Chemistry Commons^™

An Investigation Towards The Synthesis Of A Novel Conformationally Restricted Ethylenediamine Scaffold, Fanny Mai

Theses, Dissertations and Culminating Projects

This study reports the synthesis of a novel conformationally restricted ethylenediamine scaffold that can be explored for drug discovery. There was significant progress in synthesizing the target scaffolds, but future studies are needed to finish this synthesis. This potential ethylenediamine compound may offer new scaffolds for exploration in drug design and orexin receptor antagonists with improved selectivity for OX1R and OX2R.

Hands-On Stem: Chemistry, Physics, And Other Science Resources For K-12 Education, Lisa Ahlberg, G. Brendan Cross

Faculty Publications

No abstract provided.

Hepatocellular Carcinoma Image-Guided Intervention: Quantitative Characterization Of Reagents For Thermochemical Ablation, Emily A. Thompson

Dissertations and Theses (Open Access)

Thermochemical ablation (TCA) is a minimally invasive therapy under development for hepatocellular carcinoma, a leading cause of cancer death worldwide. TCA utilizes acid-base chemistry delivered simultaneously to induce local ablation when administered. When delivered via a mixing catheter placed directly into the tumor, acid (e.g., AcOH) and base (e.g., NaOH) react to completion at the catheter tip, producing the acetate salt, water, and releasing heat (Δ>50°C) in sufficient quantities to induce lethal osmotic and thermal stress in tumor cells. However, these two reagents are not distinguishable from tissues with noninvasive imaging modalities, which makes monitoring the delivery of TCA …

A Performance Evaluation Of Architectural Coatings To Preserve Aerosol Paint On Concrete, Riley Morris

All Theses

The growing movement of assigning cultural and heritage value to graffiti and street art is one without a preservation solution to ensure the longevity of these works in-situ in an outdoor environment. The goal of this thesis was to provide a comprehensive evaluation of six architectural topcoats’ performance when applied as a conservation treatment to outdoor aerosol graffiti and street art on concrete substrate. An artist’s quality, durable, color-fast spray-paint was applied to twenty-eight concrete test panels to mimic the application of graffiti or street art. Six topcoats, Prosoco SC-1, Prosoco Gloss n’ Guard WB, Keim Faceal Oleo HD®, Keim …

Synthesis Of Fluorinated Monomers And Polymers For Various Applications, Cassandra J. Hager

All Dissertations

The world of industry utilizes a variety of polymers for various applications in many prominent fields. From electronics to food storage, the versatility of this class of chemistry has been widely proven. The Thrasher research group undertook a program dedicated towards the development of a library of fluorinated materials that focused on the synthesis and characterization of perfluoroalkoxy (PFA) copolymers of tetrafluoroethylene (TFE) and perfluoroalkyl trifluorovinyl ethers. One aim of the project was to improve upon the mechanical strength and wearability of commercial PFA resins by incorporating bulkier perfluoroalkoxy trifluorovinyl ether monomers into these copolymers. In addition to focusing on …

Extractive Membranes For The Detection And Screening Of Waterborne Plutonium, James Foster

All Dissertations

The development of rapid screening tools for special nuclear materials remains a crucial focus for nonproliferation efforts. Traditional approaches for the analysis of trace-level Pu isotopes in water requires tedious and time-consuming sample preparation steps that do not lend well to expeditious screening. Therefore, a novel analytical method that combines both Pu concentration and source preparation into a single detection system would make for an invaluable tool for nuclear security applications. Extractive membranes absorbers can help to fulfill this role as they are capable of concentrating Pu to detectable limits while subsequently serving as alpha spectrometry sample sources. In Chapter …

Automated Parallel Optimization Of Simulation Parameters Using Modified Nelder-Mead Simplex Algorithm, Erina Mills

All Dissertations

Computational simulations used in many fields have parameters that define models that are used to evaluate simulated properties. When developing these models, the goal is to choose the parameters that best replicate a set of desired properties. Mathematical optimization methods can be used to optimize the simulation parameters by defining a function that uses simulation parameters as input and outputs a value describing how well a set of experimental properties are reproduced.

