Surface tension of pure water and aqueous lithium bromide with 2-ethyl-hexanol

The surface tension of water and 60% LiBr solution in the presence of 2-ethyl-hexanol (2EH) was measured using a drop volume method. The measurements were conducted at atmospheric pressure in the presence of air. The measurement results show that the effect of 2EH from the vapor side is much more significant than the effect from the liquid side. The 2EH vapor concentration must be closely controlled in order to obtain repeatable and accurate data, The different solubility levels of 2EH in water and 60% LiBr solution lead to differences in surface tension as a function of drop frequency and differences in surface tension as a function of 2EH concentration in the liquid. In addition, a new method was developed to determine the solubility limit of 2EH. The solubility limit of 2EH in water and 60% LiBr solution were found to be 835 +/- 45 and 27.1 +/- 0.56 ppm, respectively, which are significantly different from previously reported values. These measurements are relevant to the study of Marangoni convection in absorption chiller technology. (C) 2001 Elsevier Science Ltd. All rights reserved.