Measurement of interfacial curvatures in microemulsions using small-angle neutron scattering

Abstract A new method for SANS data analysis which enables one to directly compute the average Gaussian and square mean curvatures of the interface in a bicontinuous porous structure is proposed. We present the analysis of an extensive SANS data set of one-phase bicontinuous microemulsions (18 different C i E j /D 2 O/n-alkane systems) taken at the minimal specific surface point. Depending on the values of i and j , and the type of oil k , the point of minimal specific surface changes. We interpret the corresponding structural changes in terms of the interfacial curvatures and found that the dependence of the curvatures on i , j , and k cold be summarized by a single scaling law, which has a quadratic dependence of the curvatures on the surfactant volume fraction at the minimal specific surface point.