Frustration In Block Copolymer Assemblies

Frustration is ubiquitous in condensed matter systems and it provides a central concept to understand the self-assembly of soft matter. Frustration is found at multiple scales in polymeric systems containing block copolymers. At the molecular scale, frustration arises because the chemically distinct blocks repel each other whereas the chain connectivity prevents a macroscopic separation. At the mesoscopic scale, frustration occurs due to the competition between the tendency for the block copolymer assemblies to maintain their native shape and the requirement to fill the space. At an even larger scale, frustrations could be induced by external fields or spatial confinement. Recent theoretical and experimental studies provide a good understanding of the origin of various frustrations in the self-assembly of block copolymers. Furthermore, it has been demonstrated that designed block copolymer systems, either in the form of multiblock copolymers with different architectures or block copolymer blends, could be utilized to regulate frustrations resulting in the formation of complex ordered and hierarchically structured phases.