Diblock copolymers at a homopolymer-homopolymer interface: A Monte Carlo simulation

The properties of diluted symmetric A-B diblock copolymers at the interface between A and B homopolymer phases are studied by means of Monte Carlo (MC) simulations of the bond fluctuation model. We calculate segment density profiles as well as orientational properties of segments, of A and B blocks, and of the whole chain. Our data support the picture of oriented ''dumbbells'', which consist of mildly perturbed A and B Gaussian coils. The results are compared to a self-consistent field theory (SCFT) for single copolymer chains at a homopolymer interface. We also discuss the number of interaction contacts between monomers, which provide a measure for the ''active surface'' of copolymers or homopolymers close to the interface.