Chemistry Commons^™

Functionalized Gold Nanoparticles For Sensing Of Pesticides: A Review, Wei-Bin Tseng, Ming-Mu Hsieh, Che-Hsie Chen, Tai-Chia Chiu, Wei-Lung Tseng

Journal of Food and Drug Analysis

Pesticides are a family of non-biodegradable chemical compounds which widely used in agriculture to control pests and increase yield production. However, overuse or abuse of pesticides and their metabolites may cause potential toxicity for the environment as well as human health and all other living organisms, even at deficient concentrations. Consequently, the development of sensors for monitoring these compounds is significant. Recently, nanoparticles-based sensors have been extensively employed as a potential alternative or complementary analytical tool to conventional detection methods for pesticides. Among them, gold nanoparticles (AuNPs) owing to their unique optical properties have been developed as smart sensors with …

Fluorescence Spectroscopic And Molecular Modelling Studies On The Molecular Interaction Mechanism Of Bromodeoxyuridine With Human Serum Albumin, Amira Adlin Roslan

Student Works (2020-2029)

The interaction of a nucleoside analogue, bromodeoxyuridine (BrdU) with human serum albumin (HSA) was studied to investigate the binding phenomenon and analyze the protein conformation upon BrdU binding. Multiple spectroscopic techniques, viz. intrinsic and three-dimensional (3-D) fluorescence, ultraviolet-visible (UV-Vis) absorption and circular dichroism (CD) spectroscopy along with molecular docking were used. A decrease in the Stern-Volmer constant (Ksv) with the increase in temperature suggested BrdU-induced quenching of protein fluorescence as static quenching and thus implied BrdU−HSA complex formation. This was also supported by UV-Vis absorption spectral results, showing hyperchromism in the absorption spectrum of HSA upon BrdU addition. Intermediate binding …

A Library Of Low Molecular Weight Fluorescent Probes For The Detection Of Cu(Ii) And Fe(Iii) Ions, Ashley Johnson

Dissertations

This dissertation reports the synthesis and photophysical properties of a family of rhodamine dyes (compounds 3.9-3.13 and 4.6). The rhodamine dyes are prepared in two steps, and fully characterized by ESI-MS (Low and High resolution), X-Ray crystallography, NMR spectroscopy, and FT-IR spectroscopy. The coordination environment of the low molecular weight fluorescent probes (LMFPs) was systematically changed to investigate the thermodynamic behavior between the LMFPs and an array of metal ions (Cu²⁺, Fe²⁺, and Hg²⁺ ions) in protic and aprotic solvent systems. Upon coordinating to metal ions, the π-conjugation of the LMFPs changed, resulting in …

Practical Adhesion Measurements In Organic Coatings; Advancing Understanding And Mechanical Methods Development, Diana Gottschalk

Dissertations

“Adhesion” can be considered either a mechanical or chemical phenomenon. The mechanical interpretation describes the difficulty of separating surfaces and is useful for quantifying performance within applications that depend on bulk and interfacial properties. Chemical adhesion describes interfacial resistance to chemical attack and does not depend on bulk properties. Predicting chemical failure through mechanical measurement is confounded by the influence of bulk properties. However, the prospect is attractive because of the robust tolerance for sample geometries, allowing experiments to resemble an end-use system. The present work's primary goal was to elevate mechanical methods to provide a detailed interfacial characterization of …

The Circadian Clock—A Molecular Tool For Survival In Cyanobacteria, Pyonghwa Kim, Manpreet Kaur, Hye-In Jang, Yongick Kim

Chemistry Faculty Research

Cyanobacteria are photosynthetic organisms that are known to be responsible for oxygenating Earth’s early atmosphere. Having evolved to ensure optimal survival in the periodic light/dark cycle on this planet, their genetic codes are packed with various tools, including a sophisticated biological timekeeping system. Among the cyanobacteria is Synechococcus elongatus PCC 7942, the simplest clock-harboring organism with a powerful genetic tool that enabled the identification of its intricate timekeeping mechanism. The three central oscillator proteins—KaiA, KaiB, and KaiC—drive the 24 h cyclic gene expression rhythm of cyanobacteria, and the “ticking” of the oscillator can be reconstituted inside a test tube just …

