Structure–interfacial properties relationship and quantification of the amphiphilicity of well-defined ionic and non-ionic surfactants using the PIT-slope method

• Published in: Journal of colloid and interface science Vol. 448; pp. 222 - 230
• Main Authors: Ontiveros, Jesús F., Pierlot, Christel, Catté, Marianne, Molinier, Valérie, Salager, Jean-Louis, Aubry, Jean-Marie
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.06.2015; Elsevier
• Subjects: Chemical Sciences; Hydrophilic Lipophilic Balance; Optimal formulation; Phase Inversion Temperature; Surfactant classification; Phase Inversion Temperature; Surfactant classification; Hydrophilic Lipophilic Balance; Optimal formulation
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2015.02.028

[Display omitted] The Phase Inversion Temperature of a reference C10E4/n-Octane/Water system exhibits a quasi-linear variation versus the mole fraction of a second surfactant S2 added in the mixture. This variation was recently proposed as a classification tool to quantify the Hydrophilic–Lipophilic Balance (HLB) of commercial surfactants. The feasibility of the so-called PIT-slope method for a wide range of well-defined non-ionic and ionic surfactants is investigated. The comparison of various surfactants having the same dodecyl chain tail allows to rank the polar head hydrophilicity as: SO3Na⩾SO4Na⩾NMe3Br>E2SO3Na≈CO2Na⩾E1SO3Na⩾PhSO3Na>IsosorbideexoSO4Na≫IsosorbideendoSO4Na≫E8⩾NMe2O>E7>E6⩾Glucosyl>E5⩾Diglyceryl⩾E4>E3>E2≈Isosorbideexo>Glyceryl>Isosorbideendo. The influence on the surfactant HLB of other structural parameters, i.e. hydrophobic chain length, unsaturation, replacement of Na+ by K+ counterion, and isomerism is also investigated. Finally, the method is successfully used to predict the optimal formulation of a new bio-based surfactant, 1-O-dodecyldiglycerol, when performing an oil scan at 25°C.