Aggregative properties of Rhodamine dyes in polyacrylamide hydrophilic gel media

The visible absorption spectra of two Rhodamine dyes (R6G and RB) in aqueous solutions, and in the polyacrylamide hydrogel matrix with different composition were studied at room temperature. The spectral properties of the dye-loaded hydrogel were also investigated. The transport and the solute–solute interactions of the ionic dyes in aqueous solutions across the hydrophilic gels were calculated. The monomer–dimer equilibrium of these ionic dyes in water and in different composition of hydrogel environment with different soaking time has been investigated by means of UV–Vis spectroscopy. The natures of the interacting pairs in these dyes were discussed using the Kasha exciton theory.

► Hydrogel consist different structural part with unlike physical and chemical features.
► R6G and RB dyes interact with the different part of the hydrogel network.
► Aggregation properties controll by the pores sizes and swelling of the hydrogel host.