ESTIMATION OF INTERFACIAL-TENSION BETWEEN ORGANIC LIQUIDS AND WATER

The interfacial tension between organic liquids and water is an import ant parameter in determining the fate of immiscible organic compounds in the environment. In the absence of measured values, it is often nec essary to estimate this parameter for engineering calculations. Thus, it is important to quantitatively assess the methods available for est imating interfacial tension. This study compares five techniques, sele cted on the basis of wide-spread use and practicality, for the estimat ion of interfacial tension in binary systems. Based on the values of t he average relative error and the standard deviations, the most accura te methods appear to be those of Donahue and Bartell (ref 8) and Fu et al. (ref 5). Donahue and Bartell's method performs better if measured mutual solubility data are available. However, Fu et al.'s method is preferred in cases where mutual solubility data must be estimated. Bot h methods have lower accuracy for systems where the interfacial tensio n is less than 10 dyn/cm.