Non-charged PVA-SiO2 hybrid membranes are prepared from the sol-gel reaction of polyvinyl alcohol (PVA) and methacryloxypropyl trimethoxy silane (gamma-MPS) or poly(gamma-MPS). As the polymerization degree increases from gamma-MPS to poly(gamma-MPS), the sol-gel solution becomes turbid or generates precipitation, while the formed silica particles in the hybrid membranes become smaller from 1.0-3.4 mu m to 0.1-0.2 mu m or disappear. The membrane tensile strength (TS) generally increases from 35 MPa to 44 MPa, while the elongation at break (E-b) decreases from 318% to 141%. Three deductions are proposed according to the structure of poly(gamma-MPS), membrane swelling behaviors in 65-85 degrees C water and 65 degrees C alkaline solution, and the diffusion dialysis (DD) performance. (1) As poly(gamma-MPS) contains no ion-exchange groups like the multisilicon copolymer [1], it tends to become inhomogeneous during sol-gel process, which reduces its crosslinking ability. (2) The membrane structure is generally stable in 65 degrees C water with the swelling degrees of 140-347%, but is damaged in 85 degrees C water or 65 C alkaline solution. (3) Non-charged hybrid membranes can be potentially applied in DD process. The dialysis coefficient of NaOH (U-OH) is in the range of 0.0069-0.0127 m/h, and the separation factor (S) is in the range of 19-92. The OH- ions may be transferred in the hybrid membranes through PVA-OH groups and interstices between organic and inorganic phases, according to the mechanisms of adsorption-desorption and free diffusion, correspondingly. (C) 2013 Elsevier B.V. All rights reserved.