Norm descriptors for predicting the hydrophile-lipophile balance (HLB) and critical micelle concentration (CMC) of anionic surfactants

The hydrophile-lipophile balance (HLB) and critical micelle concentration (CMC) are vitally important indexes to measure the performance of surfactants quantitatively. Herein, based on the concept of norm index, new norm descriptors were proposed for describing the HLB and CMC of anionic surfactants, and two QSPR models were built to calculate the two values. Results showed that the norm descriptors-based models could give satisfactory prediction effect for the HLB and CMC of anionic surfactants with the R-2 of 0.9983 for HLB and R-2 of 0.9130 for CMC. The satisfactory results of several validations demonstrated that these models were stable, reliable and had a very good predictive ability. Moreover, for anionic surfactants without experimental values, the predicted HLB of 19 anionic surfactants and predicted CMC of 101 anionic surfactants were respectively calculated using the proposed models. The above results indicated that the norm index was suitable for evaluating the HLB and CMC.