Adsorption and Orientation of Ionic Liquids and Ionic Surfactants at Heptane/Water Interface

作者：Zolghadr Amin Reza; Ghatee Mohammad Hadi; Zolghadr Ali

来源：Journal of Physical Chemistry C, 2014, 118(34): 19889-19903.

DOI：10.1021/jp506012x

Molecular dynamics simulation of heptane/ionic-liquid/water system was performed to study the effect of hydrophobic and hydrophilic ionic liquids (ILs) on the interfacial structure of heptane/water as a model for oil/water systems. The results are compared with the simulated water/sodium-dodecyl-sulfate (SDS)/heptane interface. Also, the self-assembly and orientation of its and SDS molecules at heptane/vapor interface are studied. We observed that the behavior of these surfactants at heptane/water and heptane/vapor interfaces is very different. The computed density profiles provide a detailed view of the interfacial structure and a route to discuss quantitatively how the oil and water phases organize the surfactant molecules. The effect of ILs [C(n)mim]Cl and [C(n)mim]PF6 (with n = 4, 8, and 12) and SDS on the interfacial tension of heptane/water was simulated and compared at T = 343.15 K. The results indicate that ILs with long alkyl chain could behave similar to a conventional surfactant.

• 出版日期2014-8-28