Confined self-assembly of cylinder-forming diblock copolymers : effects of confining geometries

The effects of confining geometries on the self-assembly of cylinder-forming asymmetric diblock copolymers are studied using a simulated annealing technique. Morphological transitions of block copolymers confined inside two parallel flat walls, cylindrical channels, as well as spherical and ellipsoidal cavities are systematically investigated. Depending on the copolymer composition, confining geometry and degree of structural frustration, a very rich array of confinement-induced morphologies is predicted by the simulations. The results reveal that the dimensionality of the confinement can affect the structure, symmetry and degeneracy of the self-assembled structures. In particular, the effect of spherical confinement is much stronger than that of thin film or cylindrical confinement.