Because simulated properties are often calculated using stochastic sampling methods, this optimization involves an objective function that is noisy and expensive to evaluate. Also, optimization of the simulation …

Valorization Of Biopolymers And Biomass To Produce Materials For A More Circular Economy, Moira Lauer

All Dissertations

With a globally increasing population and largely unchecked consumption of raw materials, human society is on track for devastating consequences. Two industries responsible for utilizing massive amounts of raw materials and generating equally gargantuan quantities of waste are the packaging and infrastructure sectors. In 2017 in Europe, for example, packaging reached a record 173 kg of packaging waste per capita. One of the largest packaging consumers is the food industry, in which 40% of packaging is made of petroleum-derived single-use plastic, leading to a massive carbon imbalance. “The Built Environment,” on the other hand, is responsible for about 50% of …

Synthesis And Molecular Processes Governing Self-Healing Polymeric Materials, Siyang Wang

All Dissertations

Self-healing polymers capable of recovering from physical damages are promising materials for advanced technologies. In these studies, we developed routes to achieve self-healable properties in acrylic-based copolymers that rely on non-covalent dipolar interactions present in essentially all polymeric materials. Using a combination of spectroscopic tools, thermo-mechanical analysis, and molecular dynamic (MD) simulations, these studies have shown that dipolar interactions lead to conformational changes of macromolecular segments which, in turn, result in self-healing without external intervention. This dissertation also describes the development of novel self-healable acrylic-based covalent adaptable networks (CANs) that combine reprocessing and self-healing properties. The utilization of dipolar interactions …

Introduction Of Human Acidic Fibroblast Growth Factor (Fgf1) Variant With Increased Stability And Bioactivity, Azadeh Tavousi Tabatabaei

Graduate Theses and Dissertations

Human acidic Fibroblast Growth Factor 1 (FGF-1) involves in a broad spectrum of biological processes, including cell growth, proliferation, differentiation, migration, angiogenesis, wound healing, and embryonic development. hFGF1 non-selectively binds to cell surface hFGF receptor isoforms to elicit these cell-signaling processes. Since hFGF1 plays a significant role in tissue repair activity, that is a prime candidate for novel wound healing therapeutics. However, hFGF1 has been found to unfold near physiological temperature due to a strong electrostatic repulsion created by a dense cluster of positively charged amino acids near the c-terminus. The problem not only leads to proteolytic degradation of the …

Control Of Irradiation Wavelength And Quantum Yield Of Photocleavable Cages, Jingxuan Ma

Theses and Dissertations

An important component of biological research is the precise regulation of biomolecules in their physiological environment. Recent advances in neuroscience, have made it possible to regulate the activity of neurotransmitters using photocleavable protecting groups (PPGs), which are also known as cages. This enables the use of light as a trigger to activate selected neurons via photo release of agonists with precise control of timing as well as synaptic site, popularly referred to as spatiotemporal control. In recent years, a variety of PPGs have been developed and applied to biomolecular cages. PPGs can be classified according to their absorption wavelengths (from …

Synthesis And Characterization Of Ternary Pt Nanoally Catalysts For Fuel Cells, Ylith Peck

Undergraduate Honors Theses

A hydrogen fuel cell is an electrochemical device that converts oxygen and hydrogen into electrical energy while producing water as the only by-product, which has attracted growing interest, especially in the automotive industry. This technology is efficient and has zero pollution to the environment, in contrast to the direct use of fossil fuels in combustion engines which produce pollution and greenhouse gas emissions. One of the key components for hydrogen fuel cells is the catalyst that operates at the cathode, which currently use platinum. Due to the scarce amount of platinum in the world, the manufacturing cost for fuel cells …

The Dissolution And Recovery Of Critical Materials (Li2co3 And Uf6) From Ionic Liquid, Cassara Higgins

UNLV Theses, Dissertations, Professional Papers, and Capstones

Lithium and uranium are critical materials in both the energy industry and for national security. Lithium is necessary for the next generation of batteries and 6Li is valuable for the production of tritium necessary for both fusion energy and to maintain our nuclear stockpiles. Uranium is a fuel source or precursor fuel source for commercially operating nuclear fission power. The monitoring of uranium hexafluoride (UF6) enrichment at foreign facilities is important for the monitoring of nuclear safeguards and enforcement of non-proliferation treaties. Recovery methods for lithium at the end of life of batteries are necessary to ensure abundance of the …

Revisiting The Chemistry Of Uranium And Rhenium Fluorides: Implication To Fuel Cycle And Nuclear Forensics Science, James Amos-Aimé Louis-Jean

