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Large-Pore Mesoporous Organosilicas And Related Polymer Nanocomposites, Amanpreet Singh Manchanda

Dissertations, Theses, and Capstone Projects

The research work in this dissertation covers the synthesis of mesoporous organosilicas and (organo)silica/polymer nanocomposites. The content can be divided into 4 parts (8 chapters).

The first part of the dissertation is the introduction, which covers the background and progress in the field of mesoporous silicas, periodic mesoporous organosilicas and related inorganic/polymer nanocomposites. The second part of the dissertation (Chapter 2-5) involves the synthesis of mesoporous organosilicas from different organosilane precursors at mild acid concentration (0.1 M HCl) and low temperature (0 or 7 ℃) using Pluronic F127 (EO₁₀₆PO₇₀EO₁₀₆) as a surfactant template. Chapter …

Accessing Medicinally-Relevant Scaffolds Via Organocatalyzed Cascade Reactions, Joshua Hadley Jones

Dissertations, Theses, and Capstone Projects

The field of asymmetric catalysis embodies the efforts of chemists to mimic the stereoselectivity routinely achieved by biological systems. Asymmetric organocatalysis, a sub-field of asymmetric catalysis, is broadly based on the catalytic activity of non-transition metal, small molecules that transmit chirality to substrates. This dissertation describes experimental work towards the construction of versatile, medicinally-relevant molecular scaffolds using chiral, diarylprolinol silyl ether organocatalysts. Specifically, these catalysts were used in 1-pot, iminium-enamine catalyzed cascade reactions to functionalize α,β-unsaturated aldehydes. A comprehensive review of iminium and enamine organocatalysis is provided, including its development towards iminium-enamine cascade reactions. This review provides background for the …

Polymer Pen Printing: A Tool For Studying 2d Enzymatic Lithography And Printing 3d Carbon Features, Zhantong Mao

Dissertations, Theses, and Capstone Projects

Polymer Pen Lithography (PPL) is a promising molecular printing approach which combines the advantages of both microcontact printing (low cost, high-throughput) and the dip pen lithography (DPN) (arbitrary writing, high-resolution) into one cohesive lithography method to create 2 dimensional (2-D) patterns with micro/nano-features on different substrates. The goal of this dissertation is to design and develop a new tool based upon PPL, which is not limited to forming 2D parallel patterns, but can also create 3D complex microstructures, finding applications in both biotechnology and Micro-Electro-Mechanical systems (MEMS) technology. This novel approach is named Polymer Pen Printing. Different from PPL using …

Density Functional Theory For The Investigation Of Transition Metal Complexes: Structure, Binding, And Spectroscopy Of Metal-Siderophores And The Catalase-Peroxidase Enzyme, Bonnie I. Kruft

Dissertations, Theses, and Capstone Projects

Since the development of quantum mechanics in the 1920's and with the introduction of the Schrödinger equation in 1926, various methods to solve the Schrödinger equation have evolved. With advances in these computational methods, we are now able to solve the Schrödinger equation for systems that did not seem possible less than a century ago. Density functional theory (DFT) is a valuable tool for the exploration of the molecular properties of biological systems, and is based upon the theory that the exact energy could be determined from the knowledge of the electron density. The purpose of this dissertation is to …

Studies Toward A General Synthesis Of Poly-Substituted Alpha-Hydroxytropolones, Christine Marie Meck

Dissertations, Theses, and Capstone Projects

Chapter 1: This chapter gives a brief history of α-hydroxytropolones, how they were discovered and unique properties of these substrates. Included is a background on the bioactivity of these substrates in cellular targets such as bacteria, fungi, parasites, tumors and toxicity, as well as their ability to inhibit various metallo-based enzymes. Structure activity relationships studies are reviewed on important metalloenzymes HIV-Reverse Transcriptase (RT) and Inositol monophosphatase (IMPase). Finally the chapter finishes with a synthetic overview of α-hydroxytropolones including natural product targets such as puberulic acid, puberulonic acid, β-thujaplicinol, and β-hydroxytropolone.

Chapter 2: A brief review on β-hydroxy-γ-pyrone based oxidopyrylium cycloadditions …

Zirconium-89: Radiochemistry And Ligand Development Toward Improved Pet Applications, Melissa Ann Deri

Dissertations, Theses, and Capstone Projects

Antibodies are attractive targeting vectors for positron emission tomography (PET) based imaging agents due to their high affinity and selectivity to a variety of biological targets. Creating such imaging agents requires a radionuclide with suitable decay characteristics. This role has been filled by zirconium-89 which has a 78.41 h half-life that ideally matches the multi-day biological half-life of IgG antibodies.

