the chalcogen in transition metal chalcogenides with a different chalcogen. Here we present, a cobalt telluroselenide (Cox-Tey-Sez) series and their OER catalytic activity and stability.
Their electrochemical properties were investigated and compared to binary cobalt selenide and telluride. It was observed that the catalytic activity of the telluroselenides were higher than the selenide but lower than the telluride confirming that increasing anion electronegativity decreased catalytic activity. A systematic study of the chemistry of these new materials, their detailed characterization and OER catalytic efficiencies will discussed.
Activating Anionic Redox in Chalcogenides Materials for Battery Application
Santhosh Sundaramoorthy, Dept. of Chem., Missouri S&T
Abstract: Conventional Li-ion battery cathode’s charge storage mechanism solely depends on the transition metal redox. In the recent years Li-rich oxides are being explored owing to their high energy density compared to the existing cathodes due to the occurrence of cumulative cationic (M3+/4+, M = 3d, 4d transition metals) and anionic (O2-/O22-) redox mechanism. Yet these materials suffer from severe voltage fade, poor kinetics, and irreversible oxygen loss, which hinder its commercialization. One alternate approach to access reversible anionic redox is to replace the oxides by less electronegative sulfides, well known for their reversible dimer formation (S2-/S22-). In this work we have synthesized a host structure (Li1.33Sn0.67S2) which is electrochemically inactive due to its 3d10 (Sn4+) configuration though it has high theoretical capacity (233mAh/g). In order to trigger both the cationic and anionic redox we doped electrochemically active Fe2+ in Sn4+ site and formed a series of compounds (Li1.33-2y/3Sn0.67-y/3FeyS2; y = 0.1-0.5). Among those, y = 0.2 material showed excellent capacity of 130 mAh/g due to the cumulative Fe2+/3+ and S2-/S22- redox reactions. The material also showed no voltage fade and excellent cycle stability. Designing these type of sulfide cathodes opens up the gate for much safer and low-cost cathode materials.
Adventures in Chemical Metallurgy
Dr. Michael Moats, Dept. of Mat. Sci. & Eng., Missouri S&T
Abstract: The forthcoming energy transition has brought non-ferrous extractive metallurgy to the public conscience. The robust supply of critical elements for green energy and the electrification of mobility is a global concern. Mining and production of many critical metals are concentrated in a few countries. This has prompted governments to examine their domestic supply chains and discuss the possibility of onshoring production of certain elements. During this seminar, Professor Moats will explore his career from Rolla undergraduate to corporate research manager to professor. He will introduce the audience to various chemical metal production methods while interweaving past examples of research and technology development along with highlights from current and future research.
CO2 Utilization Via Carbonate-Promoted C–H Carboxylation and CO2 Hydrogenation
Dr. Aanindeeta Banerjee, Dept. of Chem., Stanford University, Palo Alto, CA
Abstract: With CO2 level in the atmosphere rising, finding new efficient ways to recycle this gas is of paramount importance. Though previous efforts have focused on converting CO2 to C1 compounds, the synthesis of multi-carbon compounds is advantageous because these targets have higher value and energy density. The key chemical challenge is forming C–C bonds without using energy-intensive reagents. I will describe a novel carboxylation reaction in which a C–H bond and CO2 are transformed into a carboxylate (C–CO2–) using alkali carbonates as a promoter, in absence of any catalyst or solvent. Alkali carbonate salts are capable of deprotonating C–H bonds that are ordinarily very weak acids (pKa>40 in organic solvent) to generate carbanions (C–) at intermediate temperatures (200-360 °C). In the presence of CO2, the carbanions react rapidly to form carboxylates. The chemistry has been applied in the synthesis of 2,5-furandicarboxylic acid (FDCA), an attractive green replacement for fossil fuel-derived terephthalic acid, used in polyethylene terephthalate (PET) polymer synthesis. Based on the above-described approach of C–C bond formation, I will also speak about how a mixture of alkali carbonate, CO2 and H2 can be readily converted to formate, oxalate and other C2+ carboxylates.
For more information, view the flyer here.
Carbon aerogels derived from poly(tetrahydroquinazoline) for high capacity and selective adsorption of carbon dioxide
Vaibhav Edlabadkar, Dept. of Chem., Missouri S&T
Abstract: DMF solutions of a tetrahydroquinazoline (THQ) monomer were gelled via HCl-catalyzed ring opening polymerization at 100 °C. Poly(tetrahydroquinazolines) (PTHQ) wet gels were dried with supercritical fluid CO2 in an autoclave to aerogels, which undergo complete ring-fusion aromatization at 240 °C/O2. Based on selectively 15N-enriched materials in combination with solid-state CPMAS 13C and 15N NMR, it was found that the skeletal framework of fully-oxidized PTHQ aerogels includes amide, imide and urea groups. Fully oxidized PTHQ aerogels were carbonized at 800 °C/Ar and etched at 1000 °C/CO2 yielding carbon and etched carbon aerogels respectively. PTHQ-derived carbons were evaluated for their CO2 adsorption capacity and selectivity towards other gases.
CO2-etched carbon aerogels showed very high CO2 uptake (11.2 ± 0.9 mmol g−1 at 273 K, 1 bar), which was attributed to pore filling beyond monolayer coverage starting with preferential interaction of CO2 with surface pyridinic and pyridonic N on carbon (identified by XPS) in a near energy-neutral reaction. The high selectivity of CO2 versus H2 in the range of (407 ± 104) is attractive for pre-combustion capture of CO2 and the high selectivity of CO2 versus N2 in the range of (52 ± 18) is attractive for post-combustion CO2 capture from flue gases.
Chalcogenides as sodium ion conductors for solidstate batteries
Srikanth Balijapelly, Dept. of Chem., Missouri S&T
Abstract: A lithium-ion battery is composed of cathode, anode, separator, and electrolyte. Commercial lithium ion batteries use liquid electrolyte solution. On the other hand, a solid-state battery would use a solid electrolyte. The current Li-ion batteries suffer from safety issues due to the presence of flammable liquid electrolyte solution. Solid-state batteries are, therefore, inherently safer. Solid electrolyte is a key component in solid state battery. Solid electrolytes are solid materials containing highly mobile alkali ions. Unfortunately, there are not many good solid electrolytes to enable solid state batteries. Solid electrolytes with high ionic conductivities >10–4 S/cm with good thermal stability and wide electrochemical window are necessary to enable all solid-state batteries for practical applications. Hence, our focus was directed towards synthesizing new chalcogenide-based materials employing building block approach. In this regard, a new family of compounds, Na3MGaQ4 (M = Fe, Zn; Q = S, Se), have been synthesized and their crystal structures were determined. These materials contain large channels filled with Na-ions that show high ionic conductivity. Vacancy formation energies for the Na-ions were calculated using Density Functional theory and their role in the ionic conductivity will be discussed.
Designing Chemical Sensor Materials
Dr. John Determan, Dept. of Chem., Western Illinois University
Abstract: Research presented will show the use of nanoparticles to detect illicit drugs. Throughout the world, drug related crimes and abuse are prevalent. Traditionally, analyses of drug samples involve complex reactions and the use of complex instrumentation, such as GC-MS. This causes analysis of drug samples to be difficult to be done on site or by anyone without specialized training.
Recent studies, such as those by Mao et al, Sci Total Envir. 688 (2019) 771-779, show the possibility of drug analyses, specifically for methamphetamines, being conducted with gold nanoparticles capped with DNA aptamers. A DNA aptamer is a synthetic single stranded DNA molecule. These aptamers are designed such that they interact only with target molecule and not any similar molecules. For example, a meth-aptamer will interact with methamphetamines, but not with pseudoephedrine. When the drug interacts with the aptamer capped particle, the particle structure is change and a visible color change is observed. While gold particles have been shown to work well for these analyses, we seek to use more affordable and abundant materials, to allow these techniques to be widely available. We explore the use of copper, silver and silicon oxide based nanoparticles for the detection of illicit drugs.
Gravitational waves: Astrophysics Final Frontier
Dr. Marco Cavaglia, Dept. of Physics, Missouri S&T
Abstract: In 1916 Albert Einstein demonstrated that space and time can be warped in the shape of a wave. One hundred years later, scientists from the Laser Interferometer Gravitational-wave Observatory (LIGO) Scientific Collaboration and the Virgo Collaboration announced the first observation of a "ripple of space-time" from two colliding black holes. This scientific achievement marked the beginning of a new way of exploring the "dark side" of our Universe. Less than two years later, LIGO and Virgo scientists detected gravitational waves from the collision of two neutron stars, an event rapidly followed by the observation of light in all regions of the electromagnetic spectrum by hundreds of telescopes around the world and space in what became the most observed cosmic event in the history of humankind. Nowadays, detections of gravitational waves from collisions of neutron stars and black holes have become routine. They provide a new way to map the cosmos, test gravity under extreme-gravity conditions, study the structure of stellar objects, and understand the origin of matter and the evolution of the Universe.
For more information, view the flyer here.
Protein and Small Molecule Engineering towards an Orthogonal Epigenetic Landscape
Dr. Kabirul Islam, Dept. of Chem., University of Pittsburg
Abstract: Epigenetics is a set of nucleosome-dependent biochemical processes that regulate transcriptional potential of genome and allows cells to access genetic information. Cells employ a range of epigenetic mechanisms, most prominent being the chemical modifications of DNA and histones to alter gene expression. Elucidation of how chromatin-modifying proteins remodel diploid human genome with exquisite spatiotemporal control is fundamentally important towards the understanding of eukaryotic biology and disease. Since starting at the University of Pittsburgh in 2014, my group has built the foundation of a vibrant research program guided by this question. We employ a range of small molecules, peptides, proteins, nucleotides and their unnatural analogues towards functional elucidation of chromatin modifications in transcription and nuclear reprogramming. Our interdisciplinary research spans synthetic organic chemistry, protein and oligonucleotide engineering, mechanistic biochemistry, cell and structural biology, proteomics and transcriptomics.
For more information, view the flyer here.
Syntheses of Functional Drug Delivery Systems and Activatable Prodrugs for Cancer Therapy
Dr. Santimukul Santra, Dept. of Chem., Pittsburg State University
Abstract: The design and syntheses of biocompatible materials are emerging fields of research. In particular, designer dendritic biopolymers are important for the targeted drug delivery and cancer therapy. When compared with linear counter-part, three-dimensional biodegradable nanostructures offer better solubility, aqueous stability and huge functionality to effectively target tumor, minimizing severe side-effects to the healthy cells. Our lab is focused on developing new biocompatible polymeric and polymer-based nanomedicines for the targeted delivery of theranostic agents to the specific tumor. In addition, new methods developed for the synthesis of novel activatable prodrugs for the effective treatment of cancer. The multi-step syntheses of biodegradable dendritic polymers are able to encapsulate therapeutic drugs, MR probes and prodrugs within their three-dimensional cavities during the formulation of nanomedicines. To evaluate the therapeutic efficacy of these customized nanomedicines, various in vitro and in vivo assays were performed. This presentation will highlight the important roles of organic synthesis, chemical biology and nanotechnology in the field of biochemical and biomedical applications, and our current efforts in partnering with industries to bring this technology to the clinic.
For more information, view the flyer here.
Fall Semester 2020
Nanodiamonds and Carbon Nano-Onions Ceramic Composites and their Applications
Ibrahim Abdullahi, Dept. of Chem., MS&T
Abstract: Luminescent nanodiamonds are photostable non-blinking fluorescent biocompatible, non-toxic, functionalizable materials made from high-pressure high-temperature (HPHT) microcrystalline diamonds, and have found application in biomedical imaging, nanosensing, quantum computing etc. However, search for more efficient, cost and time effective as well as commercially scalable techniques that produce small, bright, clean and high-quality fluorescent nanodiamonds is still on going. A novel scalable fabrication technique based on explosive fragmentation was developed. The particle size and photoluminesence properties of the fluorescent nanodiamonds obtained will be discussed. While ceramics and glasses are at the cutting edge of advanced materials and provide solutions to global challenges in the environment, aerospace, energy, manufacturing etc. There is, in fact, a need for more sophisticated approach to enable quick, cheaper and superior research and development of new material compositions for future applications. Annealed nanodiamonds yield carbon nano-onions, which have unique electrical, mechanical and optical properties. In situ generated carbon nano-onion/silica glass composites with varying carbon nano-onion concentration produced via base catalyzed sol-gel chemistry were investigated. Homogeneous dispersion, atomic parking density, residual porosity and tightly bonded particles network within the silica glass matrix influence the properties of the resulting composites, and their mechanical, optical and conducting properties will also be discussed.
General Laboratory Safety Training: University Laboratory Safety – Working Safely
Environmental Health and Safety, MS&T
Abstract:
General Safety
- Environmental Health and Safety Department
- General Rules/Policies and Prudent Practices
- Fire Safety
- Emergency Response
- Hazard Communication
- Engineering/Administrative Controls, and Personal Protective Equipment
- Injury / Incident Reporting
Hazardous Material Safety and Management
- Chemical/Biological/Radiological Hazards
- Compressed Gas Cylinders / Cryogenics
- Physical Hazards
- Chemtrack Inventory System
General Laboratory Safety Training: Hazardous Material and Chemical Waste Management
Environmental Health and Safety, MS&T
Abstract:
Environmental Management System
- ISO 14001
- Corrective action
Hazardous Waste Management
- Federal Regulations
- Chemical Waste – proper storage and labeling
- Chemical Waste – pick-up request
- Biological Waste
- Universal Waste
- Spill Response
Development of intelligent stimuli-responsive biomaterials and nanodevices
Shuo Yang, Dept. of Chem., MS&T
Abstract: Considerable interest has been devoted to the development of stimuli-responsive biomaterials that could adopt different conformations in response to specific environmental stimuli, leading to broad applications in the fabrication of smart biosystems. Functional nucleic acids (DNAzymes, i-motif, and DNA triplex) as a novel branch of stimuli-responsive biomaterials, have shown great potential in the assembly/disassembly of nanomaterials due to their dynamic behaviors in response to external stimuli. The reversible assembly of DNA origami nanostructures by two types of stimuli: metal ion and pH will be presented. The metal-ion stimulated assembly/disassembly of DNA origami dimers were achieved by using G-quadruplexes as dynamic bridges (reversible conformation change between G-quadruplex state and its single-strand state) induced by potassium ions (K+). To extend the capabilities of DNA origami, the stepwise assembly of DNA origami nanoclusters via pH stimulation was further studied. Structure association and dissociation were controlled through a series of consecutive pH-stimulated processes relying on the transition of DNA triplex to duplex in different pH conditions. These dynamic assembly strategies, in response to external stimuli, bring more structural complexity and intriguing functions to the resulting biosystems.
