Chemistry Commons^™

Ruthenium-Based Olefin Metathesis Catalysts Bearing Ph-Responsive Ligands: External Control Of Catalyst Solubility And Activity, Shawna Lynn Balof

Dissertations

Sixteen novel, Ru-based olefin metathesis catalysts bearing pH responsive ligands were synthesized. The pH-responsive groups employed with these catalysts included dimethylamino (NMe₂) modified NHC ligands as well as N-donor dimethylaminopyridine (DMAP) and 3-(o-pyridyl)propylidene ligands. These pH-responsive ligands provided the means by which the solubility and/or activity profiles of the catalysts produced could be controlled via acid addition. The main goal of this dissertation was to design catalyst systems capable of performing ring opening metathesis (ROMP) and ring closing metathesis (RCM) reactions in both organic and aqueous media.

In an effort to quickly gain access to new …

Adsorbents With Chemically Bonded Saccharide Surfaces: Synthesis And Application For Stereoisomer Separation And The Synthesis Of Chiral Porous Silicas Using Templates Chiral Surfactant, Edwin Vega

Seton Hall University Dissertations and Theses (ETDs)

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Photopolymerized Thiol-Ene Networks For Gas Barrier And Membrane Applications, Luke Kwisnek

Dissertations

Gas transport and free volume properties of photopolymerized thiol-ene networks for various applications are reported. For basic, commercially-available thiol-ene formulations, oxygen permeation was strictly dependent on the difference between T_test (room temperature for this work) and network T_g. Networks with T_g near T_test demonstrated the lowest values of permeability, diffusivity, and solubility. A robust, high-barrier network was selected for further modification. New networks with embedded functionality were formed using a two-step approach. Thio-Michael addition of a tetrathiol to monofunctional acrylates formed new functional thiol monomers. These functional thiols were combined with an isocyanurate-based triene and …

Synthesis And Characterization Of 4,4-Prime-Distyrylbiphenyl And Its Applications In Organic Field Effect Transistors, Nestor A. Santos Jr.

Theses and Dissertations - UTB/UTPA

4,4’-distyrylbiphenyl (DSBP), an ambipolar small molecule with electroluminescent properties, was synthesized following two synthetic protocols. Accordingly, biphenyl was bromomethylated using a mixture of paraformaldehyde and hydrogen bromide in 20% to 60% isolated yields. Bromomethylated biphenyl was then reacted with triphenyl phosphine, or with triethyl phosphate to yield the corresponding triphenyl phosphonium bromide or triethyl phosphonate, respectively. DSBP was synthesized by reaction of the triphenyl phosphonium bromide or triethyl phosphonate with freshly distilled benzaldehyde according to the Wittig, or Horner-Wadsworth-Emmons protocols. DSBP from the Wittig reaction resulted in a mixture of cis-trans isomers, while the product from the Horner-Wadsworth-Emmons reaction yielded …

Biocompatibility Of Electrospun Polymer Nanofibers (Epns) With Nih 3t3 Cell Line And Interaction Of Quercetin With Different Flavonoids: Induction Of Phase Ii Enzymes In Vitro Cancer Cell Lines, Brenda S. Benavides

Theses and Dissertations - UTB/UTPA

Part I: In this study Electrospun nanofibers, Elasthane™ 55D, Elasthane™ 75D, Biospan®, Hydrothane™ and Lycra® were evaluated for their biocompatibility to be artificial tissue substitutes using NIH-3T3 fibroblast cells. A colorimetric based MTT dye reduction assay demonstrated that EPNs did not stop cell growth in vitro. Additionally, fluorescence confocal microscope images verified that cell adhesion occurred in the nanofibers, and cell growth on the EPNs over two weeks period was confirmed by DNA quantification.

Part II: This section of the thesis is focused on evaluation of chemopreventive properties of various phytochemicals by induction of Phase II enzymes. The interaction of …

Modification And Evaluation Of Fuel Cell Membranes, Amol Prataprao Nalawade

Dissertations

The primary goals of this study were modification of existing Nafion^® membranes and characterization of newly developed hydrocarbon-based membranes for high temperature fuel cell applications. Various Nafion^®/silicate nanocomposites were formulated via in situ sol-gel reactions for tetraethylorthosilicate. Different silicate composition profiles generated across membrane cross-sections were investigated by EDAX/ESEM. Composite water uptake, proton conductivity and fuel cell performance were comparable to that of unmodified Nafion^®. Tafel analysis showed better electrode kinetics for composites having more silicate in the middle and less or no silicate at electrolyte-electrode interfaces. All composites showed reduced fuel cross-over and superior …

Sensitive Detection Of High Explosives Using Electrogenerated Chemiluminescence, Suman Parajuli

Dissertations

The core of this dissertation lies in the search of analytical tools which can be used to detect and quantify the high explosives confiscated from suspects in transportation hubs and from soil and water bodies where these explosives pose a greater threat to public health and safety. High explosives, namely, hexamethylene triperoxide diamine (HMTD), triacetone triperoxide (TATP), trinitrotoluene (TNT), and pentaerythritol tetranitrate (PETN), were detected and quantified by electrochemical methods such as electrogenerated chemiluminescence (ECL) and cyclic voltammetry (CV).

