Effect of Cu-MOFs incorporation on gas separation of Pebax thin film nanocomposite (TFN) membrane

Abstract

MOF-based membranes, which have appropriate MOF dispersion and suitable interaction, have shown high CO 2 permeability and significant CO 2 /CH 4 and CO 2 /N 2 selectivity. In this study, a layer of Pebax was coated on polysulfone (PSF), which this layer incorporated by various content of Cu-MOFs to improve the performance (permeability and CO 2 /CH 4 and CO 2 /N 2 selectivity) of all membranes. Characterization techniques such as SEM, TGA, BET, and gas adsorption verified that Cu-BTC was successfully dispersed into the Pebax matrix. Pure CO 2 and CH 4 gases permeation experiments were performed to investigate the impact of Cu-MOFs on the gas permeability of prepared MOF-based membranes. The “Pebax” embedded by 15 wt% CuBTC and 15 wt% of NH 2 -CuBTC over PSF support exhibited higher gas separation performance compared to the pristine one. They demonstrated a CO 2 permeability of 228.6 and 258.3 Barrer, respectively, while the blank membrane had a CO 2 permeability of 110.6 Barrer. Embedding the NH 2 -Cu-BTC intensified the interaction between incorporated MOF particles and the polymer phase that led to increase the CO 2 /CH 4 and CO 2 /N 2 selectivity. In addition, the performance of prepared membranes was evaluated at various feed pressures with the range of 2–10 bar. The CO 2 /CH 4 and CO 2 /N 2 separation was enhanced as the feed pressure surged.