Chemistry Commons^™

Evsc 335-001: Environmental Law, Michael Bonchonsky

Chemistry, Environmental and Forensic Science Syllabi

No abstract provided.

Evsc 385-101: Environmental Microbiology, Mengyan Li

Chemistry, Environmental and Forensic Science Syllabi

No abstract provided.

High Resolution Imaging Of Single Nanoparticles And Two-Dimensional Nano-Material By Scanning Electrochemical Microscopy, Tong Sun

Dissertations, Theses, and Capstone Projects

Electrochemistry at nanostructured interfaces is of significant current interest. Metal nanoparticles (NPs) and two-dimensional semiconductor nanomaterial are particularly important because of their applications in catalysis, energy conversion and storage, sensors, and medicine. Electrocatalytic processes at such nanostructured interfaces are essential for the generation of hydrogen and other types of fuels and photochemical energy conversion. Nanoscale electrochemical experiments require the fabrication and characterization of nanometer-size electrochemical probes. The main advantages of the nanoprobes include very fast mass-transfer rate, high signal-to-noise ratio and extremely fine spatial resolution of electrochemical imaging. During my Ph.D. research, nanoscale disk-type platinum electrochemical probes were developed for …

Iron Oxide Nanomagnets In Polymer Matrices – Synthesis And Characterization, Shenjie Qiu

Dissertations, Theses, and Capstone Projects

Magneto-responsive polymer-iron oxide materials have been fabricated by coating various polymers on iron oxide nanoparticles (NPs). The stability of magneto-responsive polymer-iron oxide materials relies on the selection of appropriate coating anchors, such as catechols and silanes. This dissertation describes two robust polymer coating systems on iron oxide NPs. One system focuses on thermo-responsive nitrated catechol-N-isopropylacrylamide polymers with binding enhancement factors (EnF) of ~40 and ~20 towards iron oxide NPs and a boronic acid compared to the polymers without the nitro group. The second system involves coating of poly(vinyl alcohol) (PVA) on iron oxide NPs via a silane anchor …

Characterization And Quantification Of Covalent Modification Of Proteins Using Mass Spectrometry, Pratikkumar N. Rathod

Dissertations, Theses, and Capstone Projects

Identification and characterization of various post-translational modifications of protein is a key to understanding many unknown cellular processes. In the last few decades, mass spectrometry has evolved as an essential and effective analytical tool for qualitative and quantitative analysis of proteins. In this research, we have developed a novel MALDI-MS² based quantification method for Desmosine and Isodesmosine, which served as cross-linking amino acids of elastin, in order to measure the elastin degradation in the body. This is the first quantification method that not only illustrates the potential of MALDI-Ion Trap MS², but also improvement over the current …

The Development Of Novel Platforms For The Imaging Of Cancer By Positron Emission Tomography, Brendon E. Cook

Dissertations, Theses, and Capstone Projects

The role of antibody-based imaging of cancer by positron emission tomography (PET) has expanded significantly in recent years and is poised to radically alter the way that cancer is diagnosed and treated. However, one hurdle that remains is the potentially harmful radiation dose that comes from these imaging agents, as the long circulation time of antibodies (days to weeks) necessitates the use of radionuclides with comparable physical half-lives (i.e. ⁸⁹Zr, ¹²⁴I, etc.). One particularly promising solution is the use of the inverse electron demand Diels-Alder (IEDDA) reaction between a 1,2,4,5-tetrazine (Tz) and a trans-cyclooctene (TCO) for pretargeting. …

Nmr Characterizations Of Candidate Battery Electrolytes, Stephen A. Munoz

Dissertations, Theses, and Capstone Projects

Enormous strides have been made in next-generation power sources to build a more sustainable society. Energy storage has become a limiting factor in our progress, and there are huge environmental and financial incentives to find the next step forward in battery technology. This work discusses NMR methods for characterizing materials for use in battery application, with a special focus on relaxometry and diffusometry. Examples are provided of various recent investigations involving novel candidate electrolyte materials with different collaborators. Works discussed in this thesis include: the characterization of a new disruptive solid polymer electrolyte technology, investigations of the dynamics of super …

