Surface tension of aqueous binary solutions at low temperatures

The paper is concerned with measurenaents of the surface tension of aqueous binary solutions at low temperatures. The eflects of both temperature and concentration on the surface tension of CaCI,. NaCIO~, and propylene glycol have been investigated. A differential capillary-rise method was employed lbr the measurements. The results showed that the surface tension of CaCI 2 and NaCIO~ increases monotonically as the concenm~tion of the solution increases, while for the propylene glycol solution the surlace tension decreases with increasing concentration. The surface tension of the testing liquids was found to be an almost-linear function of temperature from 20ʹ~C to just above the freezing temperature. Equations lbr the surface tension of the three aqueous binary solutions as a function of temperature and concentration are preseInted.