Light Scattering from Gels

Abstract

Abstract The basic principles necessary to understand light scattering from gels are now well understood. The experimental techniques necessary to measure light scattering from gels are now highly developed. Yet there are many issues that need to be clarified in practice. The spatial correlations that exist in the polymer concentration in a gel need extensive further study. Gel samples with only intrinsic permanent concentration fluctuations need to be prepared. Defects due to dust, microsyneresis or other nonintrinsic inhomogeneities must be eliminated. Then careful measurements of R (q) should yield the necessary information about the microstructure of the gel. The value of the osmotic Poisson ratio is now well understood for gels at rest. Further work needs to be done on samples in partial states of swelling. More work appears promising in the study of critical concentration fluctuations in gels as well.