COLL 405 |
| Mi-Kyoung Park, Suxiang Deng, and Rigoberto C. Advincula. Department of Chemistry, University of Houston, Houston, TX 77204 |
| We present work on core-shell and hollow-shell colloidal particles and ultrathin films of weak polyelectrolytes containing photo-cross-linkable benzophenone groups. Using the layer-by-layer assembly of polyelectrolyte systems, colloidal particles were coated with ultrathin shells. Model studies were also made with ultrathin films on flat substrates. The cross-linking reactions were initiated by controlled UV irradiation. The results showed the following interesting behavior: 1) the permeability of polyelectrolyte multilayers can be controlled via photo-cross-linking, and 2) pH-switchable ion selectivity can be obtained by manipulating the charge density of polyelectrolytes through varying the pH of dipping solution, while maintaining the stability of the films through cross-linked structure. Model drug delivery properties were observed with the cross-linked hollow shell systems. The degree of permeability is dependent on the degree of cross-linking and shell thickness. This work represents the potential for truly “smart” pH-switchable polyelectrolyte multilayer membranes and films. |
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“Smart” Polymers on Surfaces and Colloids
8:30 AM-11:40 AM, Wednesday, March 31, 2004 Marriott -- Grand Ballroom J, Oral
Division of Colloid and Surface Chemistry |