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Polymer Chemistry Commons

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Design Of Hybrid Conjugated Polymer Materials: 1) Novel Inorganic/Organic Hybrid Semiconductors And 2) Surface Modification Via Grafting Approaches, Joseph J. Peterson 2012 University of Massachusetts Amherst

Design Of Hybrid Conjugated Polymer Materials: 1) Novel Inorganic/Organic Hybrid Semiconductors And 2) Surface Modification Via Grafting Approaches, Joseph J. Peterson

Open Access Dissertations

The research presented in this dissertation focuses on the design and synthesis of novel hybrid conjugated polymer materials using two different approaches: 1) inorganic/organic hybrid semiconductors through the incorporation of carboranes into the polymer structure and 2) the modification of surfaces with conjugated polymers via grafting approaches. Hybrid conjugated polymeric materials, which are materials or systems in which conjugated polymers are chemically integrated with non-traditional structures or surfaces, have the potential to harness useful properties from both components of the material to help overcome hurdles in their practical realization in polymer-based devices. This work is centered around the synthetic ...


Preparation And Rapid Analysis Of Antibacterial Silver, Copper And Zinc Doped Sol–Gel Surfaces, Brendan Duffy, Swarna Jaiswal, Patrick McHale 2012 Technological University Dublin

Preparation And Rapid Analysis Of Antibacterial Silver, Copper And Zinc Doped Sol–Gel Surfaces, Brendan Duffy, Swarna Jaiswal, Patrick Mchale

Articles

The colonisation of clinical and industrial surfaces with microorganisms, including antibiotic-resistant strains, has promoted increased research into the development of effective antibacterial and antifouling coatings. This study describes the preparation of metal nitrate (Ag, Cu, Zn) doped methyltriethoxysilane (MTEOS) coatings and the rapid assessment of their antibacterial activity using polyproylene microtitre plates. Microtitre plate wells were coated with different volumes of liquid sol–gel and cured under various conditions. Curing parameters were analysed by thermogravimetric analysis (TGA) and visual examination. The optimum curing conditions were determined to be 50–70C using a volume of 200ul. The coated wells were challenged ...


Synthesis, Characterization And Nonlinear Optical Properties Of Silver/Pva Nanocomposites, mahdi shahmiri 2012 university putra malaysia

Synthesis, Characterization And Nonlinear Optical Properties Of Silver/Pva Nanocomposites, Mahdi Shahmiri

mahdi shahmiri

Silver/polyvinyl alcohol (PVA) nanocomposites are prepared via quick precipitation method, using hydrazine as a reducing agent. Preparing of silver/PVA nanocomposites by this method is done for the first time. The samples are characterized by Uv-Visible spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM). Nonlinear optical properties are carried out by Z-scan technique using a blue CW laser beam operated at wavelength 405 nm. It is shown that the synthesized samples have negative nonlinear refractive index and the magnitude is in the order of 10􀀀8. The nonlinear refractive index increases as amount of reducing agent increases.


Design, Synthesis, Processing, And Thermal Analysis Of Nanocomposites With Tunable Properties, Mu Seong Kim 2012 University of South Florida

Design, Synthesis, Processing, And Thermal Analysis Of Nanocomposites With Tunable Properties, Mu Seong Kim

Graduate Theses and Dissertations

Polymer composites containing nanosized fillers have generated explosive interest since the early 1980's. Many recent studies have been conducted incorporating nano-fillers into polymer matrices to design and synthesize materials with tunable mechanical, thermal, and optical properties. Conventional filled polymers, where the reinforcement is on the order of microns, have been replaced by composites with discrete nanosized fillers. Gradually, theories that predicted that composite properties are independent of particle size in the micron range were challenged by nanocomposites. Rather, nanocomposite properties are greatly influenced by the surface area of the. All of this is complicated by the fact that nanoparticles ...


Synthesis And Self-Assembly Of Polymeric Hybrid Nanomaterials, Amanda C. Kamps 2012 University of Pennsylvania

Synthesis And Self-Assembly Of Polymeric Hybrid Nanomaterials, Amanda C. Kamps

Publicly Accessible Penn Dissertations

The ability to construct functional polymeric hybrid nanomaterials is critically important for many applications. In this thesis I present the synthesis of amphiphilic polymers of various compositions including insulating coil-coil, semiconducting rod-coil, semiconducting brush-coil, and bioconjugated rod-coil polymers. The self-assembly of these polymers is presented along with methodologies for controlling the organization of nanomaterials and polymers towards the construction of functional hybrid materials with controllable structures and properties.

In this thesis, an analysis of the conditions necessary to stabilize the cooperative self-assembly of nanoparticles and amphiphilic block copolymers into a unique cavity-like structure is presented. This work reveals the mechanism ...


