Molecular Dynamic Simulations of Cross-Linked Polyamide Reverse Osmosis Membrane

Molecular dynamics simulations are used to construct an atomistic model of an aromatic polyamide reverse osmosis membrane. An aromatic polyamide membrane is generated from a highly cross-linked polymerization between m-phenylenediamine (MPD) monomers and trimesoyl chloride (TMC) monomers. An atomistic model of polyamide membrane is successfully built using a heuristic approach. The unit cell length and the target density of polyamide membrane are reached, and they are in good agreement with the experimental values. A number of water molecules is added into a polyamide membrane in order to generate the hydrated polyamide membrane. Further molecular dynamics simulations are performed. From the solvated membrane, water permeability is yielded. Furthurmore, the effects of temperature and pressure on water permeability are studied using MD simulations.