Nuclear Magnetic Resonance Studies Of Imidazolium-Based Ionic Liquids And Garnet-Type Li7la3zr2o12, Shen Lai

Dissertations, Theses, and Capstone Projects

Advancements in electrochemical energy storage materials are critical in the development and utilization of renewable energy technologies. These advancements involve obtaining a better understanding of electrochemical mechanisms and properties through scientific research towards an improved energy storage technology. Nuclear magnetic resonance (NMR), is a sensitive and selective method to probe particle dynamics (magnetic relaxation, diffusometry, etc.) and material structures (spectroscopy) down to the atomic level. In this work, several NMR techniques are employed to study imidazolium-based ionic liquids and garnet-type inorganic materials. These are being studied due to their potential use as safer alternatives to organic solvent-based electrolytes in lithium-ion …

A Stereospecific Pd-Catalyzed Suzuki Cross-Coupling Reaction And A Statistical Study Of The Ligand's Role In Stereoselection, Shibin Zhao

Dissertations, Theses, and Capstone Projects

The development of palladium-catalyzed carbon-carbon cross-coupling reactions has profoundly influenced the manner through which we approach the synthesis of complex organic molecules. Among established cross-coupling reactions, which include Kumada, Negishi, and Stille reactions, the Suzuki cross-coupling reaction exhibits particularly wide functional group compatibility, while employing non-toxic, air-stable organoboron nucleophiles. Conventional studies of Pd-catalyzed Suzuki cross-coupling reactions have focused on C(sp²)-C(sp²) cross-coupling reactions, which result in the formation of planar products. Conceptually, the use of C(sp³) (secondary) nucleophiles would enable the reliable manipulation of organic molecules in three dimensions. However, this process has not been …

Flexible And Versatile Soft Templates For Mesoporous Silicas And Organosilicas Based On Pluronic Block Copolymer Surfactants And Their Mixtures, George Farid

Dissertations, Theses, and Capstone Projects

In this dissertation, the work will be discussed that was focused on the synthesis of consolidated periodic mesoporous materials such as 2-D hexgonal ordered mesoporous silicas (SBA-15) as well as single-micelle-templated silica and organosilica nanotubes and nanospheres using triblock copolymer surfactants and their mixtures in the presence of a swelling agent. The introductory section, Chapter 1, will address the current state of the tunability of single-micelle-templated silica and organosilica nanotubes and will compare it with the work presented in this dissertation on the use of a dual-surfactant templating systems. Chapter 2 of the dissertation discusses transmission electron microscopy characterization of …

Synthesis And Evaluation Of Densely-Functionalized Troponoids, Danielle R. Hirsch

Dissertations, Theses, and Capstone Projects

Herein, we document our efforts to expand the scope of troponoid synthetic methodology towards densely-substituted scaffolds. This body of work has focused primarily on an oxidopyrylium cycloaddition/ring-opening strategy for the synthesis and biochemical evaluation of troponoids for assistance in a variety of medicinal chemistry studies. In Chapter 1, we outline the use of this synthetic strategy in the profiling of a library of synthetic αHTs against an aminoglycoside antibiotic resistance enzyme known as aminoglycoside-2’’-O-nucleotidyltransferase [ANT(2’’)-Ia]. Enzymatic mechanistic insights have been gleaned from an assessment of troponoid/antibiotic synergistic potential. In particular, two synthetic constructs were identified as promising antibiotic adjuvant candidates, …

Fundamental Chemistry Related To The Separations And Coordination Of Actinium-225, Thorium-227, And Technetium-99, Jasmine L. Hatcher

Dissertations, Theses, and Capstone Projects

This work explores the fundamental chemistry of actinium, thorium, and technetium in an effort to develop methodologies which help to address complications specific to each of these elements. Developing fundamental knowledge in inorganic chemistry has the power to meaningfully address a number of real world problems. By using simple systems and experiments like following an electron or changing the solvent system, we are able to gain invaluable information which can be used to address major issues.

