2, Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey, United States
We report a new implicit-solvent simulation model for studying the self-assembly of surfactants, which the hydrophobic interactions were captured by calculating the relative changes of the solvent accessible surface area (SASA) of the hydrophobic domains. Using histogram-reweighting grand canonical Monte Carlo simulations, we demonstrated that this approach allowed us to match both the experimental critical micelle concentrations (cmc) and micellar aggregation numbers simultaneously with a single phenomenological surface tension γSASA for the poly(oxyethylene) monoalkyl ether (CmEn) surfactants in aqueous solutions. Very good transferability was observed that the same model can accurately predict the experimental cmc and aggregation numbers for the CmEn surfactants with alkyl lengths m between 6 and 12, and poly(oxyethylene) lengths n between 1 and 9. The implicit-solvent model with SASA calculations put forward in this study is general and may be applied to study the more complex amphiphilic systems such as the surfactants with branched alkyl chains, or the surfactant and hydrocarbon mixtures.