Porous BPPO-based membranes modified by multisilicon copolymer for application in diffusion dialysis

Brominated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO)-based hybrid membranes are produced from phase inversion, partial hydrolysis, modification with multisilicon copolymer of poly(MA-co-γ-MPS) and quaternization processes. The membranes have a porous structure, as revealed by SEM observation and water flux measurement. The modification by poly(MA-co-γ-MPS) introduces 3Si3O3Si network in the BPPO matrix, and hence the membrane swelling resistance in 65 °C water is enhanced. The membranes are taken for diffusion dialysis (DD) process to recover HCl from HCl/FeCl2 solution. The dialysis coefficients of HCl (UH) are in the range of 0.020–0.025 m/h at 25 °C and the separation factor (S) can reach up to 45.5. The high permeability and selectivity are due to the unique membrane structure and the presence of different functional groups.