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Bridging The Gap Between Molecular Components And Functional Electronic Chemical Sensing Devices With 2d Layered, Conductive Metal–Organic Frameworks, Emma Katherine Ambrogi

Dartmouth College Ph.D Dissertations

Layered, conductive framework materials are a class of materials with properties that make them ideal sensing materials in electronic chemical sensors. My thesis is focused on the development of these materials for electrochemical sensing of liquid phase analytes, and on understanding the material–analyte and material–electrode interfaces, and their self-assembly and deposition onto surfaces.

Chapter 1 provides a summary of the use of layered conductive metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) in electronic chemical sensors, detailing the materials and sensor architectures employed, and the analytes detected. Relevant performance metrics are compared, and investigations into material–analyte interactions are highlighted.

Chapter …

Engineering Multifunctional Silicon Nanostructures From Biorenewable Cellulose Nanocrystals, Nancy Chen

All Dissertations

The imperative search for alternative materials to address the pressing demand for advance energy storage is underscored by the escalating environmental predicaments. Lithium-ion batteries (LIBs) with graphite anodes have become the benchmark in energy storage; however, they are approaching a saturation point in terms of energy density. Silicon emerges as a promising contender to supplant graphite, owing to its profuse availability, cost-effectiveness, and impressive specific capacity of 4200 mAh g^-1. By integrating silicon anodes, LIBs stand to undergo a radical transformation, markedly diminishing in weight and size, thus heralding a novel wave of compact, lightweight energy storage systems. …

Design And Application Of Smart Systems To Address Analytical Problems, Lucas B. Ayres

All Dissertations

This dissertation is a multidisciplinary effort that integrates low-cost analytical instrumentation, redox chemistry, and artificial intelligence to overcome existing limitations in the fields of wearable sensing technology, Deep Eutectic Solvents (DES), and antioxidant chemistry. The overall goal behind each implemented strategy is to enhance the accuracy, efficiency, and accessibility of analytical processes and technologies. A general overview of the thesis, along with the research outcomes is included in Chapter One. The theoretical framework of this dissertation is presented in Chapter Two. Chapter Three describes the development of a wearable platform (sensor and instrumentation) to rapidly detect (~20 minutes) S. aureus …

Magnetic Properties Of Zgnrs With Nitrogen And Fluorine Adsorbates, A Computational Study, Justin Petit

Electronic Theses and Dissertations

Imposing dimensional restrictions on graphene sheets and adding impurities can give rise to carbon nanostructures with magnetic properties. In this work, zigzag graphene nanoribbons, zGNRs, with nitrogen and fluorine adatoms are investigated for magnetic properties of interest for spin devices. Geometry optimizations were done determining which position along a zGNR electrode that N and F would favorably attach to. Edge positions were determined as the most stable attachment site. M-cell zGNR electrodes (M = 1-3) edge-functionalized by N and F adatoms were investigated with respect to their band structures and spin densities in antiferromagnetic and ferromagnetic, AFM and FM, configurations. …

Boron-Doped Diamond As A Resilient Electrode Material In Molten Salts, Hannah Katherine Patenaude

UNLV Theses, Dissertations, Professional Papers, and Capstones

Molten salt chemistry has a range of applications within nuclear technology, including for the Molten Salt Reactors (MSRs) and pyroprocessing to recover valuable actinides for energy and national security needs. However, the high-temperature, corrosive nature of molten salts makes them particularly challenging to deploy on an industrial scale and study in benchtop measurements. Material accountability and corrosion monitoring of MSR fuels are essential components to the successful deployment of MSRs, and electroanalytical techniques like cyclic voltammetry (CV) and spectroelectrochemistry (SEC) can provide a wealth of information to describe salt systems in situ. To perform such measurements, it is imperative to …

Performance Effects Of Dissociated Hydrogen In Nuclear Thermal Propulsion Engines, Richard Adam Gorrell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nuclear thermal propulsion (NTP) research considers hydrogen dissociation as negligible to design and analysis of propulsion engines. This study reintroduces chemically reacting flow to NTP engine analysis for investigation of the dissociation effect on engine performance. A first-principles approach observes the basic chemical mechanism and reaction within the high-speed, high-temperature NTP flow to baseline expected atomic hydrogen levels and validate equilibrium. A surface reaction study looks into hydrogen absorption through dissociation and its effect on the boundary layer, and bulk flow. For total performance, the resulting dissociated flow is analyzed through nozzle expansion and performance metrics calculated.

