Mechanical properties of one-phase microemulsion system

A theoretical approach for free Gibbs energy of microemulsion ternary systems water-oil-non-ionic surfactant of arbitrary size and shape is presented. We consider the Gibbs energy for three different geometries (flat, spherical and cylindrical) to estimate the free energy of surfactant-oil-water microemulsion. We also used a lattice-based self-consistent field (SCF) theory to calculate the free energy and the mechanical properties (the mean bending modulus k _c , and the spontaneous curvature J ₀, and the saddlesplay modulus $bar k$ ) of such system. The values obtained by our theoretical approach were compared qualitatively with those predicted by SCF theory. The results of theoretical approach were in a good agreement with those of SCF in the region where the values of free energy approach zero for the flat geometry. We demonstrated that the parameters k _c, J ₀ and $bar k$ strongly depend on the surfactant concentration.