Elevated performance of the neat, hybrid and composite membranes by the addition of nanoparticles (ZIF-67): A molecular dynamics study

In gas separation applications, a composite membrane formed by blending poly(ether‐block‐amide) and polyethersulfone seems promising due to its combined physicochemical properties. Such membranes' performance can be further improved by adding novel metal–organic frameworks such as zeolitic imidazolate framework-67 (ZIF-67). In this study, molecular dynamics (MD) simulation and Monte Carlo (MC) using material studio (MS) 2017 software were utilized to compute the structural, physical, and separation properties of the neat, hybrid, composite and mixed matrix membranes (MMMs). The morphological parameters investigated in this study include X-ray diffraction, glass transition temperature, fractional free volume and end-to-end distance. The addition of particles to the composite structure increased the amorphous state and d-space of the membrane. The glass transition temperature and fractional free volume of the MMMs increased with the increase in ZIF-67 particles, which indicates the improvement of the membrane performance in terms of thermal resistance and transport properties, respectively. Besides, transport properties such as diffusivity, solubility, permeability, and selectively for CO2, CH4, and N2 gases were studied. The evaluated parameters for the MMMs were higher than those of neat, hybrid, and composite membranes considered in this study. The mixed matrix membranes CO2 permeability filled with 20% ZIF-67 particles was improved by ~ 190 and ~ 240% for the neat Pebax and composite membranes (Pebax-PES), respectively. The selectivity of CO2/CH4 and CO2/N2 in the MMMs was improved by ~ 420 and ~ 80% compared to those of neat and composite membranes, respectively. The simulated results are in agreement with the available experimental data. Finally, the permeability and selectivity results show that the Px-PES-Z20% membrane is suitable for industrial applications, such as natural gas treatment.