Chemistry Commons^™

Natural Amino Acid Derived Iron (Iii) Catalysts For Green Oxidation Chemistry Applications, Karie Sanford

Theses and Dissertations

Tetraamido macrocyclic ligand activators are a group of catalysts that have been developed to perform green oxidation chemistries. In this thesis, the traditional synthesis of these catalysts was successfully altered to begin with natural amino acids, rather than the conventionally used synthetic derivatives of amino acids, which has never been shown in previous research. This was confirmed using a variety of characterization techniques including electrospray ionization-mass spectrometry. One of these catalysts was utilized in several dye degradation studies, where it was determined that the catalyst can remove about 98% of methylene blue and indigo carmine pollutants from water within 45 …

Halide Substitution Of Ternary Bismuth Chalcogenides For Photovoltaic Applications, Thomas Boggess

Theses and Dissertations

Semiconductors play an integral part in modern society. From computing to LEDs their use is ubiquitous, and no field is more reliant on them than that of power generation. Current political movements have seen a push to decrease reliance on traditional forms of power generation, which relies on fossil fuels, to renewable sources such as solar power. However, current commercial solar panels, based on silicon, are lacking in efficiency, only reaching between 18% and 22% efficiency.¹ In recent years, materials called perovskites have been garnering significant attention as possible replacements for silicon cells due to their favorable optoelectronic properties. …

Anti-Doping Crisis In Sports, What's Next? Ion Mobility-Mass Spectrometry For The Study Of Anabolic Androgenic Steroids, Diana Constanza Velosa

Theses and Dissertations

The main objective of this work is to augment both qualitative and quantitative measures of anabolic androgenic steroids (AAS) with ion mobility-mass spectrometry (IM-MS), laying the foundation for implementation into analytical drug testing laboratories. AAS testing requires high sensitivity and specificity. IM-MS is presented as an emerging technology workflow capable of targeted quantification of AAS and structural elucidation for potential unknowns, allowing ions to be separated and characterized based on their rotationally averaged collision cross section (CCS). Chapter 1 provides a background of the basic principles of IMS and the different types of analytical methods used for doping analysis currently …

Microwave-Assisted Depolymerization Of Poly (Ethylene Terephthalate) Via Ethanolysis, Mayra Alejandra Gomez Cortez

Theses and Dissertations

In the search of providing an alternative form of combating the complex environmental concerns rising from the rapid growth of poly (ethylene terephthalate) waste in the world, this research focused on investigating the chemical recycling of PET via ethanolysis. Parameters such as temperature, reaction time, catalyst usage and concentration were investigated to promote depolymerization.

In this work, ethanolysis of waste PET under microwave irradiation was investigated using organocatalysts 1,5,7-Triazabicyclo [4.4.0] dec5-ene (TBD) and 1,8-Diazabicyclo [5.4.0] underc-7-ene (DBU). We evaluated the effectiveness of reaction conditions through a series of experiments and determined the optimum conditions as follows: 0.5 g of PET, …

Analysis Of Steroid Hormone Isomers Using Ion Mobility-Mass Spectrometry, Shon Paul Neal

Theses and Dissertations

This dissertation presents a comprehensive study on the analysis of steroid hormone isomers using liquid chromatography-ion mobility-mass spectrometry (LC-IM-MS). The dissertation is divided into three main parts: the first part focuses on research using different drift gases and ion adducts to modify the mobility separations allowing for resolution between the isomers. The second part focuses on research exploring derivatization reactions that target structural differences between the steroid hormone isomers to amplify the differences and resolve the isomers in the ion mobility region. The final part covers a proposal on future study directions to include simultaneous derivatization reactions, mass spectrometry fragmentation, …

Water-Soluble Iron Porphyrin Complex For The Catalytic N-Dealkylation Of Fentanyl, Amanda Pitt

Theses and Dissertations

An increase in the misuse of opioids in the United States and the increasing potency of analogs necessitates novel treatments of opioid overdose. The chemical structure of synthetic opioids, such as fentanyl, carfentanil, and morphine possess a trialkyl amine functional group (-NR3) which makes for a promising target for potential catalysts. Iron (III)-tetrasulfonatophenyl porphyrin (complex 9) was synthesized as a potential catalyst for degradation of fentanyl. Complex 9a was prepared from the direct reaction of the free porphyrin and FeSO4. Complex 9b was prepared from the direct reaction of the free porphyrin and FeCl2 in refluxing DMF. The complexes were …

Design And Synthesis Of Novel Peptide-Metal Organic Frameworks, Moustafa Mahmoud Abdel Wahid Hamaad

