Surface tension of pentafluoroethane and 1,1,1,2,3,3,3-heptafluoropropane

The surface tension of pentafluoroethane (HFC-125) and 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) has been measured in the present work. The measurements were conducted at vapor–liquid equilibrium conditions. Thirty-nine data points have been obtained by the differential capillary rise method (DCRM) in the temperature range from 243 to 340 K for HFC-227ea, and 20 data points from 248 to 323 K for HFC-125. The temperature uncertainty is within ±20 mK. The accuracy of surface tension measurements is estimated to be within ±0.15 mN m−1. Also correlations of the surface tension data are proposed.