Molecular dynamics simulation of poly-m-phenylene isophthalamide polymer membrane modified by UiO-66 (NH2) MOF for separation of toluene/methanol mixture

Pervaporation is the purification technology which utilizes the transport properties of polymer membranes and has several important properties: energy efficiency, environmental friendliness, and a high degree of purification. To improve the transport properties, polymer membranes are modified with special nanoparticles. In this work we study the translational mobility of methanol and toluene molecules inside a poly-m-phenylene iso-phthalamide membrane with and without the nanoparticle of UiO-66 (NH2) metal-organic framework (UiO-66 (NH2) MOF) using full atomistic molecular dynamics simulation with microsecond trajectories. It was found that methanol has a high translational mobility inside the polymer matrix. Moreover, this mobility is significantly increased by addition of UiO-66 (NH2) MOF. Toluene molecules are practically immobile inside the polymer matrix and tend to form clusters with each other. Due to the inclusion of a nanoparticle, toluene molecules get stuck inside UiO-66 (NH2) MOF and its surface. We believe that the obtained results will contribute to the purposeful development and study of polymer matrices for the pervaporation process.

Automated summary

By modifying polymer membranes with special nanoparticles, the transport properties can be improved, resulting in higher efficiency in the separation and purification of mixtures.