All historic reactor …

Ligand-Stabilized Sno2 As A High-Performance And Scalable Electron Transport Material For Inverted Perovskite Solar Cells., Sashil Chapagain

Electronic Theses and Dissertations

Over the past decade, perovskite solar cell (PSC) technology has attracted significant attention for its low material costs, simple fabrication processes, and impressive photovoltaic performance, with recent power conversion efficiencies (PCEs) surpassing 26%. This advancement marks PSCs as strong competitors to traditional silicon-based photovoltaics. Despite the high efficiency of PSCs, the path to commercialization is hindered by challenges in stability, scalability, and module efficiency. The stability and scalability of PSCs are primarily dependent on the successive charge transfer layers (CTLs) that are interfaced with the perovskite layer. Among CTLs, metal oxide (MO_x) CTLs are preferred for their cost-effectiveness, …

Electrochemical Modulation Of Surface Plasmon Wave To Investigate Dna-Based Sensing Platforms And Detection Of Sars-Cov2., Anil Sharma

Electronic Theses and Dissertations

This study offers a thorough comparative analysis of optical and electrical signaling strategies for assessing the electrochemical properties of different redox-labeled DNA-based biosensing platforms. In addition, it illustrates the development of an optical interrogation technique with electrochemical modulation of surface plasmon waves (ECM-SPW) as a route for analyzing and implementing DNA-based hybridization sensors. For those quantitative analyses, we chose a model sensing platform composed of a methylene blue (MB)-modified single-stranded DNA (ssDNA) signaling probe and an unlabeled capture ssDNA probe that complements the signaling probe. Two types of signaling probes were employed in this work: one with MB attached to …

Revealing The Three-Dimensional Arrangement Of Polar Topology In Nanoparticles, Chaewa Jeong, Juhyeok Lee, Hyesung Jo, Jaewhan Oh, Hionsuck Baik, Kyoung-June Go, Junwoo Son, Si-Young Choi, Sergey Prosandeev, Laurent Bellaiche, Yongsoo Yang

Physics Faculty Publications and Presentations

In the early 2000s, low dimensional ferroelectric systems were predicted to have topologically nontrivial polar structures, such as vortices or skyrmions, depending on mechanical or electrical boundary conditions. A few variants of these structures have been experimentally observed in thin film model systems, where they are engineered by balancing electrostatic charge and elastic distortion energies. However, the measurement and classification of topological textures for general ferroelectric nanostructures have remained elusive, as it requires mapping the local polarization at the atomic scale in three dimensions. Here we unveil topological polar structures in ferroelectric BaTiO₃ nanoparticles via atomic electron tomography, which …

Development Of Chiral Lewis Base Catalysts For Chlorosilane-Mediated Asymmetric C-C Bond Formations, Changgong Xu

Theses and Dissertations

The chiral hydrazine is a crucial structural motif that serves as pivotal structural elements in numerous natural products and biologically significant molecules. We are particularly interested in the catalytic asymmetric reduction of hydrazones, as well as the catalytic asymmetric propargylation and allenylation of hydrazones, because they provide direct pathways to these enantio-enriched chiral building blocks. In this work, we will explore the potential of two different categories of chiral Lewis base catalysts in the said transformations.

