Membrane decoration by amphiphilic block copolymers in bicontinuous microemulsions

The effect of various amphiphilic block copolymers of different molar masse s on the structure and phase behavior of ternary amphiphilic systems (water , oil, and nonionic surfactant) is investigated. Small amounts of PEP-PEO b lock copolymer lead to a dramatic increase in the volumes of oil and water, which can he solubilized in a bicontinuous microemulsion. High-precision n eutron scattering experiments with a sophisticated contrast variation techn ique demonstrate that the polymers form uniformly distributed mushroom conf ormations on the surfactant membrane. Based on these observations, we propo se a universal mechanism for the swelling behavior, which is due to the var iation of the membrane curvature elasticity.