몰농도 또는 몰분율로 표시되는 임계 미셀 농도와 열역학적 포텐셜과의 관계

Critical Micelle Concentration Expressed in Molarity or Mole Fraction and Its Relation to Thermodynamic Potentials

The critical micelle concentration (CMC) at which micelles start to form from a surfactant solution is usually measured in terms of conventional concentration units. However, the thermodynamic potentials are expressed in terms of mole fraction XCMC and XCMC cannot be directly measured experimentally. The Gibbs free energy, △G*mic, in particular is related to XCMC through △G*mic = RTln XCMC. When it comes to CMC, the molar CMC, CCMC, differs only by the proportionality C-1w with Cw being the molarity of water. Hence, CCMC is found to be a proper representation of CMC. However, in calculation of △G*mic and other thermodynamic potentials from the CMC, XCMC or CCMC/Cw should be used.