Small-angle scattering from colloidal dispersions

Colloidal dispersions have structure on length scales from 10 to 1000 Å. Both inter- and intraparticle scattering contribute to the measured small-angle scattering spectra. Here are reviewed methods of quantitatively analyzing scattering from interacting polydisperse colloidal suspensions. The concept of a colloidal macrofluid enables the use of statistical thermodynamic theories to calculate the important effects of interparticle interactions on the scattering curves. Neglect of interparticle interactions negates the usefulness of measured distance distribution functions. Polydispersity and particle anisotropies are treated in an approximate way with decoupling approximations. Scattering data must be obtained over a wide range of q, and model fits must be consistent with all the data.