Developed by another student in our group, axial-chiral 3,3’-triazolyl biisoquinoline N,N’-dioxides derived catalysts are tested and demonstrated its capability in activating various hydrazone …

Characterizing The Role Of Chemo-Mechanical Couplings In The Activation Process Of Proteins That Undergo Conformational Changes, Ugochi Isu

Graduate Theses and Dissertations

Proteins are not static entities; rather, they are dynamic macromolecules that undergo conformational changes to perform their biological functions. These structural transitions are often coupled to chemical events such as lipid interactions, or changes in the cellular environment. Understanding the intricate interplay between chemical perturbations and the resulting mechanical response is crucial for elucidating the activation mechanisms of proteins. This dissertation aims to characterize the role of chemo-mechanical couplings in the activation process of two G protein-coupled receptors (GPCRs): Cannabinoid Receptor 1 (CB1) and Metabotropic Glutamate Receptor 1 (mGluR1). We employ molecular dynamics simulations to investigate the conformational landscapes of …

Biotinylated Protein Capture And Tween-20 Assisted Exosome Isolations Via Capillary Chanelled Polymer Fiber, Md Khalid Bin Islam

All Theses

In the past two decades, Marcus and colleagues have led the advancement of capillary-channeled polymer (C-CP) fiber stationary phases for biomacromolecule separations, including proteins and nanovesicles. These stationary phases offer notable advantages, including low cost ($5/column), straightforward column fabrication, and the capacity for on-column surface modification, enabling high chemical selectivity. This study examines a C-CP fiber modification strategy for capturing target proteins and develops a Tween-20-assisted C-CP-based hydrophobic interaction chromatography (HIC) method for the isolation and quantification of exosomes from human urine.

The quest for higher-throughput and cost-effective protein isolation techniques remains a key focus in a variety of end …

Modelling Terrestrial And Potential Extraterrestrial Photopigments Via Density Functional Theory, Dorothea Illner

Theses and Dissertations

In the search for extraterrestrial life, biosignatures play a crucial role in identifying its putative traces. A commonly known and robust biosignature is the Vegetation Red Edge (VRE), which can be described as a sharp increase of reflectance observed from a planet and stems from the light absorption of photopigments in specific regions in the electromagnetic spectrum. For Earth, this VRE is known to occur around 700 nm, however, if the photopigments absorb light in different regions and have different structures the VRE could experience a wavelenght shift.

In this work, Chlorophyll a and a potential photopigment precursor called Phot0 …

Earth Abundant Catalyst For Evironmental Sustainability Applications, Javier Hernandez

Open Access Theses & Dissertations

The development of experimental methodologies for synthesizing a diverse range of metallic and metal oxide nanoparticles tailored for sustainable water treatment applications was investigated. These nanoparticles are prepared using environmentally friendly and scalable synthesis methods, underscoring their potential for large-scale production. Synthesized nanoparticles are harnessed for various processes, including catalysis and electrocatalysis, with a primary objective of degrading and removing organic pollutants from water. Key to this research is the encapsulation of nanoparticles within solid supports. Multiple methodologies are explored to engineer supports that ensure nanoparticle stabilization, monodispersion, and prevent unintended release into the environment. Two alternative approaches were evaluated …

Electrocatalytic Degradation Of Bisphenol A Using Nickel Sulfide Supported On Graphene Oxide And Cobalt Sulfide Supported On Graphene Oxide Composite Materials, Katherine Ellynn Wright

Theses and Dissertations

The degradation of bisphenol A (BPA) by nickel sulfide supported on graphene oxide (NiS/GO) and cobalt sulfide supported on graphene oxide (CoS/GO) composite materials was investigated. The catalysts were studied to determine the optimal conditions for BPA degradation using electrocatalysis. Electrocatalytic trials were performed using varying parameters, which included electrolyte concentrations of 1.0 g/L, 2.0 g/L, and 4.0 g/L Na2SO4, pHs of 2, 4, and 6, and constant currents of either 0.100 A or 0.200 A. During the reaction samples were taken before the current was applied and 30 minutes and 60 minute intervals to observe the degradation of …

A Comparative Analysis Of Field Electron Emission From Carbon Black Embedded Within Insulated Copper Hollowed Wires And Glass Tubes, Hatem A. Al-Braikat, Ahmad M D Jaber, Adel M. Abuamr, Mazen A. Madanat, Aseel A. Al-Jbarart, M-Ali H. Al-Akhras, Marwan S. Mousa

