Chemistry Commons^™

Design And Synthesis Of Polymer-Based Advanced Nanomaterials Using Raft Polymerization And Click Reaction, Junting Li

Theses and Dissertations

This research focuses on exploring new synthetic approaches to prepare polymer-based advanced nanomaterials using highly efficient chemical tools, such as reversible addition-fragmentation chain transfer (RAFT) polymerization and click reactions.

In the first project, novel synthetic routes to produce fullerene-based polymers were designed. First, mono-alkynyl functionalized fullerene was prepared starting with pristine fullerene (C₆₀). Methyl methacrylate and 6-azido hexyl methacrylate were then randomly copolymerized via RAFT polymerization with well-controlled molecular weights and copolymer compositions. Finally, the two moieties were covalently assembled into a series of well-defined side-chain fullerene polymers (SFP's) via the copper-catalyzed click reaction. The TGA and UV-vis …

Thermal Infrared Imaging: Instrumentation And Method Development, Wayne O'Brien

Theses and Dissertations

A recently development thermal infrared camera system was improved by designing new components to downsize physical aspect and improve the instrument's performance. A new thermal infrared light source was developed and characterized. It is designed from a custom-made Macor backpiece that holds an alumina screw. High resistance wire is coiled around the screw. The coiled wire is covered with an alumina coating. Most light sources have a spectral emissivity similar to that of a blackbody emitter. This source has a spectral irradiance profile that is not similar to a blackbody source. Thus, the lamp has an improved efficiency in the …

Iridium-Ruthenium/Osmium-Gold Cluster Complexes: Unique Structures And Properties, Qiang Zhang

Theses and Dissertations

Chapter Two

The first Ir-Ru cluster complex was synthesized was the electron-rich, anionic, planar cluster complex [PPN][IrRu6(CO)23], 2.5, (PPN=Bis(triphenylphophoranylidene)-ammonium) which obtained from the reaction of [PPN][IrRu3(CO)13] with one equivalent ruthenium carbonyl (Ru3(CO)12) at 66 oC (THF reflux) for 12h. Compound 2.5 could also be synthesized by using the mono-Iridium compound [PPN][Ir(CO)4] reacts with two equivalent of ruthenium carbonyl. In compound 2.5, all seven metal atoms lie in a plane (max deviation = 0.043(1) Å) with the iridium atom in the center circumscribed by a hexagonal ring of six ruthenium atoms. The anion 2.5 contains 104 valence electrons while both the …

Study Of Porous, Crystalline Supramolecular Boronates, Vincenzo Michael Disantis

Theses and Dissertations

Porous materials with the ability to selectively absorb volatile organic compounds are of high interest for applications in sensing, sequestration and separations. Utilizing the covalent yet reversible boronate ester bonds between boronic acids and diols in conjunction with dative boron-nitrogen coordination bonds has allowed for the discovery of a new class of porous materials. Preliminary results show the ability to obtain porous, crystalline supramolecular boronate networks from the coordination of diamine linkers with boronate diester backbones. Further exploration of porous, crystalline supramolecular boronates has revealed the discovery of a porous crystalline coordination polymer that exhibits reversible, selective guest adsorption properties …

Plant Virus Based Materials For Cell Alignment And Differentiation, Elizabeth Balizan

Theses and Dissertations

This research focused on developing and using plant virus based scaffolds to understand substrate control over cell alignment and differentiation. The first part of this work centered on development of virus based patterns that were then used to align and elongate aortic smooth muscle cells (SMCs). Virus patterns were generated in capillary tubes via a simple drying method. Three experimental parameters were used to control pattern formation: (1) protein concentration, (2) salt concentration, and (3) hydrophobicity of the pre-deposition surface. By controlling these parameters several aspects of the final virus patterns were controlled. First, virus orientation was controlled. Patterns were …

