A Kinetic Approach to the Calculation of Surface Tension in a Spherical Drop

Abstract

Surface tension in drops has been investigated mainly from a thermodynamic standpoint, more rarely with kinetic methods. In the present work, this problem is studied in the framework of kinetic theory, starting from Sutherland's approximation for Van Der Waals interaction between molecules. Surface tension is calculated as a function of drop radius: it is found that it approaches swiftly an asymptotic value, for radii of several times the intermolecular distance. This theoretical asymptotic value is compared to experimental values for a few liquids, and is found in reasonable agreement.