How to calculate phase diagrams for microemulsions a simple rule

For nonionic microemulsions a simple rule is given to achieve a semiquantit ative prediction of phase boundaries. In particular, we consider the phase boundaries between a single-phase microemulsion and a 2 Phi-microemulsion ( i.e, a microemulsion coexisting with a water- or an oil-rich phase), as wel l as between a 2 Phi-microemulsion and a 3 Phi-microemulsion (i.e, a microe mulsion coexisting with a water- and an oil-rich phase). Our method treats weak and strong surfactants within a unified approach.