The Interaction of Cationic Gemini Surfactant 1,4-Butanediyl-α,ω-bis(dimethylcetylammonium bromide) with Primary Linear Alkanols

• Published in: Journal of dispersion science and technology 2010-01, Vol.31 (1), p.129-137
• Main Authors: Khan, Iqrar Ahmad, Mohammad, Riyaj, Alam, Md. Sayem, Kabir-ud-Din
• Format: Article
• Language: English
• Subjects: Alkanols; Chemistry; Colloidal state and disperse state; Exact sciences and technology; gemini surfactant; General and physical chemistry; Micelles. Thin films; mixed micelles; Surface physical chemistry; synergism
• ISSN: 0193-2691; 1532-2351
• DOI: 10.1080/01932690903110160

The critical micelle concentration (CMC) of cationic gemini surfactant 1,4-butanediyl-α, ω-bis(dimethylcetylammonium bromide; C 16 -C 4 -C 16 ) with and without additives (primary linear alcohols: butanol (C 4 OH), pentanol (C 5 OH), hexanol (C 6 OH), heptanol (C 7 OH), octanol (C 8 OH)) is measured by surface tension measurements using a du Noüy tensiometer in aqueous solution at 303 K. The CMC of C 16 -C 4 -C 16 decreased with increasing alcohol concentration and the effect followed the order: C 8 OH > C 7 OH > C 6 OH > C 5 OH > C 4 OH. The surfactant concentration required to reduce the surface tension of the solvent by 20 mN/m, C 20 , ratio of C 20 and CMC, maximum surface excess, Γ max , and minimum surface area per molecule, A min , were evaluated from surface tension versus log C t (C t is the total surfactant concentration) plots. Mixed micelles were formed and the CMC values of the mixtures were used to compute β m , the interaction parameter for mixed micelle formation in aqueous medium, β σ , the interaction parameter for mixed monolayer formation at the aqueous solution/air interface, and the respective activity coefficients (f 1 and f 2 ). The standard Gibbs energy of adsorption was also evaluated. We observed synergism in C 16 -C 4 -C 16 /alkanol systems at all concentration ratios.