PREDICTION OF CRITICAL MICELLE CONCENTRATION USING A QUANTITATIVE STRUCTURE-PROPERTY RELATIONSHIP APPROACH .2. ANIONIC SURFACTANTS

Relationships between the molecular structure and the critical micelle concentration (cmc) of anionic surfactants were investigated using a quantitative structure-property relationship approach. Measured cmc va lues for 119 anionic structures, representing sodium alkyl sulfates an d sodium sulfonates with a wide variety of hydrophobic and hydrophilic structures, were considered. The best multiple linear regression mode l involved three terms (descriptors) and had a correlation coefficient of R(2) = 0.940. Very good correlations (R(2) = 0.988) were obtained using three descriptors for a subset of 68 structures, with structural variation only in the hydrophobic domain. From the descriptors used i n these regressions, one can conclude that the cmc is primarily depend ent on the size (volume or surface area) of the hydrophobic domain and to a lesser extent on the structural complexity of the surfactant mol ecule. (C) 1997 Academic Press.