Theses and Dissertations

Metal-organic frameworks (MOFs) are a class of crystalline porous materials with extended network structures formed through the reticular assembly of inorganic and organic molecular building blocks through strong coordination bonds. Compared to other porous materials, MOFs offer a high degree of structural diversity as their shape and pore size as well as functionality can tuned by the precise selection and design of their metal centers and organic struts. Due to their high surface areas, pore volumes, and the possibility of introduction of a myriad of chemical functionalities in their structures, MOFs have gained popularity for applications in many fields such …

1. Influence Of Metal Ions And Solvents On The Photo-Generation Of Reactive Oxygen Species In Mesoporous Silicate Embedded Porphyrins 2.Water-Soluble Rhodium(Iii) Porphyrin Complex For The Biological Inactivation Of Fentanyl, Hemant Pal

Theses and Dissertations

Porphyrins are differentiated π-conjugated compounds with unique photochemical and redox properties. The tetrapyrrole macrocycle core of porphyrins is extremely favorable for the complexation of metal ions, resulting in hybrid metal-organic molecules with good catalytic properties. Porphyrin-based systems are known for their oxidative properties and are frequently utilized as bio-mimicking catalysts and environmental remediation agents. My current research aims at both of these aspects. One of the most efficient methods to create photocatalytic systems with outstanding features and applicability is the use of porphyrins on supported solid materials. A series of novel mesoporous silicate-embedded metalloporphyrins were prepared via conjugation of novel …

Bacterial-Mediated Photocatalytic Organic Oxidation, Peter J. Pellegrinelli

Theses and Dissertations

Bacteria, though well-known and widespread in scientific application, have plenty more opportunity to grow in the field of organic synthesis. The primary objective of this project was to apply the use of bioluminescent bacteria in an organic photoredox reaction intending to use the bacteria as a renewable source of light. This sustainable method, as opposed to high wattage bulbs, paves a green pathway for organic photocatalytic reactions. Using bioluminescent E. coli, the focus was on performing organic oxidation reactions with a recyclable photocatalyst. When using bacteria in conjunction with chemicals like nitromethane, it was an obstacle to keep the E. …

Sustainable Approaches To Photo-, Thermo-, And Electro-Chemical Reactions Of Amines, James David Sitter

Theses and Dissertations

In recent years, sustainable routes for chemical synthesis have garnered renewed interest. As the world continues to fight pollution and rising costs, it is imperative that new routes of synthesis that continuously fight the issues of pollution and waste are discovered, defined and explored. While traditional synthesis routes that require energy input typically require the burning of fossil fuels to produce heat, the amount of resources that go into the production of these fossil fuels and the sequestration of its waste to minimize its impact on the carbon footprint is enormous. Furthermore, sustainable chemistry research aims to decrease and minimize …

Structural And Immunological Characterization Of Inhaled Allergens And Their Complexes With Antibodies, Kriti Khatri

Theses and Dissertations

Allergy is an outcome of an allergen-antibody reaction (1). Potent airborne allergens from dust mites and pets are major causative factors for allergic conditions among predisposed individuals. Group-2 allergen Der p 2 from Dermatophagoides pteronyssinus is a major allergen which causes allergic conditions in more than 80% of mite-allergic subjects (2). Similarly, airborne allergen Can f 1 from dog (Canis familiaris) is also a major risk allergen which affects 10-20% of the population worldwide (3). Considering the increasing prevalence of inhalant allergens in the environment, antigenic characterization is crucial for improving allergy diagnostics and management. This study focuses …

The Kinetic Control Of Polymer Micelles; Chemical Functionality, Material Interactions, And Equilibration, Taylor Larison

Theses and Dissertations

Polymer micelles have found significant uses in areas such as, energy storage devices, catalysis, opto-electronics, drug-delivery, oil additives, and nanoreactors. In many of these applications the overall micelle size (aggregation number) and chemical functionalization determines performance. To progress towards more advanced materials synthesized from the facile bottom-up approach with polymeric micelles the implementation and study of thermodynamic handles were investigated. Here the kinetic control of micelles was studied across a range of applications; independent control over micelle functionality, the spatial orientation of multiple metal oxide nanoparticles in mesoporous materials via self-assembly, and the use of small-angle neutron scattering (SANS) to …

Reactive End Capped Polybenzimidazole Oligomers For High Temperature Thermosets And Improved Membranes For Electrochemical Devices, Caroline Marie Rohlfing