However, the use of a radiometal necessitates the use of a bifunctional chelator to bind the metal and conjugate to the antibody. For ⁸⁹Zr this has been the purview of various derivatives of desferrioxamine B (DFO); however, the observed …

Surface Plasmon And The Effect Of Coupled Resonances In The Enhancement Of Phonon And Molecular Modes In Semiconductors, Syed Islam

Dissertations, Theses, and Capstone Projects

The presence of surface plasmon resonance in semiconductors is not a typical point of discussion in the research community. While the presence of surface plasmon resonance in metals is widely accepted due to the presence of free electrons in conduction bands, the existence of surface plasmon in semiconductors has been generally ruled out due to the absence of free electrons in conduction bands. In this dissertation, we show that semiconductors are able to support surface plasmon in valence band. We also demonstrate, by using the Mie theory, that semiconductor nanoparticles can be designed so that the surface plasmon can be …

Dynamics And Kinetics Of Singlet Oxygen Mediated Oxidation Of Methionine In The Gas Phase, Hydrated Clusters And Solution, Fangwei Liu

Dissertations, Theses, and Capstone Projects

The reaction between methionine (Met) and electronically excited singlet molecular oxygen (O₂[a¹Δ_g]) has been investigated in a systematic fashion, using a home-built electrospray ionization (ESI) guided-ion-beam tandem mass spectrometer (MS). The study started from probing the reaction dynamics between the isolated protonated/deprotonated methionine ions with ¹O₂ in the gas phase, transited through the same systems micro-solvated with explicit water molecules in gaseous hydrated clusters, and concluded with real-time methionine oxidation kinetics determination in aqueous solution. The reaction products, cross sections, and collision energy dependence were measured by ESI-MS. Density functional theory (DFT) …

Wigner High-Electron-Correlation Regime Of Non-Uniform Density Systems: A Quantal-Density-Functional-Theory Study, Douglas Mortimer Achan

Dissertations, Theses, and Capstone Projects

The Wigner regime of a system of electrons in an external field is characterized by a low electron density and a high electron-interaction energy relative to the kinetic energy. The low correlation regime is in turn described by a high electron density and an electron-interaction energy smaller than the kinetic energy. The Wigner regime of a nonuniform electron density system is investigated via quantal density functional theory (QDFT). Within QDFT, the contributions of electron correlations due to the Pauli exclusion principle, Coulomb repulsion, and correlation-kinetic effects are separately delineated and explicitly defined. The nonuniform electron density system studied is that …

Towards The Total Synthesis Of (+/-)-Gephyrotoxin 287c, Maciej E. Domaradzki

Dissertations, Theses, and Capstone Projects

Studies directed toward the total synthesis of (+/-)-Gephyrotoxin 287C are described herein. Even though the target alkaloid has been synthesized four times to date, it still presents an interesting synthetic challenge. Our ultimate goal is to develop an efficient enantioselective synthetic route utilizing oxazolone chemistry in order to demonstrate its utility as a dienophilic component in intramolecular Diels-Alder reactions. This is part of a greater ongoing study aimed at a range of suitable alkaloid targets.

Chapter 1 provides introduction to frog toxins as secondary metabolites and subsequently shifts to the target alkaloid. (+/-)-Gephyrotoxin 287C was originally described by Daly and …

Highly-Selective Chemiresistive Sensing And Analysis Of Vapors Using Functionalized Nanotubes, Deon Hines

Dissertations, Theses, and Capstone Projects

Specifically, the project involves the development of a diversified array of nanostructured gas-sensors comprised of selectively, novel surface-functionalized carbon nanotubes (for analyte selectivity by virtue of functionality). Harnessing carbon nanotubes with various electron withdrawing and donating groups help in determining their affinity toward certain prognostic gaseous markers thus increasing specificity of such created sensors. We have devised synthetic routes that have led to the facile production of covalently polyfunctionalized nanotubes in high yield. Seven carbon nanotube analogues were systematically considered and then chemically synthesized, from pristine single-walled nanotubes (SWNT's), for use as the main component of sensory units that was …

Cationic Amphiphilic Synthetic Macromolecules With Superior Antibacterial Activity, Ashish Punia

