An obstruction-scaling model for diffusion in homogeneous hydrogels

A mathematical description of the restricted movement a solute experiences while diffusing in a homogeneous hydrogel is presented. The model is based on the premise that physical obstruction effects dominate the diffusive process, and a scaling law expression is incorporated to describe the distance between cross-links in the polymer network. The model was compared to experimental data taken from literature sources and found to provide good agreement to the effects of both polymer volume fraction and solute size on the diffusivity of a solute within the hydrogel.