Binary Diffusion Coefficients of Glycerol-Water Mixtures for Temperatures from 323 to 448 K by Dynamic Light Scattering

The binary diffusion coefficients of mixtures consisting of glycerol and water with glycerol mole fractions of 0.299, 0.500, and 0.699 were investigated by dynamic light scattering (DLS) in macroscopic thermodynamic equilibrium over the temperature range 323-448 K. Furthermore, a beam displacement method implemented in the same experimental setup was used to determine the refractive indices of the mixtures required for the evaluation of the DLS measurements. The reported results represent the first temperature-dependent data set for the binary diffusion coefficient of glycerol water mixtures, where increasing diffusion coefficients were found for increasing temperature and decreasing glycerol concentration. The latter finding is consistent with literature data that are restricted to specific temperatures. The present results are in good agreement with the absolute values and concentration-dependent trends of the binary diffusion coefficients for glycerol water mixtures available in the literature.