Electrochemical And Photoelectrochemical Properties Of Oxide And Chalcogenide Semiconductors, Farinaz Firouzan

Chemistry & Biochemistry Dissertations - Archive

Photoelectrochemical (PEC) water splitting via inorganic semiconductors has shown interest in technical applications such as harvesting sunlight as sustainable fuels. Chalcogen-based (S, Se, Te) semiconductors are important in numerous technology applications especially related to photovoltaic solar conversion, fuel cells, hydrogen generation etc. On the other hand, oxide semiconductors are great candidates due to their unique properties namely electrolyte stability, a wide range of bandgaps and easy access. In this vein, we investigated the quaternary metal chalcogenide, Ca(La1−xCex)2S4 (0 ≤ x ≤ 1) photoelectrochemical behavior in an aqueous redox electrolyte. These solid solution series were synthesized in Prof. Macaluso’s laboratory by …

1,9,10-Substituted Phenothiazine Derivatives With Strained Radical Cations And Use Thereof, Susan A. Odom, Chad Risko, Matthew D. Casselman, Corrine F. Elliott, Nuwan Harsha Attanayake, Subrahmanyam Modekrutti

Chemistry Faculty Patents

Compounds for use in a rechargeable battery are provided, including a compound according to the formula: (see patent for the formula)

wherein R₁ and R₉ are independently selected from the group consisting of H, alkyl, aryl, perfluoroaryl, perfluoroalkyl, alkylaryl, alkoxyaryl, alkylcarboxyl, aryl carbonyl, haloalkyl, perfluoroalkyl, glycols, haloaryl, a negative electrolyte, and a polymer, so long as when R₁ is H, R₉ is not H; and R₁₀ is selected from the group consisting of methyl, alkyl, aryl, alkylaryl, alkoxyaryl, alkylcarboxyl, aryl carbonyl, haloalkyl, perfluoroalkyl, perfluoroaryl, glycols, haloaryl, an oligomer, and a polymer.

Corn And Soybean Response To Wastewater-Recycled Phosphorus Fertilizers, Shane Ylagan

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

The ability to recycle phosphorus (P) from wastewaters could provide a sustainable, continuous source of P that might also help protect surface water quality from P enrichment. The mineral struvite (MgNH4PO4·6H2O) is an understudied material that can be created from Pcontaining wastewater and has been shown to have agricultural fertilizer value. The objective of this study was to evaluate the effects of electrochemically precipitated struvite (ECST), chemically precipitated struvite (Crystal Green; CG), diammonium phosphate (DAP), monoammonium phosphate (MAP), rock phosphate (RP), and triple super phosphate (TSP) on corn (Zea mays) and soybean (Glycine max) response in a 79-day greenhouse pot …

Hypervalent Iodine Compounds With Halogen-Containing And Phosphinate Ligands, Yakun Cao

Chemistry Theses and Dissertations

In modern organic chemistry, hypervalent (HV) iodine(III) compounds have been used widely as oxidizing agents but applications of λ³-iodanes in polymer and material chemistry is still underexplored. In the first project, a new series of heterocyclic HV iodine(III) compounds with I–Cl bonds and various substituents at the N atom were synthesized and successfully employed in the synthesis of highly branched polymers when added to mixtures of styrene and 1,4-divinylbenzene containing 10–80 mol% of the divinyl crosslinker, or even pure crosslinker. HV iodine(III) also can be utilized for polymer modification. HV iodine(III) compounds with fluorine-containing ligands (F, CF_{3 …}