Sensitive detection and quantification of HMTD, one commonly used explosive by terrorists, was presented first in this dissertation on the basis …

Symmetry-Based Techniques For Qualitative Understanding Of Rovibrational Effects In Spherical-Top Molecular Spectra And Dynamics, Justin Chadwick Mitchell

Graduate Theses and Dissertations

Using light to probe the structure of matter is as natural as opening our eyes. Modern physics and chemistry have turned this art into a rich science, measuring the delicate interactions possible at the molecular level.

Perhaps the most commonly used tool in computational spectroscopy is that of matrix diagonalization. While this is invaluable for calculating everything from molecular structure and energy levels to dipole moments and dynamics, the process of numerical diagonalization is an opaque one. This work applies symmetry and semi-classical techniques to elucidate numerical spectral analysis for high-symmetry molecules.

Semi-classical techniques, such as the Potential Energy Surfaces, …

Folate Receptor-Targeted Delivery Of Small Interfering Rna To Cancer Cells, Yilin Zhang

Dissertations

The vitamin folic acid (folate, FA) has been extensively explored as a targeting ligand to deliver a variety of diagnostic/prognostic/therapeutic agents into various tumors through the assistance of its receptor – the folate receptor (FR). FR is over-expressed in many types of human cancer and can mediate internalization of FA-conjugates through an endocytic pathway. The discovery of small interfering RNA (siRNA), which is cable of inducing potent gene silencing in a sequence-specific manner, provides an excellent molecular tool to suppress aberrant gene expression in malignancies, and therefore siRNA has the potential to revolutionize cancer therapeutics. Towards the goal of developing …

The Influence Of Nanoporous Crystalline Structure On Low Molecular Weight Mass Transport In Syndiotactic Polystyrene, Justin Paul Brandt

Dissertations

Solid-state structure, crystalline morphology, crystallization kinetics, thermal, free volume, and gas transport properties of semicrystalline syndiotactic polystyrene (sPS) and ethylene vinyl alcohol copolymers (EVOH) have been investigated. Solid-state structure of sPS after crystallization from the melt and glassy state was examined by differential scanning calorimetry (DSC), density and wide angle x-ray diffraction analysis (WAXD). The measurements confirmed low density of syndiotactic polystyrene crystalline forms, which in the case of α and δe was smaller and in the case of β and γ crystalline forms was slightly larger than the density of the glassy amorphous sPS. Positron annihilation lifetime spectroscopy (PALS) …

Spectral Reflectance As An Indicator Of Foliar Concentrations Of Arsenic In Common Sunflower (Helianthus Annuus), Yuridia Patricia Peralta De Gandy

Theses and Dissertations - UTB/UTPA

Studies were conducted to investigate the use of spectral reflectance by foliage of common sunflower as a potential indicator of arsenic contamination of soil. Germination method was developed for sunflower seeds, and cohorts of sunflower seedlings in hydroponic tanks were established. The cohorts were exposed to 0 ppm, 5 ppm, 7.5 ppm, and 10 ppm treatments of As (V) and reflectance measurements of foliage were collected using a spectroradiometer during two experiments.Results demonstrated the feasibility of using spectral reflectance by foliage of common sunflower as a potential indicator of arsenic contamination. In both experiments, arsenic concentrations in leaf tissues were …

Synthesis And Electrical Properties Of Functional Block Copolymer/Inorganic Nanocomposite Materials, Hongying Chen

Dissertations

Sulfonated poly[styrene-b-ethylene-co-butylene-b-styrene] (sSEBS) block copolymers/inorganic nanocomposite materials were synthesized via in situ formation of inorganic fillers and characterized particularly for their dielectric properties and proton conductivities.

