Dynamics of overall swelling profile of multiresponsive ionic dimethylacrylamide-based hydrogels and cryogels: Diffusion characteristics evaluation of salt-dependent swelling

Due to the importance of ion–polymer interactions in many technological applications, systematic measurements have been investigated on a variety of ionic poly(N,N-dimethylacrylamide) (PDMAAm) hydrogels and cryogels to determine the effect of mono- and multivalent ions on their dynamic properties. Using uniaxial compression, the influence of counter-ion valency on flexibility of charged polymer chains was investigated and the results were discussed as a function of ionic comonomer. To estimate the general swelling features, diffusion process and oscillating swelling–deswelling kinetics of ionic PDMAAm gels in salt solutions have been explained by model equations using early-time approximation as a function of characteristic response time.