COPOLYMERS AT SELECTIVE INTERFACES

The behaviour of various types of copolymers at interfaces between two immiscible solvents A and B is investigated. The copolymers consist of two monomer species A and B. Their distribution along the chain can be characterized by a structural correlation function Phi. Different adsorption scenarios can be found depending on the actual realization of Phi. While for random (weakly correlated) copolymers adsorption is caused by the random excess of A or B monomers, for periodic copolymers it is due to a weak orientation of AB-units crossing the interface. We also find a desorption related to the asymmetry of the copolymer and/or the interface. Different behaviours are predicted for the scaling properties and for the critical desorption temperature T-c for both cases. All the results are derived from a single expression for the adsorption crossover containing the correlation function Phi.