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fluorine plays a major role in the nuclear industry where F2(g) and HF(g) are critical to the preparation of UF6 and UF4. These materials are prepared for uranium enrichment to increase the isotopic concentration of 235U. During separation efforts, the isotope 99Tc (a high yield fission product, 6.1% from 235U) is extracted along with uranium and can be converted to binary technetium fluorides (i.e., TcF4, TcF6) during re-enrichment of used uranium material. This provides a route for 99Tc to reenter the reactor environment and affect the nuclear properties of fuel pellets made with reprocessed uranium. The objective of this work …

Stability, Electronic Structure, And Nonlinear Optical Properties In Clusters And Materials: A Synergistic Experimental-Computational Analysis, Maksim Kulichenko

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The main objective of Chemistry as a science is an understanding of how and why certain atoms are bonded together and what effects these bonds cause. Modern computational chemistry offers a wide range of tools that greatly assist the exploration of vast chemical space replacing expensive trial-and-error experimental approaches. Computational chemistry may serve to characterize newly synthesized compounds and provide atomic scale insights inaccessible to experimentalists’ vision. Moreover, predictive power of computational chemistry may be used as a guidance for future experiments and for the rational design of new compounds with desired properties.

This dissertation demonstrates the capabilities of joint …

Multi Elemental Analysis Of Cannabis Oil Based Products Using Icpms And Microwave Assisted Digestion., Kevin Trevon Marchbanks-Owens

Theses (2016-Present)

Due to the presence of CBD-(cannabidiol), bioavailable elements as well as industry versatility and relatively low levels of toxicity to the environment. CBD oils have driven the overall demand for Cannabis based plant products in the commercial and medical sector. However, dependent upon the environmental circumstances upon which these plants are grown can leave them susceptible to toxic heavy metal exposure. In fact, the natural metabolism of Cannabis plants makes them a hyperaccumulator of trace metals. This creates a severe health risk for CBD product consumers especially for more vulnerable populations with pre-existing conditions. Furthermore, the risk of heavy metal …

Analysis Of Polychlorinated Biphenyls In Electric Transformer Oil Using Gas Chromatography With Electron Capture Detector., Vivek Mann

Theses (2016-Present)

Polychlorinated biphenyls (PCB’s) are a group of synthetic chemicals which are environmentally insistent that were once used as coolants and lubricants in paints, heat transfer fluids, transformers, capacitors, caulking materials and other electrical materials owning to their property of good insulators. PCBs are persistent organic pollutants since they are persistent, resistant to biodegradation, bioaccumulate and have shown to cause a variety of deleterious effects on human health and the environment. Due to this the manufacturing of PCBs was banned in the United States in 1977. Although, production of PCBs has reportedly stopped, the potential or actual release of PCBs into …

Synthesis And Characterization Of Silver Thione Complexes, Audrey V. Lawrence

Honors Theses

Coordination polymers are repeating units of a coordination complex that have applications as catalysts, conductors, and magnets. In this work, silver (I) was the metal of choice because it behaves similarly to copper (I), which has been studied much more extensively and thione ligands were chosen due to their potential for forming coordination polymers. These coordination complexes with silver were synthesized by combining silver nitrate with thioacetamide, N,N'-diphenylthiourea, and 2-mercapto-1-methylimidazole. These complexes were characterized via IR spectroscopy, elemental analysis, and X-ray crystallography. Silver thioacetamide was determined to form a coordination complex through the sulfur to form a trigonal crystal lattice …

Target Of Glut4 Regulating Protein Tug-Ubl1 To Treat Insulin Resistant Type Two Diabetes, Megan Kohout

Chemistry Student Work

Type two diabetes mellitus is a highly prevalent disease for which the mechanism of insulin signaling to initiate glucose uptake in cleaving TUG-UBL1 by the protease Usp25m is currently not well understood. As increased insulin resistance can lead to the development of type one insulin deficient diabetes, the knowledge of this pathway may uncover underlying causes of insulin resistance. This research aims to understand the effect and stoichiometry of Usp25m binding to TUG-UBL1 in relationship to the cleavage of TUG-UBL1 initiating translocation of GLUT4 glucose transporter. The action of protease effector PIST will be investigated to understand the importance of …

Bis(Tryptophan) Amphiphiles: Design, Synthesis And Efficacy As Antimicrobial Agents, Michael Mckeever

Dissertations

Amphiphiles play important roles in nature. These molecules contain both hydrophilic and hydrophobic regions, leading to some astonishing properties. The lipid bilayer of the cell membrane is a fascinating organization of amphiphilic phospholipids. Natural and synthetic amphiphiles, such as antimicrobial peptides, interact with the cell membrane. Such interactions can impact transport of molecules across the cell membrane, disrupting cell functions. In this work, a library of tryptophan-containing amphiphiles was synthesized and their antimicrobial properties were explored.