Alkylation Of Benzene On Immobilized Phosphotungstic Acid, Kofi Kankam

Electronic Theses and Dissertations

Linear alkylbenzenes (LAB) are key intermediates in the synthesis of linear alkylbenzene sulfonate surfactants that are used in the manufacture of detergents. Production of LAB with traditional Lewis acids as catalysts, such as hydrofluoric acid, results in the formation of large amounts of toxic wastes and corrosion of industrial equipment. Phosphotungstic acid (PTA) has gained much attention in recent years as a solid catalyst for various alkylation reactions. This research work aims to develop a novel material based on PTA-containing silica gel, which can effectively catalyze LAB synthesis. Sol-gel synthesis of silica gel in the presence of PTA and tetraethyl …

Development Of Hplc Stationary Phases With Unique Selectivities And Introduction Of Molecular Rotational Resonance Spectroscopy In Gas Chromatography, Nimisha Thakur

Chemistry & Biochemistry Dissertations - Archive

This thesis contributes to advancing liquid and gas chromatography by introducing new stationary phases for HPLC and a new hyphenated GC technique. In the first section, new pH stable stationary phases based on geopolymers are presented for applications in liquid chromatography. The first-ever synthesis of micron-sized spherical particles of geopolymers, customized to be used as HPLC stationary phases, is reported. Complete material characterization of geopolymers using X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, laser diffraction, and porosimetry is shown. The chromatographic evaluation of geopolymers is done by comparing parameters such as hydrophilicity, ion exchange selectivity, efficiency, hydrolytic stability, and …

Chapter 1.2: Visualization Of Buffer Capacity With 3-D Topos: Buffer Ridges, Equivalence Point Canyons And Dilution Ramps, Garon C. Smith, Md Mainul Hossain

Water Topos: A 3-D Trend Surface Approach to Viewing and Teaching Aqueous Equilibrium Chemistry

The BufCap TOPOS software generates 3-D topographic surfaces for acid-base equilibrium studies that portray pH and buffer capacity behavior during titration and dilution procedures. Topo surfaces are created by plotting computed pH and buffer capacity values above a composition grid with volume of NaOH as the x-axis and overall system dilution as the y-axis. What emerge are surface features that correspond to pH and buffer behaviors in aqueous solutions. Topo surfaces are created for pH, log buffer capacity and linear buffer capacity. Equivalence point breaks become pH cliffs and logarithmic buffer capacity canyons that grow shallower with dilution. …

Predicting The Hydration Free Energy Of Small Alkanes And Alcohols From Custom, Electronic Structure-Based Force Fields, T. Ryan Rogers

Graduate Theses and Dissertations

Mathematical theories reveal the fundamental physics involved in experimentalphenomena. Computer models of such theories are routinely used to corroborate or explain experiments and predict properties of chemical systems. Therefore, an important effort in computational chemistry is the development of more accurate and efficient chemical models. Current-generation models are only beginning to approach experimental-quality predictions of hydration free energies (HFEs).Using computations of quantum mechanical (QM) forces and classical simulations based on these forces, I investigate models to predict several properties of solutes and solutions. This dissertation is a collection of projects exemplifying methods used to gain insight into chemical systems.

Simulations …

Design And Synthesis Of Novel No-Drug Hybrid Compound And Green Catalytic Activity Evaluation Of Synthesized Silver Nanoparticles-Halloysite Nanocomposite, Majed Abdullah Bajaber

LSU New Orleans Theses and Dissertations

Acetaminophen is a well-known analgesic that can manage pain and reduce fever. SCP-1 is a derivative of acetaminophen that showed significantly reduced hepatotoxicity and nephrotoxicity comparative to acetaminophen. Nitric oxides have been well known to play a key role in a wide variety of physiological and pathophysiological important processes. It was therefore of interest to synthesize a nitric oxide donor linked to SCP-1 that could have enhanced analgesic and antipyretic activity. A furoxan CAS 1609 as NO-donor was synthesized and linked to SCP-1 successfully. The furoxan CAS 1609 was initially synthesized from tetronic acid to give 1,2- dioxime in 86 …

Otolith Age Validation And Microchemical Investigation Of The Northern Stock F Atlantic Black Sea Bass (Centropristis Striata), Elise R. Koob

