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Composition Dependence Of The Flory-Huggins Interaction Parameter In Polymer Blends: Structural And Thermodynamic Calculations, Travis H. Russell 2014 University of Tennessee - Knoxville

Composition Dependence Of The Flory-Huggins Interaction Parameter In Polymer Blends: Structural And Thermodynamic Calculations, Travis H. Russell

Doctoral Dissertations

Flory-Huggins Theory has been the basis for understanding polymer solvent and blended polymer thermodynamics for much of the last 60 years. Within this theory, a parameter (χ) [chi] was included to quantify the enthalpic energy of dispersion between distinct components. Thin film self-assembly of polymer melts and block copolymers depends critically on this parameter, and in application, χ has generally been assumed to be independent of the concentrations of the individual components of the system. However, Small-Angle Neutron Scattering data on isotopic polymer blends, such as polyethylene and deuterated polyethylene, have shown a roughly parabolic concentration dependency for χ. Therefore ...


Modified-Electrodes For Redox-Magnetohydrodynamic (Mhd) Pumping For Microfluidic Applications, Christena Kayl Nash 2014 University of Arkansas, Fayetteville

Modified-Electrodes For Redox-Magnetohydrodynamic (Mhd) Pumping For Microfluidic Applications, Christena Kayl Nash

Theses and Dissertations

A new microfluidic pumping and stirring technique was demonstrated for lab-on-a-chip applications. Microfluidics was accomplished via redox-MHD, which takes advantage of a body force (FB) that is generated when there is a net movement of ions in solution (j) in the presence of a perpendicular magnetic field (B), according to the equation FB = j×B. In this work the movement of ions in solution was generated using electrodes modified with the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) rather than a redox species in solution, which can interfere with analyte detection and with biological species. The monomer solution and ...


Thiol-Michael Addition Polymerization Reactions, Shunsuke Chatani 2014 University of Colorado Boulder

Thiol-Michael Addition Polymerization Reactions, Shunsuke Chatani

Chemistry & Biochemistry Graduate Theses & Dissertations (1986-2018)

This thesis is focused on understanding and implementation of the thiol-Michael addition reaction for controlling polymer structures and properties. The thiol-Michael addition `click' reaction has numerous advantageous characteristics for polymerization reactions, such as having a high reaction rate and yield under mild reaction conditions without the formation of byproducts, starting from a large selection of easily accessible monomers. Firstly, control of the onset of the thiol-Michael addition reaction was achieved by development of two different initiator systems, i.e., a latent initiator (nucleophilic initiator and acid inhibitor) and a photoinitiator (sensitizer, base-tetraphenylborate complex and radical inhibitor). Both initiator systems provided ...


Correlating Molecular Architecture Of A Radical Polymer Based Copolymer With Its Electrical Transport Properties, Holly Chan 2014 Purdue University

Correlating Molecular Architecture Of A Radical Polymer Based Copolymer With Its Electrical Transport Properties, Holly Chan

Open Access Theses

The design and synthesis of electrically-conductive macromolecules can lead to significant improvements in the performance of polymer-based energy conversion devices (e.g., thermoelectric devices). For these organic electronic devices, conjugated polymers have dominated the area of conductive polymers; however, these materials are usually synthesized using conditions that lead to poorly-defined polymers. Furthermore, in these increasingly-standard polymers, the charge transport ability of the polymer thin films is largely affected by the degree of crystallinity, which is a difficult property to control in a reproducible fashion. Therefore, we seek to explore a new class of amorphous, non-conjugated polymers containing a stable radical ...


