We study the equilibrium morphology of an asymmetric $A\text{−}B$ diblock copolymer solution film confined between homopolymer-grafted substrates by using self-consistent-field calculations. We find that on decreasing the copolymer concentration, a reentrant structural transformation between $\text{hexagonal}\to \text{lamellar}\to \text{hexagonal}$ phases occurs as a result of the competition between the wetting effect of the brush surface and the bulk phase behavior of the asymmetric copolymer driven by the $A\text{−}B$ interfacial tension.

• Received 22 February 2005

DOI:https://doi.org/10.1103/PhysRevE.72.051804