Journal of Zhejiang University SCIENCE
(ISSN 1009-3095, Monthly)

2005   Vol. 6B   No. 6   p.597-601

Interaction of nonionic surfactant AEO₉ with ionic surfactants

ZHANG Zhi-guo^†, YIN Hong

(Department of Chemical Engineering, Zhejiang University, Hangzhou 310027, China)
^†E-mail: zhiguozhang2004@yahoo.com.cn
Received Oct. 25, 2004; revision accepted Mar. 1, 2005

Abstract: The interaction in two mixtures of a nonionic surfactant AEO₉ (C₁₂H₂₅O(CH₂CH₂O)₉H) and different ionic surfactants was investigated. The two mixtures were AEO₉/sodium dodecyl sulfate (SDS) and AEO₉/cetyltrimethylammonium bromide (CTAB) at molar fraction of AEO₉, α_AEO9 The surface properties of the surfactants, critical micelle concentration (CMC), effectiveness of surface tension reduction (γ_CMC), maximum surface excess concentration (Γ_max) and minimum area per molecule at the air/solution interface (A_min) were determined for both individual surfactants and their mixtures. The significant deviations from ideal behavior (attractive interactions) of the nonionic/ionic surfactant mixtures were determined. Mixtures of both AEO₉/SDS and AEO₉/CTAB exhibited synergism in surface tension reduction efficiency and mixed micelle formation, but neither exhibited synergism in surface tension reduction effectiveness.

Key words: Nonionic surfactant, Nonionic-ionic mixed surfactants, Molecular interaction parameter, Synergism, Mixed micelle, Mixed adsorption film
doi:10.1631/jzus.2005.B0597             CLC number: O647