Theses and Dissertations

Polybenzimidazoles (PBI) are heterocyclic polymers that possess high thermal and oxidative stability. The inherent strength and chemical and thermal stability of PBI make it ideal for use in extreme environments; however, the current processing of PBI molded parts makes the process practically and economically unfavorable. These intrinsic properties make PBIs of particular interest for many industrial applications, varying from fabrics to membrane materials to molded parts. Processing these molded parts is extremely difficult, as the high glass transition temperature and extremely high melting point (>500°C) of PBI result in poor flow properties of PBI resins even at high temperatures. …

Evaluation Of A Radium-Thorium Disequilibrium Sediment Method Used To Model And Assess Porewater And Submarine Groundwater Exchange In The Coastal Marsh, Madeline R. Bodine

Theses and Dissertations

Ground, pore, and surface water exchange has been extensively studied in beach and near shore environments but has been long neglected in saltmarsh systems due to their complexity. Saltmarsh systems are of particular importance as they are the interface between fresh and saltwater. Saltmarshes impact carbon exchange, release and sequestration, and they process particulate matter. Understanding the characteristics of a marsh system such as the nutrient and particulate loads in conjunction with the flux of water exchange through the marsh provides a deeper understanding of these systems and can impact our understanding of the global water and carbon cycles, as …

Engineering Of Bio-Based And Synthetic Polymers: Synthesis And Application In Superabsorbent Materials And Antibacterial Agents, Jihyeon Hwang

Theses and Dissertations

A polymer consists of a large number of monomer units, which can be obtained naturally or via a chemical process called polymerization. Polymers are important materials that are used in our daily life. Life would not be possible without these polymers, either from plant biomass or petroleum-derived synthetic polymers. The substitution of petroleum-derived to biomass-based polymers has been highlighted to mitigate adverse environmental impact. However, the use of bio-based polymers is still a significant challenge for more demanding applications. In this dissertation work, the engineering of both bio-based and synthetic polymers and their properties are investigated.

In Chapter 1, the …

Coordination Environment And Thermodynamics Of Colloidal Quantum Dots In Polar Solvents, Nuwanthaka Prasad Jayaweera Millaniyage

Theses and Dissertations

Colloidal semiconductor quantum dots (QDs) have been extensively investigated due to their attractive properties such as size-tunable absorption and emission spectra, large molar extinction coefficients, and significant photostability. These properties make them promising candidates for optoelectronic, photocatalytic, and biomedical applications. Common synthetic procedures of QDs produce nanocrystals capped with long-chain fatty acid derivatives which are stabilized in high boiling point solvents. Especially for bioimaging applications, the exchange of these native hydrophobic ligands with hydrophilic ligands should be performed, while preserving the smaller hydrodynamic radius. The coordination environment and thermodynamic parameters of the ligand exchanges should be carefully investigated to engineer …

Biochemical, Structural, And Immunological Characterization Of Selected Panallergens, Andrea Leigh O'Malley

Theses and Dissertations

Allergies throughout the world are increasing in prevalence and severity. Although the direct causes of the development of allergies are not confirmed, study of proteins that cause reactions will lead to a deeper understanding of allergy. This work focuses on three panallergen families, profilins, parvalbumins, and arginine kinases, to further elucidate the background of allergy from the point of view of the allergens themselves. In Chapter 1, we evaluate pollen, fruit, and mite profilins in the context of allergy, showing the relevance of conserved cysteine residues in stability and oligomerization as well as the first data on cross-reactivity between plant …

Structure Property Investigation And Applications Of Self-Assembled Triphenylamine Bis Urea Macrocycles, Md Faizul Islam

Theses and Dissertations

Porous organic crystals can be advantageous as nanoreactors and in sensing, separations, and storage. The Shimizu group utilizes bifurcated urea hydrogen bonding to direct the assembly small building block into pillars and columns affording functional porous crystals. Recently, our group has examined the incorporation of triphenylamines within the framework of bis-urea macrocycles. These macrocycles assemble into columns that contain the solvent of crystallization bound within the channels. Heating the crystals leads to removal of the solvent and activates the host for guest exchange by single-crystal-to-single[1]crystal transformations. Different electron accepting molecules can be encapsulated inside the pore of the host …

Molecular Devices For Measuring Weak Solvophobic Interactions And The Development Of Pedagogical Tools For Organic Chemistry Students, Alexander N. Manzewitsch

Theses and Dissertations

The main topics of this dissertation are: 1) the development and discussion of a new molecular balance for measuring alkyl-alkyl interactions in a wide array of organic solvents, 2) the development of linear solvation energy relationships between solvent interaction parameters and solvent accessible surface area (SASA) in CH-arene interactions, and 3) the development of online resources for helping undergraduate students perform organic chemistry mechanisms problems well.

