Molecular dynamics simulation of bis(2-chloroethyl) sulfide gas separation by metal-organic and porous aromatic frameworks

Abstract

Abstract Separation of chemical warfare agents, specially sulfur mustard, is one of the most critical issues in environmental and military objects. Investigating the ability of some porous materials to separate mustard gas is the main aim of this work, and for this purpose, molecular simulation was selected. Dreiding model has been utilized for intra-molecule and van der Waals potentials of mustard gas and ab-initio calculations have been carried out to estimate partial charge of the atoms. The model was validated by comparison between liquid density and heat of vaporization obtained from molecular simulation and experimental values. Zn4O(3,5-dimethyl-4-carboxypyrazolato)3 and Cu(1,3,5-benzenetricarboxylate) are chosen in this work due to high active metal sites and previous studies which have reported high adsorption for mustard and similar molecules (i.e. diethyl sulfide). Moreover, two porous aromatic frameworks (PAFs), with and without NO2 functional group, which have different pore sizes have been studied to intensify the performance of mustard separation. The adsorption isotherm of water on PAFs has been also calculated by grand canonical Monte Carlo simulation to inspect the influence of humid condition on the separation process.