A new silica monomer precursor, bis(4'-aminopropyldiethoxysilylphenyl) 1,3,4-oxadiazole (APDSPO), was synthesized by Barbiar-Grignard reaction. Nanofiltration membranes containing APDSPO (biocide active) and polyvinyl alcohol (PVA), were prepared by acid catalyzed sol-gel followed by formal cross-linking. These membranes were designed with good stabilities (hydraulic, mechanical and chemical), separation performance, and low surface roughness. These membranes showed microbial growth inhibiting properties and thus anti-biofilm/fouling nature. About 35.2 L m(-2) h(-1) flux and 54.5% salt rejection for feed NaCl solution (1 g/L) at 0.62 MPa applied pressure, indicate the suitability of membrane (PO-6) for water purification. Membrane performance data also ruled out anti-biofouling nature of PO-6 membrane. (C) 2012 Elsevier B.V. All rights reserved.