Molecular Dynamics Study of the Poly(oxyethylene) Surfactant C₁₂E₂ and Water

Abstract

Constant pressure and temperature (NPT) molecular dynamics (MD) simulations have been carried out to investigate the properties of a binary mixture of the poly(oxyethylene) surfactant C12E2 and water in its liquid crystalline lamellar phase (Lα). The calculated interlamellar spacing and the area per surfactant were found to be in reasonable agreement with X-ray diffraction results. The water molecules were observed to form hydrogen bonded bridged structures linking the oxygen atoms of the same surfactant chain. This interaction leads to a strong preference for the C−C bonds in the headgroup to attain a gauche conformation.