Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Aggregation (1)
- Alkaline exchange membrane (1)
- Block copolymer (1)
- Confinement effects (1)
- Crystallin (1)
-
- Crystallizable solvent (1)
- Crystallization (1)
- Epoxy (1)
- Fracture (1)
- Fracture mechanics (1)
- Fuel Cells (1)
- Healing (1)
- Hydroxide transport (1)
- In situ reinforced polymers (1)
- Light Scattering (1)
- Lithium Ion Battery (1)
- Lithography (1)
- Low molecular weight compounds (1)
- Network (1)
- Pattern transfer (1)
- Phase behavior (1)
- Phase separation (1)
- Poly(ethylene-co-vinyl acetate) (1)
- Poly(lactic acid) (1)
- Polymer (1)
- Polymer Physics (1)
- Polymer composites (1)
- Polymer structure (1)
- Polymorphism (1)
- Proton transport (1)
Articles 1 - 8 of 8
Full-Text Articles in Engineering
Phase Behavior Of Block Copolymers In Compressed Co2 And As Single Domain-Layer, Nanolithographic Etch Resists For Sub-10 Nm Pattern Transfer, Curran Matthew Chandler
Phase Behavior Of Block Copolymers In Compressed Co2 And As Single Domain-Layer, Nanolithographic Etch Resists For Sub-10 Nm Pattern Transfer, Curran Matthew Chandler
Open Access Dissertations
Diblock copolymers have many interesting properties, which first and foremost include their ability to self-assemble into various ordered, regularly spaced domains with nanometer-scale feature sizes. The work in this dissertation can be logically divided into two parts - the first and the majority of this work describes the phase behavior of certain block copolymer systems, and the second discusses real applications possible with block copolymer templates. Many compressible fluids have solvent-like properties dependent on fluid pressure and can be used as processing aids similar to liquid solvents. Here, compressed CO2 was shown to swell several thin homopolymer films, including …
Electrostatic Effects In Aggregation Of Crystallin Proteins, Deniz Elizabeth Civay
Electrostatic Effects In Aggregation Of Crystallin Proteins, Deniz Elizabeth Civay
Open Access Dissertations
The three projects utilized polymer physics theories to investigate polymer aggregation mechanics. Dynamic light scattering (DLS), static light scattering (SLS) and small angle light scattering (SALS) were the primary characterization tools. The goal of the first project was to study the aggregation of bovine βL-crystallin and apply that knowledge towards cataract formation, which is caused by aggregation of the crystallins. The first series of experiments characterized the kinetics of α-crystallin and βL-crystallin in water at room temperature. α-crystallin’s equilibrium hydrodynamic radius value was kinetically independent. βL-crystallin formed an aggregate with an Rh that was kinetically dependent. The packing structure of …
Aspects Of Network Formation And Property Evolution In Glassy Polymer Networks, Andrew Thomas Detwiler
Aspects Of Network Formation And Property Evolution In Glassy Polymer Networks, Andrew Thomas Detwiler
Open Access Dissertations
Experimental and theoretical characterization techniques are developed to illuminate relationships between molecular architecture, processing strategies, and physical properties of several model epoxy-amine systems. Just beyond the gel point partially cured networks are internally antiplasticized by unreacted epoxy and amine which leads to enhanced local chain packing and strain localization during deformation processes. Additional curing causes the antiplasticization to be removed, resulting in lower modulus, density, yield stress, and less strain localization. Physical and mechanical probes of network formation are discussed with respect to several different partially cured model epoxy-amine chemistries. The non-linear fracture energy release rate and the molecular architecture …
Organic Photovoltaics Based On P3ht/Pcbm: Correlating Efficiency And Morphology, Dian Chen
Organic Photovoltaics Based On P3ht/Pcbm: Correlating Efficiency And Morphology, Dian Chen
Open Access Dissertations
