BLOCK COPOLYMERS AT INTERFACES .2. SURFACE-ADSORPTION

We present a theory for adsorption of diblock copolymers onto surfaces. We find that a critical adsorption concentration exists, analogous to the critical micelle concentration in micellization. This critical adsorption concentration decreases as the surface attraction increases, as the copolymer-solvent compatibility decreases, as the more soluble A block length decreases, and as the size of the solvent increases. The thickness of the adsorbed layer increases as the length of the A block increases, as the surface attraction for the anchoring B block increases, and as the solvent becomes smaller. We present a number of useful scaling relationships for layer thicknesses and surface densities as functions of block lengths of both the copolymer and the solvent.