In preparation of sSEBS/SrTiO₃ nanocomposites, titanium (IV) isopropoxide [Ti(OPrⁱ)₄] complex was diffused into sSEBS film, followed by subsequent hydrolysis of [Ti(OPr i)4], diffusion of strontium cations in sSEBS domains, and in situ formation of crystalline SrTiO₃. sSEBS with sulfonation degree of 38.1% and 65.0% were employed, and relevant sSEBS/SrTiO₃ composites contain SrTiO₃ of 10-15 wt%. Elemental composition characterization with ESEM/EDX indicated uniform distribution of …

Study On Energy Absorption Behaviors Of Hydrophobic Mesoporous Materials, Zhongyuan Sun

Theses and Dissertations - UTB/UTPA

Nanoporous energy absorption system has been developed tremendously as an advanced energy storage system in recent years. This research is to optimize the mesoporous energy absorption matrixes via surface treatment to find out the optimum conditions for higher energy conversion efficiency. Five mesoporous silica matrixes with pore size in a range of 3 to 31.6 nm were investigated. Six alkylchlorosilanes were used as the modification reagents. The results showed that the energy absorption density via pressure-induced infiltration is as high as 8.0 J/g which is 100 times larger than that of conventional energy absorption materials. The controllability of the energy …

A Synthetic Approach Toward Novel Β-Lactams, Mohamed Hashim

Theses and Dissertations - UTB/UTPA

β-lactam antibiotics which is a class by itself, covers a wide range of antibiotics that includes penicillin, penicillin derivatives, cephalosporins, carbapenems, and any antibiotic agent that contains a 2-azetidinone ring.[2] In recent past research it has been established that β-lactams show therapeutic and anticancer activity with low toxicity. [2] It has also been reported by our lab that N-chrysenyl and N-phenanthrenyl 3-acetoxy-4-aryl-2- azetidinone can exhibit potent selective anticancer activity towards prostate, colon, pancreatic cancer and leukemia at low concentrations, all of this was revealed by means of a structure activity study. [2] The goal of our research is the synthesis …

Trace Analysis Of Volatile Organic Compounds In The Water Of The Arroyo Colorado And The Lower Laguna Madre Utilizing E.P.A.Sw846 Method 8260, Humberto Valdez

Theses and Dissertations - UTB/UTPA

Volatile organic compounds (VOC) can cause a major environmental concern since they create a hazard to public health and the environment. This study focused on determining concentration of VOCs in Arroyo Colorado waters and the Lower Laguna Madre (LLM) utilizing GC/MS. Little is known on the concentration and composition of VOCs. Toluene was the most common VOC. Concentrations ranged from 0.0010 mg/L to 0.0039 mg/L. Analysis of a sediment pore water sample collected near the mouth of the Arroyo Colorado also detected toluene (0.0023 mg/L). This study showed that VOCs were concentrated near the county boat launch and somewhat downstream. …

A Proposal For The Mechanism Of The Iron-Ascorbate, Fenton, And Hydroxyl Radical-Quenching Series, Jonathan Velasco

Theses and Dissertations - UTB/UTPA

The Fenton reaction between [Fe(II)] and [HOOH] is observed in the presence of ascorbic acid, [AscH-], during [Fe(III)] and HO• reduction; this is done as part of consecutive redox reactions between [Fe(III)] and [Fe(II)]. As a result, the rate orders with respect to [Fe(III)], ascorbic acid, and [HOOH] are of (approximately) 2nd, 1st, and 4 th order, respectively. However, the rate constants for each reaction in this study show patterns when measured against solution pH; empirically, reactions proceed faster at smaller pH and vice versa.

Hydrophobic Silicas With Well-Defined Chemistry And Geometry: Synthesis, Adsorption, And Interfacial Properties, Francis Bernardoni

Seton Hall University Dissertations and Theses (ETDs)

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Molecular Dynamics Simulations Of Human Quadruplexes In K+ Solution And The Role Of The Carboxyl Terminus Of Bacteriorhodopsin In Protein Stability, Farah Rezae

Seton Hall University Dissertations and Theses (ETDs)

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Synthesis Of Novel Glycosylidene-Based Quinolines, Peter H. Dobbelaar

Seton Hall University Dissertations and Theses (ETDs)

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Utilizing Concept Mapping As A Teaching And Learning Tool To Prepare For The Science Taks Test, Rosa Linda Zuniga

Theses and Dissertations - UTB/UTPA

Concept mapping was used with Donna High School students to determine its effect on the Texas Assessment of Knowledge and Skills (TAKS) test. Concept mapping was used with models such as the Sheltered Instruction Observation Protocol model (SIOP), the 5- E model, and the Learning Groups model. This measure was taken because the models used have not helped students improve their TAKS scores significantly. The findings of this research reveals that using the process of concept mapping together with the SIOP model helps students clearly see related concepts and motivates them to think more deeply. Students quickly realize what concepts …

