Development of BPPO-based anion exchange membranes for electrodialysis desalination applications

In this article, the fabrication of anion exchange membranes from brominated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO) and N-methylmorpholine (NMM) has been reported. The prepared membranes were characterized in terms of ion exchange capacity (IEC), water uptake (W-R), linear expansion ratio (LER), thermal stability, tensile strength (TS), alkaline stability, transport number and membrane area resistance. The ion exchange capacity, water uptake and linear expansion ratio of the prepared membranes are found to be increased with the increasing amount of NMM content in the membrane matrix. The membranes NMM-15 and NMM-18 are much more stable than QPPPO membrane in 2 M NaOH at room temperature. Fourier transform infrared spectroscopy was employed to confirm the functional groups in the membrane. The surface morphology of fabricated membranes was studied by scanning electron microscopy. The membranes were used in electrodialytic removal of NaCl from aqueous solution at constant applied voltage. The membrane NMM-18 with higher hydrophilicity (IEC = 1.74 mmol/g & W-R = 27.40%) and lower membrane area resistance (1.5 Omega.cm(2)) showed good ED performance than commercial membrane Neosepta AMX under the same experimental conditions. (C) 2015 Elsevier B.V. All rights reserved.