Quantifying deformation in gel swelling: Experiments and simulations

A technique for the real-time visualization of material line movement durin g transparent gel deformation was developed based on caged photo-activated fluorophores covalently attached to the gel network. It is used to quantita tively monitor the swelling of sodium polyacrylate and poly(acrylamide-sodi um acrylate) gels in quasi two-dimensional constrained geometries. The expe rimentally obtained profiles for the Finger deformation tensor and the poly mer concentration are compared with transient simulations of a model of tra nsport in polyelectrolyte gels.