Electrocatalytic processes for CO2 reduction and biomass conversion
Apurv Saxena, Dept. of Chem., MS&T
Abstract: While increasing CO2 enrichment in atmosphere has raised global concerns, major focus for mitigating this problem has been directed towards sequestration of atmospheric CO2 and converting it into value-added chemicals through CO2 reduction reaction (CO2RR). Electrocatalytic CO2RR is typically done on base metal plates such as Cu. However, these catalysts predominantly produce toxic CO which needs to be processed further to derive high-value products. The lack of product selectivity has also inhibited widespread application of these CO2RR base metal catalysts. Recently we have discovered that Cu- and Ni-based selenides, on the other hand, are highly efficient electrocatalysts for CO2RR, offering high selectivity towards C2-products under ambient conditions and low energy expense. Interestingly we have observed that these catalysts convert CO2 to methanol, ethanol, formic, and/or acetic acid at low applied potential with high product yield and selectivity. In this talk we will describe catalyst design principles to achieve high selectivity towards carbon-rich reduction products by applying fundamental concepts of inorganic chemistry. Detailed electrochemical measurements were performed to estimate conversion efficiency while products were quantified through NMR and GC-TCD. DFT calculations provided further insight of intermediate adsorption energies on catalyst surfaces which could be correlated with product specificity of various catalysts.
Analytical Method Development for Biomedical and Environmental Applications
Mousumi Bose, Dept. of Chem., MS&T
Abstract: Polymers are widely used materials for variety of applications. In biomedical field, luminescence quenching based optical oxygen sensors encapsulated in polymeric substances are gaining attention as a superior technology for continuous monitoring of oxygen. A simple and low-cost fabrication technique was developed to produce sensor arrays capable of two-dimensional oxygen tension measurement. Sensors were printed on polyvinylidene chloride film using an oxygen-sensitive ink cocktail, prepared by immobilizing Pt(II) meso-tetra(pentafluorophenyl)porphine (PtTFPP) in monodispersed polystyrene microparticles. The sensor patch along with smart phone-based readout technique is being evaluated as a smart bandage for early detection of pressure ulcer.
The environmental concerns and limited petroleum supply demand for replacing petroleum-based polymers with renewable bio-based sources completely or partially while maintaining comparable properties. Therefore, a sustainable and green approach was adopted to synthesize soy polyol-based rigid polyurethane (PU) foams for structural and thermal insulation applications. The effect of different additives, i.e., catalyst, blowing agent, surfactants, and polyol functionalities on foam properties were investigated. The focus of this work was to investigate the different synthetic formulations and potential to be used in structural insulated panel (SIP) for energy-efficient and modular building construction.
Subterranean Rhizoremediation Blues: Putting Rhizosphere Microbes to Work
Dr. David J. Westenberg, Dept. of Biological Sciences, MS&T
Abstract: Phytoremediation is an inexpensive and effective approach to the removal of environmental contaminants. One approach to expand the spectrum of contaminants removed through phytoremediation is the use of microorganisms that reside in the rhizosphere - rhizoremediation. This approach is attractive because: 1) rhizosphere microorganisms are capable of a broader range of metabolic activities relative to their host plants; 2) rhizosphere microorganisms can be manipulated to further expand their metabolic capabilities; 3) rhizosphere microorganisms are adapted to life in the rhizosphere. In combination with the appropriate host plant, it is possible to maintain the population of contaminant degrading microorganisms throughout the remediation process. This presentation will describe several rhizoremediation project in my lab in collaboration with colleagues across campus.
Simultaneous Determination of Urinary Metabolites for the Non-invasive Assessment of Traumatic Brain Injury
Austin Sigler, Dept. of Chem., MS&T
Abstract: Traumatic brain injury (TBI) is a serious public health concern for which sensitive and objective diagnostic methods remain lacking. While advances in neuroimaging have improved diagnostic capabilities, the complementary use of molecular biomarkers can provide clinicians with additional insight into the nature and severity of TBI. Growing understanding of TBI as a neurochemical cascade of events beginning with the initial insult has generated significant interest in the development of analytical methods to quantify neurologically relevant biomarkers with which to assess the severity of TBI. In the Dr. Shi lab, our group has developed several liquid chromatography tandem mass spectrometry (LC-MS/MS) methods to quantify several of these interesting metabolites in various biological fluids including urine. Urine presents unique preparatory challenges in analytical analysis due to its complex matrix and lack of homeostatic control in its production. This presentation will cover a few of the developments our group has made in biomarker discovery, as well as future directions which we are currently exploring in TBI analysis.
Corn Seed Quality Chemical Marker Discovery
Sargun Kaur, Dept. of Chem., MS&T
Abstract: The types and levels of volatile compounds emitted from seeds can be a quantitative indicator of seed quality such as germination potential and vigor. Low molecular weight compounds like short-chain aldehydes, alcohols and carboxylic acids may be used as chemical markers for assessing the seed quality since they are produced by lipid peroxidation initiated by autooxidation or enzymatic oxidation of unsaturated fatty acids during the seed storage and aging period. Therefore, a headspace – solid-phase microextraction – gas chromatography/mass spectrometry (HS-SPME-GC/MS) method was developed and validated for analyzing these volatile organic compounds in corn (Zea mays) seeds. This method allowed the fast identification and quantification of 19 volatile organic compounds including ketones, alcohols, aldehydes, limonene, and acetic acid. The headspace sampling of volatile compounds emitted from corn seeds were conducted using Carboxen/PDMS SPME fiber and desorbed directly into a heated injector for subsequent GC separation. High sensitivity and selectivity were achieved with the MS operating in SIM mode. The new method will be evaluated for quick and reproducible analysis for the assessment of seed quality and deterioration.
Design of nanocomposites and nanostructures for Energy storage and conversion in Supercapacitors and fuel cells application
Harish Singh, Dept. of Chem., MS&T
Abstract: Electrochemical capacitors (ECs) or Supercapacitors (SCs) are considered to be most promising energy storage devices and have received great attention because of their excellent electrochemical performance with high output power, short discharging time and long-term cycle stability. In the current work, transition metal telluride/selenide-based nanostructure composites were studied for SCs applications and oxygen reduction reaction as well. A specific capacitance of 1826 F/g was achieved at a current density of 1 A/g for metal telluride electrode. In terms of onset potential, kinetic current density and four-electron selectivity, metal selenide catalyst shows the comparable performance to those of commercial Pt/C towards the ORR, as demonstrated by cyclic voltammetry (CV) and polarization measurements. In this presentation we will discuss the SCs and oxygen reduction performance of these telluride/selenide nanostructures as well as the effect of transition metal doping and carbon nanostructure additives, and explain how the chemistry of transition metal chalcogenides influences their electrochemical functionality and potential as future energy storage and conversion.
Complex Chalcogenides for Heat Recovery
Srikanth Balijapelly, Dept. of Chem., MS&T
Abstract: More than two third of the energy generated across the globe is wasted in the form of heat. So, in order to build a sustainable energy source, it is very important to capture the waste heat. Thermoelectric devices are capable of direct conversion of heat to power and vice versa. Thermoelectrics are now being used in variety applications like waste auto-mobile exhaust heat recovery, thermoelectric coolers and radio isotope thermoelectric generators for NASA space craft powering. Though several solid materials have been investigated for thermoelectric activity, soft lattice, complex compositions and complex electronic structure make complex chalcogenides very attractive for thermoelectric applications. Taking advantage of plethora of mineral compositions that exist in chalcogenide family, we have targeted some complex compositions using fundamental concepts of developing high efficiency thermoelectric materials. In this presentation, the synthesis of few natural complex chalcogenide mineral compositions, challenges in their crystal structure solution, optical, electrical and thermal properties will be discussed.
Synthesis, characterization, and chemistry of two-dimensional transition metal carbides and nitrides (MXenes)
Shuohan Huang, Dept. of Chem., MS&T
Abstract: MXenes represent a relatively new and quickly growing family of two-dimensional (2D) early transition-metal carbides and nitrides, which were first synthesized in 2011 from bulk layered crystalline MAX phases. Because of their 2D structure and many extraordinary physical properties, MXenes have raised a significant interest for various applications. However, it has been found that in some cases MXene flakes are not stable and can spontaneously degrade on a time scale from hours to days. While dissolved O2 has been deemed as the main factor for the instability of MXenes in aqueous solutions, we analyze the role of water as the primary reagent, and not only a solvent, in the processes of conversion of 2D titanium carbide MXenes into titania. Moreover, we demonstrate gas analysis as a powerful technique to gain further insights into chemical reactivity of MXenes. Gases produced during chemical transformations of MXenes in aqueous solutions have been collected and analyzed via gas chromatography (GC) and Raman spectroscopy. The degradation rates of the MXenes in water were further investigated depending on their monolayer thickness within the same chemical composition, as well as depending on chemical composition of the materials within the same monolayer thickness.
Rapid Measurements of Aerosol Size Distribution and Hygroscopic Growth with a Fast Integrated Mobility Spectrometer (FIMS)
Dr. Yang Wang, Dept. of Civil, Arch. & Environ. Engr., MS&T
Abstract: Aerosol size distribution and hygroscopicity are among key parameters in determining the impact of atmospheric aerosols on global radiation and climate change. In situ submicron aerosol size distribution measurements commonly involve a scanning mobility particle sizer (SMPS). The SMPS scanning time is in the scale of minutes, which is often too slow to capture the variation of aerosol size distribution, such as for aerosols formed via nucleation processes or measurements onboard research aircraft. To solve this problem, a Fast Integrated Mobility Spectrometer (FIMS) based on image processing was developed for rapid measurements of aerosol size distributions from 10 to 600 nm. The parallel comparison between the FIMS and SMPS demonstrated excellent agreement when measuring aerosols with various size spectra, but by simultaneously measuring aerosols with different sizes, the FIMS provides aerosol size spectra nearly 100 times faster than the SMPS.
Recent deployment onboard research aircraft demonstrated that the FIMS is capable of measuring aerosol size distributions in 1s, thereby offering a great advantage in applications requiring high time resolution. Such a system reduced the time of measuring the hygroscopic properties of submicron aerosols (six sizes) to less than three minutes in total, with an error within 1%.
Click here to view the seminar flyer.
Enhancing Learning by Assessing More than Content Knowledge
Dr. Renée S. Cole, Dept. of Chem, University of Iowa
Abstract: Skills such as communication, teamwork, critical thinking, and problem solving are frequently cited as intended learning outcomes for STEM degree programs. While these skills, sometimes referred to as workplace or process skills, are highly valued, they are rarely explicitly assessed in the classroom. Assessment serves two purposes: (1) it provides a measure of achievement, and (2) it facilitates learning. The types of assessment used by an instructor also telegraphs to students what is valued in a course. However, in many instances, the lack of alignment between instructional methods and assessment detracts from the added value of engaged student learning environments. This NSF IUSE project focuses on the development and implementation of rubrics that facilitate providing feedback to students and informing the instructor as to the effectiveness of their instructional strategies in supporting process skill development. Implementation of the rubrics provides a means to better align intended outcomes with instructional activities and supports adoption of evidence-based active learning strategies that foster skill development in addition to content knowledge.
Networking with Chemistry Faculty at 9:45-10:45 am via ZOOM. Networking with Education and Certification Faculty at 10:45 am – 12 pm via ZOOM.
Adsorption studies in Colloidal Unimolecular polymers
Ashish Zore, Dept. of Chem, MS&T
Abstract: Colloidal Unimolecular polymer (CUPs) is a single chain polymer nanoparticle made by a process of self-folding or self-assembly of polymer chain to form a particle. They are 3-9 nm in size, zero VOC, spheroidal particles that are self-stabilized via electronic repulsion due to the presence of surface charges which can be anionic or cationic groups. Designing a CUPs particle to meet ones requirements is extremely easy due to the flexibility and variability it offers in terms of size, charge density (number of charges per unit area on the surface) as well as the type of hydrophobic and hydrophilic monomers. Since each polymer chain collapses into a single particles, the size can be easily controlled by manipulating the molecular weight of the polymer. It is necessary to define the limits/range of CUP formation using a suitable parameter that can be easily applied to all types and size of monomers. This will simplify the synthesis of these particles. Surface tension is an important property in coatings and can be altered by the addition of CUP particles. CUP particles reduces the surface tension of the water and is now understood with help evaporation rate study.
Development of high temperature resistant gels using low toxic polymers for conformance control
Buddhabhushan P. Salunkhe, Dept. of Chem, MS&T
Abstract: Preformed particle gels (PPGs), a type of hydrogel, are used in oilfield conformance control owing to their robust gel chemistries. Traditional PPGs are polyacrylamide based hydrogel compositions which can withstand neither higher temperatures nor high salinity conditions that are typical for many oil reservoirs. For instance, there are many deep oilfield reservoirs worldwide which demand products of long term hydrolytic and thermal stability at higher than 130 °C temperature. Current PPGs neither remain hydrated nor retain polymer integrity at these temperatures. A systematic approach was followed to develop hydrogel compositions which can withstand temperatures of at least 150 °C. A unique high temperature-resistant hydrogel composition (HT-PPG) was developed with exceptional thermal stability for more than 18 months in different brine environments. We will present the effects of salinity, pH, temperature, and multivalent ions on swelling and rheological behavior of these HT-PPGs. Phase stability of the HT-PPG was evaluated under conditions of high pressure, supercritical CO2 and concentrated acids. Core flooding is a test to confirm the conformance control suitability of HT-PPGs in reducing the effective permeability of open fractures to demonstrate porosity-plugging efficiency. HT-PPG is a nontoxic composition and a suitable candidate for conformance control operations in North Sea reservoirs.
