Comparison of the Experimental and Theoretical Structure Factors of Temperature Sensitive Polymer Gels

Abstract

The comparison of the experimental and theoretical structure factors, S(q), of weakly charged polymer gels has been carried out as a function of the gel parameters, i.e., temperatures at preparation and at observation, polymer concentration, and degrees of cross-linking and of polymerization, where q is the scattering vector. Experimental structure factors at two different q regimes, i.e., small-angle neutron scattering (SANS, 0.005 ≤ q ≤ 0.1 A-1) and light scattering (LS, q ≈ 0.001 A-1) regimes, were employed for the comparison with the Rabin−Panyukov (RP) theory for weakly charged gels. In the case of SANS, a quantitative agreement was obtained for S(q) in the poor solvent regime. For LS, S(q) was decomposed to two contributions from dynamic thermal fluctuations and static frozen inhomogeneities. The experimental results on their parameter dependence of S(q) were successfully reproduced by the RP theory.