(179x) A Molecular Dynamics Study of C12E6 and SDS Surfactants at the Silica-Water and Air-Water Interfaces

NVT molecular dynamics simulations have been carried out to investigate the adsorptions of hexaethylene glycol monododecyl ether (C12E6) and sodium dodecyl sulfate (SDS) surfactants at the silicon dioxide-water and water-air interfaces. The simulations were performed at room temperature and at different surfactant coverages, from an infinite-diluted coverage to full monolayer. We will discuss structural and dynamic properties of the molecular adsorption of surfactants by presenting results for density profiles, end-to-end distances, tilt angles, radial distribution functions, and mean square displacement of both water and surfactants. The results show an entangled structure of surfactant chains at both silica-water and air water interfaces and the interface properties are dependent of the degree of coverage. The simulations will be compared to experimental data obtained as a function of the density of surfactant molecules per unit interfacial surface area. The results are expected to secure advances in novel technologies such as admicellar polymerization.