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

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 Å -1 ) and light scattering (LS, q ≈ 0.001 Å -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.