The solvophobic effect, that is the forced association between two solutes due to intermolecular attraction of the solvent molecules, is ubiquitous in organic chemistry and responsible for many significant phenomena thereof. However, there is …

Surface And Alloy Engineering Of Halide Perovskite (Cspbx3) Nanocrystals For Efficient And Stable Optoelectronics, Sakiru L. Abiodun

Theses and Dissertations

Organic and inorganic halide perovskite quantum dots (QDs) (in form of ABX₃, where A is organic cation e.g CH₃NH₃⁺ or inorganic cation e.g Cs⁺) have emerged as an intriguing alternative to the widely studied chalcogenide and pnictide QDs. Their excellent optoelectronic properties such as large absorption coefficient, high carrier mobility, wide color gamut, long electron-hole diffusion lengths, and tunable bandgap energy are largely responsible for their wide acceptability in various electronic devices. However, despite this enthusiasm, the problem of purification, long-term stability, lead toxicity and inadequate knowledge of their surface chemistry still …

Vaccinia Virus And Measles Virus As Oncolytic Vaccines: The Modulation Of The Viral Infectivity Via Surface Conjugations, Monchupa Kingsak

Theses and Dissertations

Oncolytic virus (OV) therapy has been shown to be an effective targeted cancer therapy treatment in recent years, providing an avenue of treatment that poses no damage to surrounding healthy tissues. Not only do OVs cause direct oncolysis, but they also amplify both innate and adaptive immune responses generating long-term antitumor immunity. However, a key challenge facing oncolytic virotherapy is neutralizing antibodies in vaccinated patients, leading to the viral clearance after systemic administration and failure in the treatment. The encapsulation of OVs using biocompatible polymers is one of the promising methods to prevent the viral clearance from antiviral immune responses. …

Expanding Tailorable Nanomaterial Synthesis With Persistent Micelle Templates, Eric R. Williams

Theses and Dissertations

The control of block polymer micelle dimensions while in solution is critical for a range of emerging applications in diverse fields from drug delivery and nanoreactors to use as sacrificial templates for porous nanomaterials. When under kinetic control, micelles will maintain a constant average size and thus aggregation number (N_agg) through the suppression of chain exchange mechanisms. Such kinetic control effectively enables the decoupling of micelle dimensions from solution conditions. In other words, kinetically trapped micelles can resist reorganizations brough about by e.g., the addition of metal nanoparticles. However, such micelles are traditionally governed by a fickle �� …

Preparation And Characterization Of Salvia Triloba Extract And Evaluation Of Its Cytotoxic Effect On Bone Cancer Cell Line, Basma Hossam Abdelmonem

Theses and Dissertations

Background: Osteosarcoma is a tumor of mesenchymal origin characterized by uncontrolled production of immature osteoid tissue. It is more common in children and adults over the age of 65. Many studies reported the cytotoxic effect of many plant extracts, including Salvia triloba, on different cancer cell lines when used alone or in combination with other chemotherapeutic agents.

Methods: In our study, the methanolic extract obtained from the air-dried leaves of Salvia triloba leaves from Palestine was screened for its total phenolic and flavonoid contents. The major components of phenolics and flavonoids were detected using LC-QToF-MS technique. The two phenolics …

Polyethersulfone Thin-Film Nanocomposite Membrane Embedded With Amine-Functionalized Graphene Oxide For Desalination Applications, Ahmed Bahaeldin

Theses and Dissertations

Thin-film nanocomposite (TFN) desalination membranes were prepared based on a polyethersulfone (PES) support, where the polyamide (PA) layer was embedded with amine-functionalized graphene oxide (GO). The effect of adding various concentrations of functionalized and un-functionalized GO on the desalination performance, hydrophilicity, and morphology of the membranes was additionally assessed throughout this work. Scanning electron microscopy (SEM) measurements were used to assess the morphology of the membranes in combination with Brunauer-Emmett-Teller (BET) analysis. Contact angle measurements were used to gauge the hydrophilicity of the synthesized membranes. The membrane with the best desalination performance contained 1x10^-3 wt/vol% of functionalized GO in …

Waste-Derived Hybrid Nanocomposite For The Simultaneous Removal Of Antibiotics And Dyes From Water Bodies, Abdelkader Ahmed

