Manipulating Solid-Surface Properties with Polymeric Agents

Colloidal processing offers a way to minimize undesired heterogeneities in the fabrication of advanced ceramics. Stable dispersions can be created by manipulation of interparticle potential. Adsorption of diblock copolymer amphiphiles provides a way to obtain long range repulsive interactions between particles, at comparatively low polymer coverage, thereby enabling suspension stabilization. In this study we investigate the relationship between copolymer structure and adsorbed layer characteristics, and specifically, the nature and range of interactions. We find that the surface density and interaction range are governed by a characteristic measure of the copolymer asymmetry. In the case of copolymers where one of the blocks is ionic, and therefore water soluble, we find a hysteresis in the interaction forces, indicating a meta-stable state of the polymer layer.