Linear and nonlinear poroelastic analysis of swelling and drying behavior of gelatin-based hydrogels

The swelling and drying behavior of a gelatin-glycerol-water hydrogel are examined experimentally for different compositions and different environmental conditions. Significant asymmetry in the swelling and drying kinetics is observed from these measurements. The early time measurements are interpreted first within the context of a linear poroelastic theory, but a fully nonlinear Flory-Rehner theory is required in order to capture the long time behavior. Comparison of the experimental measurements with simulations based on both the linear and nonlinear constitutive models yields a consistent calibration of the material parameters of the models.