ISO 4311-79

Anionic and non-ionic surface active agents – Determination of the critical micellization concentration – Method by measuring surface tension with a plate, stirrup or ring

This standard specifies the method that is carried out in the following way: Determination of the surface tension of a series of solutions whose concentrations bracket the critical micellization concentration. Plotting of the graph of surface tension as a function of the logarithm of the concentration: the critical micellization concentration corresponds to a singular point on this curve. In this point the curve shows a sharp change of slope.

Tensiometer specified in ISO 304