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 i nterface between liquid decane and liquid water have been performed wi th the purpose to study the properties of these monolayers on a molecu lar and atomic level. The model used consists of two monolayers contai ning 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 p arameters, electrostatic potential, and diffusional properties are det ermined. The two surfactants have very similar physical properties but differ in the fact that the alpha-anomer head group is axially orient ed to the apolar tail, whereas the beta-anomer is equatorially oriente d, resulting in a higher degree of chain order in the beta-anomer.