Chemistry Commons^™

Synthesis And Characterization Of 4,6-Protected Glucosamine Derivatives And Branched Glycoconjugates, Jonathan Bietsch

Chemistry & Biochemistry Theses & Dissertations

Low molecular weight gelators (LMWGs) are small molecules that self-assemble in appropriate solvents to form three dimensional networks that immobilize the solvent, creating a supramolecular gel. The self-assembly of LMWGs occurs through non-covalent interactions such as hydrogen bonding, aromatic interactions, donor-acceptor interactions, Van der Waals interactions, hydrophobic forces, halogen bonding, etc. Due to self-assembly occurring through reversible non-covalent interactions, supramolecular gels can undergo a gel to solution transformation. Because of this, these materials can be sensitive to external stimuli such as temperature changes, pH changes, and other stimuli that effect non-covalent interactions. This makes the synthesis of LMWG’s an appealing …

The Development Of Novel Carbohydrate-Based Gelators And Their Applications As Advanced Soft Materials, Joedian Morris

Chemistry & Biochemistry Theses & Dissertations

Low molecular weight gelators (LMWGs) are attractive molecules that have been explored extensively due to their practical applications in many disciplines. These small molecules self-assemble forming solid-like gels via three-dimensional cross-linked networks with the solvent as the key component within the matrix. Carbohydrate-based LMWGs are small molecules that can form solid-like gels in water, organic solvents, and aqueous solutions. They have great potential to be utilized in different applications because carbohydrates are biocompatible and can be made from easily accessible and renewable resources. Designing gelators is still a challenge within the field, even though researchers have developed tools to predict …

Synthesis, Characterization, Spectroscopic, And Mesomorphic Studies Of New Schiff Base Ligands And Titanium, Cobalt, Nickel And Copper Metal Centers, Raj K. Gurung

Chemistry & Biochemistry Theses & Dissertations

Transition metal complexes with Schiff base ligands offer a wide application in the field of development of catalysis and material. The straightforward synthesis allowed the structural modification and helped to optimize in various application of such complexes. Titanium-containing complexes have been reported to be important for their catalytic and material applications through the coordination of a tetradentate Schiff base ligand, viz. N, N’-ethylene bis(salicylideneiminate) dianion (salen). Studies reporting the characterization of achiral titanium(IV) salen complexes are scarce due to their intricate nature. Such complexes would be comparatively less expensive and easier to prepare synthetically and thus could represent an …

A Dual Nanostructured Approach To Sers Amenable To Large-Scale Production, Kory Brian Castro

Chemistry & Biochemistry Theses & Dissertations

A SERS device was made using a dual-nanostructured surface comprised of silver nanoparticle and silver nanowires. The ability of each nanostructure to produce a uniform surface was characterized and the surface-enhanced Raman scattering (SERS) response of the resulting surfaces were examined using the reporter molecule 4-aminothiolphenol (ATP) and a 638 nm excitation laser.

A synthetic method was developed to produce silver nanowires with lengths of ~20 μm and diameters of ~100 nm with a narrow size distribution. The method utilized a simple, one-pot synthesis that is amenable to large-scale production. A selective precipitation method was used to the isolate the …

Development And Evaluation Of Post-Production Oxygenation Techniques For The Augmentation Of Biochar, Matthew David Huff

Chemistry & Biochemistry Theses & Dissertations

Biochar is the carbon rich solid by-product of biomass pyrolysis. Interest in biochar can be broken down to several main categories: use as a carbon sequestration agent, use as a medium for the removal via adsorption of unwanted materials in wastewater, and as a soil amendment for the increase of cation exchange capacity (CEC). In order to generate a biochar which is stable enough for carbon sequestration, higher temperature pyrolysis must be used in order to ensure a lower O:C ratio in order to increase the half-life of biochar in soil. This dissertation addresses the evaluation of biochars made from …

Multidentate Resorcinarene Surfactants For The Phase Transfer Of Metal Nanoparticles And Nanodiamonds: Applications In Catalysis And Diamond Film Growth, Vara Prasad Sheela

Chemistry & Biochemistry Theses & Dissertations

One main objective of the present work is to functionalize cuboctahedral platinum nanoparticles with various multidentate resorcinarene surfactants and study their influence in determining their catalytic activity. We hypothesized that catalytically active and recyclable catalysts can be achieved by incomplete yet strong passivation of the nanoparticle surfaces by using multidentate resorcinarene surfactants. We have developed phase transfer protocols for functionalizing cuboctahedral platinum nanoparticles with resorcinarene thiol or amine. Fluorescence assay confirmed that both these nanoparticles contained almost comparable unpassivated metal area. The activity of such phase transferred nanoparticles was tested in the catalytic hydrogenation of allyl alcohol. The conversion of …

Thermal Characterization Of Carbon Monoxide Oxidation Catalysts Using Thermogravimetric Analysts And Differential Scanning Calorimetry, Rene A. Bartgis

Chemistry & Biochemistry Theses & Dissertations

Catalysts composed of platinum and/or palladium on tin (IV) oxide supports, with and without silica gel, as well as catalysts composed of gold on manganese oxide, have been developed for the recombination of carbon monoxide and oxygen to form carbon dioxide for use in carbon dioxide lasers. A thermogravimetric method and a differential scanning calorimetric method have been developed for the thermal characterization of these catalysts. The mass loss data and the enthalpy changes determined as the catalysts lost water were then related to existing activity data for these catalysts. No relationship was found between the thermal data and the …