MULTIBLOCK COPOLYMERS AT INTERFACES

We consider the configurations and the various regimes when an alternating, symmetric, multiblock copolymer made of successive sequences of A and B monomers with equal length Z is at the interface between two immiscible solvents that are respectively good for one of the sequences and poor for the other one. We find two semi-dilute regimes, when the copolymers overlap. For monomer concentrations below Gamma**, we find a first range where the thickness of the copolymers is constant and equal to the radius of a sequence. For concentrations larger than Gamma**, a second regime appears, where the sequences stretch out and adopt a conformation similar to what was reported for grafted polymers. Finally at a concentration Gamma(sat), the interface is completely saturated, and the copolymers form micelles in the bulk: it becomes energetically more favourable to have copolymers in the bulk than at interface.