Chemistry Commons^™

Chemical Modification On Gold Slides To Gain Better Control Of Patterning Techniques, Ragini Vuppalapati

Masters Theses & Specialist Projects

Nanolithography is a rapidly evolving field that requires new combinations of techniques to improve patterning and to assist in fabricating electromechanical devices. An increasing number of applications require surfaces with defined regions of different chemical functionality. In our previous project optimum conditions for lithographic patterning were determined and potential blockers were identified to reduce force on the tip.

This work is focused on identifying good chemical modifications that will allow better control of basic patterning and to investigate the minimum force of patterning required while using each chemical system. The primary aim is to gain better control of basic pattern …

Physical And Electrical Properties Of Trimetallic Nitride Template Endohedral Metallofullerenes And Their Polymer Nanocomposites, Hanaa Mohammed Ahmed

Dissertations

The main objective of this study was characterization of pure metallic nitride fullerene, MNF, and MNF containing polymers to evaluate these materials as suitable devices for tunable applications. Polymer-fullerene nanocomposites consisting of linear polyurethane (PU) segments crosslinked via polyhydroxylated fullerenes (C₆₀ and Sc₃N@C₈₀, a metallic nitride fullerene) were prepared and characterized for their mechanical and dielectric properties using dynamic mechanical analysis (DMA) and broadband dielectric spectroscopic techniques. Polyhydroxylated fullerenes C₆₀(OH)₂₉ and Sc₃N@C₈₀(OH)₁₈ were synthesized in a high yield through a solid-state high sheer ball-milling procedure and were …

Adhesion And Durability Of Coatings On Polypropylene Exterior Sidings, Logan Riekio Stark

Master's Theses

Plastics have become a universal material for use in a myriad of commercial and consumer products. One such product, exterior siding, is the focus of this project. Although siding products were originally made from wood, vinyl siding, which offered superior performance, was introduced in the 1950’s. More recently, polypropylene (PP) siding has been introduced; PP provides a stronger product, which allows for deeper patterns and better edge detailing. PP siding, compared to traditional wood siding, doesn’t warp, crack, or degrade as easily with extended exposure to the elements, and is cheaper to maintain. However, even plastic siding must be coated. …

Synthesis Of An Antimicrobial Textile Coating, William M. Morris

Chemistry and Biochemistry

A titania nanosol was synthesized and coated onto nylon/cotton blended textile substrates. The substrates were characterized via SEM for adhesion and nanoparticle formation, then subjected to antimicrobial efficacy tests. The titania nanosol was successfully coated on to textiles samples. Particles were observed to be around 2 by 3 micrometers and formed between the interstitial space of textile fibers. Although larger than typical nanoparticles, the coatings exhibited what seemed to be antimicrobial activity. Titania nanosol coated textile samples were subjected to Kirby Bauer Assay in the presence of S. aureus. The coated textile sample exhibited an inhibition of growth around its …

The Investigation Of Asphaltene-Naphithenic Acid And Asphaltene-Surface Interactions, David Tristan Heaps

Dissertations

Asphaltenes represent a ubiquitous problem in the oil industry due to their adverse effects on recovery, production, and processing equipment. These problems have affected oil companies throughout the world, resulting in significant financial losses. In order to expand the existing body of knowledge related to asphaltenes, we have examined how the presence of naphthenic acids contributes to the particle aggregation and sedimentation behavior of asphaltene suspensions as well as how the physics and chemistry of a substrate affect asphaltene adsorption/deposition.

