Self-assembled nanofiltration membrane containing antimicrobial organosilica prepared by sol–gel process

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.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Synthesis of organosilaxane (APDSPO) by Barbiar–Grignard reaction ► Antimicrobial membrane to avoid biofouling ► Stable nanofiltration membranes ► Anti-biofouling NF membrane for water desalination/purification