Molecular Modeling of Fouling on Reverse Osmosis Membranes

Molecular simulation has become a promising alternative to study the transport phenomena as well as foulingproperties in reverse osmosis (RO)membranes. In this report, we focused on molecular simulations techniques tomodelfouling properties in RO. To assess thermodynamically antifouling properties of polymers as used for ROmaterials, free energy calculations were conducted based on the thermodynamic integration method in moleculardynamics (MD). Free energy profiles for combinations of amino acid residuesand various kinds of polymer materi-als were obtained from our calculations. For an instance, polyethylene terephthalate (PET)’s profile shows anextremely deeper and wider downward convex curve, suggesting that hydrophobic amino–acid residues adsorb ontoa PET surface without any energetically high barriers. Our methodology is certainly a promising approach to select-ing theoretically less fouling polymers. Fouling mechanism from the point of view of atomistic level is also discussed.