Actinium-225 (t_½: 9.92 d) is an alpha-emitting radionuclide with nuclear properties well suited for alpha therapy of malignant tumors. The present global …

Removal Of Cu2+ And Ni2+ From Aqueous Solution Using Sno2 Nanomaterial Effect Of: Ph, Time, Temperature, Interfering Cations, Abigail M. Zepeda, Daisy Gonzalez, Luis Gonzalez Heredia, Karina Marquez, Cesar Perez, Erika Pena, K. Flores, Carolina Valdes, Thomas Eubanks, Jason Parsons, J. Cantu

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Tin oxide, SnO2, nanomaterial was synthesized and tested for the removal of Cu2+ and Ni2+ ions from aqueous solutions. Various parameters for the binding were investigated in batch studied, which included pH, time, temperature, and interferences. In addition, isotherm studied were performed to determine the maximum binding capacity for both Cu2+ and Ni2+ ions. The optimal binding pH determined from the effects of pH were to be at pH 5 for both the Cu2+ and Ni2+ ions. The isotherm studies were performed at temperatures of 4°C, 25 °C, and 45 °C for both the Cu2+ and Ni2+ ions and were …

Three-Dimensional Carbon Nanotube Yarn Based Solid State Solar Cells With Multiple Sensitizers Exhibit High Energy Conversion Efficiency, Glenn Grissom, Jared Jaksik, Monica Mcentee, Erin M. Durke, Sayeeda Tj Aishee, Margaret Cua, Okenwa Okoli, Ahmed Touhami, H. Justin Moore, M. Jasim Uddin

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Fiber-type dye sensitized solar cells that are non-metallic, flexible, and thread-like in structure have many potential military and functional textile applications. With the use of quantum dots (QD), exciton transfer facilitators (Phenyl-C61-butyric acid methyl ester-PCBM) and Poly(3-hexylthiophene-2,5-diyl-P3HT), and careful preparation of the TiO2 oxide layer deposited on the carbon fiber working electrode, an optimized efficiency of 7.6% was obtained. Carbon nanotube yarn (CNTY) was used to prepare both the working and counter electrodes of the fabricated cells. TiCl4 annealing of the TiO2 layer was carried out and the resulting oxide layer morphology was found to be very uniform. The quantum …

Conformational Analysis Of A Taddol-Based Phosphoramidite P,N Ligand In A Palladium(Ii) Η3-Π-Allyl Complex, Tülay A. Ateşin, Abdurrahman Atesin, Oscar Rodriguez, Diego Rivera, Lohany Y. Garcia

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Highlights

• Two lowest energy conformers differ in allyl conformation, conformer with exo allyl having lower energy.

• Lowest energy conformer has “chair” conformation of 7-membered ring and “edge-on/face-on/face-on/edge-on” array of pH groups.

• Next lowest energy conformer with exo allyl has alternating “edge-on/face-on” arrangement and “twist” 7-membered ring.

• Changes in “chair/twist” conformations with different substrates is possible due to 2.4 kcal/mol energy difference.

• These results explain stereochemical outcome of the reaction, and will guide design of new catalysts.

Abstract

The most stable conformations of a TADDOL-based phosphoramidite P,N ligand coordinated to a palladium(II) η3-π-allyl fragment have been investigated using …

Vertical Vs. Adiabatic Ionization Energies In Solution And Gas-Phase: Probing Ionization-Induced Reorganization In Conformationally-Mobile Bichromophoric Actuators Using Photoelectron Spectroscopy, Electrochemistry And Theory, Maxim Vadimovich Ivanov, Denan Wang, Depeng Zhang, Rajendra Rathore, Scott A. Reid