New Bimetallic Iridium Cluster Carbonyl Complexes, Mingwei Chen

Theses and Dissertations

Platinum group metal derived bimetallic clusters have been used as precursors to nanoscale catalysts which have been proven to be more effective than their monometallic counterparts. Iridium is a platinum group metal and its applications in catalysis continue to grow. To take advantages of synergies between mixed-metals, we modified iridium clusters with other metal ligands like tin, germanium, and group IB (gold, silver, copper) etc. and obtained a fairly large amount of new iridium derived bimetallic clusters which could be precursors to catalysts with superior properties than that available nowadays. The reaction of Ir4(CO)12 with Ph3SnOH in the presence of …

Programmable Polymers Preparation Optimization And Applications On Solute Templates, Yinyan He

Theses and Dissertations

Programmable polymer is a type of stimuli-responsive polymer which can keep their induced properties after removal of the stimulu, as well as programmable polymers maintain the general properties as stimuli-responsive polymers, such as recognize and respond to the stimulus. The previous reported solvent Caryl-Nimide bonds based programmable polymers (SPP-1) can freely rotate and change the carboxylic acid recognition group orientation in response to templates. Solvent templates were used in the SPP-1. One potential application for SPPs is using their recognition and memory properties for the identification and separation of mixture solutions of various analytes. In my first project, I wanted …

Biomaterial-Induced Osteogenesis Of Mesenchymal Stem Cells By Surface Roughness And Functionalization, Pongkwan Sitasuwan

Theses and Dissertations

For tissue engineering and regenerative medicine, it is important to understand factors directing the stem cell fate, including self-renewal, proliferation, differentiation, and apoptosis. Bone marrow derived mesenchymal stem cells (BMSCs) have the potential to differentiate into osteoblasts, chondrocytes, adipocytes, and smooth muscle cells. Specifically, in the field of bone tissue engineering, BMSCs are commonly used for in vitro osteogenesis studies. However the mechanisms and signaling pathways that these cells recognize material surface and utilize to differentiate are still unclear. This dissertation focuses on investigating the effect of surface nanotopography and functionalization on the promotion of osteogenic differentiation of BMSCs. Surface …

Structural And Photoluminescent Characterization Of Substituted A3mo4f (A = Sr, Ba, Ca; M = Al, Ga, In, Si And Ge), Robert Lenwood Green

Theses and Dissertations

In this dissertation, the structure and photoluminescent properties of A3MO4F-type materials (A = Sr, Ba, Ca; M =Al, Ga, In, Si, Ge) are studied as potential phosphors for compact fluorescent lamps (CFLs) and phosphor converted light emitting diode (pc LED) lights. Chapter 1 outlines background information of the evolution of lighting technology as well as detailing the synthesis, structural characterization and photoluminescence measurements. Chapter 2 focuses on the changes that the Sr3AlO4F structure undergoes as a result of exposure to a 5% H2/95% Ar atmosphere. High-resolution neutron powder diffraction is used to probe for minute structural changes. Chapter 3 is …

Functional Block Copolymers For Applications In Advanced Materials, Energy Storage, And Lithography, Christopher George Hardy

Theses and Dissertations

Block copolymers spontaneously self-assembly into a wide variety of ordered nanostructures on the length scale of 5 - 100 nm due to the thermodynamic immiscibility between the covalently linked, chemically distinct polymer chains. Incorporating desirable functional groups into block copolymer systems can lead to confinement of the functional group to a specific domain upon microphase separation of the block copolymer. The resulting materials display desirable characteristics of the functional group in a well-ordered nanostructure. Such systems have been utilized in a wide variety of applications including catalysis, ceramic materials, and membranes. This dissertation is focused on the synthesis, characterization, self-assembly …

Renewable Bio-Based Polymers And Degradable Functional Polymers, Kejian Yao

Theses and Dissertations

In this dissertation, polymers derived from renewable bio-based resources and degradable functional polymers with stimuli-responsive properties by various polymerization techniques were investigated. The properties of these polymeric materials were characterized and discussed.

In Chapter 1, the overall background and recent development of renewable bio-based polymers as well as degradable stimuli-responsive polymers was introduced. Major research objectives of my doctoral work were described.

The first section of the dissertation, on the preparation of renewable bio-based polymers was provided from Chapter 2 to Chapter 4. In Chapter 2, the preparation of novel polymers derived from renewable gum rosin by atom transfer radical …