Surface age

The surface age is the period of time from the beginning of the production of a surface or interface to the time of the observation or measurement. With surfactant solutions, the surface tension depends on the surface age. The time-dependent value is referred to as the dynamic surface tension - in contrast to the surface tension in thermodynamic equilibrium.

Tensiometers which use dynamic methods, such as a bubble pressure tensiometer or a drop volume tensiometer, for example, enable the surface age to be specified over a large time range and thus enable fast processes such as painting, printing, spraying and cleaning to be simulated.