Rheology And Application Of Thermoreversible Polymer Networks Based On The Diels-Alder Cycloaddition, Richard James Sheridan 2012 University of Colorado at Boulder

Rheology And Application Of Thermoreversible Polymer Networks Based On The Diels-Alder Cycloaddition, Richard James Sheridan

Chemical & Biological Engineering Graduate Theses & Dissertations

A model thermoreversible network based on the Diels-Alder cycloaddition reaction was synthesized. These materials exhibit extreme changes in material properties near a critical temperature. The model network was used to test theoretical predictions of viscoelasticity near this critical temperature. The resulting data supported the theory and allowed for the description of the complex process of stress relaxation in transient networks to be written in terms of a simple linear scaling relationship. To use the scaling relationship, we revisited earlier work on externally triggered healing, in which the thermal reactivity of the material could be activated by self-limited RF hysteresis heating ...


Fundamental Characterization Of Photodegradable Hydrogels: Spatiotemporal Control Of The Cellular Microenvironment, Mark William Tibbitt 2012 University of Colorado at Boulder

Fundamental Characterization Of Photodegradable Hydrogels: Spatiotemporal Control Of The Cellular Microenvironment, Mark William Tibbitt

Chemical & Biological Engineering Graduate Theses & Dissertations

Synthetic hydrogels are an attractive class of materials for the design of well-defined cell culture platforms to better understand how cells receive and integrate signals present in the extracellular environment. Within this class, responsive hydrogels have emerged to investigate questions as to how cells sense and respond to dynamic changes in the mechanical and biochemical nature of the cell niche. To complement this growing body of research, this thesis aimed to develop photoresponsive, synthetic hydrogels that enable experimenters to explore how spatiotemporally varying cues from the extracellular matric influence biological function in real time. Specifically, cytocompatible, chain and step polymerized ...


Polymers Used In Medicine: Common Types And Benefits Of Drug Delivery Systems, Camille Andrews 2012 Parkland College

Polymers Used In Medicine: Common Types And Benefits Of Drug Delivery Systems, Camille Andrews

Natural Sciences Poster Sessions

This poster describes the common types and benefits of drug delivery systems.


Sustainability Through Blockcopolymers: Novel Ion Exchange Cathode Membranes And Soybean Oil Based Thermoplastic Elastomers, Nacú Bernardo Hernández-Cantú 2012 Iowa State University

Sustainability Through Blockcopolymers: Novel Ion Exchange Cathode Membranes And Soybean Oil Based Thermoplastic Elastomers, Nacú Bernardo Hernández-Cantú

Graduate Theses and Dissertations

This work studies the sustainable use of blockcopolymers (BCPs) in aims to reduce dependency in oil. This work focused on the design and development of new materials that can provide "green" substitutes to petroleum based products. Our two main areas of interest are: alternative power sources, more specifically polymer electrolyte fuel cells (PEFCs), and the synthesis of vegetable oil based thermoplastic elastomers. Research on PEFCs focused on developing a new cathode catalyst layer membrane comprised of a mesoporous block copolymeric nanocomposite that will satisfy (1) electrical conductivity, (2) proton conductivity, (3) oxygen transport in, (4) and water transport out via ...


Romp-Based Thermosetting Polymers From Modified Castor Oil With Various Cross-Linking Agents, Rui Ding 2012 Iowa State University

Romp-Based Thermosetting Polymers From Modified Castor Oil With Various Cross-Linking Agents, Rui Ding

Graduate Theses and Dissertations

Polymers derived from bio-renewable resources are finding an increase in global demand. In addition, polymers with distinctive functionalities are required in certain advanced fields, such as aerospace and civil engineering. In an attempt to meet both these needs, the goal of this work aims to develop a range of bio-based thermosetting matrix polymers for potential applications in multifunctional composites. Ring-opening metathesis polymerization (ROMP), which recently has been explored as a powerful method in polymer chemistry, was employed as a unique pathway to polymerize agricultural oil-based reactants.

Specifically, a novel norbornyl-functionalized castor oil alcohol (NCA) was investigated to polymerize different cross-linking ...


Learning From "Coffee Rings": Ordered Structures Enabled By Controlled Evaporative Self-Assembly, Wei Han 2012 Iowa State University

Learning From "Coffee Rings": Ordered Structures Enabled By Controlled Evaporative Self-Assembly, Wei Han

Graduate Theses and Dissertations

Drying droplets containing nonvolatile solutes (polymers, microspheres, nanoparticles, single-walled carbon nanotubes, DNA, etc.) on a solid surface have been utilized to yield self-assembled, dissipative structures, possessing dimensions of a few hundred submicrons and beyond. However, these dissipative structures created via evaporation are often irregular and far from equilibrium. Yet for many applications in microelectronics, data storage devices, and biotechnology, it is highly desirable to achieve surface patterns that have a well-controlled spatial arrangement. To date, only a few elegant studies have centered on establishing a means of harnessing the drying process of an evaporating droplet to produce highly regular structures ...