Controlling the morphology of thin films is key in optimizing the efficiency of polymer-based photovoltaic (PV) devices. The morphology and interfacial behavior of the multicomponent active layers confined between electrodes are strongly influenced by the preparation conditions. Results obtained in this work quantitatively show the photovoltaic device performance is strongly affected by the nanoscopic morphology, crystal orientation, composition distribution and the interdiffusion behavior of the photoactive layer. To better understand the physics of the photoactive layer in the organic photovoltaic devices, it is necessary to gain a quantitative understanding of the morphology and the manner in which it develops. A …
Effects Of Molecular Architecture On Crystallization Behavior Of Pol(Lactic Acid) And Ethylene-Vinyl Acetate, Jeffrey Paul Kalish
Effects Of Molecular Architecture On Crystallization Behavior Of Pol(Lactic Acid) And Ethylene-Vinyl Acetate, Jeffrey Paul Kalish
Open Access Dissertations
The relationship between polymer chain architecture, crystallization behavior, and morphology formation was investigated. The structures formed are highly dependent on chain configuration and crystallization kinetics. Poly(lactic acid) (PLA) and Poly(ethylene-co-vinyl acetate) (EVA) random copolymers were studied. Sample characterization was performed using a variety of techniques, including spectroscopy, scattering, and calorimetry. In PLA, structural differences between α’ and α crystalline phases were analyzed using cryogenic infrared and Raman spectroscopy. Compared to the crystal, the ’ crystal has slightly looser packing and weaker intermolecular interactions involving carbonyl and methyl functional groups. Simulations in conjunction with Raman scattering analyzed the …
Ion Mobility Studies Of Functional Polymeric Materials For Fuel Cells And Lithium Ion Batteries, Shilpi Sanghi
Ion Mobility Studies Of Functional Polymeric Materials For Fuel Cells And Lithium Ion Batteries, Shilpi Sanghi
Open Access Dissertations
The research presented in this thesis focuses on developing new functional polymeric materials that can conduct ions, H+, or OH- or Li+. The motivation behind this work was to understand the similarities and/or differences in the structure property relationships between polymer membranes and the conductivity of H+ and OH- ions, and between polymer membranes and the anhydrous conductivity of H+ and Li+ ions. This understanding is critical to developing durable polymer membranes with high H+, OH- and Li+ ion conductivity for proton exchange membrane fuel cells (PEMFCs), …
In Situ Reinforced Polymers Using Low Molecular Weight Compounds, Onur Sinan Yordem
In Situ Reinforced Polymers Using Low Molecular Weight Compounds, Onur Sinan Yordem
Open Access Dissertations
The primary objective of this research is to generate reinforcing domains in situ during the processing of polymers by using phase separation techniques. Low molecular weight compounds were mixed with polymers where the process viscosity is reduced at process temperatures and mechanical properties are improved once the material system is cooled or reacted. Thermally induced phase separation and thermotropic phase transformation of low molar mass compounds were used in isotactic polypropylene (iPP) and poly(ether ether ketone) (PEEK) resins. Reaction induced phase separation was utilized in thermosets to generate anisotropic reinforcements. A new strategy to increase fracture toughness of materials was …
Fiber Formation From The Melting Of Free-Standing Polystyrene, Ultra-Thin Films: A Technique For The Investication Of Thin Film Dynamics, Confinement Effects And Fiber-Based Sensing, Jeremy M. Rathfon
Open Access Dissertations
Free-standing ultra-thin films and micro to nanoscale fibers offer a unique geometry in which to study the dynamics of thin film stability and polymer chain dynamics. By melting these films and investigating the subsequent processes of hole formation and growth, and fiber thinning and breakup, many interesting phenomena can be explored, including the nucleation of holes, shear-thinning during hole formation, finite-extensibility of capillary thinning viscoelastic fibers, and confinement effects on entanglement of polymer chains. Free-standing films in the melt are unstable and rupture due to instabilities. The mechanism of membrane failure and hole nucleation is modeled using an energy barrier …