Self-assembly of diblock copolymers under confinement

Block copolymers are a class of soft matter that self-assemble to form ordered morphologies at nanometer scales, making them ideal materials for various applications. The self-assembly of block copolymers is mainly controlled by the monomer-monomer interactions, block compositions and molecular architectures. Besides these intrinsic parameters, placing block copolymers under confinement introduces a number of extrinsic factors, including the degree of structural frustration and surface-polymer interactions, which can strongly influence the self-assembled morphologies. Therefore confinement of block copolymers provides a powerful route to manipulate their self-assembled nanostructures. In this review, we discuss the relationship between confining conditions and the resulting structures, focusing on principles governing structural formation of diblock copolymers under two-dimensional and three-dimensional confinement. In particular, the effects of commensurability condition, surface-polymer interactions, and confining geometries on the self-assembled morphologies are discussed.