Hydrophile–lipophile balance and solubility parameter of cationic surfactants

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Vol. 214; no. 1; pp. 167 - 171
• Main Authors: Proverbio, Z.E., Bardavid, S.M., Arancibia, E.L., Schulz, P.C.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 12.03.2003
• Subjects: Cationic surfactants; Hydrophile–lipophile balance values; Solubility parameter; Solubility parameter; Hydrophile–lipophile balance values; Cationic surfactants
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/S0927-7757(02)00404-1

By using hydrophile–lipophile balance (HLB) values of cationic surfactants obtained from literature, two methods to determine this property were tested to verify if they are applicable to such amphiphiles: Little's method with the surfactant solubility parameter ( δ) and the water number of Greenwald et al., related to their ability to promote inversion of emulsions. Cationic surfactants did not follow the behaviour of anionic and non-ionic surfactants. Little's method gave non-realistic values of HLB for cationic surfactants, whereas the Greenwald et al. treatment gave a non-linear relationship. However, both δ and water numbers are related with the HLB values, but these relations are different from those for anionic and non-ionic surfactants. This is not surprising on dealing with water number (anionic and non-ionic surfactants follow different equations in the paper of Greenwald et al.), but in the case of δ, Little has shown that both, anionic and non-ionic surfactants, follow the same equation. The solubility parameters of dodecyltrimethylammonium and dioctadecyldimethymammonium bromides, and the HLB value of dodecylpyridinium chloride are reported.