Porous BPPO-based membranes modified by aromatic amine for acid recovery

• Porous anion exchange membrane was prepared via phase inversion method.
• The membranes morphology can be controlled by gelatin medium.
• The membranes possess both good stability as well as high DD performance.
• The membranes have got high potential applications in acid recovery.

This study reports novel triphenylamine based porous anion exchange membranes (AEMs) with brominated poly(2,6-dimethyl-1,4-phenyleneoxide) (BPPO) acting as a polymer backbone for acid recovery via diffusion dialysis. Physiochemical properties and electrochemical performance of prepared membranes were tuned by varying the dosage of triphenylamine and concentration of gelatin medium. Thermal property like thermogravimetric analysis (TGA) was investigated along with water uptake (WR), ion exchange capacity (IEC), linear expansion ratio, etc. The effect of triphenylamine content inside BPPO backbone was discussed in brief relation with acid recovery. The porous AEMs showed the water uptake (WR) values of 159.3–243.5%, ion exchange capacity (IEC) of 0.97–1.49 mmol/g and linear expansion ratios of 3.23–6.45%. The acid dialysis coefficients (UH) for different AEMs were found to be 0.0056–0.0104 m/h while the separation factors (S) between HCl and FeCl2 varied from 21.9 to 38.8 at 25 °C. The obtained values are comparable to those of commercial membrane DF-120B (0.004 m/h for UH, 24.3 for S at 25 °C). The effect of gelation medium on the morphology and DD performance of the selected membrane has also been investigated. The membranes reported in this manuscript are promising candidate for acid recovery via diffusion dialysis.

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