Initial structure of cetyltrimethylammonium bromide micelles in aqueous solution from molecular dynamics simulations

A series of molecular dynamics simulations were performed in order to explore the initial (10.5 ns) structure of CTAB micelles formed in aqueous solutions. The determination of the aggregation number of CTAB is a long-standing and fundamental problem. Therefore we simulated eight model systems of micelles in aqueous solution. Some micellar structural characteristics, local solvation environments, and counter ion distributions are described. Topological and geometrical concepts are used to characterize the resulting micelle structures. Our findings indicate that for certain aggregation numbers micelles are formed by layered spherical structures.