Theses and Dissertations

A novel eco-friendly approach was used to synthesize a hydroxyapatite-carbon nanocomposite (HAP-C) by utilizing the industrial waste of cement kiln dust (CKD) as a source of calcium for the synthesis. Citric acid was first used to chelate the calcium from CKD, then the chelate was converted into a mixture of calcium carbonate and carbon by calcination at 450°C for 1 h. The mixture was used as a precursor for the synthesis of HAP-C by reacting it with ortho-phosphoric acid via a precipitation method. HAP-C was then calcined at different temperatures of 400, 500, and 700°C under inert atmosphere, with a …

Carbon Dioxide Capture Potential Of Chitosan-Nanocrystalline Cellulose Aerogel Composite Materials: Synthesis, Functionalization, And Characterization, Victor Oghenekohwo

Theses and Dissertations

The carbon dioxide capture technology has been established as an invaluable player in the current global efforts to allay the warming of the planet and climate change. In this connection, the study centers on the valorization of waste organic materials for the application described herein. The sorbents, sourced from a combination of by-products of food processing and agricultural residue waste products, viz. seafood waste and sugarcane bagasse, showed prospects for selective carbon dioxide capture, adsorbing up to 5.78 mg/g of the gas at 273 K and 2.82 mg/g at 298 K, as observed on the Micromeritic ASAP 2020 surface area …

Adsorption Of Antibiotics In Wastewater By Stevia Rebaudiana Zinc Oxide Nanoparticles, Hania Guirguis

Theses and Dissertations

Green zinc oxide nanoparticles (ZnO NPs), synthesized using Stevia rebaudiana extract, are investigated as novel adsorbents for the removal of the antibiotics ciprofloxacin (CIP) and tetracycline (TET) from water. The green ZnO NPs were synthesized using a novel, rapid and ecofriendly technique that utilized a natural source with high sugar content as a reducing agent and a less energy intensive approach that did not require annealing or calcination at high temperatures. The particles are mesoporous, with a hexagonal wurtzite structure, a BET surface area of 15.28 m2/g and a size range of 37.36-71.33 nm. At pH 5, the green ZnO …

Phytochemical Screening, Chemical Composition And Antimicrobial Activities Of Ethanol, Methanol And Chloroform Extracts From The Leaves Of Digitaria Sanguinalis, Digitaria Ischaemum And The Bark Of Carapa Guianensis Found In Guyana, South America., Rajendra Kumar Khelawan

Theses and Dissertations

Chloroform, Ethanol and Methanol extracts of the leaves from DIGITARIA SANGUINALIS, DIGITARIA ISCHAEMUM and the bark from CARAPA GUIANENSIS found in Guyana were obtained via maceration and reflux extraction processes. Ethanol extracts obtained from the 25-minute reflux process produced the best percentage yield and the most thin layer chromatographic spots. All further analyses were conducted on the ethanol extracts of all plant materials. The ethanolic extracts showed positive phytochemical testing results for Terpenes, Flavonoids, Steroids, Tannins, Phenolic, Proteins, Cardiac Glycoside, Reducing Sugars, and Carbohydrates. Conversely, Saponins were absent in Smooth Crabgrass and Crabwood’s bark but present in Long Hairy Crabgrass. …

Synthesis And Characterization Of Mixed Ligand Complexes Of Ruthenium(Ii) Containing 2,2’-Bipyridine And 3,3’-Dimethyl-1,1’- Methylenebisimidazolium Ligands; A New Synthetic Approach, Matthew Schneider

Theses and Dissertations

Research into solar cells has been prioritized given the global demand for better renewable energy technologies. This demand is a result of the long-term use of fossil fuels, which generates significant pollution in highly populated urban areas. One potential solar cell technology is the dye-sensitized solar cell (DSSC). This kind of solar technology utilizes organometallic dyes to expand the types of wavelengths solar cells can use to generate electricity.12 Ruthenium(II) metal complexes of this type have been investigated heavily for this purpose.13,14,36 The main reasoning behind this is the metal-to-ligand charge-transfer (MLCT) phenomenon that such complexes exhibit. MLCT has often …

Molecular Organic Photovoltaic Cells And Applications, Julie Liu

Theses and Dissertations

The absorption, light scattering, and anti-Stoke’s fluorescence of chlorophyll and closely related sodium copper chlorophyllin were examined in various solutions with a wide range of refractive index and permittivity. It was evident that radiative photo electron decay corresponded to low permittivity solvents, but not to solvent refractive index. Additionally, non-radiative decay was dominant in high permittivity solvents. The properties suggest evolution has provided plants with an ability to redirect light to the chlorophyll in the high permittivity (water) photosynthesis center. Exploratory solar cells exploiting lifetime switching were developed and tested, wherein strong photovoltaic response was exhibited, along with the unique …