The flocculation of asphaltenes in the presence of naphthenic acids was investigated using dynamic light scattering (DLS), near-infrared spectroscopy (NIR), …

Development And Utilization Of Digital Image Correlation Techniques For The Study Of Structural Isomerism Effects On Strain Development In Epoxy Network Glasses, Stephen Robert Heinz

Dissertations

The specific aim of this dissertation is to present the findings regarding the effects of molecular structure on macroscopic mechanical performance and strain development in epoxy networks. Network molecular structure was altered through monomer isomerism and crosslink density/molecular weight between crosslinks. The use of structural isomerism provided a pathway for altering mechanical performance while maintaining identical chemical composition within the network. Isomerism was investigated primarily by the curing of diglycidyl ether of bisphenol A (DGEBA) using either the para- or meta-substituted derivatives of diaminodiphenyl sulfone (DDS). Additional insights into isomerism were gained through the investigation of networks composed of either …

Opacity Of P(Mma-Maa)-Pmma Composite Latex System With Varying Maa Concentration, Gilbert U. Yu, Jerry T. Dy, Erwin P. Enriquez

Chemistry Faculty Publications

Polymer composites of core-shell morphology are commonly used in the paint industry as opacity enhancer. These are usually made of block copolymer systems wherein the core is formed from a polymer that swells in the presence of a solvent and surrounded by a high glass transition polymeric shell. Thus, upon drying, the swollen regions turn into voids while leaving a hard shell. Here, composites based on poly(methyl methacrylate-butyl acrylate) [P(MMA-BuA)] (seed stage), poly(methyl methacrylate-methacrylic acid) [P(MMA-MAA)] (second stage), and poly(methyl methacrylate) [PMMA] (third stage) were synthesized through a multistage sequential emulsion polymerization and their opacity was investigated. The second stage …

Effects Of Molecular Architecture On Fluid Ingress Behavior Of Glassy Polymer Networks, Matthew Blaine Jackson

Dissertations

This manuscript demonstrates the synthesis of glassy polymer network isomers to control morphological variations and study solvent ingress behavior independent of chemical affinity. Well-controlled network architectures with varying free volume average hole-sizes have been shown to substantially influence solvent ingress within glassy polymer networks. Bisphenol-A diglycidyl ether (DGEBA), bisphenol-F diglycidyl ether (DGEBF), Triglycidyl p-aminophenol (pAP, MY0510), Triglycidyl maminophenol (mAP, MY0610), and tetraglydicyl-4,4’-diamino-diphenyl methane (TGDDM, MY721) were cured with 3,3’- and 4,4’-diaminodiphenyl sulfone (DDS) at a stoichiometric ratio of 1:1 oxirane to amine active hydrogen to generate a series of network architectures with an average free volume hole-size (V_h) …

Free Volume Studies Of Various Polymeric Systems Using Positron Annihilation And Pvt-Eos Analyses, Mukul Kaushik

Dissertations

The glass transition phenomenon and free volume behavior below and above the glass transition temperature of various polymeric systems have been investigated. Several novel polymeric systems were considered for this study. Two generations of hyperbranched polyols, H40 and H20, were selected due to large number of hydroxyl groups on the periphery and within the bulk. The effect of hydrogen bonds and molecular weight was related with the glass transition and free volume behavior for the whole range of experimental temperature. The free volume behavior was experimentally studied using PVT and PALS to determine occupied volume, fractional free volume and number …

Design Of Covalently Dynamic Films And Coatings: Analysis Of Biocatalyzed Kinetic Behavior In Soft Condensed Matter, Pirro Cipi

Dissertations

Reversibly adjusting surface and bulk properties of materials is advantageous to many applications and will vastly expand current polymer capabilities. A novel strategy was developed to render materials capable of “smart” surface and bulk properties with the aid of embedded biocatalyst and latent functional groups that are selectively activated in the presence of biocatalyst to undergo chemical transformation. The research presented herein focused on systematically characterizing the activity of lipase catalysts embedded in poly (alkyl methacrylate)s simultaneously with functionalized components, either as diffusing within the polymeric matrix or tethered to the matrix. Lipase activity, ester forming (synthetic) or ester breaking …

