MOLECULAR-DYNAMICS SIMULATIONS OF CARBOHYDRATE-BASED SURFACTANTS IN SURFACTANT WATER OIL SYSTEMS

Molecular dynamics simulations of two monolayers of carbohydrate-based surfactants (decyl alpha-glucoside and decyl beta-glucoside) at the interface between liquid decane and liquid water have been performed with the purpose to study the properties of these monolayers on a molecular and atomic level. The model used consists of two monolayers containing a total of 72 molecules. Two simulations of 300 ps were performed, 250 ps at constant volume and 50 ps at constant pressure, both at a temperature of 315 K. Distribution functions, surface tension, order parameters, electrostatic potential, and diffusional properties are determined. The two surfactants have very similar physical properties but differ in the fact that the alpha-anomer head group is axially oriented to the apolar tail, whereas the beta-anomer is equatorially oriented, resulting in a higher degree of chain order in the beta-anomer.