Oil-in-Oil-Emulsions: Tailor-Made Amphipolar Emulsifiers

摘要

In order to obtain stable biphasic solvent mixtures such as emulsions and miniemulsions, distinct emulsifiers are required for the liquid/liquid interface. Until recently, nanoscale polymer particles have been mainly gained from waterborne heterophase techniques in radical processes, herein nonaqueous emulsions are presented. For these biphasic systems consisting of two aprotic organic nonmiscible solvents, high molecular weight amphipolar block copolymers were developed which show selective solubility in both phases and give additional stability by sterical shielding. Different emulsifiers, ranging from low molecular weight surfactats up to long chain block copolymers, were designed for the stabilization of hydrocarbon/perfluorocarbon mixtures and the metallocene-catalyzed synthesis of polyolefins therein. Furthermore, PI-b-PMMA emulsifiers were applied for mixtures of DMF dispersed in n-hexane. By these emulsions high molecular weight polyester and polyurethane particles were recieved, while further developments led to more sophisticated morphologies like core-shell structures.