Density and Temperature Dependencies of Liquid Surface Tension

In this paper the density and temperature dependencies of surface tension are investigated. Using the Lennard-Jones (۱۲,۶), as an effective pair interaction potential, a linear expression is derived for isotherms of g /r۲  versus r۲ for some normal and ChloroFluoroCarbons (CFCs) fluids, where  is surface tension and r = ۱/v is molar density. The linearity behavior of the derived equation is well fitted onto the experimental data of surface tension for monatomic, diatomic, nonpolar, polar, hydrogen-bonded and chlorofluorocarbons. In addition, the temperature dependence  of surface tension for ۲۰ different fluids is examined, in which the contributions of both terms of the average effective pair potential to the g  are determined. For all liquids investigated in this work, surface tension increases with density except for water. The surface tension of water for isotherms within ۲۸۰-۳۰۰ K decreases with density, whereas increases within the range of ۳۱۰-۳۲۰ K.

کلیدواژه ها:

Equation of State (EOS) ، Linear Isotherm Regularity (LIR) ، Surface tension ، Effective pair potential