Critical Micelle Concentration (CMC) Measurement

The critical micelle concentration (CMC) is defined as the concentration above which micelles form. In surfactant based systems the formation of micelles is linked with the cleaning ability of the surfactant, The micelles are able to solubilise dirt oil etc aidig in their removal from surfaces and allowing them to dispersed into solution. The lower the CMC for a surfactant the less is needed to ensure stable cleaning performance.

There are a number of methods used to measure the CMC point one being surface tension. For concentrations below the CMC the surface tension will reduce as the concentration is increased. When the CMC point is reached, the surface tension is essentially invariant as the concentration of surfactant is increased.

LPD Lab Services Ltd uses a DataphysicsDynamic Contact Angle Tensiometer (DCAT21) tensionmeter to surface tension of liquids with different concentrations to enable the CMC point to be found. The equipment has a heatable stage to allow measurements of liquids up to 80°C.

If you would like to discuss your measurement requirements in more detail call us now.