Polyelectrolyte complexes (PECs)/polyvinyl alcohol (PVA) membranes are prepared from PVA, anion exchange and cation exchange multisilicon copolymers, which contain plenty of functional groups of -OH, -N+(CH3)(3)/-Si(OCH3)(3), and -SO3Na/Si(OCH3)(3), respectively. The -OH and -Si(OCH3)(3) groups can undertake sol-gel reaction to form crosslinking structure, while the -N+(CH3)(3) and -SO3Na groups can be combined through electrostatic interaction. The PECs/PVA membranes exhibit improved thermal stability, swelling resistance and flexibility as compared with single anion or cation exchange hybrid membranes. The PECs/PVA membranes have the water uptakes (W-R) of 25.3-70.4%, initial decomposition temperatures (IDTs) of 246-285 degrees C, tensile strength of 23.1-33.8 MPa, and elongation at break of 3.5-13.1%. The membranes can be potentially applied for both acid and alkali recovery through diffusion dialysis (DD) process. The separation factor (S) for HCl/FeCl2 mixture can reach up to 89.9, which is about five times higher than that of commercial DF-120 membrane (18.5 at 25 degrees C). The dialysis coefficients of NaOH (U-OH) are in the range of 0.014-0.019 m/h, around 7-9 times higher than the value of commercial SPPO membrane (0.002 m/h at 25 degrees C). The membranes also show potential usefulness for industrial acidic and alkali wastes treatment. (C) 2013 Elsevier B.V. All rights reserved.