Synthesis of monolithic porous carbon aerogels without use of supercritical fluid drying from polymer-crosslinked xerogel powders
Rushi Umeshkumar Soni, Dept. of Chem., MS&T
Abstract: Carbon aerogels are well known for their high surface areas and high porosities with applications in CO2-capture, electrodes for electrochemical cells and catalyst-supports. They are typically made by pyrolysis of carbonizable polymeric aerogels. The latter are obtained from corresponding wet-gels by replacing their pore-filling solvent with liquid CO2 that is converted to a supercritical-fluid and vented off as a gas. The high porosity of carbon aerogels is derived from both the innate porosity of the precursor polymeric aerogels, and the porosity created by the pyrolytic decomposition reactions. Here we report a new route for the synthesis of carbon aerogels from xerogel powders, which speeds-up solvent exchange processes and bypasses supercritical-fluid drying, resulting in time, energy, and materials efficient synthetic methodology.
Part-1: Amorphous carbon aerogels were prepared either via free-radical surface-initiated polymerization of acrylonitrile on the network of functionalized silica or from polyurea-crosslinked silica xerogel powders, which were compressed into pellets, aromatized, pyrolyzed and treated with HF and/or CO2 to remove SiO2 particles and/or carbon, respectively, creating high surface area and porosity.
Part-2: Graphitic carbon aerogels were prepared from metal catalyzed polyacrylonitrile-crosslinked xerogel powders at lower temperatures compared to conventional graphitization. All aerogels were characterized using powder-XRD, Raman spectroscopy, and TEM.
Spring Semester 2020
Intellectual Property Basics; Patents, Copyrights, and Trade Secrets
Lauren Hatfield, Assistant Director, Career Opt & Employer Relation, MS&T
Abstract: Career Opportunities and Employer Relations (COER) is located on the 3rd floor of Norwood Hall. COER is dedicated to helping Missouri S&T students and alumni pursue their career goals assisting in all stages from summer internships, to co-ops and full-time employment. Services include student advising, LinkedIn reviews, professional development workshops,
career fairs and more!
The application of Freeze-Thaw coupled with HPLC-MS/MS and SPME-GC-MS on the analysis of emerging pollutants in plant tissues
Xiaolong He, Dept. of Chem., MS&T
Abstract: Emerging and fugitive contaminants (EFCs) generated by anthropogenic activities have caused a fugitive legacy threaten to the quality and quantity of food and water, which are closely linked through plants. Therefore, it is highly desirable to enable to effectively screen the plant uptake of emerging pollutants. In this study, rapid freeze-thaw/centrifugation extraction followed by high performance liquid chromatography -tandem mass spectrometry (HPLC-MS/MS) methods were developed for determination of twelve EFCs, including Estriol, Codeine, Oxazepam, 2,4-DNT, RDX,
Acetaminophen, Bisphenol-A, Triclosan, Caffeine, Carbamazepine, Lincomycin, DEET. The methods centrifuge the sap out of the plant tissue through a molecular sieve membrane filter directly in the centrifugation tube to remove macromolecules and particulates from the sap. The sap solution can then be analyzed directly by HPLC-MS/MS. For the volatile environmental contaminants, 1,4-Dioxane and 1,2,3- Trichoropropane (1,2,3-TCP), an freeze-thaw and solid phase micro extraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) method was developed for determination. Three different kinds of plant, i.e. corn (Zea mays), tomato (Solanum lycopersicum) and wheat (Tritcum spp) were chosen as representative plants. These methods offer ultrasensitive and very rapid green approaches to determine the EFCs
concentrations in agriculture crops, and have been applied to study the plant uptakes and distributions of the selected EFCs.
Emerging phases and phase transitions in quantum matter
Dr. Thomas Vojta, Dept. of Physics, MS&T
Abstract: Condensed matter physics deals with the complex behavior of many-particle systems. Novel phases of matter can emerge as a result of strong interactions between the constituent particles. A natural place to look for these phenomena are quantum phase transitions, the boundaries between different quantum ground states of matter. This talk first gives an introduction into quantum phase transitions and then discusses several novel phases of matter that have been discovered in their vicinity in solids and in ultracold atomic gases. These include exotic superconductors and magnets as well as Griffiths phases that are dominated by strong disorder.
What Can We Learn from Nuclear Inelastic Scattering?
Dr. Fernande Grandjean, Dept. of Chem., MS&T
Abstract: Most solid state materials scientists are familiar with what can be learned from the recoil-free emission and resonant absorption of γ-rays, i.e., the Mössbauer-effect. However, fewer materials scientists are familiar with what can be learned from the emission and absorption of γ-rays that involves nuclear recoil, i.e., nuclear inelastic scattering. Because these γ-rays exchange energy with the solid lattice, information about the lattice vibrations can be obtained. First, this talk will briefly describe the theoretical basis of nuclear inelastic scattering and the experimental conditions required for its measurement. Second, the use of nuclear inelastic scattering of γ-rays to study lattice vibrations in thermoelectric compounds, specifically the CeFe 4 Sb 12 and EuFe 4 Sb 12 filled skutterudites will be discussed.
Mössbauer Spectral Study of the FePO4 polymorphs and Related Iron Phosphate compounds
Dr. Gary J. Long, Dept. of Chem., MS&T
Abstract: The Mössbauer spectra of trigonal α-FePO4 , the most stable polymorph of FePO4 , have been measured between 4.2 and 300 K and exhibit hyperfine parameters characteristic of high-spin iron(III) in a pseudotetrahedral oxygen coordination environment. Between 24.5 and 300K, the spectra show a paramagnetic quadrupole doublet and at 24.0 K the spectrum reveals the
onset of antiferromagnetic exchange. At 4.2 and 16 K, a single magnetic sextet is observed with hyperfine fields of 51.36(1) and 42.74 T, respectively, with an angle, θ, of 90º between the principal axis of the electric field gradient tensor in the basal plane of the trigonal unit cell and the hyperfine field along the c-axis. The spectra obtained between 18 and 21 K have been fitted with two magnetic sextets with equal areas and with θ angles of 25 and 85º, angles which indicate that the iron(III) magnetic moments are canted away from the c-axis; the alternative symmetry lowering of the trigonal structure seems unlikely. The reduced hyperfine field versus reduced temperature plot indicates a departure from a Brillouin S = 5/2 behavior, most likely as a result of some magnetostriction at and below the Néel temperature or 24.2(2) K.
For more details see: F. Grandjean and G. J. Long, “Mössbauer Spectral Study of the Low Temperature Magnetic Properties of FePO4 and the Mixed Valence Iron(II/III) Phosphate, SrFe3(PO4)3 ,” Inorg. Chem., 58, 13314-13322 (2019).
Bioapplications of Reversible Addition-Fragmentation Chain Transfer (RAFT) Polymerization
Dr. Anthony Convertine, Materials Sci. & Eng., MS&T
Abstract: The clinical translation of nanoparticle-based therapies is challenging because of the three-dimensional structure, complex formulation parameters, as well as the multicomponent nature of these systems. In this talk we will detail the development of the polyDrug approach in which therapeutic agents and all of the functional components necessary for solubility, cell targeting, blood brain delivery, and imaging are integrated together in a single polymerization step. This
approach, which is based on the use of polymerizable prodrug monomers (Drugamers), polymerizable peptide targeting monomers (Targamers), polymerizable gadolinium chelates (Probamers), and polymerizable solubilizing monomers (Dissolvamers) overcomes the shortcomings of dispersal formulations (i.e. burst release and complex formulation steps)
allowing polyDrugs to be prepared with tunable, linear dosing profiles. We will also discuss the incorporation of Drugamers into novel nanostructured morphologies via controlled radical polymerization (CRP). Specifically, we will detail the development of radiant star single polymer nanoparticles (RSNs) via the RAFT homopolymerization of chain transfer monomers (Transmers) followed by linear polymerization from the hyperbranched cores. We will also discuss the preparation of double hydrophilic core-shell nanostructures via RAFT polymerization induced self-assembly PISA in acetic acid. Finally, we will show pH-endosomalytic segments can be integrated into these nanostructures to facilitated the
intracellular delivery of biologic drugs.
Microscale Platforms for Low-cost Chemical Analysis and Protein Separation
Dr. Keiichi Yoshimatsu, Dept. of Chem., Missouri State University
Abstract: Intermolecular interactions between molecules ubiquitously play important roles in living matters. Antibody-antigen interactions are one of the biomolecular interactions that occur in a highly specific manner. On the other hands, there are less specific biomolecular interactions that are playing critical roles (e.g. self-assembly of amphiphilic lipids into membrane structures). It appears that biological systems have adapted a various type of intermolecular interactions in order to meet different needs. Taking inspiration from nature, our group have been interested in the fundamental science on intermolecular interactions and applied research in the areas of chemical/biomolecular analysis and separation. In this presentation, I will introduce our recent efforts in applying fundamental insights on intermolecular interactions to the
development of new microscale platforms for low-cost chemical analysis, protein separation, and engineering applications.
For more information, visit the webpage here. Find an itinerary of the visit here.
Enhancing Learning by Assessing More than Content Knowledge
Dr. Renée S. Cole, Dept. of Chem., University of Iowa
Abstract: Skills such as communication, teamwork, critical thinking, and problem solving are frequently cited as intended learning outcomes for STEM degree programs. While these skills, sometimes referred to as workplace or process skills, are highly valued, they are rarely explicitly assessed in the classroom. Assessment serves two purposes: (1) it provides a measure of achievement, and (2) it facilitates learning. The types of assessment used by an instructor also telegraphs to students what is valued in a course. However, in many instances, the lack of alignment between instructional methods and assessment detracts from the added value of engaged student learning environments. This NSF IUSE project focuses on the development and implementation of rubrics that facilitate providing feedback to students and informing the instructor as to the effectiveness of their instructional strategies in supporting process skill development. Implementation of the rubrics provides a means to better align intended outcomes with instructional activities and supports adoption of evidence-based active learning strategies that foster skill development in addition to content knowledge.
Tuesday, March 17, 9:30 – noon, Dept. Teacher Educ., Centennial Hall 103
ELIPSS Workshop: Assessing more than content knowledge
Abstract: Skills such as communication, teamwork, critical thinking, and problem solving are frequently cited as important outcomes for STEM degree programs. However, the development of these skills is often taken for granted, and they are rarely explicitly assessed in the classroom. Assessment serves two purposes: (1) providing a measure of achievement, and (2) facilitating learning by conveying what is valued in a course. This project has developed feedback-focused rubrics that serve as a resource for instructors to assess and support student skill development. In this interactive workshop, participants will work in collaborative teams to explore the meaning and role of practical skills in STEM fields, practice assessment strategies, and reflect on how the development and assessment of practical skills enhances learning. In this interactive workshop, participants will work in collaborative teams to explore the meaning and role of practical skills in STEM fields, practice assessment strategies, and reflect on how the development and assessment of practical skills enhances learning. Participants will complete a short student assignment and analyze how both content knowledge and practical skills are developed through this task. They examine how the task cues students to provide evidence of skills that could be assessed. Participants then use ELIPSS rubrics to assess authentic student artifacts and videos of student interactions. These activities and videos are applicable and accessible to a broad range of STEM instructors provide participants with the opportunity to explore and use two student interaction rubrics (information processing and teamwork) and one product rubric (critical thinking). The teams of participants reflect on how they could elicit and assess practical skills in their own classrooms, then share ideas with the group.
- ? Explore practical skills and identify how a student task might elicit evidence of these skills
- ? Identify characteristics of student artifacts and student interactions that provide evidence of practical skills
- ? Gain experience using rubrics to assess practical skills in student work and group interaction
Ultrafast Dynamics of Photochromic Molecules
Dr. Christopher Elles, Dept. of Chem., University of Kansas
Abstract: Photochromic molecular switches are compounds that change color upon optical excitation. The color change is a response to the making, breaking, or rearranging of bonds in the molecule. We use femtosecond laser pulses to monitor these dynamics on the same timescale that the atoms rearrange. One laser pulse excites the molecule, then a second pulse probes the evolving spectrum as a function of time to reveal changes in the molecular structure. Beyond simply observing the reaction unfold, sequential excitation with two, time-delayed laser pulses allows us to control the dynamics of the molecule
and influence the outcome of the reaction. These experiments probe the potential energy surfaces that determine the motions of the atoms, and provide unique insight on the dynamics of molecules in highly excited electronic states, which is an important frontier in chemical reaction dynamics.
Fabrication technique, mechanical, and optical properties of carbon nano-onions/silica glass composites
Shuohan Huang, Dept. of Chem., MS&T
Achieving Superlubricity with 2D Transition Metal Carbides (MXenes) and MXene/Graphene Coatings
Ibrahim Abdullahi, Dept. of Chem., MS&T
Novel Aerosol Measurement Techniques for Energy and Environmental Applications
Dr. Yang Wang, Civil, Arch., & Environmental Eng., MS&T
Designing Correlation Consistent Basis Sets for Use with Density Functionals
Dr. John Determan, Dept. of Chem., Western Illinois University
Analytical Method Development for Biomedical and Environmental Applications
Mousumi Bose, Dept. of Chem., MS&T
Electrocatalytic processes for CO2 reduction and biomass conversion
Apurv Saxena, Dept. of Chem., MS&T
Fall Semester 2019
General Laboratory Safety Training
Environmental Health and Safety, MS&T
General Safety
- Environmental Health and Safety Department
- General Rules/Policies and Prudent Practices
- Fire Safety
- Emergency Response
- Hazard Communication
- Engineering/Administrative Controls, and Personal Protective Equipment
- Injury / Incident Reporting
Hazardous Material Safety and Management
- Chemical/Biological/Radiological Hazards
- Compressed Gas Cylinders / Cryogenics
- Physical Hazards
- Chemtrack Inventory System
General Laboratory Safety Training
Environmental Health and Safety, MS&T
Environmental Management System
- ISO 14001
- Corrective action
Hazardous Waste Management
- Federal Regulations
- Chemical Waste – proper storage and labeling
- Chemical Waste – pick-up request
- Biological Waste
- Universal Waste
- Spill Response
Development of real-time PCR assays to detect and identify foodborne pathogen threat agents
Dr. Kelly Elkins, Dept. of Chemistry, Towson University, Towson, MD
Abstract: Foodborne pathogens including Escherichia coli, Salmonella enterica, Shigella flexneri, Listeria monocytogenes, Vibrio parahaemolyticus, and Clostridium difficile routinely cause foodborne illness in the United States reported by the Centers for Disease Control and Prevention (CDC). Foods including uncooked or undercooked meats and shellfish, salads can cause illness. The CDC classifies these as bioterrorism threat agents and rapid, specific and sensitive assays are essential for identification and treatment. Several of these pathogens are classified in the CDC's Category B, or second highest priority, as they can be disseminated with moderate ease, require enhanced disease surveillance and result in moderate morbidity and low mortality rates. Salmonella was used to intentionally contaminate an Oregon salad bar, creating the largest incidence of foodborne pathogen illness in the U.S. in 1984 and S. flexneri was used to contaminate donuts in a hospital break room in Texas in 1997. In this presentation, I will describe the development of new polymerase chain reaction (PCR) high resolution melt (HRM) assays to detect and identify these food-borne pathogens by the different melt temperatures of the amplified DNA. Developmental validation results including reproducibility, specificity, sensitivity, and robustness will be presented. Experiments demonstrating the performance of multiplex assays targeting multiple pathogens simultaneously will also be presented.