Chemistry Faculty Research and Publications

Ionization-induced structural and conformational reorganization in various π-stacked dimers and covalently linked bichromophores is relevant to many processes in biological systems and functional materials. In this work, we examine the role of structural, conformational, and solvent reorganization in a set of conformationally mobile bichromophoric donors, using a combination of gas-phase photoelectron spectroscopy, solution-phase electrochemistry, and density functional theory (DFT) calculations. Photoelectron spectral analysis yields both adiabatic and vertical ionization energies (AIE/VIE), which are compared with measured (adiabatic) solution-phase oxidation potentials (E_ox). Importantly, we find a strong correlation of E_ox with AIE, but not VIE, reflecting variations …

Rational Design Of Superhydrophilic/Superoleophobic Surfaces For Oil-Water Separation Via Thiol-Acrylate Photopolymerization, Li Xiong, Wei Guo, Benjamin M. Alameda, Reese Sloan, William D. Walker, Derek L. Patton

Faculty Publications

We report a simple, rapid, and scalable strategy to fabricate surfaces exhibiting in-air superoleophobic/superhydrophilic wetting via sequential spray deposition and photopolymerization of nanoparticle-laden thiol–acrylate resins comprising both hydrophilic and oleophobic chemical constituents. The combination of spray deposition with nanoparticles provides hierarchical surface morphologies with both micro- and nanoscale roughness. Mapping the wetting behavior as a function of resin composition using high- and low-surface-tension liquid probes enabled facile identification of coatings that exhibit a range of wetting behavior, including superhydrophilic/superoleophilic, superhydrophobic/superoleophobic, and in-air superhydrophilic/superoleophobic wetting. In-air superhydrophilic/superoleophobic wetting was realized by a dynamic rearrangement of the interface to expose a greater …

The Importance Of Solvent Effects On The Mechanism Of The Pfeiffer Effect, Jamie Lunkley, Ngoc Nguyen, Kristina Tuminaro, Dana Margittai, Gilles Muller

Faculty Publications, Chemistry

The Pfeiffer effect is observed when an optically active compound such as an amino acid is introduced to a solution containing a labile racemic metal complex, and an equilibrium shift is obtained. The “perturbation” results in an excess of one enantiomer over the other. The shift is a result of a preferential outer sphere interaction between the introduced chiral species and one enantiomeric form (Λ or ∆) of a labile metal complex. Speculations regarding the mechanism of the Pfeiffer effect have attributed observations to a singular factor such as pH, solvent polarity, or numerous other intermolecular interactions. Through the use …

Stylolites Cathodoluminescence Under Cross Polarized Light, Katherine Dvorak

The Hilltop Review

Devil's Gate limestone under cathodoluminescence. Bright yellow and orange areas are calcite and the bright blue indicates trace minerals along the solution seam. Trace minerals left in the seam are heavy metals and other silicate minerals.

Bis(Triphenylphosphine) Iminium Tetrafluoroborate Chloroform Monosolvate, Rachana Manandhar, Nigam Rath, Myron Jones

Chemistry & Biochemistry Faculty Works

In the title compound, C36H30NP2+·BF4−·CHCl3 or [PPN]BF4·CHCl3, where [PPN] = [(Ph3P)2N]+, two tri­phenyl­phosphine units are attached to a central N atom. The P—N—P bond angle is 137.69 (11)°. The two P—N bonds are nearly equivalent, with lengths of 1.5834 (18) and 1.5798 (17) Å. Both the BF4− anion and the chloro­form solvent mol­ecule are disordered over two positions, with occupancy ratios of 0.872 (3):0.128 (3) and 0.9628 (9):0.0372 (9), respectively. In the crystal, C—H⋯F and C—H⋯Cl hydrogen bonds link the [PPN]+ cations, the BF4− anions, and the chloro­form solvent mol­ecules into an array which extends along the b-axis direction.

