Fabrication of polyarylate thin-film nanocomposite membrane based on graphene quantum dots interlayer for enhanced gas separation performance

Interlayered-thin film nanocomposite (i-TFN) membranes with nanomaterials as the interlayer has attracted more and more attention of researchers in recent years due to the effective regulation of the separation layer structure in the membrane separation field. In this work, the amino-functionalized graphene quantum dots (NGQDs) were synthesized and applied as an interlayer to modify the polyethersulfone (PES) ultrafiltration substrate. Then interfacial polymerization (IP) between trimesoyl chloride (TMC) and beta-cyclodextrin (beta-CD) was performed to prepare novel i-TFN polyarylate membranes for CO2/N-2 separation. The effect of the N-GQDs deposition amount on the structure and gas separation performance of the composite membrane was studied thoroughly. The results indicated that the i-TFN polyarylate membrane presented a particular sandwich structure and provided an effective transport channel for the diffusion of CO2. Moreover, the affinity of the N-containing groups (e. g. amino and amide groups) in the i-TFN membrane and the CO2 molecules helped to increase the CO2/N-2 separation selectivity. At the optimal preparation condition, the obtained i-TFN membrane showed CO2/ N-2 selectivity of 23.3 with CO2 permeance of 174.5 GPU. This work proposes a novel nanomaterial interlayer to effectively improve the gas permselectivity by regulating the structure of i-TFN membranes, which has significant instruction for the preparation of high-performance i-TFN by exploring the interlayer of other nanomaterials.

Automated summary

The interlayered-thin film nanocomposite (i-TFN) membranes with nanomaterials as the interlayer have gained increasing attention in recent years. In this study, amino-functionalized graphene quantum dots (NGQDs) were used as the interlayer to modify the polyethersulfone (PES) ultrafiltration substrate, and novel i-TFN polyarylate membranes for CO2/N-2 separation were prepared. The results showed that the i-TFN polyarylate membrane had a specific structure and high CO2/N-2 selectivity.