For more information, visit the webpage here. Find the itinerary of the visit here.
Dr. Wipula P. Liyanage, Dept. of Chemistry, MS&T
Abstract: Fabricating high-efficiency photovoltaic devices largely rely on nanostructuring the photoabsorber layers due to the ability of improving photoabsorption, photocurrent generation and transport in nanometer scale. Vertically aligned, highly uniform nanorods and nanowire arrays for solar energy conversion have been explored as potential candidates for solar energy conversion and solar-fuel generation owing to their enhanced photoconversion efficiencies. However, controlled fabrication of nanorod and especially nanotube arrays with uniform size and shape and a pre-determined distribution density is still a significant challenge. In this talk, we demonstrate how to address this issue by fabricating nanotube arrays by confined electrodeposition on lithographically patterned nanoelectrodes defined through electron beam as well as nanosphere photolithography. This simple technique can lay a strong foundation for the study of novel photovoltaic devices because successful fabrication of these devices will enhance the ability to control structure-property relationships. The nanotube patterns fabricated by this method could produce an equivalent amount of photocurrent density produced by a thin film like device while having ~ 10% of semiconducting material coverage. This talk also focuses on solar fuel generation through photoelectrocatalytic water splitting for which efficient electrocatalysts were developed from non-precious elements.
Interface Engineering for Lithium-Ion Batteries
Dr. Jonghyun Park, Mech. & Aerospace Engineering, MS&T
Abstract: Battery performance is highly dependent on the interfacial phenomena among the components of the battery materials. This talk introduces the key interfacial physics on anode and cathode particles, and the engineering process that controls their behavior towards improved battery performance. The dissolution of the active materials and the instability of the Solid Electrolyte Interphase (SEI) are two of the key phenomena responsible for the degradation. These two phenomena, in particular, cannot be considered independent at elevated temperatures, since a significant amount of the ions dissolved at elevated temperatures move to the anode side and modify the SEI layer. The findings on the chemical degradation of the SEI layer induced by dissolved Mn ions and its mechanism through XPS and AFM will be discussed. Further, the use of electrolyte additives is one of the most effective and economical ways to improve battery performance by stabilizing the electrode/electrolyte interface. The impact of fluoroethylene carbonate (FEC), which was found to have different impacts on anode and cathode, will be discussed. In this talk, the study on composition-/structure-dependent elasticity of the SEI layer via AFM measurements coupled with XPS analysis, and atomistic calculations will be discussed.
Novel Analytical Methods for Anticancer Drug Discovery by Using High-Resolution Mass Spectrometry
Ke Li, Dept. of Chemistry, MS&T
Abstract: Cancer is a major public health concern and one of the leading cause of death. Millions of people were diagnosed with cancer each year. Many cancers such as lung cancers and brain cancers, the 5-year survival rate is pretty low, less than 20%. Currently, traditional chemotherapy is still the predominant therapy for many cancers. However, the severe side effects are the common problems due to the non-selectivity of the chemotherapy drugs. Therefore, developing new targeted anticancer drugs to lower the systematic toxicity are in high demand. During any anticancer drug discovery, advanced analytical technology must be used to characterize the structures of the drugs and evaluate the effectiveness of the drugs. High resolution mass spectrometer (HRMS) is a powerful technology and is often used for the new anticancer drug discovery. The high resolution, high mass accuracy, multiple mode of fragmentation and capability of coupling to liquid chromatography make it an indispensable instrument for qualitative and quantitative analysis in anti-cancer drugs discovery. In this presentation, several novel HRMS analytical methods will be introduced and applied for discovery of new targeted anticancer drugs including antibody−drug Conjugates and small molecule drug. The detailed experimental conditions and results will described in my presentation.
Folding- and Dynamics-based Electrochemical Biosensors
Dr. Rebecca Y. Lai, Dept. of Chem., University of Nebraska-Lincoln
Abstract: This seminar will cover the recent advances in the design and fabrication of folding- and dynamics-based electrochemical biosensors. These devices, which are often termed electrochemical DNA (E-DNA), aptamer-based (E-AB), and peptide-based (E-PB) sensors, are fabricated via direct immobilization of a thiolated and methylene blue (MB)-modified oligonucleotide or peptide probe onto a gold electrode. Binding of an analyte to the probe changes its structure and/or flexibility, which, in turn, influences the electron transfer between the MB label and the interrogating electrode. These sensors are resistant to false positive signals arising from the non-specific adsorption of contaminants, and perform well even when employed directly in whole blood, saliva and other realistically complex sample matrices. Furthermore, because all of the sensing components are chemisorbed onto the electrode surface, they are readily regenerable and reusable. Our results show that many of these sensors have achieved state-of-the-art sensitivity, while offering the unprecedented selectivity, reusability and operational convenience of direct electrochemical detection.
Nanomaterial Assembly & Analytical Characterization
Dr. Wenyan Liu, Dept. of Chemistry, MS&T
Abstract: Nanotechnology- the manipulation of tiny elements, is bringing amazing impact on our daily lives and is helping to improve, even revolutionize, many technologies including material science, energy, biomedicine, food safety, and environmental science. Therefore, the development of novel nanomaterials and the characterization of those tiny nanoparticles are critically important in those fields. First, I present the bottom-up assembly of nanoparticles forming novel nanostructures. Fabrication of nanoparticles into superstructures has attracted tremendous research interest due to their interesting collective properties different from those of individual components or their randomly packed aggregates. DNA-mediated self-assembly is one of the most widely used approaches in nanoparticle superlattice construction, which has led to the realization of various superlattices. However, effective assembly of prescribed nanoparticle superstructures remains a difficult challenge. This presentation will demonstrate our efforts on how to use DNA origami nanostructures, serving as both topological linkers and symmetry breakers, to facilitate the synthesis of tailor-made nanoparticle super-architectures. Examples include the creation of polychromatic nanoparticles for assembly of arbitrarily shaped nanostructures and the construction of low-coordinated diamond-type superlattices from gold nanoparticles. Following this, I talk about the characterization of nanoparticles by using state-of-the-art bioanalytical tools: the detection of nanoparticles in soil via single particle (SP)-ICP-MS.
Next-generation Battery Technologies
Dr. Arumugan Manthiram, Mechanical Engineering & Materials Sciences & Engineering, University of Texas-Austin
Abstract: Rapid increase in global energy use and growing environmental concerns have prompted the development of clean, sustainable, alternative energy technologies. Renewable energy sources like solar and wind are a promising solution, but electrical energy storage (EES) is critical to efficiently utilize them as they are intermittent. EES is also the only viable near-term option for transportation. Rechargeable batteries are prime candidates for EES, but their widespread adoption for electric vehicles and grid electricity storage requires optimization of cost, cycle life, safety, energy density, power density, and environmental impact, all of which are directly linked to severe materials challenges. After providing a brief account of the current status, this presentation will focus on the development of advanced materials and new battery chemistries. Specifically, lithium-based batteries based on low-cobalt oxide and sulfur cathodes and interdigitated alloy anodes will be presented. The challenges of bulk and surface instability and chemical crossover during charge-discharge cycling, advanced characterization methodologies to develop an in-depth understanding, and approaches to overcome the challenges will be presented.
Synthesis, Characterization and DSC and TGA Investigation of a Colloidal Unimolecular Polymer
Peng Geng, Dept. of Chemistry, S&T
Abstract: CUP particles are unimolecular spheroidal particles suspended in water and are thermodynamically stable. CUP size is directly related to the molecular weight and are typically between 2.5 and 9 nm in diameter. The surface of these particles per gram is extremely large. Since any surface in contact with water will have a layer of “surface” or associated water on it. The surface water has different physical properties than bulk water. Differential scanning calorimetry (DSC) can determine the free versus surface water based upon the heat of fusion since only free water freezes at zero, giving an estimation of the thickness of surface water by measuring the heat of fusion. Using this data calculation of the specific heat of surface water; determination of the average surface area of functional groups on the CUP surface by knowing the freezing point depression of CUP suspensions; establishment of a relationship between CUP surface water, the molecular weight and ions per nm of surface area. TGA was then used to investigating the evaporation rate for colloidal unimolecular polymer systems. CUP solutions from 5-25% solution up to the point when the gelation occurs. Various models were explored to understand how water evaporates as a function of time, temperature, molecular weight, charge density and ionic group.
Applications of the confocal microscope for chemistry and biology
Dr. Katie Shannon, Dept. of Biology, MS&T
Abstract: Confocal microscopy allows for improved imaging of thick samples due to reduction of out-of-focus light. In this seminar, the principles of confocal microscopy will be discussed, and examples of applications in chemistry and biology provided. Attendees will learn about the capabilities of Missouri S&T’s Nikon A1R laser scanning confocal microscope and how this instrument could benefit their research.
Ultrafast Dynamics of Photochromic Molecules
Dr. Christopher Elles, Dept. of Chem., University of Kansas
Abstract: Photochromic molecular switches are compounds that change color upon optical excitation. The color change is a response to the making, breaking, or rearranging of bonds in the molecule. We use femtosecond laser pulses to monitor these dynamics on the same timescale that the atoms rearrange. One laser pulse excites the molecule, then a second pulse probes the evolving spectrum as a function of time to reveal changes in the molecular structure. Beyond simply observing the reaction unfold, sequential excitation with two, time-delayed laser pulses allows us to control the dynamics of the molecule and influence the outcome of the reaction. These experiments probe the potential energy surfaces that determine the motions of the atoms, and provide unique insight on the dynamics of molecules in highly excited electronic states, which is an important frontier in chemical reaction dynamics.
Lab-in-a-Particle: Enginnering Nano- and Microparticles to Combat Infectious Diseases
Dr. Sutapa Barua, Dept. of Chemical and Biochemical Engineering, MS&T
Abstract: Non-spherical drug nanoparticles selectively invade and kill cancer cells by enhancing multivalent receptor-ligand interactions. Breast cancer cells overexpress human epidermal growth factor 2 (HER-2) receptor proteins that are targeted for selective binding using Trastuzumab, a humanized IgG monoclonal antibody from Genentech. Trastuzumab- conjugated shape-engineered drug nanoparticles are shown to enhance multivalent interactions with breast cancer cells, release cytotoxic drug molecules and induce a significant reduction in the cancer cell population.
In a second project, we have demonstrated for the first time the effective removal of endotoxins from pharmaceutical formulations using polymer nanoparticles. The nanoparticles are shown to remove >99% endotoxins from pharmaceutical protein formulations with >99% product recovery.
We have also developed a technology to grow mammalian cells on the surface of biodegradable microparticles in liquid cell culture suspension for traumatic burn injury. An overview of this lab-in-a-particle approach will be presented as a suitable and cost-effective way to carry out treatment and prevention for a range of human diseases.
Novel Transition Metal Catalysts for the Intermolecular Amination of Light Alkanes and Benzenes
Meenakshi Mehta, Dept. of Chemistry, MS&T
Abstract: Transition metal catalyst frameworks supported by tripodal [N3N] ligands mediate nitrene transfer from nitrogen sources such as PhI=NR to a diverse group of aliphatic and aromatic hydrocarbons and olefins. These reactions are categorized as amination and aziridination reactions. Novel tripodal ligands and their complexes with late first- and second-row transition metals (Cu, Ag) with different axial atoms such as B, Si, CH, and 2,4,6-substituted benzene systems have been designed to impart weaker axial ligand field which in turn enhances the electrophilicity of nitrene potentially affording more reactive and site-selective aminated products. Synthetic efforts to generate these ligands as well as novel Z-type ligands featuring heavier Group 15 elements (Sb, Bi) placed on the axial apex of a tripodal ligand scaffold will be discussed in detail.
Spring Semester 2019
Intellectual Property Basics; Patents, Copyrights, and Trade Secrets
Keith Strassner, Assistant Vice Provost for Technology & Business Development, MS&T
Abstract: Intellectual property issues are constantly in the news – the Apple vs. Samsung, Alice Corporation vs. CLS, Myriad – these legal cases are just a few of those that have had and will have a significant impact on how universities and companies built on technology will conduct business in the future. In the Myriad case, the US Supreme Court ruled that naturally occurring genes and their uses cannot be patented, Alice vs. CLS will set a new standard for patentability of software code and so-called business method patents; think Amazon one-Click® method. In today’s technology based world, it is critical to have a basic understanding of the types of intellectual property, how they are created and protected. This talk will explore patents, copyrights, trademarks and trade secrets. In addition, intellectual property policy within the University setting will be described.
