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Research work on chemically-modified interfaces deals with the preparation, characterization, and applications of surfaces onto which macromolecules or organosilanes are adsorbed or chemically grafted. An important component of the program deals with the kinetics of silylation and graft-polymerization, atmospheric plasma-induced graft polymerization, the topology and surface properties of surface layers formed by the above methods and the dynamics of tethered polymer chains.
Polymer-solid interfaces are relevant to various applications such as low-fouling polymer-modified membrane, liquid chromatography of synthetic and biopolymers and water reclamation with ceramic-polymer resins. Other application areas include chemical sensors, biocompatibility of synthetic surfaces and adhesion improvement in polymer composites. Graft-polymerization techniques developed at PolySep have been applied to the synthesis of novel grafted polymer-silica (GPS) separation resins and ceramic- supported polymer (CSP) membranes. Our patented CSP membranes are effective for pervaporation applications and as low-fouling ultrafiltration membranes. Our GPS resins are being evaluated for high performance size exclusion chromatography of polyelecrolytes and proteins as well as the adsorptive removal of low solubility organics from contaminated water. Recent work also includes the development of fouling-resistant membranes and multi-array chemical sensors.
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Although much is known about homogenous crystallization in liquid systems, little fundamental information is available on the impact of the surface chemistry and nano-scale topology of heterogeneous surface crystallization, kinetics of surface crystallization and morphology of the formed crystals. Similarly, while there is vast literature on the adsorption of organics onto polymeric resins and membranes, the kinetics of surface sorption and observation of surface deformation (or swelling of surface chains) at the nano-scale level are lacking.
Last Updated ( Thursday, 17 February 2011 14:40 )
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Example of the impact of reaction conditions on the characteristics of a surface with tethered Poly(vinyl acetate) chains prepared by a two-step graft polymerization process.
Last Updated ( Thursday, 17 February 2011 15:05 )
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In recent years there has been a growing interest in modifying surface properties of inorganic oxides, polymer films and other solid substrates with tethered polymers. Applications of such surfaces include, colloid stabilization, adhesion promotion or reduction, wetting, lubrication, biocompatibility, size exclusion chromatography, and reducing fouling of ultrafiltration membranes.
Last Updated ( Thursday, 17 February 2011 15:10 )
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Graft polymerization typically involves polymer grafting and/or graft polymerization as shown in the Figure to the left. Engineering of ceramic-supported polymer surfaces, consisting of with a terminally anchored polymer layer, requires careful control of the surface density and molecular weight of the polymeric chains.
Last Updated ( Thursday, 17 February 2011 15:15 )
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This area of investigation focuses on anhydrous silylation of multi-alkoxy silanes onto inorganic oxide surfaces. In recent work, the silylation of vinyl trimethoxysilane (VTMS) onto silica and zirconia substrates was investigated experimentally to demonstrate and quantify the effects of surface water on multilayer silylation.
Last Updated ( Thursday, 17 February 2011 15:19 )
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