COLL 109 |
| Scott S. Perry1, Nicholas D. Spencer2, Xiaoping Yan1, Seunghwan Lee2, and Markus Mueller2. (1) Department of Chemistry, University of Houston, 4800 Calhoun Rd, 136 Fleming Bldg, Houston, TX 77204-5003, (2) Department of Materials, Laboratory for Surface Science and Technology, ETH Zurich, Switzerland, NO H64, Sonneggstrasse 5, CH-8092 Zurich, Switzerland |
| Interfacial friction between polymer brush surfaces under aqueous environments has been probed with the atomic force microscope. The brush surfaces, comprised of poly(L-lysine)-g-poly(ethylene glycol) (PLL-g-PEG), have been generated through the spontaneous adsorption of the polymer from solution onto silicon oxide (substrate) and sodium borosilicate surfaces (AFM tip). The interfacial friction measurements have been carried out on polymer-coated substrates with bare or polymer-coated, microsphere-attached tips in HEPES buffer solution. It was found that the adsorption of polymer on metal oxides strikingly reduced the interfacial friction. By using a series of PLL-g-PEG polymers differing from each other in PEG side-chain length and grafting ratio, we observed that frictional properties of polymer-coated interfaces strongly depend on the architecture of PLL-g-PEG. Polymer-film formation, the influence of polymer architecture, the role of solvent, and the relationship to macroscopic investigations and applications will be discussed. |
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Friction, Lubrication, and Adhesion in Micro- and Nano-Scale Devices
8:30 AM-12:00 PM, Monday, March 29, 2004 Marriott -- Orange County 5, Oral
Division of Colloid and Surface Chemistry |