MOLECULAR-DYNAMICS SIMULATIONS OF THE WATER OCTANOATE INTERFACE IN THE PRESENCE OF MICELLES

Molecular dynamics (MD) simulations have been used to study structural and dynamical aspects of a sodium octanoate micelle. The model micell e contains 15 octanoate molecules and 15 sodium atoms in an aqueous so lution containing 792 water molecules in a cubic 31.1 Angstrom box. Th e coordinate trajectory from a 300 ps simulation has been used to anal yze the hydrophobic core region, the distribution of counter ions and water molecules around the monomer head groups. Of special interest is to investigate the mechanism of water penetration into the hydrophobi c hydrocarbon core region. The results are discussed in relation to so me recent findings on the properties of medium-chain surfactants.