Karbala International Journal of Modern Science

In this study, two different methods are used to investigate carbon black as a cold field electron emitter. The first method is to incorporate carbon black into a specially designed insulated copper hollowed wire. The wire has a cup-shaped structure created by electrochemical etching. The second method involves the incorporation of carbon black into narrow glass tubes. A Comparative analyses is carried out to evaluate the effectiveness of each method. To evaluate the performance of the samples, the current-voltage characteristics will be examined using field electron microscopes. This analysis will provide an understanding of the emission of the carbon black …

Extraction Of Natural Dyes From Delonix Regia Flowers For Cotton Fibres, Lutamyo Nambela, Liberato V Haule

Tanzania Journal of Science

Textile colouration is among the major industry that pollutes the environment with effluents rich in dye chemicals. Most of the dyes used are synthetics which possess health and environmental impacts. Potentially, the use of bio-based dyes and other chemicals can lessen the environmental challenges of the textile effluents. This study reports on sustainable extraction and dyeing of cotton fabric using extract of Delonix regia flowers. The extraction process was done using acidified water as a solvent and the dyeing process was free from hazardous auxiliary chemicals. To improve the dyeing performance, banana sap was used as an affordable and eco-friendly …

Surface Treatments' Effects On The Capacitor's Dielectric Performance Under Electro-Thermal Stresses, Haider. M. Umran, Feipeng Wang

Karbala International Journal of Modern Science

Biaxial-oriented polypropylene (BOPP) films are characterized by unfavorable aging behavior because of their poor susceptibility to high temperatures, humidity, and high electric fields. This makes them unqualified to withstand harsh operating conditions, such as in capacitor applications. This study investigates the impact of annealing BOPP samples at 100 °C for five hours after fluorination at different times (15, 30, and 60 minutes) on their electrical and mechanical performance under electro-thermal stresses. Scanning electron microscope (SEM) images confirm that there is an increase in surface roughness and the formation of a dense layer of fluorine-containing groups monotonically with fluorination time. So, …

Electrocatalytic Cyclopropanation Of Active Methylene Compounds, Liang-Hua Jie, Hai-Chao Xu

Journal of Electrochemistry

The development of novel strategies to access cyclopropanes has become increasingly important due to the vital role of these three-membered ring structures in synthetic intermediates, natural products, and pharmaceuticals. Herein, we present an electrocatalytic method for the synthesis of cyclopropanes through intermolecular dehydrogenative annulation of active methylene compounds and arylalkenes. This electrochemical process requires no chemical oxidants, allowing for a speedy access to various functionalized cyclopropanes from inexpensive and readily available materials.

Electrochemical Syntheses Of Aryl-Substituted Benzothiophenes And Phenanthrenes Using Benzenediazonium Salts As The Aryl Radical Precursors, Li-Yuan Lan, Yang-Ye Jiang, Raymond Daniel Little, Cheng-Chu Zeng

Journal of Electrochemistry

Aryl-substituted benzothiophene and phenanthrene are important structural units in medicinal chemistry and materials science. Although extensive effort has been devoted to prepare these compounds and a variety of approaches have been developed to construct the 2-substituted benzothiophene core structure, environmental-friendly and efficient synthetic means are still desired. Based on our previous electrochemical Minisci-type arylation reaction with aryl diazonium salt as the aryl precursor, as well as the work from König’s group, herein, we described the use of paired electrolysis to achieve 2-aryl benzothiophenes and 9-aryl phenanthrenes employing benzenediazonium salts as the aryl radical precursors. Initially, 2-methylthiobenzendiazonium salt 1a and 4-methylbenzene …

Electrochemical Advanced Treatment Of Desulfurization Wastewater From Coal-Fired Power Plants, Ju-Cai Wei, Juan Yi, Xu Wu

Journal of Electrochemistry

Zero-emission of desulfurization wastewater is one of the main demands for coal-fired power plants. As typical high salinity wastewater, it is hard to purify the desulfurization wastewater from coal-fired power plants through traditional physicochemical treatment or biochemical treatment, e.g., COD and Cl^–. A high concentration of Cl^– ion in desulfurization wastewater restricts wastewater reuse and zero-emission. Electrochemical technology is an attractive method for high salinity wastewater zero-emission, which provides a versatile, efficient, cost-effective, easily automatable, and clean industrial process. For advanced treatment of effluent after triple box process treatment in power plants, this paper reports an electrochemical …

Synthesis And Characterization Of Silver(I) And Manganese(Ii) Complexes With Thione Imidazoles, Shannon Keyser, Audrey Lawrence, Jaime M. Murphy Ph.D.

