Influence of Water Concentration on Its Mobility in Matrimid®

Abstract

Mobility of water in polyheteroarylene (Matrimid®) was simulated at 300 K and different concentrations of water (0.5 wt.%–3 wt.%). Parameters of anomalous diffusion were calculated from molecular dynamics simulations on the base of mean square displacements of water molecules. It was found that mobility of water has nonmonotonic dependence on its concentration. Lower diffusion rates at concentrations below than 1 wt.% can be attributed to the sorption of water onto the polar groups of polymer (sorption sites). Decreasing of diffusion rate with increasing of water concentration is due to the formation of clusters of water molecules, which hampers the penetration of water between polymer chains.

Investigation of the Side Chain Effect on Gas and Water Vapor Transport Properties of Anthracene-Maleimide Based Polymers of Intrinsic Microporosity

“…Numerous publications report that imide-based membranes are extensively used for water separation since they possess good mechanical stability, high thermal resistance and high water vapor permeability [ 57 , 58 , 59 ]. It is known that the imide group increases the polarity of the molecule and provides an environment for water molecules to form hydrogen bonding [ 60 , 61 , 62 ]. Hence, the introduction of this group into the polymer chain would lead to an improvement in the interaction between the water molecule and the polymer.…”