An Investigation Of Poly(N-Isopropylacrylamide) For Applications With Microfluidic Paper-Based Analytical Devices, Haydn Thomas Mitchell 2014 California Polytechnic State University, San Luis Obispo

An Investigation Of Poly(N-Isopropylacrylamide) For Applications With Microfluidic Paper-Based Analytical Devices, Haydn Thomas Mitchell

Master's Theses and Project Reports

N,N′-methylenebisacrylamide-crosslinked poly(N-isopropylacrylamide), also known as P(NIPAM), was developed as a fluid delivery system for use with microfluidic paper-based analytical devices (microPADs). MicroPADs are postage-stamp-sized devices made out of paper that can be used as platforms for low-cost, simple-to-use point-of-care diagnostic assays. P(NIPAM) is a thermally responsive polymer that absorbs aqueous solutions at room temperature and will expel the solutions to microPADs when heated. The fluid delivery characteristics of P(NIPAM) were assessed, and P(NIPAM) was able to deliver multiple solutions to microPADs in specific sequences or simultaneously in a laminar-flow configuration. P(NIPAM) was ...


Development And Implementation Of Dispersion Phase Diagrams (Dpds) For Four Different Hydrophobically Modified Ethoxylated Urethane (Heur) Based Acrylic Paint Systems, Tyler J. Bell 2014 California Polytechnic State University, San Luis Obispo

Development And Implementation Of Dispersion Phase Diagrams (Dpds) For Four Different Hydrophobically Modified Ethoxylated Urethane (Heur) Based Acrylic Paint Systems, Tyler J. Bell

Master's Theses and Project Reports

Latex polymers serve as binders in a wide range of architectural paints and coatings. A latex is an aqueous colloidal dispersion of polymer particles that when dried above the polymer’s film formation temperature coalesces into a dry polymer film (Dragnevski, Routh, Murray, & Donald, 2010). The other main components of paint include associative thickeners, surfactants, pigments and fillers with the thickener being the primary area of focus for this study.

The relatively simple system of latex, associative thickener and surfactant has been studied extensively. These studies have shown the mechanism of thickening for the associative thickener, and surfactant effects on both latex and thickener; however, there are few studies conducted for a fully-formulated system. The introduction of pigments, fillers, coalescing aids, functional amines, and other additives greatly increases the difficulty of research in this area. The addition of many additives ultimately affects the stability and physical properties of the end-product. Phase separation of the paints, also called syneresis, is a major ...


Improving Hybrid Solar Cells: Overcoming Charge Extraction Issues In Bulk Mixtures Of Polythiophenes And Zinc Oxide Nanostructures, Grant T. Olson 2014 California Polytechnic State University, San Luis Obispo

Improving Hybrid Solar Cells: Overcoming Charge Extraction Issues In Bulk Mixtures Of Polythiophenes And Zinc Oxide Nanostructures, Grant T. Olson

Master's Theses and Project Reports

Organic photovoltaics (OPVs) have received a great deal of focus in recent years as a possible alternative to expensive silicon based solar technology. Current challenges for organic photovoltaics are centered around improving their lifetimes and increasing their power conversion efficiencies. One approach to improving the lifetime of such devices has been the inclusion of inorganic metal oxide layers, but interaction between the metal oxides and common conjugated polymers is not favorable. Here we present two methods by which the interactions between polythiophenes and nanostructured ZnO can be made to be more favorable. Using the first method, direct side on attachment ...


Enhanced Thermoelectric Behaviour And Visible Light Activity Of Ag@Tio2/Polyaniline Nanocomposite Synthesized By Biogenic-Chemical Route, M. O. Ansari, Mohammad Mansoob Khan Dr, S. A. Ansari, J. Lee, M. H. Cho 2014 Universiti Brunei Darussalaam

Enhanced Thermoelectric Behaviour And Visible Light Activity Of Ag@Tio2/Polyaniline Nanocomposite Synthesized By Biogenic-Chemical Route, M. O. Ansari, Mohammad Mansoob Khan Dr, S. A. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

This paper reports the synthesis of visible light-active Ag@TiO2/Pani nanocomposite through a facile biogenic-chemical route. Ag@TiO2/Pani nanocomposite was prepared by the in-situ oxidative polymerization of aniline in the presence of Ag@TiO2 nanocomposite, which was obtained via a biogenic route. The synthesized Ag@TiO2/Pani nanocomposite was confirmed by UV-visible spectroscopy, photoluminescence spectroscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and thermogravimetric analysis. The Ag@TiO2/Pani nanocomposite was doped with HCl or para-toluene sulfonic acid to render it conducting. An analysis of the thermoelectrical behavior using a cyclic aging technique showed that the electrical ...


