Multisilicon copolymer has a long main chain and many branched chains, with plenty of ion-exchange (-N+(CH3)(3)Cl-) and -Si(OCH3)(3) groups. Multisilicon copolymer with the low molecular weight (M-r of 795) is difficult to gel, while that with the high molecular weight (M-r of 4152) has two gelation times. One is the "pseudo gelation" within 0.03-2.5 days, and the other is within 14-48 days. The two types of multisilicon copolymers are crosslinked with polyvinyl alcohol (PVA) to prepare anion exchange hybrid membranes. Membranes from the low molecular weight copolymer have lower water uptakes (W-R, 62-87%), ion exchange capacities (IECs, 0.6-0.9 mmol/g), thermal stability (223-239 degrees C) and mechanical strength (7-12 MPa, 42-97%). Membranes from the high molecular weight copolymer are homogeneous, transparent and colourless. They have higher W-R of 195-464%, IECs of 1.0-1.5 mmol/g, short-term thermal stability of 244-247 degrees C, mechanical strength (15-23 MPa, 122-208%) and organic solvent resistance. All the membranes can be potentially applied in diffusion dialysis (DD) process for recovery of CH3COOH and HCl. The dialysis coefficients of CH3COOH (U-CH3COOH) can reach up to 0.009 m/h, and the dialysis coefficients of HCl (U-H) are in the range of 0.01-0.043 m/h with the separation factors of 22-39 (0.01-0.029 m/h and 28-39 for the low molecular weight, and 0.024-0.043 m/h and 22-26 for the high molecular weight), superior to those of commercial DF-120 membrane (0.009 m/h, 18.5). (c) 2012 Elsevier B.V. All rights reserved.