Study of Schultz distribution to model polydispersity of microemulsion droplets

Abstract

We have employed a histogram analysis method to study the spectra obtained by small-angle neutron scattering (SANS) in order to investigate the size distribution of a model water-in-oil three-component microemulsion. It is found that the often used Schultz distribution function is indeed one of the reasonable choices to represent the moderately polydispersed droplet system. Analysis based on mean spherical approximations of the SANS data and inverse Laplace transformation of quasi-elastic light scattering data, assuming a Schultz distribution, yield consistent results compared with the histogram method. The polydispersity index, M/R, found in the model microemulsion is roughly constant at larger R, but increases at small R, consistent with a theory proposed by Safran.