Structure Determination of Five-membered Silene Rings Using Microwave Spectroscopy
Frank Marshall, Grad. Stud., Dept. of Chem., MS&T
Abstract: Rotational spectroscopy relates the rotational energy transitions of a gas phase molecular system to the locations of atoms utilizing mass displacement throughout the system. These separations are generally low in energy and fall in the microwave (3-300 GHz) region of the electromagnetic spectrum, leading the phrase “rotational spectroscopy” to be termed “microwave spectroscopy.” A brief introduction to microwave spectroscopy will be provided. Spectrometers of this sort cannot be purchased, so the construction and implementation of a chirped-pulse, Fourier transform microwave (CP-FMTW) spectrometer will be discussed. Because not all desired systems are gas phase, various sourcing techniques to get liquids or solids into the gas phase on the CP-FTMW will also be presented and discussed. As an example of the usefulness of these experimental techniques, the rotational spectra of four 5-membered Silane rings (1,1-di?uorosilacyclopent-3-ene, silacyclopent-3-ene, 1,1-di?uorosilacyclo-pentane, and 1,1di?uorosilacylopent-2-ene) was observed, collected, and analyzed. The molecules were observed in the 6 to 18 GHz range of the electromagnetic spectrum. Isotopic substitution spectra for many of these molecules have been obtained in natural abundance and been used to identify differences in molecular structure amongst the family. These differences in structure will be presented, showing how different functional groups and bond locations affect the overall structure and behavior of each system both quantum chemically and mechanically (ring puckering effects, etc….). These effects will then be compared to 6 membered Silane rings with similar functional groups. The behavior between the 5 and 6-membered families will be analyzed and presented.
Hydrogen Tunneling at Metallic Active Sites
Dr. Darrin Bellert, Dept. of Chemistry, Baylor University
Abstract: From cracking or reforming in the oil industry to the activity of metalloenzymes, metal mediated catalysis is pervasive throughout society. The reason for this is the energy cost reduction that catalysis affords during chemical transformations. It is commonly understood that an active site provides alternant, lower energy pathways to a chemical reaction thus subverting the total energy cost associated with crossing over an activation barrier. But what are these alternant pathways?
This talk discusses the possibility of hydrogen atom tunneling as another mechanism to lower the energy requirements of metal mediated catalysis. Several years ago, the Bellert group at Baylor University developed a novel method to measure the kinetics and dynamics of gaseous metal mediated reactions. The single photon initiated dissociative rearrangement reactions (SPIDRR) technique has been applied to various metal mediated reactions with results that defy contemporary (transition state theory or over the barrier) interpretations. This talk will explore the possibility of hydrogen atom tunneling as the controlling kinetic paradigm in certain metal mediated reactions.
Synthesis of Tripodal Based Chiral Framework Guanidines
Anshika Kalra, Grad. Stud., Dept. of Chem., MS&T
Abstract: Part 1: Comparative Nitrene-Transfer Chemistry to Olefinic Substrates Mediated by a Library of Anionic Mn(II) Triphenylamido-Amine Reagents and M(II) Congeners (M = Fe, Co, Ni): An Experimental and Computational Study. Aziridination of styrenes is examined via anionic MII catalysts (M= MnII, FeII, CoII, and NiII), supported by trisamido-amine moieties through a nitrene transfer reaction. We demonstrated that attenuated levels of electrophilicity are more suitable for discriminating aromatic from aliphatic olefins for aziridination purposes. The high-spin nature of the compounds encountered in the present work gives rise to putative metal-nitrene intermediates possessing more complex electronic structures than the common singlet/triplet manifolds explored with Cu, Ag or Ru nitrenes. We concluded – from experiments and computations – that carboradical intermediates are generated by initial nitrene-addition to one of the olefinic carbons, and play a key role in the stepwise C−N bond?formation. In this combined experimental and computational study, we present a family of anionic Mn(II) reagents that offer guidance with regards to ligand selection for effecting olefin aziridination, and subsequently extend to the corresponding Fe(II), Co(II), and Ni(II) reagents to gain insights in their comparative reactivity/selectivity patterns that enable aromatic over aliphatic alkene aziridinations.
Part 2: Enantioselective, Intermolecular Aziridination of Alkenes and Amination of Alkanes Catalyzed by Metal Reagents Supported (Cu, Ag) by Tripodal Ligands with a Chiral Framework. C-H and C=C bonds are ubiquitous structural units of organic molecules. Although these bonds are generally considered to be chemically inert, the recent emergence of methods for C-H and C=C functionalization seems to be quite promising. The intermolecular amination of C-H bonds and aziridination of C=C bonds represents a particularly desirable and challenging transformation. Recognizing the potential of this transformation we are currently developing guanidine based chiral ligands and catalysts for intermolecular C-H Amination and C=C Aziridination.
Guanidines are known as powerful organic bases and act as base catalysts in a variety of organic synthetic reactions. Introduction of chiral centers at the guanidinyl moiety can create new types of chiral organocatalysts. We have prepared several types of guanidine compounds with chiral centers and are examining their catalytic activity in asymmetric intermolecular C-N bond synthesis. Enantioselecive intermolecular C-H amination and C=C aziridination via the generation and transfer of metal nitrenoids is under development using Cu (I) and Ag (I) catalysts.
Smart Materials for Energy Conversion: The Story of Transition Metal Chalcogenides
Dr. Manashi Nath, Associate Professor, Dept. of Chem., MS&T
Abstract: This talk will focus on the elucidating a proper understanding of the structure-property correlation of transition metal chalcogenides and employing concepts of solid state chemistry to design optimal nanostructured electrocatalysts for application in energy conversion technologies. Energy harvesting from solar and water has created ripples in solid state materials chemistry research for the last several decades, complemented by the rise of Hydrogen as a clean fuel. Another aspect that has become more relevant is the electroreduction of atmospheric carbon dioxide into fuel or other value-added chemicals, thereby offering environmental remediation without the need to store large amounts of pressurized CO2. It has become very apparent that hydrogen-on-demand technology needs to be developed to complement the growth of hydrogen fuel economy without adding on to the process cost by storing hydrogen in pressurized tanks or non-reactive framework. In this regard, water electrolysis leading to generation of oxygen and hydrogen on demand, has been one of the most promising routes towards sustainable alternative energy generation and storage without depleting fossil-fuel based natural resources. However, the efficiency and practical feasibility of water electrolysis is limited by the anodic oxygen evolution reaction (OER), which is a kinetically sluggish, electron-intensive uphill reaction. A slow OER process also slows the other half-cell reaction, i.e. the hydrogen evolution reaction (HER) at the cathode. Hence, designing efficient catalysts for OER and HER process from earth-abundant resources has been one of the primary concerns for advancing solar water splitting. In the Nath group we have focused on transition metal chalcogenides nanostructures as efficient electrocatalysts for several energy conversion processes. In this talk we’ll discuss the design principles illustrating with several examples of new catalyst compositions discovered in the laboratory.
Zintl Phases for Thermoelectric Applications
Dr. Susan Kauzlarich, Dept. of Chemistry, Univ. of California-Davis
Abstract: There are many areas of science where progress is materials limited. The synthesis and identification of new compounds that can lead to enhancements in existing technologies, or serve as the basis of revolutionary new technologies, is essential for developing new and improved technologies. Zintl compounds can be described by a combination of ionic and covalent bonding, composed of electropositive cations which donate electrons to the more electronegative components that utilize the electrons to form various bonding motifs. My group has focused on Zintl compounds for their structural, chemical, and electronic properties and I will present research on Zintl phases for thermoelectric applications such as waste heat to electrical power conversion.
Inelastic Collisions of Ozone and Argon
Sangeeta Sur, Grad. Stud., Dept. of Chem., MS&T
Abstract: The formation and destruction of ozone is an important cycle in the atmosphere. An important step in the formation process is the stabilization of a metastable ozone molecule, which occurs through energy transfer: usually a highly excited ozone molecule loses the extra energy through collision with a third body. However, the details of this mechanism are still not well known and one of the reasons is the lack of an accurate potential energy surface (PES). In theoretical studies, Ar is often selected as the third body when considering the dynamics. However, there are no reported electronic structure calculations for the PES of the O3 - Ar complex. The PES of the O3-Ar complex is a 6D problem in full-dimensionality, or 3D for rigid O3. Here I present global 3D PESs for O3 fixed at equilibrium, interacting with Ar. Ab initio electronic structure calculations using explicitly-correlated coupled-cluster (CCSD(T)-F12b) extended to the complete basis set limit, and explicitly-correlated multi-reference configuration interaction (MRCI--F12) were employed. The AUTOSURF code was used to construct the PESs automatically, represented by a local interpolating moving least-squares (L-IMLS) method. Global RMS fitting errors of less than 1 cm–1 were obtained. Symmetry equivalent minima with a well depth of –229 cm–1 are located above and below the plane of O3. I will present bound state calculations of the O3-Ar vdW complex obtained by variational rovibrational calculations, as well as results of quantum scattering studies for rotationally inelastic collisions. The isotopic effect is also studied using the 16O18O16O and 16O16O18O isotopologues. Moving from a symmetric system to an asymmetric one, roughly a doubling in the density of states is observed due to nuclear spin statistics.
Advanced Pulse Techniques for Analysis and Compensation of Inhomogeneous Magnetic Fields in NMR Spectroscopy
Emma Schmittzehe, Grad. Stud., Dept. of Chem., MS&T
Abstract: NMR pulse sequences are continuously being designed both to improve the current capabilities as well as to provide for new applications. In this process theoretical methods ranging from the simple vector model to more involved density matrix calculations and product operator formalism are used to predict the fate of the magnetization that will be observed with NMR. However, the reliability of NMR pulse sequences is critically dependent on the accuracy of the radiofrequency (RF) pulses, and the inaccuracies of the RF pulses are not always obvious or predictable. A new imaging protocol has been developed to independently record the x, y, and z components of the net magnetization during any point in a pulse sequence while eliminating the observation of the other components. This protocol provides an experimental method of tracking magnetization which then can be used in conjunction with theoretical methods to scrutinize the predicted outcome of each step in a pulse sequence and potentially find further improvements to the effectiveness and efficiency of NMR pulse sequences. The protocol utilizes a Rapid rotating-frame Imaging Pulse Train (RIPT) on a sample with a single resonance (e.g., CHCl3) to obtain RF-field (B1) and resonance-offset (ΔB0) dependent profiles for each Cartesian component in the magnetic coordinate system.
Folding- and Dynamics-based Electrochemical Biosensors
Dr. Rebecca Y. Lai, Dept. of Chemistry, Univ. of Nebraska-Lincoln
Abstract: This seminar will cover the recent advances in the design and fabrication of folding- and dynamics-based electrochemical biosensors. These devices, which are often termed electrochemical DNA (E-DNA), aptamer-based (E-AB), and peptide-based (E-PB) sensors, are fabricated via direct immobilization of a thiolated and methylene blue (MB)-modified oligonucleotide or peptide probe onto a gold electrode. Binding of an analyte to the probe changes its structure and/or flexibility, which, in turn, influences the electron transfer between the MB label and the interrogating electrode. These sensors are resistant to false positive signals arising from the non-specific adsorption of contaminants, and perform well even when employed directly in whole blood, saliva and other realistically complex sample matrices. Furthermore, because all of the sensing components are chemisorbed onto the electrode surface, they are readily regenerable and reusable. Our results show that many of these sensors have achieved state-of-the-art sensitivity, while offering the unprecedented selectivity, reusability and operational convenience of direct electrochemical detection.
Synthesis of Ceramic and Metal Aerogels from Xerogels and Applications in High Temperature Thermal Insulation and Thermites
Parwani Rewatkar, Grad. Stud., Dept. of Chem., MS&T
Nitrogen-phosphorus-associated Metabolic Activities During the Development of a Cyanobacterial Bloom Revealed by Metatranscriptomics
Dr. Jingrang Lu, National Exposure Research Lab., EPA, Cincinnati
Abstract: This seminar will cover the latest discoveries of association of cyanobacteria-caused harmful algal blooms (CyanoHAB) with nitrogen and phosphorus, especially the impact of ammonium on CyanoHAB). Our study demonstrated that expressions of genes involved in N2-fixation (nifDKH) and P-scavenging were significantly upregulated during the bloom compared to pre-bloom in Harsha Lake. The activities of N2-fixation occurred during early summer after a late spring phytoplankton bloom, and were associated with high phosphorus and low nitrogen. The highly active cyanobacterial N2-fixers were dominated by Nostoc and Anabaena. Following the activities of N2-fixation and production of new nitrogen, an early summer Microcystis-dominated bloom, a shift of dominance from Nostoc and Anabaena to Microcystis and an increase of microcystin occurred. By contrast, P-scavenging activities dominated also by Nostoc and Anabaena were associated with low P and the Microcystis bloom. This information can be used to aid in the understanding the impact that nitrogen and phosphorus have on the early summer CyanoHAB and the functional activities of Nostoc- and Anabaena-dominated or Microcystis-dominated communities, and aid in making management decisions related to harmful algal blooms.
DNA Engineering: Application from drug delivery to plasmonic metamolecules
Dr. Risheng Wang, Assistant Professor, Dept. of Chem., MS&T
Abstract: DNA (deoxyribonucleic acid), the natural hereditary material in humans and almost all other organisms, can be fabricated into functional nanostructures through Watson-Crick base paring in biochemistry and engineering fields. Over the past four decades, researchers in the emerging field of DNA nanotechnology have synthesized a diversity of DNA nanostructures with excellent programmability, biocompatibility, and low/no cytotoxicity. These self-assembled nanostructures have been used to precisely organize functional components into deliberately designed patterns, which exhibit a wide range of applications in material science, biomedical, electric and environmental fields. In this talk, I will present our efforts in the design and construction of several DNA nanostructures for nanotechnology and biomedical applications. For example, DNA origami-assisted cancer drug delivery, integrated hydrogen peroxide biosensing, self-assembled plasmonic metamolecules, and stimuli-responsive DNA nanostructures.
Mechanically Strong and Transparent Silica Aerogel for Applications in Thermally Insulated Windows
Chandana Mandal, Grad. Stud., Dept. of Chem., MS&T
Abstract: A hypothesis that is under intense current investigation by the scientific community states that the mechanical properties of nanostructured polymers depend on their nanomorphology. Aerogels are nanostructured ultra-lightweight nanoporous materials with skeletal frameworks that can display a wide range of nanomorphologies. Thereby aerogels comprise a suitable platform for testing not only that hypothesis but also a wide range of other properties such as light scattering for applications, for example, in thermally insulating windows.
