Analysis of Dynamic Light Scattering from Transient Gels

Abstract

The possibility of using dynamic light scattering to measure parameters describing the dynamic response of transiently bonded gels is investigated. When a sample is subjected to externally imposed mechanical excitation, a resonance in the frequency dependence of the response will be observed if the relaxation times for bond formation and breakage are long on a timescale determined by the dimensions and the instantaneous shear modulus of the sample. However, if the relaxation is fast on such a timescale, the response does not show resonance behavior and is maximal at zero frequency. Analytical expressions are provided that relate the half-widths of spectral response to kinetic parameters pertaining to the internal restructuring of the gel matrix.