Morphology control of giant vesicles by composition of mixed amphiphilic random block copolymers of poly(methacrylic acid)-block-poly(methyl methacrylate-random-methacrylic acid)

The morphology of giant vesicles comprised of mixed amphiphilic poly(methacrylic acid)-block-poly(methyl methacrylate-random-methacrylic acid), PMAA-b-P(MMA-r-MAA), was effectively controlled by its composition. The mixed copolymers with different lengths of the hydrophilic PMAA blocks varied the morphology depending on the composition at a constant length of the hydrophobic P(MMA-r-MAA) block. Large contorted vesicles formed by the copolymer containing a short PMAA block (PMAA-S) were changed into more severely contorted vesicles, accompanied by the formation of much smaller spherical vesicles as the composition of the copolymer with a middle PMAA block (PMAA-M) increased. Spherical vesicles produced by the PMAA-M copolymer were transformed into worm-like vesicles, followed by key-shaped vesicles with the increasing composition of the copolymer with a long PMAA block (PMAA-L). Worm-like vesicles with an uneven surface formed by the PMAA-L copolymer were changed into various spherical and elliptical vesicles due to the coexistence of the PMAA-S copolymer.