DEVELOPENT OF A COARSE-GRAINED POLYOXYETHYLENE GLYCOL NON-IONIC SURFACTANT MODEL USING THE SAFT-γ MIE FORCE-FIELD FOR MOLECULAR DYNAMICS SIMULATIONS - poster

Emma C L Richards, Erich A Müller and George Jackson

Department of Chemical Engineering, Imperial College London, London, UK

Robust coarse-grained (CG) models which exhibit both quantitative accuracy and representability are needed if one expects to obtain valuable insights to complex fluid systems. Within this study the SAFT-γ force-field methodology previously introduced in our group is employed to develop a CG surfactant model for use in the molecular simulation of non-ionic alkyl poly(oxyethylene) glycols (POE). In this approach, the effective Mie (generalized Lennard-Jones) interactions between the CG beads are estimated directly from target macroscopic thermodynamic properties with the aid of the molecular-based SAFT-γ Mie equation of state. Aqueous mixtures of alkyl poly(oxyethylene) glycol surfactants, C_iE_j , are considered as prototypical systems, where the interactions between the CG constitutive chemical moieties (alkyl, ether and hydroxyl groups), and their interactions with water are parameterised using appropriate experimental data for the vapour-liquid equilibria, liquid-liquid equilibria, enthalpy of mixing, and interfacial tension of selected pure components and mixtures. Here, a breakdown of the development and theory of the model will be discussed, as well as discussion of future applications such as the study of rheology and mesophase morphology.