In Vivo Evaluation Of A Biomimetic Polymer-Doxorubicin Conjugate For Cancer Therapy, Matthew Skinner, Samantha McRae Page, Xiangji Chen, Sangram S. Parelkar, Kaitlyn Wong, Maria Mora, Sallie S. Schneider, Todd S. Emrick 2014 University of Massachusetts Amherst

In Vivo Evaluation Of A Biomimetic Polymer-Doxorubicin Conjugate For Cancer Therapy, Matthew Skinner, Samantha Mcrae Page, Xiangji Chen, Sangram S. Parelkar, Kaitlyn Wong, Maria Mora, Sallie S. Schneider, Todd S. Emrick

UMass Center for Clinical and Translational Science Research Retreat

This poster will describe a novel polymer pro-drug platform designed for conjugation and delivery of chemotherapeutics. Specifically, polymer pro-drugs were prepared from functional polymer zwitterions and doxorubicin (DOX), and evaluated in vivo to assess toxicological, pharmacokinetic and therapeutic properties. The biocompatible polymer scaffold (PolyMPC) consists of zwitterionic phosphorylcholine pendent groups, which mimic the natural hydrophilic moieties of phospholipids in cell membranes, and hydrazone linkages that allow for pH-triggered release of DOX. PolyMPC-DOX pro-drugs were isolated as dry solids using a facile strategy that allows for precise control of molecular weight and DOX incorporation. In vivo toxicity of PolyMPC and PolyMPC-DOX ...


Enhanced Thermal Stability Under Dc Electrical Conductivity Retention And Visible Light Activity Of Ag/Tio2@Polyaniline Nanocomposite Film, M. O. Ansari, Mohammad Mansoob Khan Dr, S. A. Ansari, K Raju, J Lee, M. H. Cho 2014 Universiti Brunei Darussalaam

Enhanced Thermal Stability Under Dc Electrical Conductivity Retention And Visible Light Activity Of Ag/Tio2@Polyaniline Nanocomposite Film, M. O. Ansari, Mohammad Mansoob Khan Dr, S. A. Ansari, K Raju, J Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

The development of organic-inorganic photoactive materials has resulted in significant advancements in heterogeneous visible light photocatalysis. This paper reports the synthesis of visible light-active Ag/TiO2@Pani nanocomposite film via a simple biogenic-chemical route. Electrically conducting Ag/TiO2@Pani nanocomposites were prepared by incorporating Ag/TiO2 in N-methyl-2-pyrrolidone solution of polyaniline (Pani), followed by the preparation of Ag/TiO2@Pani nanocomposite film using solution casting technique. The synthesized Ag/TiO2@Pani nanocomposite was confirmed by UV-visible spectroscopy, photoluminescence spectroscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and thermogravimetric analysis. The Ag/TiO2@Pani nanocomposite film showed superior activity towards ...


Morphology Characterization Of Low Band Gap Polymer-Based Organic Photovoltaics, Feng Liu 2014 University of Massachusetts Amherst

Morphology Characterization Of Low Band Gap Polymer-Based Organic Photovoltaics, Feng Liu

Doctoral Dissertations

In bulk heterojunction (BHJ) thin film organic photovoltaics (OPV), morphology control is critical to obtain good device efficiency. Nanoscale phase separation that creates bicontinuous interpenetrating structure on a size scale commensurate with exciton diffusion length (~10 nm) is thought to be the ideal morphology. Results obtained from this work indicate that morphology can be affected by chemical structure of the polymer, processing conditions, blending ratio and post treatments. Physical properties of the material, such as crystallinity, crystal orientation, material interactions and miscibility, surface energy and particle aggregations are critical for determining the morphology and thus the device performance. Previous investigations ...


