Dilational properties of anionic gemini surfactants with polyoxyethylene spacers at water-air and water-decane interfaces.

Abstract

The dilational properties of anionic gemini surfactants (oligooxa)-alpha,omega-bis(m-octylbenzene sulfonate) (C(8)E(x)C(8)) with polyoxyethylene spacers at the water-air and water-decane interfaces were investigated via the oscillating barriers method. The influences of oscillating frequency and bulk concentration on dilational properties were explored. The interfacial tension relaxation method was employed to obtain dilational parameters in a reasonably broad frequency range. The experimental results show that the number of ethylene oxide groups is one of the principal factors to control the nature of the interfacial film. With an increase of ethylene oxide groups, the dilational modulus of C(8)E(8)C(8) shows two maxima with the increasing concentration. Furthermore, the dilational moduli at the water-decane interface are remarkably lower than those at the water-air interface for C(8)E(1)C(8) and C(8)E(4)C(8), while the dilational modulus at the water-decane interface is close to that at the water-air interface for C(8)E(8)C(8), which indicates that the structure of the adsorption sublayer plays a more important role. Possible schematic diagrams of adsorbed molecules with different polyoxyethylene spacers at the water-air and water-decane interfaces are proposed. The results of relaxation experiments and Cole-Cole plots can support our provided mechanism strongly.

DOI: 10.1021/la101131v

Cite this paper

@article{Feng2010DilationalPO, title={Dilational properties of anionic gemini surfactants with polyoxyethylene spacers at water-air and water-decane interfaces.}, author={Jie Feng and Xue-Peng Liu and Lu Zhang and Sui Zhao and Jia-yong Yu}, journal={Langmuir : the ACS journal of surfaces and colloids}, year={2010}, volume={26 14}, pages={11907-14} }