Dependency of swelling on the length of subchain in poly(N,N-dimethylacrylamide)-based gels

Abstract
The equilibrium swelling degree of poly(N,N-dimethylacrylamide) (polyDMAAm)-based gels in water was systematically studied with various initial monomer (cm) and cross-linker (cxl) concentrations, and as a function of initial concentration of fully ionized co-monomer, 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS). Proportionality of the length of a subchain (N) in the gels to [cxl(cm+cxl)]−1 was revealed, both theoretically and experimentally. Equilibrium swelling data indicate non-Gaussian elasticity of the gel network.