Selective metallization of well aligned block copolymers in thin films and confined geometries
Block copolymers are ideal templates for the fabrication of polymer-metal nanocomposites since they self-assemble into ordered, well-defined arrays of nanometer size domains. In this research, well aligned, microphase-separated structures of styrene-2-vinylpyridine block copolymers were used to prepare polymer-metal nanocomposites. Under optimal conditions, templates were prepared as thin films, confined in aluminum oxide membranes or sheared and metallized without disturbing the ordered structure. Using these methods, we developed a procedure that deposits metal within the polymer using supercritical carbon dioxide-soluble metal precursors. Supercritical carbon dioxide was used to allow for selective metallization of the polymer without disruption to its morphology. In addition, similar procedures have been investigated using metal salts and acids. Using these techniques, metals and metal-sulfides including silver, gold, platinum, iron and zinc sulfide were each selectively deposited.