First, a library of bis(tryptophan) amphiphiles was synthesized. Preparation included a coupling reaction of a diamine with tryptophan residues, via their carboxy-termini, at …

Design, Synthesis, And Analysis Of Paired Coiled-Coil Peptidic Molecular Building Blocks Used For Linearly Controlled Self-Assembly Of Α-Helical Coiled-Coil Heterodimer Peptide Pairs, Jason Distefano

Chemistry Theses

Molecular building blocks are fundamental to biological synthesis and processes and have been utilized in advanced materials, drugs and drug delivery systems, and biotechnology. Proteins have been used as molecular building blocks for the construction of complex, well-ordered structures. Coiled-coil protein domains are essential subunits used for the oligomerization of protein complexes, gene expression, and structural elements of biological materials. The synthesis and assembly of proteins utilizing coiled-coil motifs are of great scientific interest due to their potential applications in disease treatment, biomechanical motors, nanoscale delivery systems, etc. However, assembling protein complexes with specific morphology is still challenging because …

Synthesis And Study Of Unsymmetrical Bidentate Bis(Phosphino)Pyrrole Ligands And Their Transition Metal Complexes, Julia F. Vidlak

Honors Theses

Our laboratory has reported the synthesis and characterization of a broad library of unsymmetrical bidentate bis(phosphino)pyrrole (BPP) ancillary ligands for use in nickel-catalyzed cross-coupling reactions. The electronic and steric properties of nickel complexes bearing these ligands are examined, and our data support the hypothesis that these ligands produce nickel complexes with electron-deficient metal centers. The syntheses of (BPP)Ni(o-tolyl)Cl precatalysts for utilization in nickel-catalyzed Buchwald-Hartwig Amination are described, and preliminary reactivity studies reveal that (BPP)Ni(o-tolyl)Cl precatalysts are effective in promoting C–N cross-coupling reactions. Finally, we report steric measurements and electronic properties obtained from computed (BPP)NiCl2 and (BPP)Ni(CO)2 complexes, respectively. Additional reactivity …

Investigation On Electrochemical Processes Of P-Aminothiophenol On Gold Electrode Of Nanostructures, Hui-Yuan Peng, Jia-Zheng Wang, Jia Liu, Huan-Huan Yu, Jian-De Lin, De-Yin Wu, Zhong-Qun Tian

Journal of Electrochemistry

Electrochemical reactions on nanostructured noble electrodes have received much attention, however, the reaction mechanism and reaction kinetics are still difficult to be studied. Probe molecule can give an insight to the investigation of electrochemical reactions on noble electrodes with nanostructures. In this paper, the electrochemical process of p-aminothiophenol (PATP) adsorbed on the gold electrode was studied by electrochemical cyclic voltammetry and surface-enhanced Raman spectroscopy (SERS). Here, we used one-step sodium citrate reduction method (Frens method) to synthesize gold nanoparticles, which are used to construct the nanostructured gold electrode. The Raman electrolytic cell used was based on the traditional three-electrode electrolytic …

Study On Electrochemical Conversion Of Ammonium Sulfate To Ammonium Persulfate In Acetylpyrazine Wastewater, Yi-Jie Wang, Dong-Fang Niu, Xin-Sheng Zhang

Journal of Electrochemistry

Acetylpyrazine is an important spice and also plays important roles in biology, medicine and other fields. However, the wastewater containing ammonium persulfate, ferric ion (Fe³⁺), pyrazine, and a large amount of ammonium sulfate was produced during the production of acetylpyrazine. In this study, ammonium sulfate in acetylpyrazine wastewater was electrolytically converted into ammonium persulfate for economic benefits. Using platinum as an anode and graphite as a cathode, the influence factors of the electrolysis process (including the composition of the anolyte, the current density, the temperature, etc.) were firstly investigated without interference from other compositions. Under the optimal condition, …

Study On Electrodeposition Of Antimony In Choline Chloride-Ethylene Glycol Eutectic Solvent, Hao Wang, Xiao-Zhou Cao, Xiang-Xin Xue

