Constitutive Modeling of the Mechanical Response of Nanocomposite Hydrogels for Tissue Engineering

A model is developed for the elastic behavior of nanocomposite hydrogels subjected to swelling-drying under an arbitrary deformation with finite strains. Novel constitutive equations are derived based on the Flory concept of flexible chains with constrained junctions and solvent-dependent reference configuration. Adjustable parameters in the stress-strain relations are found by fitting observations on N,N-dimethylacrylamide/hectorite nanoclay hydrogels. The constitutive model describes adequately the mechanical response of nanocomposite hydrogels subjected to swelling-drying and solvent exchange.