Measurement of mutual diffusion coefficients and thermal diffusivities by quasi‐elastic light scattering

Quasi‐elastic light scattering techniques have been employed to measure the mutual diffusion coefficient D AB as a function of concentration in eight binary mixtures and the thermal diffusivity x in nine pure liquids and two binary mixtures. The mass diffusivities obtained are typically accurate to 3% while thermal diffusivities are known to be accurate to 5%; both types of values are in substantial agreement with the available bulk values. Under most circumstances light scattering is found to offer distinct advantages over the standard techniques for determining mass and thermal diffusivities.