Coarse-grained simulation study on the self-assembly of miktoarm star-like block copolymers in various solvent conditions.

The self-assembly processes of miktoarm star-like block copolymers (Ax1)y-C-(Bx2)y, in which y homopolymer chains of type A with chain length x1 as well as y chains of type B with chain length x2 are connected to a center core C, are investigated by using Brownian dynamics simulations. We focus on the selective solvent condition, i.e., the solvent is poor for components B and C, but varies from good to poor for component A. The miktoarm star-like block copolymers with A and B arms of equal length can form spherical micelles when the solvent is good for component A. In the same solvent conditions, the micelles contain fewer miktoarm star-like block copolymers as the arm length increases. When the solvent is poor for component A, the miktoarm star-like block copolymers can self-assemble into cylindrical or disk-like micelles with decreasing solvent quality. For the miktoarm star-like block copolymers with longer B arms but shorter A arms, self-assembly into spherical vesicles is possible in a wide range of solvent conditions.