RELATION BETWEEN THE SIZE OF LAMELLAR DROPLETS IN ONION PHASES AND THEIR EFFECTIVE SURFACE-TENSION

A closed packed system (''onion phase'') of so-called lamellar droplet s, consisting of concentric surfactant bilayers which are separated fr om one another by water, may be obtained by subjecting a continuous la mellar phase to shear. We propose a model for the size of these lamell ar droplets under shear as a function of their effective surface tensi on. This model fits the available experimental data quantitatively and explains the dependence of the size on surfactant volume fraction.