To study the mechanical properties of nanostructured matter as a function of nanomorphology, various shape-memory polyurethane aerogels were prepared with identical density, porosity, and chemical composition, but with vastly different nanostructures. That was accomplished based on our understanding that nanostructure is intimately related to the rate of gelation, which in turn was controlled by developing an array of new catalysts, some much more and some less active than the classic Sn-based dibutyltin dilaurate used in polyurethane synthesis. Depending on the gelation time, the morphology ranged from spheroidal to bicontinuous. Irrespective of the catalyst and its concentration, the morphology was the same for equal gelation times pointing to chemical cooling-induced spinodal decomposition as the gelation mechanism. Based on 5 different catalysts at 5 different concentrations each, the elastic modulus of all materials followed a well-defined trend whereas, all other factors being equal, bicontinuous structures were by several times stiffer than spheroidal nanostructures, in strong support of the standing hypothesis above.
In order to develop silica aerogels as thermal insulators for windows, one must achieve a balance of clarity, strength, and thermal insulation value. The combination of the three properties was studied by applying statistical design of experiments methods on the synthesis of polymer-crosslinked silica aerogels with the concentrations of the silica precursor and the monomer of the crosslinking polymer as explanatory (independent) variables. Light scattering (haze) was studied with an integrating sphere, thermal conductivity with the hot plate method and mechanical strength with uniaxial compression. Along the way, the source of haze was identified with light scattering from secondary silica particles. Delamination of wet-gels from glass substrates during drying into aerogels was traced to the nature mass fractal of the secondary particles that allows them to merge with one another. Based on these data, optimal synthetic and processing conditions were identified.
Fall Semester 2018
Ionic Liquids in Separations and Mass Spectrometry
Daniel W. Armstrong, University of Texas at Arlington
Abstract: Room-temperature ionic liquids (RTILs), are a class of nonmolecular ionic solvents with low melting points. Most common RTILs are composed of unsymmetrically substituted nitrogen-containing cations (e.g., imidazolium, pyrrolidinium, pyridinium) or phosphonium cations with inorganic anions (e.g., Cl?, PF6?, BF4?). Most of these more common ILs are of limited use analytically. Consequently many ILs containing a variety of cations and anions of different sizes have been synthesized to provide specific characteristics. In this presentation an overview of the structure and properties of ILs and a description of their expanding use in various applications in separations, chromatography and mass spectrometry will be given. A number of studies have appeared indicating that ILs have exceptional promise as stationary phases. They have a dual nature selectivity in that they separate nonpolar molecules as would a nonpolar stationary phase and they separate polar molecules as would a polar stationary phase. Many ILs have exceptional thermal stability. They are being used increasingly in a variety of applications including 2-D GC, enantiomeric separations, the measurement of water in samples/solvents/materials and compact field GC units. ILs have proven to be the best liquid MALDI-MS matrix since we introduced them as such a few years ago. The properties of ILs that make them effective will be discussed. Further, the dications developed for high stability ILs have found another novel use in electrospray ionization (ESI) MS as a reagent for ultra sensitive anion analysis. These will be discussed as well.
General Labratory Safety Training: Safety
Environmental Health and Safety, MS&T
Abstract:
- General Safety
- Environmental Health and Safety Department
- General Rules/Policies and Prudent Practices
- Fire Safety
- Emergency Response
- Hazard Communication
- Engineering/Administrative Controls, and Personal Protective Equipment
- Injury / Incident Reporting
- Hazardous Material Safety and Management
- Chemical/Biological/Radiological Hazards
- Compressed Gas Cylinders / Cryogenics
- Physical Hazards
- Chemtrack Inventory System
General Labratory Safety Training: Environmental Compliance
Environmental Health and Safety, MS&T
Abstract:
- Environmental Management System
- ISO 14001
- Corrective action
- Hazardous Waste Management
- Federal Regulations
- Chemical Waste – proper storage and labeling
- Chemical Waste – pick-up request
- Biological Waste
- Universal Waste
- Spill Response
Analysis of Inorganic and Organic Water Contaminants by Mass Spectrometry
Ariel Donovan, Dept. of Chem., MS&T & Organic Geochemistry Research Laboratory, Lawrence, KS
Abstract: Water quality is imperative to preserve human, animal, and environmental health and can be impacted by a variety of contaminants including inorganic and organic constituents. They can be naturally occurring or anthropogenically introduced or influenced. This seminar will discuss two types of water contaminants; nanoparticles and algal and cyanotoxins. Nanoparticles (NPs) studied include those that are comprised of metals and metal oxides that have at least one dimension less than 100 nm. They are used in many commercial and industrial applications including food packaging, antimicrobial socks, and paint/coatings. The toxicology of these materials is controversial; thus, developing tools to monitor their introduction into recreational and drinking waters is important. Single particle – inductively coupled plasma – mass spectrometry (SP-ICP-MS) methods were developed to assess the presence of five commonly used NPs in natural water and after coagulation processes, commonly used methods to remove particulate material from influent water. In the second part of the seminar, the analysis of toxins produced by cyanobacteria and algae at the land-sea interface will be discussed. Cyanobacteria are commonly known to proliferate in freshwater systems, but there is growing evidence that cyanotoxins are present along with algal toxins in coastal systems. This poses another potential exposure risk for humans, animals, and aquatic life. Advantages and limitations of the analytical techniques will be discussed, as well as results from select studies.
Highly Accurate Thermochemical Computations of Combustion and Atmoshperic Species: Comparisons with Active Thermochemical Data
Bradley Welsch, Dept. of Chem., MS&T
Abstract: The Active Thermochemical Tables (ATcT) have been said to be one of the greatest advances in thermochemistry in the last thirty years. The ATcT is a self-consistent thermochemical network that provides thermochemical values and uncertainties that are more accurate than any individual experiment. The ATcT can consider multiple sources of thermochemical values including those generated by computation. The ATcT is valuable beyond its role in thermochemistry, because it also serves to benchmark high accuracy computational methods under development. These benchmarks allow for the assignment of uncertainty to these computations, something not commonly studied over wide classes of systems.
High accuracy computational thermochemistry involves generate multiple inputs and running several codes. If done manually there is a possibility of human error. This has motivated work on a family of codes that, starting from an approximate initial geometry, will generate the necessary input for each step, execute each calculation and, once done, process them and combine the results to produce an enthalpy of formation. Work on a second generation of a more flexible and all-one-package will also be discussed. This first generation of code has been used to generate accurate thermochemical data with a user-defined scheme for a large family of 60 molecules up to fluorobenzene. This family was also used to generate very accurate data for the alkyl peroxy family of molecules and data from these computations was used to update the thermochemical network to include this new knowledge.
Designing Bifunctional Catalyst Composites for Oxygen Evolution and Oxygen Reduction Reactions
Siddesh Umapathi, Dept. of Chem., MS&T
Abstract: Water splitting is one of the cleanest methods to produce hydrogen with less environmental impact. However, the efficiency and practical feasibility of water electrolysis is limited by the anodic oxygen evolution reaction (OER) which is a kinetically sluggish, electron-intensive uphill reaction. Hence finding appropriate earth abundant and environmentally benign materials for electrocatalytic water splitting has become critical for renewable energy technologies. In spite of tremendous efforts to develop a catalyst with low cost, high activity and stability, it remains a challenge to match the performance of platinum group catalyst. Hence, designing an efficient catalyst for this energy demanding process has been primary focus for advancing the technology of producing hydrogen and oxygen from water. In this presentation hybrid composites containing iron nickel selenide (FeNi2Se4) nanoparticles supported on nitrogen doped reduced graphene oxide (N-rGO), i.e., FeNi2Se4-NrGO, and iron cobalt selenide (FeCo2Se4) supported on functionalized nanoonions (FeCo2Se4-NH2-OLC) will be discussed as efficient and dependable electrocatalysts for oxygen evolution reaction (OER) under alkaline conditions. The constructed hybrid catalyst composites were capable of catalyzing water oxidation at a small overpotential and exhibited extended stability in harsh conditions. Presence of carbonaceous composite in the matrix also yielded high current density. Additionally, the catalysts also showed good activity for oxygen reduction reaction (ORR) which is the primary reaction occurring in the fuel cell. This study gives a new direction to design the selenide based bifunctional hybrid catalyst composites, which can be extended to prepare other ternary based selenide catalyst composites for a broad range of energy conversion and storage applications.
Anecdotes for the Lifetime Experiences of a 96 Year Old Emeritus Professor of Chemistry
William J. James, Dept. of Chem., MS&T
Topological Superconductors
Yew San Hor, Dept. of Physics, MS&T
Abstract: Topological superconductors are predicted to have a full superconducting pairing gap in the bulk and gapless surface states consisting Majorana fermions which are spinless quasiparticles with no charge. This Majorana fermionic surface state, if detectable, could be useful for quantum computer. However, topological superconductors and the associated Majorana quasiparticles have not been conclusively established in real materials so far. This presentation will show by chemical doping, a topological insulator can be tuned into a bulk superconductor that could be a candidate for topological superconductor. The first example i.e. CuxBi2Se3 was discovered few years ago to be a promising one. Recently, SrxBi2Se3 and NbxBi2Se3 are found to be other promising systems for the topological superconductivity studies. Several other promising candidates of topological superconductors will be shown.
History and Restoration of the Rolla Mural
Dan Woodward, Rolla Artist, Member of American Association of Art Conservation
Abstract: In 1952 Edward Sower, Publisher of the Rolla Daily News, commissioned a mural about Rolla, its creation and history, by Sidney Lawson, a student of Thomas Hart Benton. The mural hung for more than 60 years in the Rolla Daily News building in Rolla and suffered from cigarette smoke and water damage. In 2017, the Sowers’ family presented the mural to Missouri University of Science and Technology. Not without difficulties, the mural was transferred to the second floor of the Curtis Laws Wilson Library, where it can now be admired by all. For several long painstaking weeks, Dan Woodward, artist and conservator, accurately restored the mural to its original splendor – it was publicly rededicated on 4 October 2018.
In this seminar, Dan Woodward will interpret the mural, and describe the various steps involved in its difficult restoration including the unique problems encountered with the use of water, milk, and egg-based paints and their chemical proclivities.
Solid-state NMR Derived Structure: Applications to Boron-carbide Materials
Nathan Oyler, Dept. of Chem., UMKC
Abstract: Basic concepts in solid-state NMR, including magic angle sample spinning, are introduced for the purpose of discussing dipolar recoupling techniques for measuring constraints in the internal structure new materials. These techniques will be applied to the elucidation of the local physical structure in a side product of the plasma-enhanced chemical vapor deposition of thin-film amorphous hydrogenated boron carbide from orthocarborane. Experimental 1H, 13C, and 11B chemical shifts and dipolar recoupling methods are used in conjunction with ab initio calculations of model molecular compounds to assign chemical environments and determine atomic connectivities. The results of these studies and a discussion of various complicating factors will be presented.
Electrode Materials for Li/Na-ion Batteries: Improving Electochemical Performance Through Carbon Addition During Synthesis
Abdelfattah Mahmoud, GREENMat, CESAM Research Unit, Institute of Chemistry, University of Liège
Abstract: Lithium-ion batteries (LIBs) have outperformed other rechargeable battery systems since 1980 and advances in LIBs technology have improved living conditions around the globe. However, Li-ion batteries face many challenges and limitations. Na-ion batteries are considered to be an alternative to Li-ion batteries owing to the natural abundance of sodium. New electrode materials are required to increase the energy density of Li/Na-ion batteries. However, their electronic conductivity usually has to be improved through the preparation of composite powders ensuring intimate contact between the active material and conductive carbon. In this presentation, we report on the one-step synthesis of composite materials using spray-drying or hydrothermal synthesis routes, two techniques which are easily up-scalable[1-6].
In order to evidence the effect of the carbon on the microstructural and electrochemical properties of the prepared materials by a spray-drying [1-3] or hydrothermal methods [4-6]. The crystal and local structures were analyzed by combining XRD and 57Fe Mössbauer spectroscopy. The morphological properties were characterized by SEM and TEM (Figure 1). The carbon content was determined by TG/TDA and carbon analyzer. The electrochemical properties were studied by impedance spectroscopy and galvanostatic cycling in lithium and sodium cells. The reaction mechanism during cycling was investigated by combining operando X-ray diffraction and 57Fe Mössbauer spectroscopy.
Thermal Transport from First Principles: Theory and Applications
A. Chernatynskiy, Dept. of Physics, MS&T
Abstract: Recent advancements in the computational power and methodologies now permit calculations of the thermal transport properties of materials ab initio. In this presentation we will overview the technique based on the Boltzmann Transport Equation coupled with the perturbation theory at the level of cubic anharmonicity for these calculations and present applications in various areas illustrating the power of the method. Firstly, we will present calculations of the thermal transport in the sequence of the technologically important compounds Mg2X, where X= C, Si, Ge, Sn, and Pb. The accuracy of the method will be demonstrated, as well as thorough insight into the thermal transport properties of these materials. Next, we will turn to the materials at the extreme environment of high pressure and temperature and discuss applicability of the methodology in these conditions on the example of the MgxFe1-xO, an important material in the Earth’s mantle. Finally, we will turn to the calculations of the individual phonon lifetimes and present comparison with the experimental data where available.
