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

• Thin graphene quantum dots interlayer-based polyarylate membranes were prepared by interfacial polymerization. • The influence of two kinds of graphene quantum dots towards membrane structure was discussed in detail. • The quantum dots partially or fully released from the interlayer further optimized the intrinsic properties of the separation layer. • The polyarylate membranes showed excellent CO 2 /N 2 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 (N-GQDs) were synthesized and applied as an interlayer to modify the polyethersulfone (PES) ultrafiltration substrate. Then interfacial polymerization (IP) between trimesoyl chloride (TMC) and β-cyclodextrin (β-CD) was performed to prepare novel i-TFN polyarylate membranes for CO 2 /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 CO 2. Moreover, the affinity of the N-containing groups (e. g. amino and amide groups) in the i-TFN membrane and the CO 2 molecules helped to increase the CO 2 /N 2 separation selectivity. At the optimal preparation condition, the obtained i-TFN membrane showed CO 2 /N 2 selectivity of 23.3 with CO 2 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. [ABSTRACT FROM AUTHOR]