Functional Phosphorylcholine Polymers: Prodrugs And Biomaterials, Samantha B.M. Page 2014 University of Massachusetts - Amherst

Functional Phosphorylcholine Polymers: Prodrugs And Biomaterials, Samantha B.M. Page

Doctoral Dissertations

This thesis describes the synthesis and applications of multifunctional, hydrophilic polymers consisting of a methacrylate backbone and zwitterionic phosphorylcholine (PC) pendent groups, prepared by free radical polymerization of the zwitterionic monomer, 2-methacryloyloxyethyl phosphorylcholine (MPC). Advances in polymer chemistry, applied to PC polymers, allowed for the preparation of well-defined structures with controlled molecular weight, narrow polydispersity, and facile incorporation of functional comonomers, giving breadth to the range of materials accessible for different applications. Built-in functionality included fluorophores and reactive groups for post-polymerization transformations, such as drug conjugation or cross-linking. The ability to form well-defined structures based on the polyMPC backbone is ...


Visualizing And Controlling Charge Transport In Conjugated Polymer Networks And Films, Andrew Davis 2014 University of Massachusetts - Amherst

Visualizing And Controlling Charge Transport In Conjugated Polymer Networks And Films, Andrew Davis

Doctoral Dissertations

VISUALIZAING AND CONTROLLING CHARGE TRANSPORT IN CONJUGATED POLYMER NETWORKS AND FILMS

MAY 2014

ANDREW R. DAVIS,

B.S., UNIVERSITY OF VIRGINIA

M.S., UNIVERSITY OF MASSACHUSETTS AMHERST

Ph.D., UNIVERSITY OF MASSACHUSETTS AMHERST

Directed by: Professor Kenneth R. Carter

The desire for more commercially feasible flexible electronic plastics has led to the development of increasingly complex conjugated polymer architectures and device geometries. Through these efforts, tremendous advances have been made in the design and performance of electronic devices fabricated with solution-processable semiconducting polymers. However, none of these materials have yet reached commercial maturity, so the opportunity for their further exploration ...


Functional Nanoparticles At Interfaces: Emulsion Stabilization And Triggered Inversion, Caroline Laure Marie Miesch 2014 University of Massachusetts - Amherst

Functional Nanoparticles At Interfaces: Emulsion Stabilization And Triggered Inversion, Caroline Laure Marie Miesch

Doctoral Dissertations

Encapsulation of materials can be performed through the stabilization of fluid-fluid interfaces and the formation of emulsion droplets, which is commonly achieved with surfactants, including small molecules and polymers, as well as particles that are, typically, micron-scale in diameter. The worked contained in this dissertation centered on droplets that are stabilized by nanoparticles, including metallic nanoparticles and semiconductor quantum dots, which bring the conductive and fluorescent properties inherent to such nanoparticles into the droplet construction.

Double emulsion droplets, both oil-in-water-in-oil (o/w/o) and water-in-oil-in-water (w/o/w) were formed using nanoparticles as the only surfactant in solution. Different types ...


Study Of The Structure-Property Relationships That Determine The Effects Of Latexes And Starch Containing Latex Emulsions On The Performance Of The Barrier Coatings (Sub-Coat) For Paper, JoAnna Marie Monfils 2014 University of Southern Mississippi

Study Of The Structure-Property Relationships That Determine The Effects Of Latexes And Starch Containing Latex Emulsions On The Performance Of The Barrier Coatings (Sub-Coat) For Paper, Joanna Marie Monfils

Master's Theses

The history of carbonless paper dates back to the 1940s. Before this, a carbon copy sheet was needed between sheets of paper to be able to produce one or more copies simultaneously during writing. The pressure from a pen or typewriter would help deposit the ink of the carbon paper onto the blank sheet of paper under the original written sheet to create a “carbon copy.” This method did however, have its disadvantages. Not only did it produce a limited number of copies, but it was also a messy process. So came the creative process of using microencapsulated dyes to ...


