Facile and cost effective PVA based hybrid membrane fabrication for acid recovery

• A facile and cost effective method was proposed to fabricate PVA based hybrid membrane.
• The membranes have both good stability and high DD performance.
• The membranes have high potential applications in acid recovery.

A new route for a hybrid anion exchange membrane was proposed for diffusion dialysis (DD) using polyvinyl alcohol (PVA) and glycidyl trimethyl ammonium chloride (EPTAC) as starting materials and aminopropyltriethoxysilane (KH550) as crosslinking agent. A series of membranes were prepared by varying the content of EPTAC. The obtained membranes were characterized with ion exchange capacity (IEC), water uptake (WR), linear expansion ratio (LER), tensile strength (TS), elongation at break (Eb), thermal decomposition temperature (Td) and initial decomposition temperature (IDT), etc. Their diffusion dialysis (DD) performance was conducted with a simulated feed containing 0.81 M HCl + 0.18 M FeCl2. The results show that the membranes not only have good chemical/thermal stability, but possess high DD performance. The dialysis coefficients (UH) are in the range of 0.011–0.018 m/h and the separation factors (S) are in the range of 18.5–21 at 25 °C, both are higher than those of the commercial DF-120 membrane (0.009 m/h for UH, 18.5 for S) determined at the same conditions. Considering its low cost and easy fabrication, the route for hybrid anion exchange membranes provides better candidates in DD process for acid recovery.