ABSTRACT
The surface tension / is the reversible work (i.e., the reversible increase in the Gibbs free energy G) as a result of the creation of a unit surface area, at constant temperature, pressure and composition [1-4]. The increase in G upon the creation of new surface area is caused by the imbalance of the molecular forces acting on the molecules at the surface, compared with the forces acting on molecules in the interior (bulk) of a liquid or a solid. The surface tension is the key physical property of the surface of a material. It is
expressed in units of energy/area, such as J/m2 which is identical to 1000 dyn/cm.
Dyn/cm are quoted more often than J/m2. There are many independent methods for measuring / for liquids, including both
ordinary molecular liquids and polymer melts. Melts of oligomers of relatively low average molecular weight are commonly used instead of polymers of high molecular weight in measuring the surface tension of a polymer melt.
