PARTITIONING OF POLYMER AND INORGANIC COLLOIDS IN 2-PHASE AQUEOUS POLYMER SYSTEMS

The well-known phenomenon of partitioning of bioparticles in two-phase aqueous polymeric systems is extended to a variety of polymer (acryli c latex) and inorganic (TiO2) colloidal particles. It is demonstrated that particle partitioning into a particular phase is controlled in ra tional ways by particle surface chemistry, vie., hydrophobicity, funct ional groups such as hydroxyl and carboxyl, and pH effects, in relatio n to the chemical nature of the water soluble polymers (WSPs) that com prise the phase-separated system. WSPs include poly(ethylene oxide), p oly(N-vinylpyrrolidone), dextran, and a hydrophobe-terminated water so luble polyurethane based on polyethylene oxide. Mixtures of colloidal particles can be separated by selective partitioning.