Noor Ul Afsar

Preparation of pyrrolidinium-based anion-exchange membranes for acid recovery via diffusion dialysis

ABSTRACT In this manuscript, the preparation of pyrrolidinium-based anion-exchange membranes (AEMs) from brominated poly(2,6-dimethyl-1,4-phenyleneoxide) (BPPO) is reported. Prepared membranes were completely characterized in terms of Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), atomic force microscopy (AFM), ion-exchange capacity (IEC), water uptake (WR), linear expansion ratios (LER), mechanical stability, acid stability, etc. Excellent thermal, mechanical and acid stability can be observed for prepared membranes. Prepared membranes were used in diffusion dialysis (DD) process for acid recovery from model waste HCl/FeCl2 solution. The dialysis coefficient of HCl (UH) is found to be in the range of 0.018–0.049 m/h, whereas the separation factor (S) was obtained as 36.24–66.39. Prepared membranes show much better DD performance than that of commercial fibre–supported DF-120B membrane (0.004 m/h for UH, 24.3 for S at 25°C). Prepared membranes got the potential to be used as a promising candidate for acid recovery via DD.

Fabrication of cation exchange membrane from polyvinyl alcohol using lignin sulfonic acid: Applications in diffusion dialysis process for alkali recovery

ABSTRACT We report polyvinyl alcohol (PVA)-based hybrid membranes composed of salt of lignin sulfonic acid (LSA) and tetraethyl orthosilicate. The concentration of LSA with respect to PVA varied from 10% to 40%. The hybrid membranes showed water uptake (WU) in the range of 122–210%, ion exchange capacities in the range of 0.32–0.75 mmol g−1, dialysis coefficient (UOH) from 0.0068 to 0.0119 m h−1, and selectivity (S) from 15 to 26. The hybrid membranes also showed thermal and mechanical stability.