Thermophysical properties of binary and ternary fluid mixtures from dynamic light scattering

Several thermophysical properties of R507, a binary refrigerant mixture, and R404A, a ternary mixture, have been determined by dynamic light scattering (DLS), in both the liquid and the vapor states, along the saturation line approaching the vapor-liquid critical point. Data for the thermal diffusivity a and sound speed c(s) cover a range of temperatures down to 270 K, and data for the surface tension sigma and kinematic viscosity nu down to 230 K. For both mixtures the behavior of all properties determined can be correlated well by the mass-weighted sum of the respective pure component data, when all data are represented as a function of the reduced temperature.