Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 13 of 13 for “"polymer diffusion"”.
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Origin, evolution, and control of sidewall line edge roughness transfer during plasma etching
… films seem especially prone, perhaps due to polymer diffusion into the pore structure. Control of polymerization during the etch through the use of lower-polymerizing fluorocarbons or the addition of oxygen was shown to effectively control excessive roughening on solid films, while porous …
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Measurement of the dependence of the averaged internal mode on the scattering vector and of the first internal mode on the concentration of polystyrene in solution using photon correlation spectroscopy
… from local concentration fluctuations in the polymer and autocorrelation function was calculated; The autocorrelation function can be written as a sum of decaying exponentials. The center-of-mass mode with a decay constant Dq{dollar}\sp2{dollar} is contained in every mode. D is the polymer …
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Structure-Property Relationships of 3D Printed Thermoplastics for Implantable Orthopedic Devices
… the strength of materials as it inhibited polymer diffusion across the weld and prevented strong bonds from forming. Increasing crystallinity of as-printed amorphous samples through annealing did not result in higher strength for PLA or PEEK, due to the inability to co-crystallize across …
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Long Chain Molecules in the Molten State: Surface Adsorption, Near Surface Structure, and Mutual-Diffusion
<p>The surface segregation in a binary mixture of polymer due to surface energy difference or end-grafting is studied. The surface energy difference induced segregation is compared with the mean-field theory. The end-labeling of chains strengthens the ability of the chain to bind to the surface, …
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In-Situ Monitoring and Simulations of the Non-Isothermal Crystallization of FFF Printed Materials
… for part performance by ensuring that the polymer extrudate is flowing at an appropriate temperature and flow rate during the part build process. Testing was performed using Acrylonitrile butadiene styrene filament and a modified Monoprice Maker Select 3D printer. Tests using the default …
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Polymer Structure and Dynamics in Nano-Confinements: Polymer Nanocomposiets and Cylindrical Confinement
Polymers have been used for variety of products for decades, and the usage of polymer products is still growing. Innovative methods (e.g. adding other materials) have been created to improve properties of polymer products to fulfill targeted requirements for applications and many of these …
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Nanoparticle transport via holographic photopolymerization
… of silica nanoparticles into holographic photopolymerization systems for the purpose of controlling the location of the nanoparticle within the periodic structure based upon control of the surface chemistry of the nanoparticle. Herein we report the successful sequestration of methacrylate …
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Material Extrusion based Additive Manufacturing of Semicrystalline Polymers: Correlating Rheology with Print Properties
… is to enable MatEx of semicrystalline polymers with mechanical properties approaching that of injection molded parts. Tailored molecular architectures of blends that can control the crystallization kinetics from the melt state are investigated. By modifying the crystallization time …
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New Applications of Fluorescence Correlation Spectroscopy in Materials Science
… We have synthesised a set of dye-labelled polymers that served as a well-defined system to study polymer diffusion and that was used to characterise the beam path and focal volume in environments with refractive indices different from that of water. Furthermore a new method for the …
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Ion and polymer transport in polymerized ionic liquids
Polymerized ionic liquids (PILs) is a novel type of ionic polymers in which small molecule ionic liquids (ILs) are covalently attached to a polymer backbone. The advantages of ILs include high thermal and electrochemical stability, high ionic conductivity, negligible volatility and board design …
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Phase behavior of dipolar fluids and ion-dipole mixtures, and surface diffusion of adsorbed polymers
… the last part of this dissertation discusses the diffusion behavior of adsorbed polymers over the full concentration range. In Chapter 2, I study the phase behavior of dipolar fluids by means of Monte Carlo simulations. My goal in this chapter is to examine the possibility of phase separation in a …
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MRI and NMR Investigations of Transport in Soft Materials and Explorations of Electron-Nuclear Interactions for Liquid-State Dynamic Nuclear Polarization
… the use of magnetic resonance techniques for polymeric material characterizations in solutions, with emphasis on methods utilizing magnetic field gradients - magnetic resonance imaging (MRI) and pulsed-field-gradient (PFG) NMR. The second part (Chapter 5) presents enhancements to dynamic …
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The dynamics of polymer solutions: Effects of concentration, chain architecture, and flow
The dynamics and rheology of polymer solutions are crucial to understanding and designing a broad range of polymer processing applications and biological systems. The microscopic conformational dynamics of polymers are directly related to the rheological response of solutions in processing flows. …