Can purely repulsive soft potentials predict micelle formation correctly?
We determine the free energy of micelle formation for surfactants in a solvent by employing a hybrid semi-grand Monte Carlo simulation scheme in combination with umbrella sampling and configurational bias techniques. We compare results of two surfactant models: one based on Lennard-Jones interactions and one based on the soft repulsive potential that is often used in dissipative particle dynamics (DPD). The free energies of micellization in both models show similar behavior. However, although the critical micelle concentration for the Lennard-Jones systems lies within the experimental range, it is 13 orders of magnitude lower for the soft repulsive model. We discuss the implication for the applicability of soft repulsive potentials for the study of micelle formation.
van't Hoff Institute for Molecular Sciences, Universiteit van Amsterdam, Nieuwe Achtergracht 166, 1018 WV, Amsterdam, The Netherlands. rpool@science.uva.nl
René
R
Pool
Peter G
PG
Bolhuis
D003102:Colloids / Q000737:chemistry*; D003198:Computer Simulation; D057927:Hydrophobic and Hydrophilic Interactions; D008823:Micelles; D008958:Models, Molecular; D009010:Monte Carlo Method; D013501:Surface-Active Agents / Q000737:chemistry*; D013816:Thermodynamics
D003102:Colloids; D008823:Micelles; D013501:Surface-Active Agents