Quantum Chemical Computations Analysis of Biodiesel Pyrolysis for Production of Transportation Fuels and Fine Chemicals
Matthew R. Siebert, Dept. of Chem., Missouri State University
Exploring Chalcogenides for Highly Efficient Water Oxidation Electrocatalysts
Umanga de Silva, Dept. of Chemistry, MS&T
Abstract: The development of a highly active catalyst for water splitting to produce oxygen and hydrogen fuel is in rising demand to fulfill the increasing human need for clean and renewable energy. However, the most crucial step for efficient electrocatalytic water splitting is the oxygen evolution reaction (OER) that takes place at the anode. Traditionally, metal oxides have been introduced for this purpose however, recent developments have shown that transition metal chalcogenides also show better catalytic activity towards OER surpassing most of the conventional oxide electrocatalysts. Herein we present how the family of chalcogenide electrocatalysts can be extended to transition metal selenides and tellurides and present a comprehensive study pf the effect of anion electronegativity on the OER catalytic properties. We will also present the investigation of composition of the active surface obtained through detailed surface analytical techniques as well as electrochemical characterizations. Nickel selenides and tellurides were synthesized by hydrothermal reactions as well as electrodeposition technique, and these catalysts exhibited lower overpotential at 10 mA/cm 2 for OER electrocatalytic activity in 1 M KOH, than conventional state-of-the-art precious metal electrocatalysts. In addition, we will present findings concerning the composition of the active surface, that answers the perpetual question, whether the catalytic surface is pre-oxidized to an oxide layer which shows further catalytic activity, or does it retain it chalcogenide composition which inherently shows better catalytic activity. We will present the synthesis, characterization and electrochemical investigations of this new catalyst and additionally, we will also discuss the stability of this catalyst during long-term OER conditions.
Spring 2023
Intellectual Property and Entrepreneurship
John E. Woodson, Interim Director of Technology Transfer & Economic Development, Office of Technology Transfer & Economic Development
Abstract: Whether you work for someone else or work for yourself, you should have a basic understanding of the different types of intellectual property and what it takes to insure they retain their value. Corporations and entrepreneurs both need and use intellectual property to create value for the enterprise. This talk will cover the patent process, patents, trademarks, and trade secrets, and it will also cover main considerations for seriously considering entrepreneurship. In order to have any chance to make it as an entrepreneur, you need more than a product, most importantly, you need a customer and a plan.
Quantum computing, quantum teleportation and time crystals
Cheng Hsiao Wu, Professor of Electrical Engineering, Electrical & Computer Engineering, Missouri S&T
Abstract: Quantum computing are parallel computing and are nonlocal in nature. Geometry, physics and computing are triangularly interrelated. There exist four new fundamental nonlocal operator-state relations for an entangled atomic chain. Computation states are then cyclic. There exists a minimum entanglement distance between any two atoms of the chain. Any addition of four times of that distance provides the foundation for quantum teleportation in a piece-wise Euclidean chain. Time crystals are the direct computation results that an entangled chain is capable of computing. There are four interacting planar time crystals with the same Poincare cycle, but only half of the results are observable as we predict and thus quantum computing is “irreversible”. However, when geometry changes, there exist “spherical time crystals” from the rotational symmetry breaking. Thus, we predict “time” can be “curved” in the Fourier space, the space we observe all the parallel computation results. In long entangled chain, a small section of time crystal can be duplicated elsewhere of the chain with “birth-and-death’ capability in addition to the “perpetual motion” claimed by the Google group last July. Sierpinski triangle with self-similar features provides the foundation for the true artificial intelligence where larger scales of operator-state space-time relations emerge.
Click to view Dr. Cheng Hsiao Wu's seminar flyer
A Sinuous Search for the Solid Structure of Fe3(CO)12
Fernande Grandjean and Gary J. Long, Emeritus Professor of Physics, University of Liège, Belgium and Adjunct professor of Missouri S&T
Abstract: The search for the solid structure of Fe3(CO)12 beautifully illustrates the mechanism of scientific research, specifically the modification, adjustment, and correction of knowledge through more advanced measurements. This search will use x-ray diffraction, infrared, NMR, and Mössbauer spectral measurements to determine the now well accepted solid structure of Fe3(CO)12 and to better understand the dynamics present in the cluster.
Click to view Dr. Grandjean and Dr. Long's seminar flyer
Development of Machine Learning Potentials for Multicomponent Systems
Ridwan Sakidja, Professor, Physics Astronomy and Materials Sci., Missouri State University, Springfield
Vibronic coupling in N-methylpyrrole
Alexander Davies, Post-doctoral fellow, Chemistry, Missouri S&T
Abstract: The 1A2 ← 1A1 (S1 ← S0) electronic transition of N-methylpyrrole (NMP) is electric dipole forbidden. Therefore, one would not expect to observe any structure arising from this electronic transition; however, this is not the case and there is extensive structure, even at low internal energies (> 1100 cm-1 above the S1 origin). Herzberg-Teller coupling (more generally, vibronic coupling) is a complicated, although well-established phenomenon whereby intensity is ‘stolen’ from a nearby electronic state, to which a transition from the 1A1 electronic state is allowed — this is the key to explaining the observed structure. Assignments of the observed bands are made through a combination of resonance-enhanced multiphoton ionisation (REMPI) and zero-electron-kinetic-energy (ZEKE) spectroscopies, briefly mentioning the two-dimensional laser-induced fluorescence (2D-LIF) technique.
Many of the ZEKE spectra are consistent with the 3s Rydberg nature of the 1A2 electronic state (in the Franck Condon region) and the Herzberg-Teller coupling schemes required to prepare the intermediate; however, there is also some activity which is a little more difficult to explain. Comparisons will be drawn to meta-fluorotoluene (mFT), whose S1 ← S0 electronic transition is electric dipole allowed, as well as a brief discussion on how vibrational couplings within the S1 state, arising from anharmonicity, further add to the complexity of an already intriguing molecule.
Click to view Dr. Alexander Davies's seminar flyer
Addressing diffusion in the solid photo- and photoeletrocatalysts
Pravas Deria, Associate professor, School of Chemical & Biomolecular Science, Southern Illinois University-Carbondale
Abstract: Light-driven reactions hold promise to develop processes that can encompass solar energy conversion, organic transformation, to contamination management. To ease the transformations that are energetically challenged or otherwise not thermally allowed—like, kinetically challenged CO2 reduction, organic transformations involving C-H activation, or thermally inaccessible cycloaddition reactions—one needs to build an efficient deployable photocatalysts platform. Traditional solution-dissolved photosensitizers, exploiting their long-lived triplet state, function by providing a time window for slower diffusion and chemical time scale. However, special care must be taken even for those reactions that do not require a triplet excited state (like cycloaddition) to avoid singlet oxygen-derived side products. The primary criteria for scalable solid photocatalysts are challenging it requires efficient exciton/energy transport to the reaction sites and the ability to split the delivered exciton without the involvement of molecular (i.e., photosensitizer) diffusion. This is simply because of fixed photosensitizers where only a small portion, at the outer surface, is exposed to the light. A porous solid, such as a MOF system that allows substrates to diffuse, can only work if the molecular excitons are spatially dispersed and/or easy to displace -possibly along the direction of the major substrate diffusion channel (i.e., anisotropic exciton transfer). System design with the appropriate ground and excited-state potential will, therefore, be the next step to
driving a redox reaction. A picosecond timescale exciton transport and sub-nanosecond timescale exciton splitting should be the primary target to develop such a platform. With such a design in hand, we will show how MOF-based photo redox chemistry works and what are other benefits of this development.
Click to view: Dr. Pravas Deria's seminar flyer
Spatially resolved spectroscopy: Exploring systems at the nanoscale
Dr. Sabine N. Neal, Research Associate Interface Science and Catalysis group Center for Functional Nanomaterials Brookhaven National Laboratory
Abstract: Vibrational spectroscopy is a sensitive probe of complex physical phenomena in both inorganic and organic systems. The analysis of vibrational mode trends and displacement patterns allows for insight into a material’s properties including lattice distortions, phase transitions, charge ordering, and spin-lattice coupling constants, just to name a few. When coupled with external stimuli, such as temperature, pressure, or magnetic field, infrared spectroscopy can reveal the relationships between charge, structure, and magnetism. However, the ability to obtain real space information has proved to be a challenge due to the inability to focus an infrared beam tightly enough to probe nano-sized samples. This issue, however, has been circumvented with the advent ofspatially resolved infrared spectroscopy, such as O-PTIR and tipbased near-field infrared. These techniques have allowed for the comprehensive studies of nanomaterials, from single layer systems to organic high energy materials.
Dr. Sabine Neal's seminar flyer
Metal-Free Photoredox Catalysis for the S-Trifluoromethylation of Heteroaromatic Thiols
Raheemat Rafiu, Graduate Student, Chemistry, Missouri S&T
Abstract: The S-Trifluoromethylation of thiols provides access to pharmaceutically interesting compounds. The current synthetic methods for this trifluoromethylation reaction involve the use of either expensive noble metal-based organometallic catalysts and expensive or hazardous reagents. We have demonstrated a convenient visible-light photoredox catalyzed S-trifluoromethylation of various thiols under metal-free conditions, using the cost-effective sodium trifluoromethanesulfinate (Langlois regent) and diacetyl as the photocatalyst. This novel organocatalysis-based synthetic method provides a convenient and cost-effective alternative to the transition-metal catalyzed photoredox reactions.
Investigation of RNA binding by the eIF4B translation initiation factor, and dynamics studies of proteins utilizing NMR and other biophysical techniques
Dr. Somnath Mondal, Postdoctoral Research Scientist, Pennsylvania State University, USA
Abstract: Eukaryotic initiation factor 4B (eIF4B) is a multidomain protein with a range of activities that serve primarily to promote the association of messenger RNA to the 40S ribosomal subunit during the translation initiation process. Deletion and site-directed mutagenesis studies have identified a few functional domains within eIF4B, two of which are involved in RNA binding and are implicated in linking mRNA to the 40S ribosomal subunit during translation initiation. An N-terminal RNA recognition motif (RRM; residues 97-175) has been shown to bind the 18S rRNA of the 40S ribosomal subunit in the earlier report. However, it has not been completely explored except for the RRM domain from eIF4B. A second RNA binding domain is located toward the C-terminus (residues 367-423) and has been termed the basic domain (BD) since it contains two arginine-rich motifs (ARMs). This region, which has not been assigned to a particular structural family, binds RNA nonspecifically but with high affinity and has been proposed to bind mRNA during initiation. In addition, eIF4B has been reported to bind several proteins related to translation, ribosomal RNA, and mRNA, but again only in a few studies. More than three-quarters of the eIF4B protein is intrinsically disordered and tends to display phase separation, attributing the reason why eIF4B has not been explored in depth, except for the RRM domain. We have utilized NMR spectroscopy and other biophysical techniques (smFRET, ITC, CD, Fluorescence, etc.) to address RNA binding properties from different constructs from the C- and N- terminus of eIF4B and addressed the phase separation behavior from the C-terminal domain of eIF4B. In addition, I will briefly discuss studies on various protein dynamics utilizing NMR spectroscopic techniques and other biophysical methods.
Crystal Engineering of Programmable Sponges for Energy, Environmental and Health Applications
Dr. Mario Wriedt, Kodak CAMP Distinguished Professor, Department of Chemistry and Biomolecular Science, Clarkson University, NY, USA
Abstract: Metal-organic frameworks (MOFs) are crystalline porous materials composed of metal clusters or ions connected by polytopic organic linkers. Their framework structures, pore environment, and functionality make them uniquely tunable by the choice and connection of metal and organic building blocks, allowing the design of innovative materials with customized properties. Our research programs all address interrelated fundamental aspects of the design, synthesis, and characterization of functional MOF materials. This presentation is a comprehensive overview on how the synergy of crystal engineering and X-ray diffraction will pave the way for the rational design of novel advanced functional MOF materials to address our society’s most pressing energy, environmental, and health needs (e.g., carbon capture, water remediation, viral testing).
Evaluation of N-acetylcysteine Amide as a Potential treatment option for Traumatic Brain Injury using tandem LC-MS
Olajide Adetunji, Graduate Student, Chemistry, Missouri S&T
Abstract: Physical injury from sports and freak accidents are common causes of Traumatic Brain Injury (TBI). Commonly overlooked, is TBI via exposure to explosives with prevalence in military personnel and veterans. Existing diagnostics are costly, time consuming, and sometimes insensitive to milder TBI forms, influencing a need for fast and sensitive techniques for mild TBI detection by investigating potential biomarkers that may be altered due to TBI. A pathophysiological consequence of TBI is oxidative stress from reactive oxygen species proliferation after physical disruption of neurons and glial cells leading to alteration in the levels of endogenous antioxidants and their oxidized products in the brain and peripheral fluids. Antioxidant therapy using N-acetylcysteine Amide can be useful mitigators of this oxidative stress characteristic. Additionally, lipid peroxidation by-products and other important small molecule biomarkers can give invaluable information about TBI progression. In our study, rats were exposed to open-field blasts mimicking of a real-life explosion to induce TBI and evaluate antioxidant therapy. Subsequently, various biomatrices were harvested from test animals for analysis. Coupling rigorous sample clean-up with LC-MS/MS analysis, levels of potential biomarkers for TBI in the groups and sample matrices were determined in this study. The LC-MS/MS methods yielded excellent sensitivity, linearity, recovery, and reproducibility for all the investigated analytes.
Explorations of the Synthesizability and Photoelectrochemical Properties of Metastable Semiconductors
Dr. Paul A. Maggard, Professor of Chemistry, North Carolina State University, USA
Abstract: Metastable semiconductors have been discovered in many chemical systems that have desirable properties for driving fuel-producing redox reactions from sunlight, including broad visible-light absorption, optimal band edge energies, defect tolerance, and functional carrier mobilities. These photoelectrochemical properties have frequently been found to stem from their metastable nature, e.g., specific features in their crystalline structures and/or compositions lead to being thermodynamically unstable with respect to phase segregation. Recent results will be presented on mixed-metal oxides and carbon nitrides that demonstrate new flux-mediated syntheses and kinetic stabilization in this growing class of semiconductor systems.1-3 Their syntheses have been achieved by reactions that leverage the exothermic formation of stable salt side products as well as shortened reaction diffusion pathways and low reaction temperatures. Kinetic stabilization of the products has also been enhanced via the application of a) high cohesive energies of an underlying substructure that is maintained during the reaction, and b) solid solution compositions which help to inhibit phase segregation while also providing for percolation pathways. These approaches have yielded, e.g., the first known Sn(II)-perovskites that are isoelectronic to widely commercialized Pb(II)-containing piezoelectrics. Photocatalytic properties in these systems will primarily be described for light-driven H2O and CO2 reduction as polycrystalline films and as suspended powders when in aqueous solutions under ultraviolet and visible-light irradiation.
