Liquid Viscosity and Surface Tension of R1234yf and R1234ze Under Saturation Conditions by Surface Light Scattering

Abstract

In the present study, surface light scattering (SLS) was used for the simultaneous determination of liquid kinematic viscosity and surface tension of 2,3,3,3-tetrafluoroprop-1-ene (R1234yf) and of trans-1,3,3,3-tetrafluoroprop-1-ene (R1234ze) under saturation conditions. A new SLS apparatus was built up and checked with 1,1,1,2-tetrafluoroethane (R134a), and a good agreement of our data from SLS with literature could be found. With the new apparatus, R1234yf and R1234ze were investigated in the temperature ranges between (293 and 365) K and between (295 and 373) K. For determination of the liquid kinematic viscosity the expanded uncertainties on a confidence level of more than 95 % (k = 2) are estimated to be ± 2 % for reduced temperatures Tr (= T/Tc) < 0.95, and ± 6 % for Tr close to 0.99. For the surface tension, the expanded uncertainties are less than ± 1.5 % (k = 2) in the whole temperature range.