Self-assembly of neutral and ionic surfactants: An off-lattice Monte Carlo approach

We study self-assembly of surfactants in two dimensions using off-lattice Monte Carlo moves. Here the Monte Carlo moves consist of slithering snake reptation motion of the surfactant chains and kink-jump of the individual monomers. Unlike many previous studies an important feature of our model is that the solution degrees of freedom are kept implicit in the model by appropriate choice of the phenomenological interaction parameters for the surfactants. This enables us to investigate rather large systems with less number of parameters. The method is powerful enough to study multimicellar systems with regular and inverted micelles for both neutral and ionic surfactants. As a function of several parameters of the model, we study self-assembly of neutral surfactants into micelles of various forms and sizes and compute appropriate cluster-size distributions. Ionic surfactants exhibit, apart from micellization, additional intermicellar ordering. We further study the role of host particles to mimic recent experiments on surfactant-silicate cooperative self-assembly, and demonstrate the possibility of generalized pathways leading to host encased micellization. © 1998 American Institute of Physics. @S0021-9606~98!50124-9#