A molecular dynamics study of surface structure of spherical SDS micelles

A series of molecular dynamics calculations have been carried out for spherical sodium dodecyl sulfate micelle of various sizes in order to investigate surface structure of the micelle as a function of its size. Two-dimensional surface pair correlation function of the hydrophilic head group projected on the sphere of the micelle showed a gas-like structure for small micelle, e.g. N = 31, and a liquid-like one for large micelles, e.g. N ⩾ 61, depending on the surface density of the head group. Coordination structure of the sodium ion near the surface has been analyzed in detail, too.