Assemblies And Properties Of Asymmetric Supercapacitors Based On Wo3/Carbon Cloth, Wen-Ke Shao, Lei Zhao, Chao Liu, Yan-Ying Dong, Yuan-Jie Zhu, Qiu-Fan Wang

Journal of Electrochemistry

The demand for a new generation of flexible, portable, and high-capacity power sources increases rapidly with the development of advanced wearable electronic devices. One dimensional (1D) nanowires structures have been demonstrated as one of the most ideal electrode materials in energy storage systems due to their advantages in both micorstructures and their high surface areas. Here we report a simple process for large-scale fabrication of self-standing composite film electrodes composed of WO₃ nanorods on carbon cloth. In order to improve the energy density of supercapacitor, we assembled an asymmetric supercapacitor using WO₃ nanorods and activated carbon cloth as …

Modifications And Electrochemical Properties Of Graphite Fluoride, Liang Zhang, Hong-Mei Zhang, Wei-Hua Wan, Jun-Hua Wei

Journal of Electrochemistry

The commercial fluorinated graphite (CF_x) was used as the raw material, which was modified by the reduction of hydrazine hydrate (N₂H₄·H₂O). The effects of hydrazine hydrate contents on the electrochemical properties of fluorinated graphite were systematically studied. The crystal phases and electrochemical properties of the modified fluorinated graphite were analyzed by XRD, SEM, EDS, XPS, EIS techniques and constant current discharge measurement. The results showed that the voltage hysteresis response of Lithium-fluorocarbon battery prepared by the modified fluorinated graphite was obviously improved, while the amount of hydrazine hydrate had an important influence …

An Aqueous All-Metal Oxide Asymmetric Supercapacitor With High Gravimetric And Volumetric Energy Densities, Xin Jing, Xu Zhang, Wei Wang, Jun-Wei Lang

Journal of Electrochemistry

Only with both high gravimetric and high volumetric energy densities, can supercapacitors find more extensive applications.In this paper, by making good use of the interesting nanostructures and the high packing densities of RuO₂ (nanoshpheres,1.69 g·cm^-3) and Co-Ni oxide (nanoflakes, 2.14 g·cm^-3), the RuO₂//KOH//Co-Ni oxide all-metal oxide asymmetric supercapacitors with high performance were successfully fabricated, which led to the maximum specific capacitance of 217.5 F·g^-1 (412.3 F·cm^-3) and specific energy density of 61.8 Wh·kg^-1 (121 Wh·L^-1) in a cell voltage between 0 and 1.5 V in KOH electrolyte. …

Highly Crystalline Nickel Borate Nanorods As Oxygen Evolution Reaction Electrocatalysts, Xi Xu, Juan Liu, Hua-Zong Wu, Wen-Jie Jiang

Journal of Electrochemistry

Hydrogen energy, a kind of clean and renewable energy, is considered to be the solution to the problems of energy crisis and environmental deterioration. Electrochemical water splitting is an efficient and promising technology for the production of high-purity hydrogen. However, oxygen evolution reaction (OER) at the anode of water electrolyzer limits the efficiency of water splitting due to the high overpotential. Therefore, the challenges still remain for the exploration of highly active, stable and low-cost catalysts with superior activity for OER. Herein, nickel borate nanorods with high crystallinity were prepared via high-temperature calcination. The as-obtained nickel borate nanorods with 2 …

High-Dimensional Isotope Relationships, Yuyang He

LSU Doctoral Dissertations

High-dimensional isotope relationships describes the relationships of two or more element or position-specific (PS) elements in the same molecule or ion. It provides us more powerful tools to study reaction mechanisms and dynamics. Chapter 1 is about dual or multiple stable isotope relationship on δ-δ (or δ'-δ') space. While temporal data sampled from a closed-system can be treated by a Rayleigh Distillation Model (RDM), spatial data should be treated by a Reaction-Transport Model (RTM). Here we compare the results of a closed-system RDM to a RTM for systems with diffusional mass transfer by simulating the trajectories on nitrate's δ'^{18 …}

Acetylcholinesterase Biosensor Platform Based On Bp2000 For The Detection Of Carbaryl, Ming-Han Zhang, Jun-Qiao Jiang, Jun-Jie Ge, Wei Xing

