▎ 摘　　要

Composite anion exchanges membranes are prepared by incorporating quaternized graphene oxide (QGO) within poly(vinyl alcohol) (PVA) or the mixture of PVA and quaternized polyethyleneimine (QPEI), followed by cross-linking with formaldehyde. The PVA-QGO series of membranes have low ion exchange capacities (IECs) of 0.10-0.37 mmol/g and low water uptakes (W-R) of 16.1%-22.0%, leading to high area resistances (>60 Omega cm(2)). The PVA-QPEI-QGO series of membranes show much lower area resistances of 2.47-6.04 Omega cm(2), which is ascribed to the improved IECs (0.86-1.37 mmol/g) and W-R (46.8%-71.4%). Both series of membranes show higher alkali resistance than commercial membrane AMV. Their weight losses are in the range of 0.5%-8.9% after immersion in 60 degrees C 2 mol/L NaOH alkaline solution for 32 days, while the value of AMV membrane is 19.2%. When utilized for electrodialysis (ED) application to recover NaOH from NaOH/Na2WO4 mixture, the prepared membranes exhibit high selectivity, as evidenced by the low leakage ratio of Na2WO4. The leakage ratio of the optimized composite membrane to WO42- is only 5.1%, while the leakage ratio of AMV membrane is up to 61.4%. To explore this reason, the composite membranes are selected for the ED separation of monovalent ions. The separation efficiency (S) of the optimized membrane is 83.9%, which is similar to the value of commercial anion selective membrane NEOSEPTA (R) ACS (88.7%), confirming further the selectivity of the composite membranes. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.