Small-angle X-ray scattering of systems with inhomogeneous particles

Stabilization procedures are used to deduce the distance distribution function p(r) for the specific case of inhomogeneous particles where the scattering curve I(q) is dominated by a peak resulting from the particle form factor. The system sodium dodecyl sulfate (SLS)/water micellar solution is studied by small-angle X-ray scattering for low concentrations (up to 9 wt% of SLS). Subsequent computation of the electron-density distribution ρ(r) from the function p(r) confirms the existence of micellar anisometry, which is also deduced from D_max values. The modelling of ρ(r) by two- and three-step functions is discussed; both give reasonable agreement with the p(r) function.