Computational Studies Of Ion Transport In Polymer Electrolytes, Hui Wu

Doctoral Dissertations

Improving ionic conductivity and lithium mobility in polymer electrolytes is important for their practical use for battery electrolytes. In this study, a combination of molecular dynamics and Monte Carlo simulations was used to bring insight into lithium ion transport in poly(ethylene oxide) (PEO) with plasticizers and also next to alumina solid surface doped with lithium salt. The simulations were performed using a moderately high molecular weight polymer (Mn = 10,000 g/mol) at an EO:Li ratio of 15. For the plasticized system, the PEO with LiN(CF3SO 2)2 (LiTFSI) was mixed with 10 wt% plasticizers that included either cyclic ethylene carbonate …

Wetting Properties Induced In Nano-Composite Poss-Ma Polymer Films By Atomic Layer Deposited Oxides, Kyle A. Vasquez, Anita J. Vincent-Johnson, W. Chris Hughes, Brian H. Augustine, Kyoungmi Lee, Gregory N. Parsons, Giovanna Scarel

Department of Physics and Astronomy - Faculty Scholarship

Due to their unique properties, nano-composite polyhedral oligomeric silsequioxane (POSS) copolymer films are attractive for various applications. Here we show that their natural hydrophobic character can become hydrophilic when the films are modified by a thin oxide layer, up to 8 nm thick, prepared using atomic layer deposition. A proper choice of the deposition temperature and thickness of the oxide layer are required to achieve this goal. Unlike other polymeric systems, a marked transition to a hydrophilic state is observed with oxide layers deposited at increasing temperatures up to the glass transition temperature (∼110 °C) of the POSS copolymer film. …

Effects Of Ambient Gases On Icf Target Capsules, Bryan Chambers, Steve Letts, Michael Stadermann

STAR Program Research Presentations

We researched how the chemical and physical properties of a plasma polymer fuel capsule change as they are exposed to ambient gases. The fuel capsules contain the deuterium fuel inside them, they serve as the outer shell for the fuel and act as a ablator for the process. If they are reactive or diffusive with the atmosphere this can change their mass and effect the outcome of the fusion shots performed at the National Ignition Facility where High Powered Lasers are incident upon a gold hohlraum containing a capsule. We discovered that nitrogen and water vapor diffuse into the material …

Synthesis And Structure Of A Substituted Pyridazine, Kiranmai Byrichetti

Masters Theses & Specialist Projects

Pyridazines are heterocyclic compounds with an N-N bond in their ring structure. Heterocyclic aromatic compounds are of great interest as a result of their novel properties and commercial applications. Our current research is focused on the potential role of pyridazines in next generation electronic devices that utilize organics as the semiconducting material. The synthesis of 5, 6-fused ring pyridazines beginning from fulvenes (Scheme 1) is described herein. These fused heterocycles will serve as synthetic models and building blocks for potential organic or organometallic conducting polymers.

Our goal was to modify the route of Snyder et al. previously reported for the …

Introduction To Molecular Motion In Polymers (Book Review), Jeffrey H. Glans

Chemistry & Physics Faculty Publications

A book review by Jeffrey H. Glans.

Pethrick, Richard A., T. Amornsakchai, and A. M. North. Introduction to Molecular Motion in Polymers. Dunbeath, Scotland: Whittles Pub.; Boca Raton, FL: Distributed in North America by CRC, 2011.

ISBN 9781849950084

Self-Repairable Polymeric Networks: Synthesis And Network Design, Biswajit Ghosh

Dissertations

This dissertation describes the design, synthesis and development of a new class of polymeric networks that exhibit self-repairing properties under UV exposure. It consists of two parts: (a) modification and synthesis of oxetane (OXE), and oxolane (OXO) substituted chitosan (CHI) macromonomer, and (b) design, and synthesis of self-repairing polyurethane (PUR) networks consisting of modified chitosan. Unmodified CHI consisting of acetamide (-NHCOCH₃), primary hydroxyl (-OH), and amine (-NH₂) functional groups were reacted with OXE or OXO compounds under basic conditions in order to substitute the 1° –OH groups, and at the same time, convert -NHCOCH₃ functionalities …