Accessing anionic and cationic redox in metal chalcogenides through building block approach
Santhoshkumar Sundaramoorthy, Graduate Student, Chemistry, Missouri S&T
Abstract: Boosting the energy density of Li-ion batteries is of prime importance in the current era to meet the energy demands for electric vehicles (EV’s). In this regard cathodes play an important role as the specific capacity is directly related to the number of Li-ions to be extracted from or inserted into the cathode as a function of redox. Towards achieving this goal, researchers are looking into combining both cation and anion redox in the new generation cathode materials. In this regard, we have developed building block approach of synthesis targeting specific compositions that can potentially act as candidate for cathodes and solid
electrolytes. Through this technique we discovered two new polyanion sulfidebased cathodes with Cu+and Fe2+ cations exhibiting high reversible specific capacities. Further their charge storage mechanism and structural stability were evaluated by spectroscopic (XAS and XPS) and diffraction studies (Synchrotron XRD). Following these works we also synthesized two new ternaryselenidebased building blocks (Li5MSe4, M = Al & Ga) and measured their ionic conductivity. Aliovalent doping in these building block showed improvement in Li-ion conduction showing promises in search of potential solid electrolytes for Li-solid state batteries. At the end, an overall overview on chalcogen based materials and its optimization for energy storage devices will be summarized.
Harnessing the chemistry of cementitious materials towards the next-generation eco-efficient concretes
Monday Okoronkwo, Assistant professor, Chemical and Biochemical Engineering, Missouri S&T
Abstract: The production of conventional cement is an energy and CO2-intensive process contributing to over 8 % of the global anthropogenic CO2 emissions. To reduce the carbon footprint of cement and concrete, efforts are increasingly directed toward developing sustainable low-carbon alternative cementitious materials. Chemistry is at the heart of such efforts, helping us to understand what forms when cements react with water (hydration), and how they may impact the properties and performance of the resulting cement-based products. Through such understanding, the design and optimization of new alternative cements are enabled. This talk will present some of our work in understanding the hydration reactions and the development of phase assemblages and properties of some candidate low-carbon alternative cements, including blended cements, alkali-activated cements, sulfoaluminate cement, and carbonated cements.
New NLO Materials: Design, Synthesis, and Crystal Growth
Prof. P. Shiv Halasyamani, Department of Chemistry, University of Houston
Abstract: Nonlinear optical (NLO) materials are critical in generating coherent light through frequency conversion, e.g., second harmonic generation (SHG). From the ultraviolet (UV) to the infrared (IR), NLO materials have expanded the range of the electromagnetic spectrum accessible by solid-state lasers. Wavelengths where NLO materials are still needed include the UV (~200 - 400nm) and deep UV (< 200nm). Coherent deep-ultraviolet (DUV) light has a variety of technologically important uses including photolithography, atto-second pulse generation, and in advanced instrument development. Design strategies will be discussed, as well as synthetic methodologies. In addition, the crystal growth, characterization, and structure-property relationships in new UV and DUV NLO materials discovered in our laboratory will be presented. Finally, our crystal growth capabilities and recent crystal growth of functional materials will be described.
Development of Catalytic Membranes and Composites for Energy Storage Devices and Nonenzymatic Biosensors
Harish Singh, Graduate Student, Chemistry, Missouri S&T
Abstract: The continuous excessive usage of fossil fuels has resulted in its fast depletion, leading to an escalating energy crisis as well as several environmental issues leading to increased research towards sustainable energy conversion. Electrocatalysts play crucial role in the development of numerous novel energy conversion devices, including fuel cells and solar fuel generators. In particular, high-efficiency and cost-effective catalysts are required for large-scale implementation of these new devices. Over the last few years, transition metal chalcogenides have emerged as highly efficient electrocatalysts for several electrochemical energy conversion processes such as water splitting, oxygen reduction reaction and solar energy conversion. These transition metal chalcogenides exhibit high electrochemical tunability, abundant active sites, and superior electrical conductivity. Hence, they have been actively explored for various electrocatalytic activities. Herein, we have explored of transition-metal chalcogenide electrocatalysts for oxygen evolution, oxygen reduction, and illustrated structure–property correlation with the help of density functional theory (DFT). Lastly, we will discuss the electrocatalytic activity of the transition metal chalcogenides towards biomolecule conversion, enhancing their applicability as biosensors for detecting potentially life-threatening disorders. Detailed studies of the chemical reactivity, electrochemical activity, interfacial chemistry, and functional stability of the transition metal chalcogenides that make all these applications feasible will be discussed in depth.
Molecular Spectroscopy and Dynamics on Multiple Potential Energy Surfaces
Dr. Jinjun Liu, Department of Chemistry, University of Louisville
Abstract: Research in the University of Louisville Laser labs (UL3) (https://sites.google.com/site/uofllaserlabs/) consists of spectroscopic studies of gas-phase molecules and condensed-phase materials using state-of-the-art high-resolution and ultrafast laser systems and cutting-edge spectroscopy techniques. Our high-resolution spectroscopy studies center on the detection and characterization of open-shell molecules on multiple potential energy surfaces (PESs). Our target molecules include molecular free radicals as reactive chemical intermediates in combustion and atmospheric chemistry. The spectroscopic methods employed include laser-induced fluorescence/dispersed fluorescence (LIF/DF) spectroscopy for alkoxy (RO⸱) radicals and cavity ring-down (CRD) spectroscopy for peroxy (ROO⸱) radicals. These two techniques are also used to study metal-containing molecules, e.g., alkaline-earth monoalkoxide radicals (MORs), which have been proposed as candidates for direct laser cooling and will have important applications in quantum computing, quantum information, and fundamental physics. Recently, our group has built a mid-infrared high-resolution laser spectroscopy apparatus to support the observations of the James-Webb Space Telescope (JWST) and started developing a novel cavity-enhanced double-resonance spectroscopy technique to investigate molecular “dark states” and to decipher the complex energy level structure and intramolecular interactions. On the theoretical side, we are particularly interested in molecular species with the Jahn-Teller (JT) and pseudo-Jahn-Teller (pJT) effects, symmetry-specific vibronic (vibrational-electronic) interactions that cause spontaneous distortion of the geometry and PESs of polyatomic molecules in degenerate or nearly degenerate electronic states. Spectroscopic models and software have been developed to predict, analyze, simulate, and fit vibronic, rotational, and fine structures in high-resolution spectra of open-shell molecules. High-level quantum chemistry calculations are used to help understand the geometry, energy level structure, and dynamics of molecules on multiple PESs.
The nature and strengths of inter-state coupling can also be directly detected in time-resolved spectroscopy, a powerful tool for investigating energy and charge transfer processes. I will use the femtosecond pump-probe transient absorption study of excited-state dynamics of molecule-like ligand-passivated (CdSe)34 nanoclusters (d=1.6 nm) to demonstrate the capabilities and limitations of ultrafast spectroscopy in understanding charge carrier dynamics in nanostructures and on their interfaces, which can aid in the design of high-efficiency photovoltaic and light-emitting devices.
Reactivity of Coinage Metal Complexes Supported by Tetramethylguanidinyl Triphenyl Stibine and Bismuthine Ligands towards Nitrene Transfer Chemistry
Meenakshi Sharma, PhD Candidate, Department of Chemistry, Missouri S&T
Abstract: Carbon Nitrogen (C-N) bonds are ubiquitous in pharmaceuticals, agrochemicals, natural products, and ligands for transition metal catalysts. Transition-metal catalysts introduce new C-N bond into the desired molecules by C-H bond activation or by addition of nitrene across a C=C bond to form aziridines, which can easily be converted into an amine by various chemical transformations.
Transition-metal catalyst frameworks supported by tripodal [TMG3trphen] ligands mediate nitrene transfer from nitrogen sources such as PhI=NR (PhI=NTs or PhINTces) to a diverse group of aliphatic and aromatic hydrocarbons and olefins. These reactions are categorized as amination and aziridination reactions. Novel tripodal ligands and their complexes with coinage transition metals (Cu, Ag, Au) with different axial atoms such as CH, Sb and Bi and benzene platform have been designed to impart weaker axial ligand field, which, in turn, enhances the electrophilicity of nitrene, potentially affording more reactive and site-selective aminated products. The trinuclear copper catalysts [TMG3trphenSbCu3(μ2-Cl)3] and [TMG3trphenBiCu3(μ2-Cl)3] have shown promising results towards aziridination of styrenes with excellent yields though the reactivity of the silver catalyst [TMG3trphenSbAg3(μ2-Cl)3] needs to be explored more for comparative studies. The copper complexes are also reactive for the selective amination of various hydrocarbons at benzylic and tertiary C–H sites.
Meenakshi Sharma's seminar flyer
Chemistry for Environment and Health
Dr. Michael Eze, Postdoctoral Scholar, Bioinstrumentation and BioMEMS Laboratory, University of California Davis.
Abstract: Industrialization and increasing demand for energy have led to an unabating exploitation of natural resources, especially fossil fuels. Even beneficial activities (such as pest control in agriculture) are leaving behind unwanted and toxic effects. This often results in anthropogenic contamination of aquatic and terrestrial ecosystems, which threatens the survival of our planet and species. Similarly, the experience of the recent pandemic brought to bare the havoc that infectious diseases can cause. Even more important, it has shown the need for rapid and non-invasive diagnostic tools for early detection of diseases. Sadly, most traditional diagnostic methods are both invasive and expensive. In view of the environmental and health impacts of toxic contaminants and infectious diseases, it is worth asking: can science provide the urgently needed panacea? This talk will examine the answers to this question. Specifically, it will
amine eco-friendly approaches for environmental pollutant remediation. It will also highlight how advances in (bio)analytical techniques, metabolomics andchemometrics are helping to innovate non-invasive diagnostic tools for early detection of human and plant diseases.
Development of Machine Learning Potentials for Multicomponent Systems
Ridwan Sakidja, Professor, Physics Astronomy and Materials Sci., Missouri State University, Springfield
Abstract: Developing the interatomic potential models for muti-component systems has been “the holy grail” in the field of computational materials science. In this talk, I will discuss the use of Machine Learning as the means to address this issue quite effectively. With the advancement of GPU resources and GPU-based neural network algorithms, we have a great opportunity nowadays to utilize ML potentials to simulate a wide range of materials phenomena and processing in various scales. Typically, the potential development starts from the database generation through electronic structure calculations within the DFT approximation at ground state as well as elevated temperatures. The subsequently extracted critical data (of energy, stress, and forces) is then fed to the neural network with various schemes of invariant/equivariant representations. The key here is the linear scalability associated with these AI-driven models which in turn enable us to develop large scale atomic-based simulations with potential technological implications. Within this context, I would like to also discuss the feasibility in constructing AI-powered Virtual Autonomous Materials Discovery (v-AMD) to help accelerate materials development.
A journey in electrochemistry: From single nanoparticle to in operando electrochemistry and future opportunities
Dr. César A. Ortiz-Ledón, Postdoctoral Scholar, Department of Chemistry, University of Wisconsin-Madison
Abstract: Electrochemistry is an attractive field that offers a wide range of applications. In the last decade, electrochemistry has found applications to study single entity systems, from developing ultrasensitive sensors for single molecule detection to studying electron transfer reactions at individual metal nanoparticles and extract valuable kinetic information. Besides this, several research groups have coupled electrochemistry with other fields such as spectroscopy, this combination becomes a powerful tool to probe electrochemical reactions and obtained chemical information in situ. In this seminar, first section will explain how electrochemistry is used to study electrocatalysis at single nanoparticles and nanoparticle ensembles with ultramicroelectrode dimensions. What are the advantages of these studies and potential applications to obtain kinetic information at the single nanoparticle level. Following by a section that will cover development of in operando electrochemistry to study electrode-electrolyte interfaces in Li-ion batteries. This section aims to demonstrate how combining other techniques such as gravimetry and infrared spectroscopy with electrochemistry helps to understand the origin of electrolyte degradation in Li-ion. Understanding this interface from Li-ion batteries is of high importance, as these devices are widely used for energy storage and found in multiple electronic devices such as cell phones, laptops, and electric vehicles. The third and last part of this talk will explore what are the future opportunities in electrochemistry and why electrochemical interfaces are important. In this section will bring new strategies to study these interfaces by implementing in operando electrochemistry to study nanoconfined spaces and surface reactivity of electrocatalytic materials. Concluding how electrochemistry is of huge importance to study chemical problems found in energy conversion, energy storage, and electrodeposition of metals.
Forging Robust Nanoscale Catalytic Interfaces for a Sustainable Future
Dr. Junrui Li, Postdoctoral research associate in the Voiland School of Chemical Engineering and Bioengineering, Washington State University
Abstract: There has been increasing interest in achieving a sustainable future with fuels, chemicals and materials obtained from renewable sources. Sustainable materials and energy production requires efficient catalytic processes. Rational design and development of robust catalysts for such processes remains a key challenge. Despite extensive efforts in this research area, new innovations in effective catalytic design at nanoscale levels are limited. This talk covers examples of how robust catalytic interface can be precisely tailored at nanoscale dimensions to achieve an improved performance in green energy power source-fuel cells and in catalytic valorization of renewable biomass derived molecules. The first section illustrates: (1) intermetallic nanostructures with ordered atomic arrangements can stabilize base metals under the aggressive condition of fuel cells; (2) hard-magnet intermetallic nanostructure interfaced with atomically thin Pt overlayers that exhibit extraordinary fuel cell performance; (3) identification of a structural descriptor to guide high-throughput screening and discovery of high-performance catalysts for fuel cells. The second and third sections detailing oxidative valorization of biomass-derived molecules outlines: (1) the discovery and investigation of a Pt-based ternary nanoscale interface that steers the favorable reaction pathway for efficient electrocatalytic utilization of biomass-derived liquid fuels; (2) interfacing Pt with Au at nanoscale dimensions to suppress the oxidation/dissolution of Pt during thermocatalytic oxidation of glucose to achieve high yields to value-added products and long-term stability.
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