Corroboration of Princen's theory to cosmetic concentrated water-in-oil emulsions

The rheological behavior of cosmetic concentrated water-in-oil emulsions ha s been investigated in relation to their microstructure. Oscillatory measur ements and droplet-size distribution have been performed as a function of t he dispersed phase percentage. The elastic shear modulus is shown to exhibi t a universal dependence on the volume fraction Phi (v) according to Prince n's equation, i.e., increasing as Phi (1/3)(v) (Phi (v) - Phi (c)) where Ph i (c), the critical volume fraction, is equal to approximate to 0.714, a va lue close to the one obtained by Princen (0.712). (C) 2001 The Society of R heology.