MICELLAR AND SOLUBILIZING BEHAVIOR OF PLURONIC L-64 IN WATER

The temperature effect in aqueous solutions of a polyoxyethylene-polyo xypropylene-poloxyethylene (POE-POP-POE) block copolymer, Pluronic L-6 4 in water, was examined by means of viscosity, sedimentation, scatter ing and sound velocity measurements. Micelle formation in L-64 was str ongly dependent on concentration and temperature. An increase in tempe rature shifted the micelle formation markedly to lower concentration; the micelle grew large particularly at temperatures near the cloud poi nt. The viscosity data were analyzed to estimate various parameters, i ncluding the hydrated micellar volume, hydration number, hydrodynamic radius, etc. An increase in diazepam solubility in L-64 micelles with increasing concentration and temperature was observed.