Simulations of micelle self-assembly in surfactant solutions

A simple model of surfactants in aqueous solution is described and molecular dynamics simulations are presented. This model qualitatively reproduces the energy ordering of interactions for surfactants in solution, instead of using the symmetric solvent-solvent and hydrocarbon-hydrocarbon interactions used previously in similar models. The effects of surfactant chain length and concentration are investigated. The results show that the tendency toward micelle formation in the model increases as the chain length is increased and that the type of micelle formed varies with surfactant concentration. Transitions from loose aggregates to spherical micelles to cylindrical micelles are seen as surfactant chain length is increased. A transition from cylindrical micelles to spherical micelles is also seen as surfactant concentration is lowered.