Effects Of Adding An Enhanced Material Instructional Model To A Collaborative Grouping Instructional Strategy In A College Preparatory Chemistry Course, Chinyere Fidelia Shaw-Nnajiofor

Theses and Dissertations - UTB/UTPA

This research study investigated comparable academic achievement outcomes between an experimental group (EG) and a control group (CG) in a college preparatory chemistry course using a mixture of instructional pedagogies. The subjects comprised native and non-native English speakers, often identified as Limited English Proficiency (LEP) students. The study found no statistically significant difference between the pre-test scores of EG and CG students and a significant difference between the post-test scores of students in the experimental group compared to those of the control group. No significant difference was observed when comparing the test scores of the post-tests of the LEP-EG students …

Synthesis And Characterization Of Two Metal-Organic Frameworks, Roxanna Schaffino Moore

Theses and Dissertations - UTB/UTPA

Herein, the design and synthesis of two metal-organic frameworks, Zn 4O(FMA)3 (FMA = fumaric acid) and Zn2(CNC) 2(DPT) (CNC = 4-carboxycinnamic acid; DPT = 3,6-Di-4-pyridy1-1,2,4,5-tetrazine) via solvothermal methods are reported. Zn4O(FMA)3 was isolated as light yellow cubic crystals and Zn2(CNC)2(DPT) as light pink-block shaped crystals. The structures of both MOFs were characterized by single X-ray diffraction. Integrity of both MOFs were determined via powder X-ray diffraction and thermal gravimetric analysis. Zn4O(FMA) 3 is an isoreticular MOF exhibiting 6.8 Å pores taking up 5.2 wt % of hydrogen gas at 40 bar and 77K. Zn2(CNC)2(DPT) is a 3D primative cubic net …

Completing Chemistry Taks Objective 4(9d): The Effect Of Flash Animation, Judith B. Dano

Theses and Dissertations - UTB/UTPA

This study examines the effect of flash animation on learning effectiveness. The main goal of the study was to verify if using flash animation on learning chemistry concepts particularly Chemistry TAKS Objective 4 (9D) will have an impact on students learning achievement. The subjects in this study were 10th grade students from PSJA Memorial High School. Two class sections were randomly assigned as the treatment group each with 20 subjects (n=40) and another two class sections were assigned as the control group (n=40). The treatment group was exposed to flash animation while the control group had the traditional lecture type …

Electrospinning Polystyrene Reinforced With Multi-Walled Carbon Nanotubes: Parameters For Obtaining Nanofibers With Enhanced Thermal Properties, Ana Veronica Rodriguez Ybarra

Theses and Dissertations - UTB/UTPA

Various concentrations of multi-walled carbon nanotubes (MWCNTs) were dispersed in a polystyrene matrix in order to determine the optimal MWCNT concentration that would enhance the thermal properties of the composite. The MWCNTs were dispersed in the polystyrene matrix by high energy sonication and then electrospun. The microstructural characterization such as fiber diameter, fiber orientation, fiber morphology, porosity, cross-section shape, and surface roughness of the nanofibers electrospun from these composites were made by scanning electron microscopy and transmission electron microscopy. Spectroscopic characterization for these nanofibers was conducted using Fourier Transform infrared spectroscopy and Raman spectroscopy was utilized to establish a nanotube/matrix …

The Effect Of Adsorbent Geometry And Surface Chemistry On Hplc Retention, Zhaoxia Liu

Seton Hall University Dissertations and Theses (ETDs)

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Synthesis And Evaluation Of Cyclopropanated Carbohydrates For Cns Disorders, Jaime Talisman

Seton Hall University Dissertations and Theses (ETDs)

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Synthesis And Characterization Of Arylmethyl Sulfone Dendrimers And Hyperbranched Poly (Phenylene Sulfide) / Poly (Sulfone), Qiuxia Zhao

Seton Hall University Dissertations and Theses (ETDs)

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Studies Toward Improving The Reactivity And Chemoselectivity Of Chloroarenes In Palladium-Catalyzed Cross-Coupling Processes, Joseph P. Simeone

Seton Hall University Dissertations and Theses (ETDs)

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The Biophysical Analysis Of The Human Telomeric Repeat (Ttaggg)4 And Characterization Of Porphyrin Binding In Potassium Solutions, Cosimo Antonacci

Seton Hall University Dissertations and Theses (ETDs)

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Understanding Charged Aerosol Detection With High Performance Liquid Chromatography, Brian John Forsatz

Seton Hall University Dissertations and Theses (ETDs)

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