Dissertations, Theses, and Capstone Projects

The increasing prevalence of antibiotic resistant bacteria (superbugs) has created a pressing need for new systems of antimicrobial agents. In this dissertation, I report on my extensive research on the design, synthesis, and development of synthetic amphiphilic macromolecules with antimicrobial activity and very low hemolytic impact. Synthetic amphiphilic polymers attack bacteria directly to rupture the cell membrane through electrostatic and hydrophobic interactions. However, the toxicity of such synthetic amphiphilic polymers against mammalian cells have impeded their therapeutic applications. We investigated the systematic structure/activities relationships for antibacterial and hemolytic activities of amphiphilic polyacrylates and poly(vinyl esters). Acrylate homopolymers with various lengths …

Label-Free Detection Of Cancer Cells With Polysilicon Sensor Chips And Biomolecule-Assisted Synthesis Of Shape-Controlled Nanoparticles, Menglu Shi

Dissertations, Theses, and Capstone Projects

Constant effort has been made for the detection of cancer cells. Recently, ovarian and kidney cancer cell lines have been shown to have higher cellular elasticity as compared to normal cells assessed by monitoring the degree of deformation under hyposmotic pressure. This method has been modified and applied to various cases. In cancer cells, the oncogenic mutant p53 (mtp53) protein is present at high levels and contributes to tumor growth and metastasis. Herein the influence of mtp53 on the mechanical property of breast cancer cells was assessed by monitoring the swelling ratio of cells with time using the impedance measurements. …

Biomolecule Mediating Synthesis Of Inorganic Nanoparticles And Their Applications, Zengyan Wei

Dissertations, Theses, and Capstone Projects

Project 1.

The conventional phage display technique focuses on screening peptide sequences that can bind on target substrates, however the selected peptides are not necessary to nucleate and mediate the growth of the target inorganic crystals, and in many cases they only show moderate affinity to the targets. Here we report a novel phage display approach that can directly screen peptides catalytically growing inorganic nanoparticles in aqueous solution at room temperature. In this study, the phage library is incubated with zinc precursor at room temperature. Among random peptide sequences displayed on phages, those phages that can grow zinc oxide (ZnO) …

Synthesis And Characterization Of A Novel Polyacetal & Design And Preparation Of Superhydrophobic Photocatalytic Surfaces, Yuanyuan Zhao

Dissertations, Theses, and Capstone Projects

Polyacetal polymers are thermoplastic resins that play an important role in industry because of numerous industrial applications including automobile; household appliance; etc. The first part of this thesis (Chapter 2) is about the synthesis of a new acetal copolymer that exhibits superior thermal stability. The second part of this thesis (Chapter 3) is about the preparation and applications of TiO₂-based polymer nanocomposite films, where the reactive oxygen species (ROS) are generated on the solid surface. Catalytic nanocomposite films are an active area of research because of their potential uses for environmental remediation and chemical synthesis. Furthermore, to …

Comparing Three Methods For Estimating Ozone Depleting Substance Substitute Greenhouse Gases: Case Study Of The New York City Region, Wallace A. Murray Iii

Theses and Dissertations

This thesis evaluates the United States Environmental Protection Agency (EPA) method for estimating emissions from one source, Ozone Depleting Substances Substitutes (ODS substitutes) by comparing results for the New York City Metropolitan Statistical Area (NYC-MSA) with results from two other methodologies. The EPA’s method utilizes population data and GDP data to estimate and geographically allocate emissions, with little regard for the geographies of industrial activity. The two alternative methods use data for industrial employment and activity to provide results for comparison and perhaps a more accurate accounting and allocation of emissions throughout the NYC-MSA.

Degradation Of Carbon Tetrachloride Using Hydrophobic Green Rust, Sheena Bowman

Dissertations and Theses

Hydrophobic green rusts (GR) were produced using aerial oxidation of solutions containing bis (2-ethylhexyl) sulfosuccinate (BIS) and sodium N-lauroylsarcosinate (SNLS), iron (II) sulfate and sodium hydroxide. The synthesis was conduced at constant pH 8.0±0.1 for the duration of 1-3 hrs. Partition tests showed GRBIS and GRSNLS suspended in the organic phase (tetrachloroethylene). Through X-ray diffraction analysis both GRs exhibit similar patterns to Green Rust II, an inorganic form of GR. The kinetics of GR reductive dechlorination of carbon tetrachloride (CT) was investigated. CT at high concentrations was degraded at high percentages for GRBIS-3, 88.5% and GRSNLS-5, 97.6%. Their reactions were …