Facile preparation of azido nanofiber (NF) membrane for various applications

Polyvinyl chloride (PVC) nanofiber (NF) membrane functionalized with azido groups (Az-PVC NF) was prepared using various techniques with the aim of enhancing azide substitution of chlorine in the PVC backbone. Azidation strategies that were investigated include: (1) catalyst-assisted azidation in organic solvent, (2) phase transfer catalyzed azidation in aqueous media, (3) phase transfer catalyzed azidation in aqueous media using pre-iodinated membrane, and (4) phase transfer catalyzed azidation in aqueous media of electrospun pre-iodinated PVC granules prepared via Finkelstein reaction. Results showed that azidation was greatly enhanced when PVC NF membrane or PVC powder underwent pre-iodination prior to azidation. As far as it is known, this is the first time that preparation techniques for azidized PVC NF membrane in aqueous media that involve halogen exchange have been studied. Hence, the optimized conditions for the preparation of azidized PVC NF membranes and the resulting membrane properties are hereby reported. Furthermore, the utility of Az-PVC NF in the development of water treatment technologies was demonstrated with successful grafting of cucurbiturils via nitrene insertion.