Phase Behaviour of Alkyl Ethoxylate Surfactants in a Dissipative Particle Dynamics Model

Abstract

We present a dissipative particle dynamics (DPD) model capable of capturing the liquid state phase behaviour of non-ionic surfactants from the alkyl ethoxylate (CnEm) family. The model is based upon our recent work [Anderson et al., J. Chem. Phys. 2017, 147, 094503] but adopts tighter control of the molecular structure by setting the bond angles with guidance from molecular dynamics simulations. Changes to the geometry of the surfactants were shown to have little effect on the predicted micelle properties of sampled surfactants, or the water-octanol partition coefficients of small molecules, when compared to the original work. With these modifications the model is capable of reproducing the binary water-surfactant phase behaviour of nine surfactants (C8E4, C8E5, C8E6, C10E4, C10E6, C10E8, C12E6, C12E8 and C12E12) with a good degree of accuracy.