Investigation of the diffusion of dyes in agar gels

► The diffusion of rhodamine 6G and methylene blue dyes in agar gels was investigated. ► Experiments were run at 30, 50, and 70 °C until equilibrium was reached. ► A Fickian approach was used to analyse and model the experimental data. ► Diffusion depended on temperature and size of the diffusing molecule. ► Diffusion coefficients were estimated and values agreed with literature.