Spontaneous vesicle formation in a block copolymer system
We have investigated the formation of vesicles in the binary system of a triblock copolymer of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) with the average composition EO5PO68EO5 in water. Vesicles are formed when a solution of unimers is heated into a two-phase region where, at equilibrium, a concentrated lamellar phase coexists with a dilute solution of unimers. The vesicles were