Journal of Electrochemistry

With the purpose of providing a new method for carbaryl (a pesticide) detection, on the basis of the principle that acetylcholinesterase (AChE) activity can be restrained by carbaryl, an AChE biosensor platform based on BP2000 (as a fixation) was constructed by dropping method. As a result, it revealed that AChE immobilized on BP2000 maintained its catalytic activity for acetylcholine (ATCl), and due to the introduction of the BP2000 material, the effective electrochemical surface area of the modified electrode was enlarged. In addition, the electrochemical oxidation at the modified electrode occurred at low potential (0.630 V) accompanied by proton transmission. The …

Hybrid Battery-Capacitor System Based On Liti5O12 Anode And Ptpan Cathode, Xiu-Li Su, Xiao-Li Dong, Yao Liu, Yong-Gang Wang, Ai-Shui Yu

Journal of Electrochemistry

Owing to its high safe, high rate and long life characteristics, lithium titanate (Li₄Ti₅O₁₂) anode material has attracted extensive attention in recent years, and many efforts are being made to develop the Li₄Ti₅O₁₂ based high performance hybrid supercapacitors and Li-ion batteries. Herein, we prepared the organic cathode material polytriphenylamine (PTPAn) through chemical oxidation and polymerization of triphenylamine (TPAn), and investigated its charge storage mechanism and electrode kinetics withthe typical electrochemical methods in an organic electrolyte. It was demonstrated that the PTPAn exhibited the reversible capacity of 85 mA·g^{-1 …}

Complex Coordination Silver Electrocrystallization Mechanism On Glassy Carbon Electrode Surface, Shuai-Shuai Huang, Cheng Liu, Lei Jin, Fang-Zu Yang, Zhong-Qun Tian, Shao-Min. Zhou

Journal of Electrochemistry

Cyclic voltammetry and potential step methods were successfully used to study the electrochemical crystallization mechanism of silver deposition on glassy carbon electrode (GCE) in the practical cyanide-free silver plating electrolyte containing composite complexing agents. Scharifker-Hill (SH) theory was used to fitting the experimental data. The results showed that the electrodeposition of silver is a diffusion controlled irreversible electrode process according to three-dimensional instantaneous nucleation mechanism. When the step potential shifted from -750 mV to -825 mV, the peak deposition current Im was increased, while the induced nucleation time tm shortened. The calculated kinetic parameters showed that the diffusion coefficient (D) …

Preparations Of Nano-Manganite Loaded Titanium Electocatalytic Membrane Electrode For Phenolic Wastewater Treatment, Le Li, Hong Wang, Rong-Hua Ma, Hong-Sen Hui, Xiao-Ping Liang, Jian-Xin Li

Journal of Electrochemistry

Nano-manganese oxide loaded on titanium electrocatalytic membrane electrodes (nano-MnO_x/Ti) were synthesized bysol-gel method using porous Ti membrane as a substrate and the manganese acetate as a raw material without releasing NO_x. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Field-emission scanning electron microscopy (FESEM) were employed to characterize crystal form, valence state and surface morphology of nano-MnO_x, respectively. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA) were used to investigate the electrochemical properties of nano-MnO_x electrode. The results indicated that the MnO_x catalysts consisted of γ-MnO₂ and Mn_{2 …}

Electrochemical Performances Of Neodymium Doped Lead Dioxide Composite Anode, Hong-Hui Wang, Ming-Jie Ma, Jie Feng, Huang-Ya Kang, Wen-Jie Huang

Journal of Electrochemistry

Neodymium (Nd) doped titanium (Ti)-based lead dioxide (PbO₂) composite anode was prepared by electrodeposition. The surface morphologies and crystal structures of the as-prepared anodes were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) technique, respectively. The electrochemical performances of PbO₂-Nd anode were studied by electrochemical impedance spectroscopy, linear sweep voltammetry and cyclic voltammetry. Additionally, the electrocatalytic activity and durability of PbO₂-Nd anode were investigated through the degradation of simulative refractory organic wastewater of phenol. The results showed that Nd doping made the PbO₂ anode surface structure dense and uniform with smaller …