Journal of Electrochemistry

Antimony is a chemically stable metal that has been widely used in industry, military and other fields. The use of electrodeposition to prepare antimony coating has the advantages of simple operation and low cost. The deep eutectic solvent (DES) is a eutectic mixture composed of a hydrogen bond donor and a hydrogen bond acceptor at a fixed molar ratio. It has the advantages of wide electrochemical window, high thermal stability, easy preparation, and low cost. Selecting DES as the electrolyte for electrodeposition can avoid the hydrogen evolution reaction of the aqueous system and the toxicity of ionic liquids. In recent …

Adjusting The Alloying Degree Of Pt3Zn To Improve Acid Oxygen Reduction Activity And Stability, Tian-En Zhang, Ya-Ni Yan, Jun-Ming Zhang, Xi-Ming Qu, Yan-Rong Li, Yan-Xia Jiang

Journal of Electrochemistry

Proton exchange membrane fuel cell (PEMFC) is a new type of energy device, a relatively excellent way to achieve carbon neutrality. However, due to the relatively slow reaction rate of oxygen reduction reaction (ORR) at the cathode, platinum (Pt) is the key material of the cathode catalyst. However, Pt is a kind of noble metal, and its high cost restricts the PEMFC commercialization process. At present, the main approach is to combine transition metals with Pt to prepare Pt-based alloys and to reduce the use of Pt. Pt-based alloys are excellent catalysts for ORR, improving both the activity and stability, …

Effects Of Electrode Shape On Lithiation Process Of Lithium-Ion Battery Electrodes, Shi-Wei Sun, Jian-Jun Nie, Yi-Cheng Song

Journal of Electrochemistry

This paper studies the influence of electrode shape on the lithiation process of lithium ion batteries. Both experimental observation and numerical simulation are employed to investigate the competitive interaction between the diffusion of lithium ions in both solid and liquid phases and the lithium intercalation reaction at the electrode surface. Experimental cells were prepared with the anode and cathode being placed parallel, leaving the latter embracing the former. An experimental device based on CCD camera was set up for in situ observation of electrode lithiation. The lithiation levels of the graphite anodes were estimated according to the observed color profile. …

Electrochemical Degradation Of Oxytetracycline Catalyzed By Fe3O4 Magnetic Nanoparticles, Fang Ying, Shan-Shan Xu, Yan-Bing Xu, Miao-Miao Liang, Jian-Feng Li

Journal of Electrochemistry

The purpose of this study is to optimize the electrochemical degradation of oxytetracycline (OTC) in water using a low cost and simple preparation method. In this paper, the Fe₃O₄ magnetic nanoparticles were used as catalysts to activate the electrochemical oxidation system of peroxydisulfates (PDS) which acted as electrolytes to provide active free radicals in order to improve the degradation of OTC under the condition of applying current. As one of the tetracycline antibiotics (TCs), OTC is one of the most used antibiotics in the world, therefore, it is necessary to study the effective degradation of OTC. By …

Preparation Of Pt@Basrtio3 Nanostructure And Its Properties Towards Photoelectrochemical Ammonia Synthesis, Jing Zhang, Rui-Xia Guo, Jian-Jun Fu, Shi-Bin Yin, Pei-Kang Shen, Xin-Yi Zhang

Journal of Electrochemistry

Ammonia is an important industrial raw material and a potential green energy. Using renewable energy to convert nitrogen into ammonia under ambient condition is an attractive method. However, the development of efficient photoelectrochemical ammonia synthesis catalysts remains a challenge. Perovskite such as BaSrTiO₃ (BST) is a good photocatalytic material. However, BST is active under ultraviolet light and has a high recombination rate of photogenerated electron-hole pairs. By dispersing precious metals, it can effectively regulate the absorption of sunlight by BST. In this work, we used a two-step method to prepare BST. The H₂PtCl₆·6H₂O …

Multi-Scale Simulation Revealing The Decomposition Mechanism Of Electrolyte On Lithium Metal Electrode, Yan-Yan Zhang, Yue Liu, Yi-Ming Lu, Pei-Ping Yu, Wen-Xuan Du, Bing-Yun Ma, Miao Xie, Hao Yang, Tao Cheng

Journal of Electrochemistry

Lithium metal is considered as an ideal anode material for next-generation high energy density batteries with its high specific capacity and low electrode potential. However, the high activity of lithium metal can lead to a series of safety issues. For example, lithium metal will continuously react chemically with the electrolyte, forming unstable the solid electrolyte (SEI) films. In addition, lithium dendrites can be formed during cycling, which can puncture the SEI film and cause short circuits in the battery. These drawbacks greatly hinder the commercial application of lithium metal. To solve the above problems, it is important to understand the …