Graduate Masters Theses

Black sea bass (Centropristis striata) is a demersal marine species that supports extensive commercial and recreational fisheries along the Atlantic coast. A recent expansion into the Gulf of Maine raises questions about this species’ movement and population dynamics in the region. Additionally, the 2016 catch-at-age stock assessment model for the northern stock incorporated a population split at the Hudson Canyon. Though this model better accounts for differences in populations, several issues remain. First, validation of the otolith ageing technique for this stock is incomplete; and, second, the origin of fish that moved into the northern ranges of the Gulf of …

Selective Electrocatalytic Reduction Of Co2 To Co With Iron Nheterocyclic Carbene Complexes And Near-Infrared Absorbance Of Ruthenium(Ii) Photosensitizers Containing A Merocyanine Π-Acceptor, Peter Andrew Catsoulis

Graduate Masters Theses

The catalytic proton-coupled reduction of carbon dioxide into C-1 or “common engine” liquid fuels is currently a highly desirable and green approach to removing anthropogenic CO2 from the atmosphere. The most common approach to this is through electrocatalytic homogeneous reductions utilizing inorganic complexes as catalysts. Current research has moved towards the use of first-row transition metals in catalysts due to their high natural abundances and cheap cost. Iron porphyrin complexes have been vastly studied due to their high product selectivity and turnover frequencies. However, these complexes exhibit short lived activity because of competing reactions in their catalytic cycles, rendering them …

The Application And Development Of Metabolomics Methodologies For The Profiling Of Food And Cellular Toxicity, Jade Woods

Department of Chemistry: Dissertations, Theses, and Student Research

Metabolomics is a rapidly growing field of study. Its growth reflects advancements in technology and an improved understanding of the impact of the environment on metabolism. As a result, metabolomics is now commonly employed to investigate and characterize human and plant metabolism. The first chapter of this thesis provides an introduction to metabolomics and an overview of the protocols for sample preparation, data collection and statistical analysis. The second thesis chapter describes in explicit detail the step-by-step process of extracting and analyzing metabolites collected from mammalian cells, specifically brain tissue with a focus on Parkinson’s disease. The chapter highlights important …

Observed Defects Of Swiss Cheese Based On The Microbiome Contribution To The Production Of Organic Acids, Vannessa D. Campfield

Boise State University Theses and Dissertations

The United States Department of Agriculture downgrades on the order of 17% of all Swiss cheese produced in the United States due to defects. Many of these defects are related to improper eye formation, number, distribution, or size; leading to an industry loss of over $69 million per annum. The microbiome in Swiss-type cheeses plays a significant role in eye development due to production of organic acids and gaseous emissions contingent on bacterial abundance and phenotype. The relationship between bacteria and the organic acids they produce leading to Swiss cheese defects can be correlated using Next-generation sequencing and high-performance liquid …

Clarity On Cronbach’S Alpha Use, Jack Barbera, Nicole Naibert, Regis Komperda, Thomas C. Pentecost

Chemistry Faculty Publications and Presentations

The Cronbach’s alpha (α) statistic is regularly reported in science education studies. However, recent reviews have noted that it is not well-understood. Therefore, this commentary provides additional clarity regarding the language used when describing and interpreting alpha and other estimates of reliability.

The Dmap-Catalyzed Acylation Of Alcohol -- A Mechanistic Study, Tania Veronica Alvarez Castro

Theses and Dissertations

The mechanistic studies of Acylation of Alcohols catalyzed by 4-(N,N- Dimethyl-amino)-pyridine (DMAP) has been heavily studied in the literature. This reaction has attracted considerable interest from the synthetic and mechanistic points of view in recent years. In this research, the acylation of alcohols is prepared from cyclohexanol and acetic anhydride that is catalyzed by DMAP using triethyl amine (NEt3) as the auxiliary base and dichloromethane (DCM) as solvent. The reaction and final product will be analyzed by using gas chromatography (GC) and reaction progress kinetic analysis (RPKA). The mechanistic insights obtained in the present study should be useful for understanding …

