Imidazolium‐Based Ionic Liquid as Modulator of Physicochemical Properties of Cationic, Anionic, Nonionic, and Gemini Surfactants

• Published in: Journal of surfactants and detergents 2018-05, Vol.21 (3), p.355-366
• Main Authors: Kumar, Amit, Banjare, Manoj K., Sinha, Srishti, Yadav, Toshikee, Sahu, Reshma, Satnami, Manmohan L., Ghosh, Kallol K.
• Format: Article
• Language: English
• Subjects: Ionic liquid; Micellization; Surface properties; Thermodynamics
• ISSN: 1097-3958; 1558-9293
• DOI: 10.1002/jsde.12032

The aggregation morphology of 2 cationic surfactants (cetyldimethylethanolammonium bromide and cetyldiethylethanolammonium bromide), an anionic surfactant (sodium dodecylbenzenesulfonate), a nonionic surfactant (Triton X‐100), and 2 gemini surfactants (16‐4‐16,2Br−[butanediyi‐1,4‐bis(dimethyldohexylammonium bromide)] and 16‐6‐16,2Br−[hexanediyi‐1,6‐bis(dimethyldohexylammonium bromide)]) in the presence of the ionic liquid (IL) 1‐ethyl‐3‐methylimidazoliumbromide [Emim][Br] is studied using various techniques such as surface tension, conductivity, and UV–visible and fluorescence spectroscopy. Increasing the concentration of [Emim][Br] results in a decrease in the critical micelle concentration (CMC) value of the surfactants. Various interfacial properties, namely the surface excess concentration (Гmax), minimum area per molecule at the air–water interface (Amin), and surface pressure at the CMC (πcmc), as well as the thermodynamic parameters such as free energy of the given air/water interface (Gmins), Gibbs free energy of micelle formation (ΔGm°), Gibbs free energy of micellization per alkyl tail (ΔGm,tail°), Gibbs energy of transfer (ΔGtrans°), and standard free energy of adsorption (ΔGads°) were also investigated. The aggregation number (Nagg) was determined by the fluorescence method. It was observed that Nagg decreased with increasing weight‐percent of the IL.