Enthalpy and entropy of micellisation

Comparison with Equation (3.11) clearly shows that for similar AG, , the (cmc) is about two orders of magnitude higher for ionic surfactants when compared to a nonionic surfactant of the same alkyl chain length (see Table 3.1). 

In the presence of excess added electrolyte, with mole fraction x, the free energy of micellisation is given by the expression  

It is dear from Equation (3.15) that as p 0, that is when most charges are assodated with counterions, 

The enthalpy of micellisation can be calculated from the variation of cmc with temperature. This follows from. 

The entropy of micellisation can then be calculated from the relationship between AG° and AH°, that is 

---