Raft Polymerization Of Sulfonamide-Containing Methacrylamides, Michael B. Sims 2014 The University of Southern Mississippi

Raft Polymerization Of Sulfonamide-Containing Methacrylamides, Michael B. Sims

Honors Theses

Targeted delivery of cancer therapeutics offers an exciting new opportunity for utilization of controlled polymerization techniques. However, a major obstacle in achieving the desired therapeutic effect is facilitating endosomal release of active agents following endocytosis. Peptides and pH-responsive polymers have been utilized as a means of triggering endosomal release via phase transition-induced membrane disruption. Unfortunately, the fidelity by which the pKa of these polymers/peptides can be varied is limited, such that it reduces their versatility in altering the phase transition point to best match the endosomal pH of a particular cell-type. Herein, we report the controlled polymerization of library ...


Effects Of Varying The Cure Profiles Of An Epoxy-Amine System, Patrick W. Hollingsworth 2014 The University of Southern Mississippi

Effects Of Varying The Cure Profiles Of An Epoxy-Amine System, Patrick W. Hollingsworth

Honors Theses

The cure of an epoxy prepolymer with an amine hardener induces stress in thermosetting systems. The extent of residual stresses in the cured epoxy-amine thermosets are dependent on several factors; one of which is the cure profile utilized. The effect of cure profile on cure induced stresses of an epoxy-amine thermoset was examined in the current study. A difunctional epoxide based on diglycidyl ether of bisphenol-A (DGEBA) and a tetrafunctional amine curative were used to conduct this study. Two cure profiles were selected to prepare samples of varying degrees of stress in the cured thermosets. The first was constant heating ...


Characterizing The Morphology Of Solvent Annealed Pcbm/P3ht Bilayers Using Gixrd And Raman Spectroscopy, Tyler Evan McPherson 2014 University of Tennessee - Knoxville

Characterizing The Morphology Of Solvent Annealed Pcbm/P3ht Bilayers Using Gixrd And Raman Spectroscopy, Tyler Evan Mcpherson

Masters Theses

A growing demand for new forms of renewable energy has been at the forefront of scientific research. Organic photovoltaics (OPVs) provide a promising alternative to the expensive inorganic solar cells used today. Poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) are common donor and acceptor materials used in the active layer of an OPV device. These systems have reached power conversion efficiencies of approximately 12 %. However, little is known about the actual morphology. A better understanding of the morphology would allow researchers to optimize device fabrication to increase the device performance. As-cast devices are limited by ...


A Study In Conjugated Polymers: From Solution Properties Of P3ht To Synthesis Of Highly Functionalized Conjugated Polymers; Moving Toward Block Copolymers And Beyond, Justin Taylor Roop 2014 University of Tennessee - Knoxville

A Study In Conjugated Polymers: From Solution Properties Of P3ht To Synthesis Of Highly Functionalized Conjugated Polymers; Moving Toward Block Copolymers And Beyond, Justin Taylor Roop

Doctoral Dissertations

Conjugated polymers have been the focus of intense research for more than a decade now, and advances in this field are beginning to materialize in the production of high-efficiency opto-electronic materials that may led to the generation of energy without the need for fossil fuels. However, these current materials have not been shown to be capable of reaching efficiency levels high enough to be competitive with the siliconbased solar cells that are the standard today. We embarked on a journey in this work to help the next step in conjugated polymer research be attained. We have done just that through ...


Ab Initio Studies Of Proton Transport In Proton Exchange Membranes, Jeffrey Keith Clark 2014 University of Tennessee - Knoxville

Ab Initio Studies Of Proton Transport In Proton Exchange Membranes, Jeffrey Keith Clark

Doctoral Dissertations

A molecular-level understanding of the factors that contribute to transport properties of proton exchange membranes (PEMs) for fuel cell applications is needed to aid in the development of superior membrane materials. Ab initio electronic structure calculations were undertaken on various PEM ionomer fragments to explore the effects of local hydration, side chain connectivity, protogenic group separation, and specific side chain chemistry on proton dissociation and transfer at low hydration. Cooperative interactions between both intra- and inter-molecular acidic groups and hydrogen bond connectivity were found to enhance proton dissociation at very low degrees of hydration. The energetics associated with proton transfer ...


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