What are the methods to determine critical micellar concentration of a surfactant?

Answer 1

The critical micellar concentration (CMC) of a surfactant can be determined using several methods, including surface tension measurements, where a plot of surface tension versus surfactant concentration shows a breakpoint corresponding to the CMC. Other methods include conductivity measurements, which increase with micelle formation, and light scattering techniques, where a sudden increase in scattered light intensity indicates micelle formation. Additionally, fluorescence probing can be employed, using a hydrophobic fluorescent dye that increases in intensity once micelles form. Each of these methods provides a reliable means to identify the CMC of surfactants.