Why do surface tensions of most of organic liquids demonstrate close values?

TL;DR

This paper explains why most organic liquids have similar surface tension values, attributing it to London dispersion forces that depend mainly on molecular size and ionization potential, which vary little among these liquids.

Contribution

It clarifies the fundamental reasons behind the close surface tension values of organic liquids, emphasizing the role of London dispersion forces and molecular parameters.

Findings

Surface tension values are of the same order of magnitude for most organic liquids.

Surface tension depends primarily on ionization potential and molecular diameter.

London dispersion forces are the main governing factor for surface tension in these liquids.

Abstract

Values of surface tension of most of organic liquids are of the same order of magnitude. The natural explanation for this lies in the fact that surface tension is governed by London dispersion forces, which are independent of the permanent dipole moment of molecules. The surface tension of organic liquids (with the exception of polymers and polymer solutions) depends on the ionization potential and the diameter of the molecule only. These parameters vary slightly for organic liquids.