Orientational wetting in hybrid liquid crystalline block copolymers

The wetting behavior of hybrid isotropic/smectic block copolymers is examined. For symmetric diblocks, the generic parallel ordering of the lamellae is suppressed, and the copolymer wets the surface with the lamellae perpendicular to the surface. The parallel ordering, however, can be restored in asymmetric lamellar diblocks. We propose an explanation in terms of block-specific interface wetting, and configurational frustration induced by the incommensurability between the smectic spacing and the smectic block size defined by the diblock lamellar period.