Self-assembly of AB diblock copolymer solutions confined in cylindrical nanopores

Abstract

The self-assembly of AB diblock copolymer solutions confined in a cylindrical nanopore is investigated systematically via Monte Carlo simulations. Two types of diblock copolymers, i.e. hydrophobic and amphiphilic AB diblock copolymers, are examined to reveal the effects of the wall surface properties, copolymer concentration, and diameter of the cylindrical nanopore on the self-assembled nanostructures. It was found that the wall surface properties and the nanopore diameters dominate the self-assembled nanostructures, whereas the copolymer concentration has little influence on the resulting nanostructures. Moreover, the contact number and mean-square radius of gyration of hydrophobic polymer segments were used to monitor the evolutions of the chain configurations under cylindrical confinement. It is interesting to note that the polymer chains were more folded when the confinement effect (le/d) exceeded a critical value, thus causing a transition in the self-assembled structures. This result indicates that the block copolymer can automatically adjust its chain configuration to adapt to the strongly confined environment, which provides new opportunities to explore more novel self-assembled nanostructures based on existing block copolymers.