The structures of micelles and microemulsions consisting of polyglycerol polyricinoleate (PGPR) were investigated by small-angle X-ray scattering (SAXS) and rheological measurements. The SAXS results show that amphiphilic PGPR molecules form stable micelles in glycerol. When vitamin E is added to the PGPR micelles, it is encapsulated in the micelles and forms an emulsion. These micelles are stable towards mechanical shearing up to a shear rate of 1000 s-1, with shear thinning occurring in the emulsion above 100 s-1, indicating that the emulsion may undergo break up by shearing, but recovers the structure by releasing shear strain.
Keywords: microemulsion; polyglycerol polyricinoleate; rheology; small angle X-ray scattering; vitamin E.