Nerve Response To Superelastic Shape Memory Polyurethane Aerogels, Martina Rodriguez Sala, Omar Skalli, Nicholas Leventis, Firouzeh Sabri

Chemistry Faculty Research & Creative Works

We have previously shown the suitability of aerogels as scaffolds for neuronal cells. Here, we report on the use of super elastic shape memory polyurethane aerogels (SSMPA). SSMPA have a distinctly different stiffness than previously reported aerogels. The soft and deformable nature of SSMPA allowed for radial compression of the aerogel induced by a custom designed apparatus. This radial compression changed the pore diameter and surface roughness (Sa) of SSMPA, while maintaining similar stiffness. Two varieties of SSMPA were used, Mix-14 and Mix-18, with distinctly different pore diameters and Sa. Radial compression led to a decreased pore diameter, which, in …

Chemical Investigation Of Avocado (Persea Americana) Seed Husk (Testa): A Waste Of Waste, Orlando A. Castillo Scheren

Theses and Dissertations

Food chemistry is a new field in the world and is currently still expanding into the types of market in which it can be tapped into. There are about 1.3 billion tons of food waste produced in 2016 in the world, and food chemistry is going to help get rid of that waste by finding new and exciting applications to the things currently considered as waste. In these products, there might be new and undiscovered drugs that can be used in the market to help treat diseases for which might not have a cure at the current moment. The avocado …

Synthesis, Characterization, And Application Of Meso-Tetraphenyl Metalloporphyrin Photocatalysts Under Visible Light, Alexis Echavarria

Theses and Dissertations

The photocatalytic activity of meso-Tetraphenyl Metalloporphyrins with different metal centers was investigated. The synthesized metalloporphyrin photocatalysts was performed and analyzed using FT-IR spectroscopy, UV-VIS spectroscopy, and powder X-Ray Diffraction analysis. The synthesized TPP crystals were determined to be tetragonal crystal structure and the structure was observed in all synthesized metalloporphyrin catalysts. The Soret (B) bands, Q bands, FT-IR functional groups were identified. Reaction progress was investigated by sampling at intervals of one hour and analysis of the samples was performed using Gas Chromatography-Mass Spectrometry. GC-MS analysis was used to identify the products of the photochemical catalytic redox reactions performed under …

Thermal And Spectroscopic Investigations On Polymer-Based Nanofibers, Omosola Oriretan

Theses and Dissertations

Nanofibers of Poly (ethylene oxide), PEO, Poly (vinylpyrrolidone) PVP, Co-nanofiber of PEO-PVP and PEO nanocomposite of various Fullerene compositions were prepared by dissolving PEO, PVP and Fullerene in water. The Fullerene nanoparticles were added to the PEO solutions, the mixtures were homogenized under high power sonication. The PEO solutions, PVP solutions, the co-polymer solutions of PEO-PVP and the PEO -Fullerene solutions were centrifugally spun using Force spinning™ machine. The obtained nanofibers and the nanocomposites were subjected to FTIR analysis, Raman analysis and various heating and cooling cycles with heating and cooling rates ranging from 10C/min to 600C/min using differential scanning …

Chemical Modification And In Silico Validation Of Medicinally Privileged Molecular Scaffolds As Kras And Sars-Cov-2 Protease Inhibitors, Precious M. Okwuchukwu

Theses and Dissertations

Coronavirus disease was declared a global pandemic by WHO in March 2020, cancer is the second leading cause of death by a disease. Several scientists around the world are working relentlessly to discover an effective remedy to eradicate these deadly diseases. A natural polyphenol (magnolol) has been isolated from a tree Magnolia grandiflora (family Magnoliaceae) found on UTRGV campuses. This research is focused on design of a series of chemically modified sulfonyl derivatives based on the isolated magnolol framework and other medicinally privileged molecular scaffolds framework that can effectively bind to the COVID-19 main protease, SARS- CoV-2 3CL protease …

