Molecular simulation of a reverse osmosis polyamide membrane layer. In silico synthesis using different reactant concentration ratios

We use molecular dynamics simulations at the atomistic level to build a model of aromatic polyamide polymer used in reverse osmosis membranes, from mixture m-phenylene diamine (MPD) and trimesoyl chloride monomers (TMC). Our purpose is different MPD TMC ratios reproduce compositional depth-dependence observed experimentally during interfacial polymerization. range 1:4 5:1 have been employed. Reproducibility polymerization algorithm thoroughly studied through building several samples under identical conditions. notice that simulation time few microseconds are necessary order reach equilibration. show initial monomer ratio has strong influence onto final composition chemical structures created. Large differences seen concerning cross-linking degree remaining un-reacted groups. Comparison with available experimental data built using intermediate values MDP closely resemble membranes. conclude simulated created local concentrations can describe properly heterogeneities