An optically active rod-coil-rod tfibloek eopolymer containing poly(ethylene oxide)(PEO) as the flexible segment and poly {(+)-2

5-bis[4’-((s)-2-methyl butoxy) phenyl] styrene} (PMBPS) as the rigid segment

PMBPS-b-PEO-b-PMBPS．was synthesized via atom-transfer radical polymerization．The PMBPS block had a stable helical conformation with an excess of screw sense in solution．The self-assembly behavior of the tnblock copolymer in dioxane/water mixed solvents was examined by means of TEM and turbidity measurements．The tfiblock copolymer molecules aggregated when water content in the system was about 2wt％ The higher the initial polymer concentrations

the lower the critical water content．They formed vesicles with highly dispersed outside diameters

but they had a relatively uniform wall thickness of (27±3) nm．