Coarse-Grained Simulations of Solute Diffusion in Crosslinked Flexible Hydrogels

In this work, the longtime diffusion of a solute in a chemically crosslinked and flexible hydrogel is computed from a coarse-grained model of a polymeric network. The effects of different key parameters of this model on diffusion are assessed. The relevance of chain flexibility becomes important by increasing the polymer volume fraction and the solute size. In fact, the solute particle can moderately diffuse in flexible hydrogels even when its diameter is comparable to the mesh size. The diffusion coefficients obtained here are tested by comparing with the previously reported experimental data. A reasonably good agreement between the experiment and simulation is found without requiring any adjustable parameter.