Honors Theses

Coordination polymers are chemical complexes with versatile applications such as catalysts, electrical conduc-tors, non-linear optics, magnetics, chemical sensing, and molecular storage. The polymers are comprised of a repeating series of metal-ligand complexes, which form various structures in varying ratios depending on the metal and ligand used. Certain metal-ligand combinations have shown particular promise as potentially being polymers or, if not polymers, possessing other useful features such as electromagnetic conductivity. Complexes were synthesized using silver(I) and manganese(II) with the ligands methimazole, 2-mercaptoimidazole, and thiocarbanilide with counterions of either chloride or nitrate. These com-plexes were characterized using elemental analysis, infrared spectroscopy, and …

The Purification And Thermal Stability Of The Peroxidase Enzyme In Cucurbita Moschata, Garen Hamner

Senior Honors Theses

Peroxidases are enzymes that catalyze the reduction of hydrogen peroxide to water while oxidizing organic substrates and are valuable in spheres like industrial and medical applications and histochemistry. Limitations still exist in the use of the well-studied horseradish peroxidase for certain activities due to limitations like poor thermal stability, thus the search for novel peroxidases that can overcome these limitations is an active area of research. Butternut squash peroxidase (Cucurbita moschata) (BSP) shows promise due to significant activity being found in the skin and apparent enhanced thermal stability, but an efficient purification scheme for it is lacking, as well as …

Piezochromic Behavior Of 2,4,6-Triphenylpyrylium Tetrachloroferrate, Princess Canasa, David King, Petrika Cifligu, Adrian F. Lua Sanchez, Si L. Chen, Haesook Han, Trimaan Malik, Brant Billinghurst, Jianbao Zhao, Changyong Park, George R. Rossman, Michael Pravica, Pradip K. Bhowmik, Egor Evlyukhin

Chemistry and Biochemistry Faculty Research

In advanced photonics, there is a growing interest in piezochromic luminescent materials that exhibit multicolor switching, driven by their potential applications in optical recording, memory, and sensors. Here, the piezochromic behavior of 2,4,6-triphenylpyrylium tetrachloroferrate (Py-FeCl₄) under high pressures from 0 to 9 GPa is reported. The observed multicolor changing properties of Py-FeCl₄ (yellow–orange–red–maroon–black) are found to be fully reversible upon decompression to ambient conditions. The mechanism of Py-FeCl₄ piezochromism is investigated via Raman, infrared, and UV–vis spectroscopy combined with powder X-ray Diffraction. The absence of structural phase transitions as well as the abrupt shifts of bandgap …

Performance Test Of Zn-Astaxanthin Complex-Sensitized Solar Cell: Effect Of Light Intensity On Open-Circuit Voltage And Short-Circuit Current Values, Septiani Septiani, Winda Rahmalia, Thamrin Usman

Turkish Journal of Chemistry

The sensitizer is one of the most essential dye-sensitized solar cell (DSSC) components. In the present research, a Zn-astaxanthin complex was investigated as a sensitizer, compared to pure astaxanthin. The complex with a 1:1 mole ratio between astaxanthin and Zn2+ was synthesized in a reflux reactor at 37–60 °C. The product was analyzed using Proton Nuclear Resonance (1H-NMR), which indicates the presence of chelate formation between Zn2+ with two atoms of oxygen on the terminal cyclohexane ring of astaxanthin. The interaction of sensitizers (astaxanthin and Zn-astaxanthin) on the photoelectrode surface in this study was analyzed using a Fourier Transform Infra-Red …

Development Of A New Nanosensor For The Determination Of Food Coloring Sunset Yellow In Powder Drinks Using L-Cysteine Coated Copper Nanoclusters, Mehmetcan Bi̇lkay, Büşra Karataş, Hayri̇ye Eda Şatana Kara

