Self-assembly of ABA triblock copolymers under soft confinement

Using Monte Carlo method, the self-assembly of ABA triblock copolymers under soft confinement is investigated in this study. The soft confinement is achieved by a poor solvent environment for the polymer, which makes the polymer aggregate into a droplet. Various effects, including the block length ratio, the solvent quality for the blocks B, and the incompatibility between blocks A and B, on the micellar structures induced by soft confinement are examined. By increasing the solvent quality of B blocks, the micellar structure transforms from stacked lamella to bud-like structure, and then to onion-like structure for A(5)B(8)A(5) triblock copolymers, while the inner micellar structure changes from spherical phase to various cylindrical phase, such as inner single helix, double helixes, stacked rings and cage-like structures, for A(7)B(4)A(7) triblock copolymers. Moreover, the formation pathways of some typical aggregates are examined to illustrate their growth mechanisms. (C) 2015 Elsevier B.V. All rights reserved.