Synthesis, Characterization, Spectroscopic, And Mesomorphic Studies Of New Schiff Base Ligands And Titanium, Cobalt, Nickel And Copper Metal Centers, Raj K. Gurung

Chemistry & Biochemistry Theses & Dissertations

Transition metal complexes with Schiff base ligands offer a wide application in the field of development of catalysis and material. The straightforward synthesis allowed the structural modification and helped to optimize in various application of such complexes. Titanium-containing complexes have been reported to be important for their catalytic and material applications through the coordination of a tetradentate Schiff base ligand, viz. N, N’-ethylene bis(salicylideneiminate) dianion (salen). Studies reporting the characterization of achiral titanium(IV) salen complexes are scarce due to their intricate nature. Such complexes would be comparatively less expensive and easier to prepare synthetically and thus could represent an …

Synthesis, Characterization, And Kinetics Studies Of New Cobalt Complexes For The Production Of H2 In Acidic Media, Michael John Celestine

Chemistry & Biochemistry Theses & Dissertations

The kinetics and mechanism of the oxidation of [Co(dmgBF₂)₂(OH₂)₂] (where dmgBF₂ = difluoroboryldimethylglyoximato) by sodium hypochlorite (NaOCl), sodium bromate (NaBrO₃), and bromine (Br₂₎ was investigated by stopped-flow spectrophotometry at 450 nm over a wide temperature range. The pK_a1 value for [Co(dmgBF₂)₂(OH₂)₂] was calculated as 5.27 ± 0.14 at I = 0.60 (NaCl). From the variation in pH studies, the activation parameters were derived from the proposed mechanisms for NaOCl, ΔH_1*, ΔH_2*, ΔS_1*, and …

Photoelectrical And Photoelectrochemical Characterization Of The Materials Used In Dye-Sensitized And Perovskite Solar Cells., Pom Lal Kharel

Electronic Theses and Dissertations

Solar energy is one of the most important alternative renewable energy sources to fulfill the increasing demand of energy in the world. Third-generation solar cells like dye-sensitized solar cells, perovskite solar cells, quantum dot solar cells, and organic solar cells are extensively studied to increase their photoconversion efficiency, and ultimately for their large-scale implementation. A dye-sensitized solar cell consists of a photoanode of a mesoporous film of titania sensitized with dye sandwiched with a counter electrode, which is usually a platinum-coated transparent conducting oxide, and a redox couple injected between the photoanode and counter electrode. Doping titania with rare-earth metal …

Design, Synthesis And Application Of Janus Gold Nanoprisms For Directed Self-Assembly., Md. Emtias Chowdhury

Electronic Theses and Dissertations

Colloidal Janus particles that possess more than one type of surface chemistry or functionalities have drawn significant interest due to their enormous potential in bottom-up synthetic strategies for complex superstructures. Moreover, the property of molecular recognition, tunability, and predictability of the DNA-mediated interactions enable a high degree of control over particle assembly to generate highly ordered nanostructures with emergent applications. In this dissertation, we present our works on the synthesis of Janus particles from anisotropic gold nanoprisms, and DNA- mediated assembly of nanoprisms and polymer beads in four major areas: 1) Facet selective asymmetric functionalization of gold nanoprisms for Janus …

Strain Control Of Layer-Resolved Negative Capacitance In Superlattices, Raymond Walter, Sergey Prosandeev, Charles Paillard, L. Bellaiche

Physics Faculty Publications and Presentations

Negative capacitance in BaTiO₃/SrTiO₃ superlattices is investigated by Monte Carlo simulations in an atomistic effective Hamiltonian model, using fluctuation formulas for responses to the local macroscopic field that incorporates depolarizing fields. We show that epitaxial strain can tune the negative capacitance of the BaTiO₃ ferroelectric layer and the overall capacitance of the system. In addition, we predict and explain an original switching of the negative capacitance from the BaTiO₃ layer to the SrTiO₃ layer at low temperatures for intermediate strains.