A new thermodynamic method to estimate surface tension of liquids

A new thermodynamic model equation of Vapor-Liquid surface tension γ is derived, γAm=Φ(V)(E(L)−E(V))−TΔS; where Am is the molar surface area, E(L) and E(V) are the molar cohesive energy of liquid phase and vapor phase correspondingly, Φ(V) the mean volume fraction exposed to vapor phase of a surface molecule, ΔS the excess surface entropy. Φ(V) is a function of (E(L)− E(V))/nsRT, ns denotes the segment number in a chain molecule, Φ(V) increases slowly with elevating temperature T. This model has been verified for surface tension estimation of simple liquids, organic liquids (non-polar, polar and hydrogen-bonding) and metallic liquids at various temperatures with successful results.