Precision Synthesis Of Functional Materials Via Raft Polymerization And Click-Type Chemical Reactions, Joel Diez Flores

Dissertations

The need to tailor polymeric architectures with specific physico-chemical properties via the simplest, cleanest, and most efficient synthetic route possible has become the ultimate goal in polymer synthesis. Recent progress in macromolecular science, such as the discoveries of controlled/“living” free radical polymerization (CRP) methods, has brought about synthetic capabilities to prepare (co)polymers with advanced topologies, predetermined molecular weights, narrow molecular weight distributions, and precisely located functional groups. In addition, the establishment of click chemistry has redefined the selected few highly efficient chemical reactions that become highly useful in post-polymerization modification strategies. Hence, the ability to make well-defined topologies afforded by …

The Effects Of Cure Schedule On Properties Of Glass-Fiber Reinforced Epoxy Matrix Composites, Trevor J. Lee

Materials Engineering

Two different two-component resin systems were cured, via Differential Scanning Calorimetry, for the times recommended by their respective manufacturers. The resin cure schedules were designed to simulate typical and attainable processing conditions; they were cured at 120°F, 140°F, and 160°F, and in-mold post-cured at 200°F, 230°F, and 260°F. The resulting scans were then compared to a baseline cure for each resin system, consisting of two heating-cooling cycles at a constant rate of temperature change. These baseline cures were then used to determine the percent cure of each sample and the shift in glass transition temperature between the baseline cure and …

Artificial Muscle Project: Process Development Of Polydimethyl Siloxane Thin Films For Use In Dielectric Electroactive Polymer Artificial Muscle Actuators, Vincent J. Gayotin, Richard W. Morrison, Paul A. Preisser

Materials Engineering

An artificial muscle design was created founded on the principles of a dielectric electroactive polymer (DEAP), which is fundamentally similar to a capacitor. A polydimethyl siloxane (PDMS)-based elastomer, Sylgard 184 from Dow Corning, was chosen for the design and spun coat onto polystyrene (PS) Petri dishes at varying speeds to create a thin film, using speeds of 2000 rpm, 3000 rpm, 4000 rpm, 5000 rpm, and 6000 rpm. The film thicknesses were measured optically through use of a microscope with coupled computer imaging software to generate a characteristic curve of film thickness to spin speed, achieving a minimum film thickness …

Synthesis And Characterization Of Linear And Branched Polylactic Acid For Use In Food Packaging Applications, Kyle C. Bentz

Master's Theses

Polylactic acid (PLA) resins of various molecular weights and molecular weight distributions were synthesized. Linear, narrow molecular weight distribution (MWD) PLA resins were synthesized, as well as resins containing both high molecular weight branched structures and low molecular weight chains and oligomers. Narrow MWD resins were synthesized for use as adhesives for corrugated paperboard and broad MWD resins were synthesized for use as a waterborne coating. PLA resins were dispersed for use as a waterborne coating. Success has been made at forming films utilizing various plasticizers and surfactants as well as polyvinyl alcohol as dispersing agents. A cold dispersion procedure …

The Preparation Of Functional Surfaces, Philip Thomas Dirlam

Master's Theses

Diels-Alder chemistry was utilized to manipulate the surface energy of glass substrates in reversible manner. Glass slides and capillaries were functionalized with hydrophobic dieneophiles resulting in a  non-wetting surface.  A retro Diels-Alder reaction facilitated by the thermal treatment of the surface’s function to cleave the hydrophobic dieneophile and resulted in the fabrication of a hydrophilic surface. Contact angle (CA) measurements were used as preliminary measurements for monitoring the changes in surface energy exhibited during the initial hydrophobic state (CA - 70±3°), after attachment of the dieneophile creating  a hydrophobic state (CA - 101±9°) followed by reestablishment of the hydrophilic state …

Part A: The Use Of Nonionic Associative Polymers For The Thickening And Emulsifying Of Personal Care Products/ Part B: The Synthesis Of A Manganese Sod Mimetic For Reactive Coatings, Mallory Lynn Mcmahon