Turkish Journal of Chemistry

Sunset Yellow (SY), which is an artificial azo dye, is preferable for its high stability and low cost. The determination of SY in foods is extremely important for human health because excessive consumption of SY has harmful effects, such as hyperactivity disorder and cancer. In this method, L-cysteine ​​coated copper nanoclusters (CuNCs) were used as a fluorescence probe. L-cysteine ​​has been used as both a reducing and stabilizing agent. One-step green hydrothermal synthesis of CuNCs was made. L-cysteine-coated CuNCs have been characterized using several of methods. CuNCs quenching mechanism is static and inner filter effect (IFE). The linear range is …

Improving The Water Solubility Of Cannabidiol Using A Peptide Carrier, Melek Parlak Khalily

Turkish Journal of Chemistry

Cannabidiol (CBD), nonpsychotropic cannabinoid found in Cannabis sativa, is a very promising drug candidate offering many differential effects such as sedative, antiinflammatory, antioxidant, and neuroprotective properties. Nevertheless, the therapeutic use of CBD is hindered by its lack of water solubility and relatively low bioavailability. Various carriers have been used to address the solubility issues of CBD and other highly lipophilic drugs so far. However, self-assembled peptide nanostructures as carrier have not been used to improve the water solubility of CBD yet. In this study, a self-assembling peptide micelle was demonstrated to be an effective vehicle for encapsulation of CBD and …

Phosphorus And Nitrogen-Containing Soybean Oil Polyols: Effect On The Mechanical Properties And Flame Retardancy Of Polyurethane Foam, Deni̇z Öztaşkin, Lütfullah Yusuf Yi̇vli̇k, İlayda Acaroğlu Degitz, Tarik Eren

Turkish Journal of Chemistry

In recent years, there has been an increasing interest in producing new materials that use renewable resources and halogen-free flame retardants with nonleaching properties. This research focuses on designing and synthesizing phosphorus-nitrogen-based biopolyols for use in polyurethane (PU) foam production. Polyol (ESBO-DYM) with dual functionalities, renewability, and nonflammability is synthesized through the epoxy ring-opening reaction of epoxidized soybean oil with phosphorus and nitrogen-containing tetraol products (DYM). The mechanical and flame retardant properties of PU foams with the addition of an ESBO-DYM were investigated. Increasing the amount of phosphorus in the PU foams increased the thermal stability properties. Using 100% ESBO-DYM …

Graphene Aerogels: Part 1 - Derived From Graphene Oxide And Thermally Reduced Graphene Oxide Via Supercritical Carbon Dioxide Drying, Meryem Samanci, Ayşe Bayrakçeken

Turkish Journal of Chemistry

Graphene aerogels have become promising materials in many areas of industry, especially in energy applications due to their superior physical and electrochemical properties. Generally, graphene oxide (GO)-derived aerogels (A) are synthesized by using the hydrothermal method. In this study, both GO and reduced graphene oxide (RGO)-derived aerogels were synthesized by using the sol-gel method coupled with the supercritical carbon dioxide (SCCO2) drying process. It aims to examine the changes in the structure of the final aerogel by changing the amount (0.25–0.5–1% wt.) and type of graphene-based precursor materials used in the synthesis. Physical characterizations of graphene aerogels were conducted using …

Hummers’ Method-Assisted Liquid-Phase Exfoliation Enables The Fabrication Of Few-Layer Borophene From Bulk Boron, Mehmet Semih Bingöl, Mehmet Yilmaz, Ahmet Emre Kasapoğlu

Turkish Journal of Chemistry

The fabrication of few-layer borophene (BP) from bulk boron (b-B) is of great importance and still a scientific challenge due to the complex structure and crystallinity of b-B. Herein, we propose a novel technique to prepare a few-layer BP on a large scale with a large lateral size in a well-controlled manner. For this, we employed the Hummers’ method-assisted liquid-phase exfoliation. In the first step, the chemical exfoliation of the b-B as a precursor was performed by the modified Hummers’ method. After chemical exfoliation, mechanical delamination was employed by using an immersion sonicator. Finally, BP sheets were collected with dimensions …