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 20 of 28 for “"Grafting Density"”.
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Linear and star-shaped poly(ethylene oxide) grafted surfaces : grafting density and protein adsorption
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1996.
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Self-Assembly of Matching Molecular Weight Linear and Star-Shaped Polyethylene glycol Molecules for Protein Adsorption Resistance
… from the compression of longer chains and ii) grafting density contribution which may provide shielding from the underlying material. Recent studies have suggested that PEG interaction with water may also play a role in its ability to resist protein adsorption suggesting that steric exclusion …
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Simulation of Weak Polyelectrolyte Brushes
… to pH, salt concentration, monomer sequence and grafting density. While PEBs have only acidic or basic monomers, PABs contain both types of monomers, resulting in more complex interactions that require advanced simulation methods to properly investigate. As expected, the simulation results of …
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Polymers as directing agents for motions of chemical and biological species
… as a function of the chain molecular weight, grafting density, and temperature. Above the lower critical solution temperature (LCST) of 32°C, the collapse of the water swollen chains, determined by ellipsometry, depends on the grafting density and molecular weight. Ellipsometry, radio assay, …
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Advancing fast relaxation imaging to determine protein stability and folding kinetics on poly(n-isopropyl acrylamide) films
… temperature of PNIPAM (32℃) is dependent on the grafting density and molecular weight of the end grafted PNIPAM. The work presented here applies a novel technique to demonstrate how protein adsorption on PNIPAM affects protein thermodynamic stability and kinetics. Fast Relaxation Imaging (FReI) …
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Designing Microporous Polymers for Separations
… are synthesized to demonstrate the role of grafting density on separation performance and CO₂ plasticization resistance. Sorption experiments are performed to determine improvements to selectivity. In Chapter 4, we describe the optimized SN Ar synthesis of a poly(arylene ether) (PAE) that …
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Hierarchical layered-silicate-- lamellar triblock copolymer nanocomposites
… the molecular weight of the surfactant and the grafting density and shows remarkable agreement with the theory proposed by Balazs et al. Due to the increase surface volume ratio of the clay, a flipping transition of the block copolymer morphology was observed during roll-casting producing a near …
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Molecular dynamics simulations of polyelectrolyte brushes
… polyelectrolyte brush anchored with varying grafting density to a plane. Results show that chains are extended up to about 2/3 of their contour length. The brush thickness slightly grows with increasing anchoring density. This slight dependence of the brush height on grafting density is in …
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DNA Driven Assembly at Solid and Liquid Interfaces
… this simple method provides a relatively higher grafting density of DNA anchors at the interface. Further, it is possible to kinetically control the surface coverage of oil droplets with colloidal particles while preserving fully ergodic colloidal dynamics on the droplets. The equilibrium nature …
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Characterization of Spin Coated Polymers in Nano-environments as a Function of Film Thickness
… spin coating techniques. The effects of both grafting density and solvent washes were analyzed using contact angle analysis and atomic force microscopy. In addition, hydrolysis was successfully performed on existing polymer brush samples to produce polymer brushes of the di-block copolymer …
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Trajectory features as surrogate measures of the nanoparticle-microenvironment interaction space
… features (surface functionality, PEG grafting density, PEG chain length) in determining in vitro and ex vivo transport behavior. This method of analysis highlights the potential of nanoparticles to be used both as pre-clinical diagnostic probes without the use of complex chemistries …
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Surface Modification of Nanoparticles Using Controlled Radical Polymerization For Designed Interfaces
… weight, molecular weight distribution and grafting density of the individual populations on the surface of nanoparticles. </p> <p> The last part of this work describes the synthesis of benzimidazole side chain containing monomers and polymers. A new monomer …
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Mechanophore activation at heterointerface and surface crowdedness as a determining factor
… the mechanophore grafted with lower density activated significantly faster than that grafted with higher grafting density. These results provide a greater understanding of mechanotransduction processes at heterogeneous interfaces and thus allow design of mechanoresponsive composite …
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Gold nanorod surface functionalization: construction of dynamic surfaces and heterogeneous silica coating
… graft-from the GNR surface in situ so that the grafting density and polymer composition can be fine-tuned for further application. The second part of this thesis focuses on the heterogeneous silica coating of GNRs. A robust method has been developed for synthesis of side-specific silica coating …
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Synthesis and supramolecular assembly of biomimetic polymers
… length and flexibility, as well as branch grafting density and chemical identity. We utilized a two-step scheme based on enzymatic incorporation of non-natural nucleotides containing bioorthogonal dibenzocyclooctyne (DBCO) functional groups along the main polymer backbone, followed by …
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Nanomechanical Properties of Polymer-Grafted Nanoparticle Ultrathin Films
… PMMA chains of molecular mass (59.4 kg/mol) and grafting density (0.44/nm2) were dispersed in tetrahydrofuran (THF) solution to produce thin films of varying thickness ranging from 45nm to 200nm. The nanoparticle distribution throughout the film thickness and surface roughness were studied using …
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Elastomeric Stamping: Design Considerations for Long -Term Maintenance of Neuronal Networks
… (AFM), from which the surface concentrations and grafting density were calculated. Fourier transform infrared spectroscopy was used to examine the structure and organization of the organosilane surfaces. Long-term film stability was evaluated using ellipsometry and static water contact angles. As …
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Development and Characterization of Fatty Acid-Coated Microgels Within Microfluidic Systems
… determined by several factors, such as the grafting density, hydrophobicity, total thickness, and fluidity of the fatty acid chains that functionalize the mugel.
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Tuning Melt/Brush Interactions for Functional Polymer Films
… bottom. The PS-PMMA lm thickness (t) and brush grafting density (Σ) were systematically varied to examine their impacts on in-plane and out-of-plane ordering. A combination of high resolution microscopy and grazing-incidence small angle X-ray scattering characterizes lateral order and …
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Polymer Dispersity Affects Conformation of Brushes Grafted on Nanoparticles
… conformation. Polymer brush properties, such as grafting density \sigma and degree of polymerization N, can drastically affect conformation of neutral and pH-responsive PGNPs and further influence their efficacy in applications. Surprisingly, how dispersity Đ (related to the breadth of the …
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