Developing Benzobisazole-Containing Conjugated Polymers For Semiconducting Applications, Jeremy Joseph Intemann 2012 Iowa State University

Developing Benzobisazole-Containing Conjugated Polymers For Semiconducting Applications, Jeremy Joseph Intemann

Graduate Theses and Dissertations

Benzobisazoles are electron deficient moieties whose polymers are known to possess high thermal and mechanical strength. To date, howeverm they have not been well developed for semiconducting applications due to their poor solubility in organic solvents and an inability to functionalize these materials. This thesis describes the synthesis and properties of a variety of new benzobisazole-containing conjugated polymers and reports their performance in organic light-emitting diodes. The new polymers are soluble in common organic solvents and have been synthetically tuned to possess a wide variety of properties by copolymerizing benzobisazole with an assortment of different comonomers. Furthermore, the first examples ...


Hydrophilic Polymers Of Poly (2-Hydroxy Ethyl Methacrylate) With Tunable Properties For Drug Release, Sequestration Of Blistering Agent, Preparation Of Ultra-Strong Hydrogels & Thermal Stability Of Various Organic Azides, Ramakanth Ananthoji 2012 University of South Florida

Hydrophilic Polymers Of Poly (2-Hydroxy Ethyl Methacrylate) With Tunable Properties For Drug Release, Sequestration Of Blistering Agent, Preparation Of Ultra-Strong Hydrogels & Thermal Stability Of Various Organic Azides, Ramakanth Ananthoji

Graduate Theses and Dissertations

The design and synthesis of new finely tunable porous materials has spurred interest in developing novel uses in a variety of systems. Zeolites, inorganic materials with high thermal and mechanical stability, in particular, have been widely examined for use in applications such as catalysis, ion exchange and separation. A relatively new class of inorganic-organic hybrid materials known as metal-organic frameworks (MOFs) has recently surfaced, and many have exhibited their efficiency in potential applications such as ion exchange and drug delivery. A more recent development is the design and synthesis of a subclass of MOFs based on zeolite topologies (i.e ...


Nanoscale Toughness And Behavior Of Graphene/Epoxy Interfaces, Nima Rahbar, Hossein Salahshoor 2011 Worcester Polytechnic Institute

Nanoscale Toughness And Behavior Of Graphene/Epoxy Interfaces, Nima Rahbar, Hossein Salahshoor

Nima Rahbar

Atomistic simulations are performed to investigate the nano-scale interfacial fracture toughness between graphene and epoxy. Nano-mechanical properties of graphene and epoxy are initially studied using molecular dynamics simulations. A novel method is suggested to accurately model the behavior of the graphen/epoxy interface during the curing process of the epoxy as a function of temperature. The computed interfacial fracture energy is computed at about 0.203 J/m2, which is in good agreement with available experimental data. It is also shown that the adhesion between cured epoxy and graphene layer increases the pre-existing waviness of the 2-dimensional graphene sheet in ...


Synthesis Of An Antimicrobial Textile Coating, William M. Morris 2011 California Polytechnic State University, San Luis Obispo

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 ...


Physical And Electrical Properties Of Trimetallic Nitride Template Endohedral Metallofullerenes And Their Polymer Nanocomposites, Hanaa Mohammed Ahmed 2011 University of Southern Mississippi

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 ...


Synthesis And Characterization Of Acceptor: Donor Block Copolymers For Organic Photovoltaics, Brandon Cory Achord 2011 University of Southern Mississippi

Synthesis And Characterization Of Acceptor: Donor Block Copolymers For Organic Photovoltaics, Brandon Cory Achord

Dissertations

Mankind needs sources of clean power. Photovoltaic (PV) cells, in use since 1839, have proven reliable and practical for certain applications. PV cell efficiency has changed over the years from 1-2% to ultra-high efficiency cells operating at efficiencies greater than 40%. Organic photovoltaics are a potential transformative technology platform. The potential for cell use, efficiency and cost are all parts of the research and development focus at the time this document was written. This research was initiated with a focus on the synthesis and understanding of the variables effecting acceptor-donor block copolymer. The self-assembled morphology resulting from varying volume ratios ...


Effects Of Molecular Architecture On Fluid Ingress Behavior Of Glassy Polymer Networks, Matthew Blaine Jackson 2011 University of Southern Mississippi

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 Studies Of Various Polymeric Systems Using Positron Annihilation And Pvt-Eos Analyses, Mukul Kaushik 2011 University of Southern Mississippi

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 ...


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 2011 University of Southern Mississippi

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 ...


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