The effect of binary block-selective solvents on the self-assembly of ABA amphiphilic triblock copolymer in dilute solution was studied by means of Monte Carlo study. The simulative results showed that the proportion of the binary block-selective solvents is one of the key factors that determines the morphologies of the copolymer aggregates. The morphologies formed by ABA amphiphilic triblock copolymers changed from vesicle to lamella, ring, rod, and then to spheres by changing the proportion of binary solvent mixtures. The results revealed that changing the proportion of binary solvent mixtures and adjusting core-solvent interaction of single solvent had an equivalent effect on the self-assembled structure for the ABA amphiphilic triblock copolymers. Moreover, the dynamical pathways leading to ring and vesicle are analyzed in detail. It was found that the oblate membranes closed up to form vesicles, while the oblate membranes dissolved a hole to form ring.

Key words: binary block-selective solvents, amphiphilic triblock copolymer, self-assembly, Monte Carlo simulation