Graphene Quantum Dots-Doped Thin Film Nanocomposite Polyimide Membranes with Enhanced Solvent Resistance for Solvent-Resistant Nanofiltration

Shuxuan Li; Can Li; Xiaojuan Song; Baowei Su; Bishnupada Mandal; Babul Prasad; Xueli Gao; Congjie Gao

doi:10.1021/acsami.8b19834

Graphene Quantum Dots-Doped Thin Film Nanocomposite Polyimide Membranes with Enhanced Solvent Resistance for Solvent-Resistant Nanofiltration

ACS Appl Mater Interfaces. 2019 Feb 13;11(6):6527-6540. doi: 10.1021/acsami.8b19834. Epub 2019 Jan 29.

Authors

Shuxuan Li¹, Can Li¹, Xiaojuan Song¹, Baowei Su¹, Bishnupada Mandal², Babul Prasad², Xueli Gao¹, Congjie Gao¹

Affiliations

¹ Key Laboratory of Marine Chemistry Theory and Technology , Ocean University of China, Ministry of Education , Qingdao 266100 , China.
² Department of Chemical Engineering , Indian Institute of Technology Guwahati , Guwahati 781039 , India.

PMID: 30633865
DOI: 10.1021/acsami.8b19834

Abstract

The core of the organic solvent nanofiltration (OSN) technology is solvent-resistant nanofiltration (SRNF) membranes. Till now, relative poor performance of solvent resistance is still the bottleneck of industrial application of SRNF membranes. This work reports a novel polyimide (PI)-based thin-film nanocomposite (TFN) membrane which was embedded with graphene quantum dots (GQDs) and showed an improved solvent resistance for OSN application. This kind of SRNF membrane, termed (PI-GQDs/PI)_XA, was synthesized via serial processes of interfacial polymerization (IP), imidization, cross-linking, and solvent activation. The IP process was performed between an aqueous m-phenylenediamine solution doped with GQDs, having an average size of 1.9 nm, and an 1,2,4,5-benzenetetracarboxylic acyl chloride n-hexane solution on the PI substrate surface. The prepared (PI-GQDs-50/PI)_X SRNF membranes without organic solvent activation achieved an ethanol permeance of nearly 50% higher than those of the GQD-free membranes under the same preparation conditions, while no compromise of the dye rejection was observed. Further, after the solvent activation using N, N-dimethylformamide (DMF) at 80 °C for 30 min, the ethanol permeance achieved about an 8-folds increment, from 2.84 to 22.6 L m^-2 h^-1 MPa^-1. Interestingly, the rejection of rhodamine B also increased from 97.8 to 98.6%. A long-term permeation test of more than 100 h using rose bengal (RB, 1017 Da)/DMF solution at room temperature demonstrated that the synthesized (PI-GQDs-50/PI)_XA membranes could maintain the DMF permeance and the RB rejection as high as 18.3 L m^-2 h^-1 MPa^-1 and 99.9%, respectively. Moreover, the immersion test of the prepared (PI-GQDs-50/PI)_XA SRNF membranes in both DMF and ethanol at room temperature for about one year also demonstrated the long-term organic solvent stability, indicating their good potential for OSN application.

Keywords: chemical cross-linking; chemical imidization; graphene quantum dots (GQDs); interfacial polymerization (IP); solvent resistant nanofiltration (SRNF).