COLL 220 |
| Sunil Kulkarni, Department of Chemistry 016-00, Temple University, 13th and Norris Streets, Beury Hall, Philadelphia, PA 19122 and Stephanie L. Wunder, Department of Chemistry, 016-00, Temple University, 13th. & Norris St., Philadelphia, PA 19122. |
| Polyethylene oxide (PEO) is used to form protein resistant surfaces and in stabilization of emulsions. When attached to a small spherical inorganic substrate such as silica (SiO2), the surface density of the attached chains and their chain dimensions in solution can be measured by a combination of thermogravimetric analysis (TGA), light scattering and viscosity measurements. A model system was prepared from SiO2 nanoparticles of 70 and 100 nm nominal diameter, functionalized with the oligomeric PEO silanes PEO(350)-Si-(Cl)3 or PEO(375)-Si-(OCH3)3; in both cases the PEO segments were polydisperse with number average molecular weights of 350 or 375, respectively. TGA indicated that the measure weight loss was less than that expected for close packed helical crystalline PEO chains. In the solid state, the PEO (completely crystalline unattached) was amorphous when attached to the SiO2. The dimensions of the PEO functionalized silica were compared with those of the original silica nanospheres in solution. |
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Posters: Fundamental Research in Surface and Colloid Chemistry
6:00 PM-8:00 PM, Monday, March 29, 2004 Disneyland -- North Exhibit Hall, Poster
Division of Colloid and Surface Chemistry |