Quantitative structure–property relationships of surfactants: prediction of the critical micelle concentration of nonionic surfactants

The quantitative structure–property relationship was used to predict the critical micelle concentration (cmc) of a nonionic surfactant in aqueous solution. Several structural, electronic, spatial and thermodynamic properties were selected as descriptors to build the relationship between the macroscopic properties (such as the cmc) and microscopic structures. These descriptors include the octanol/water partition coefficient, the heat of formation, the volume of a molecule and the energy of the lowest unoccupied molecular orbital. A general four-parameter structure–property relationship between the logarithm of the cmc and the descriptors, which was developed for a set of 37 nonionic surfactants (r2=0.990, F-test=802.970), can be used to predict the cmc of nonionic surfactants without the experimental data. The success of this approach indicates that the prediction of the cmc for other surfactants, such as anionic, cationic and zwitterionic surfactants, as well as the prediction of other surfactant properties, can be obtained.