Study of self-diffusion in two binary solutions, glycerol-water and methanol-water using di usion-ordered spectroscopy

The concentration and temperature behaviors of the self-diffusion coecient were analyzed in glycerol-water and methanol-water solutions using diffusion-ordered spectroscopy (dosy) experiment. our results indicate that the self-diffusion coecient dips with increasing concentration and decreasing temperature. the concentration behavior shows that there is hydrogen bond interaction between water and alcohol, which declines the self-diffusion coecients of both in the aqueous binary mixtures. the self-diffusion activation energies were estimated 13.6, 29.4, and 32.8 (kj/mol) for methanol and 24.8, 25.5, and 27.6 (kj/mol) for water in the methanol-water solutions with 0.03, 0.10, and 0.20 mole fractions of methanol, respectively. the methanol self-diffusion activation energy, in the very dilute methanol-water solution (0.03 mole fraction of methanol), is consistent with the formation of iceberg-like structure which helps methanol to diuse quickly. the water self-diffusion activation energies indicate that water network is not significantly perturbed by methanol and the water molecules diffuse in the same manner in methanolwater solutions.