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Showing 1 to 20 of 31 for “"porous silica"”.
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Study of Freeze-Cast Porous Silica Nanoparticle-Based Composites
Porous silica-based nanocomposites are promising ceramics, as they exhibit high specific surface area, highly porous network, and a surface that can be easily functionalized. This dissertation describes the results of a study on the formation and properties of porous silica nanoparticle-based …
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Development of Soft-Matter Delivery Systems: Coupling pH Responsive Polymers to Porous Silica Particles
… induced self-assembly (EISA) mesoprous silica nanoparticles for potential use in controlled drug release and therapeutics. As demonstrated here, lipid bilayer coatings can be easily replaced with different polymer analogs allowing for dynamic response to environmental stimuli. In …
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Design, Synthesis and Characterization of Porous Silica Nanoparticles and Application in Intracellular Drug Delivery
… of intracellular bacteria. Among them, the porous silica nanoparticles deserve special attention due to their multifunctional properties such as high drug loading, controlled drug release and targeting of organs/cells. A review of the functional requirements of an ideal drug delivery system …
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The Removal and Recovery of Oxo-Anions from Aqueous Systems using Nano-Porous Silica Polyamine Composites
… This led us to the development of silica polyamine composites (SPCs) functionalized with metal selective ligands for the removal of heavy metals from wastewater streams. High capacities were obtained for arsenic, selenium, molybdenum, and tungsten oxoanions by immobilizing zirconium …
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The Removal and Recovery of Oxo-Anions from Aqueous Systems using Nano-Porous Silica Polyamine Composites
… This led us to the development of silica polyamine composites (SPCs) functionalized with metal selective ligands for the removal of heavy metals from wastewater streams. High capacities were obtained for arsenic, selenium, molybdenum, and tungsten oxoanions by immobilizing zirconium …
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Nuclear Magnetic Resonance Under Extreme Conditions: High-Pressure NMR Probe Development, and NMR Applications to the Dynamics of Confined Liquids
… acid, and pentafluoropropionic acid confined to porous silica glasses with well-defined pore sizes. The $\sp{13}$C NMR spin-lattice relaxation times were measured and analyzed in terms of the two-state-fast exchange model, which allows separation of the surface layer relaxation rates. The …
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NMR relaxation studies of liquids in confined geometries
… of molecular liquids in sol-gel prepared porous silica glasses. The NMR relaxation times of a variety of nuclei, including $\sp1$H, $\sp2$H, $\sp{14}$N, and $\sp{13}$C, of a series of liquids with different polarities confined to the glasses, are reported as a function of pore size in the …
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Material and fabrication developments in the ion-electrospray propulsion system
… Additionally, a new monodisperse, sintered porous silica ceramic was developed for use in emitter substrates. The highly-modifiable, photocurable ceramic resin used to cast the emitter substrates is a strong contender to replace the state-of-the-art borosilicate glass chips. An experimental …
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Deuterium NMR relaxation studies of liquids in confined geometries
… reorientational dynamics of molecular liquids in porous media. The relative role of the pure geometrical confinement and the strength of the surface effect is investigated. The deuteron NMR spin-lattice relaxation times, T$\sb1$, of several molecular liquids in porous silica glasses are reported …
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Development of stationary phase materials and methods for analysis of pharmaceuticals via high-performance liquid chromatography and electrochemical detection
… and characterises a novel polymer immobilised porous silica particle phase for fast LC analysis of selected pharmaceutical actives. In this thesis, a Nafion polymer-coated silica stationary phase material for the fast and efficient separation of pharmaceutical solutes is reported. Initially, …
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Hierarchical and size dependent mechanical properties of silica and silicon nanostructures inspired by diatom algae
… For example, diatom algae contain nanoporous hierarchical silicified shells that provide mechanical defense from predators and virus penetration. These shells generally have a morphology resembling honeycombs within honeycombs, meshes, or corrugated folds, and are surprisingly tough …
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Fabrication of Random Hole Optical Fiber Preforms by Silica Sol-Gel Processing
… photonic crystal fibers) comprise of a pure silica core, and a pure but porous silica cladding of air holes [1]. This provides a huge difference in the refractive indices on the cladding and core without doping. This translates into radiation resistant fibers with very low losses and very …
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Self-Structuring of functionalized micro- and mesoporous organosilicas using boron-silane-precursors
The structuring of porous silica materials at the nanometer scale and their surface functionalization are important issues of current materials research. Many innovations in chromatography, catalysis and electronic devices benefit from this knowledge. The work at hand is dedicated to the targeted …
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Lab-on-a-Chip Integration of Size-based Separation Techniques for Isolation of Bacteria from Blood
… capture methods. First, we developed the porous silica monolith elements integrated into thermoplastic devices for isolation of intact bacteria from blood, enabling the application of emerging detection methods that supports bacterial identification from purified cell populations. Second, …
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Plasmonic Nanoshells: Synthesis, Functionalization, and Photonic Applications
… cores included coating the particles with porous silica, a protective layer that reduces aggregation but does not prevent access to the core by ions in solution. In addition, the silica coating afforded these nanostructures stability under a wide range of pH conditions. To demonstrate the …
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Chromatographic Properties of Silica-Based Monolithic HPLC Columns
Silica-based monolithic HPLC columns contain a novel chromatographic support in which the traditional particulate packing has been replaced with a single, continuous network (monolith) of porous silica. The main advantage of such a network is decreased backpressure due to macropores (2 μM) …
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Characterization of Methyltrimethoxysilane Sol-Gel Polymerization and the Resulting Aerogels.
Methyl-functionalized porous silica is of considerable interest as a low dielectric constant film for semiconductor devices. The structural development of these materials appears to affect their gelation behaviors and impact their mechanical properties and shrinkage during processing. 29Si solution …
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Investigation Of Parameters Enabling Admicellar Reversible Addition-Fragmentation Chain Transfer (Raft) Polymerization
… the admicellar polymerization of styrene on silica particles was studied using cetyltrimethylammonium bromide (CTAB) as the adsorbed surfactant bilayer template, 2,2'-azobisisobutyronitrile (AIBN) as a water-insoluble initiator or 4, 4'-azobis (4-cyanovaleric acid) (V-501) as a water-soluble …
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Dynamics of biopolymers and their hydration water studied by neutron and X-ray scattering
… TL than that confined in hydrophilic MCM-41-S (a porous silica material). We then observe an interesting phenomenon that TL of water confined in a hydrophobic mesoporous material CMK-1 occurs in-between the above two. Our results indicate that besides the obvious surface effect brought about by …
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