Master's Theses

Part A

The use of nonionic associative thickeners was proposed for personal care applications.  Various limitations of current rheology modifiers used in personal care were discussed.  Nonionic associative polymers were examined as both thickeners and emulsifiers.  The structure/property relationship for nonionic polymers and their ability to thicken and emulsify were fully examined.  Results showed an increase in thickening efficiency for nonionic associative polymers with higher log(P) (partition coefficient) values.  This was due to the formation of smaller aggregates and increased bridging between aggregates.  The connection between oil polarity, log(P) of the associative polymer, and emulsion stability showed no relationship however; …

Development And Extrapolation Of An Undergraduate Laboratory Experiment To An Elastomeric Spinal Muscular Atrophy Brace, Richard Sterling Brose

Master's Theses

Ever since the advent of polymer science, polyurethanes have played a huge role in the industrial world. They have been used in endless applications from furniture padding to aircraft coatings, to binders for insensitive munitions. It is therefore important that the chemistry of polyurethanes is well understood as well as the ability to draw relationships between the raw materials selected and the end-use properties of the polymer. Because of the multitude of practical applications, the development of an undergraduate polymer chemistry laboratory focused on polyurethane elastomers is developed and described herein. Polymer chemistry students are exposed to hydroxyterminated polybutadiene (HTPB) …

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 …

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 …

Resorbable Polymer-Hydroxyapatite Composites For Bone Trauma Treatment: Synthesis And Properties, Troy E. Wiegand

Department of Chemistry: Dissertations, Theses, and Student Research

Contemporary therapies for hard tissue replacement involve allographs, where the donor and recipient are of the same species, or the use of xenogenic transplants.  Intraspecies materials are often in short supply and interspecies materials are subject to immunological barriers such as disease and tissue rejection.  Synthetic composites are unencumbered by these limitations.  Poly lactic acid (PLLA) and its copolymers have been used in medicine due to their ability to be resorbed by the body without adverse effects.  PLLA’s are currently most commonly used in resorbable sutures and gauzes, but there is increasing interest in using them in conjunction with hydroxyapatite …

Sequencing Of Amine Nucleoside Polymers: Understanding The Fidelity Of Dna-Directed Reductive Amination, Sarah M. Anderson

Honors Student Works

DNA replication is a form of template-directed polymerization that occurs with the aid of numerous enzymes. By developing a DNA replication mimic that can undergo template-directed polymerization without enzymes, the scope of template-directed polymerization will be broadened beyond biological systems. One template-directed polymerization method that has proven successful is reductive amination on a DNA template, a two-step polymerization reaction involving equilibrium imine formation followed by reduction of the imine to the amine. Because DNA-directed reductive amination is an information transfer system, it should proceed with fidelity; however, the extent of fidelity must be explored. These studies will require the ability …

Evaluation Of Stain Blocking Primer Coatings With Low Volatile Organic Compound (Voc) Content And Effects Of Drying Conditions On The Properties Of Water Reducible Coatings For Polypropylene, Megan Alexandra Hart

Master's Theses

The California Air Resources Board (CARB) plans to reduce the volatile organic compound (VOC) limit of specialty primers, sealers, and undercoaters (SPSU), also referred to as stain blocking primers, from 350 g/L to 100 g/L in January of 2012. These coatings are primarily used as stain blocking primers over a variety of substrates, such as wood and drywall. Currently the stain blocking primers that are considered most effective are solvent based primers that contain VOC levels much higher than 100 g/L. The goal of this study is to determine if primers on the market today with a VOC content of …

Micro- And Nanoparticles In Uv-Cured Thin Films, T. Christopher Corkery, Joseph Chan, Mike J. Idacavage, Elizabeth R. Gillies, Paul J. Ragogna

Chemistry Presentations

No abstract provided.

Encapsulation And Release Of Small Molecules From Polymeric Micelles, Monica Boatwright

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.