SWNTs-PAN/TPU/PANI composite electrospun nanofiber membrane for point-of-use efficient electrochemical disinfection: New strategy of CNT disinfection

Abstract

Single-walled carbon nanotubes (SWNTs) can be used as 1D electrochemical disinfection material for point-of-use water treatment but are limited by their poor durability and possible cytotoxicity. Immobilizing SWNTs in nanofibers with electrospinning served as slow-release technology develop a novel with a lasting antibacterial and (eco-) toxicological alleviation of SWNTs. Hence, the single-walled carbon nanotubes-polyacrylonitrile/polyurethane/polyaniline (SWNTs-PAN/TPU/PANI, SPTP) composite electrospun nanofiber membrane was successfully fabricated by co-electrospinning process and the electrochemical filtration and disinfection system of point-of-use drinking water treatment is constructed. In the absence of electrolysis, the SPTP filter is effective for complete removal of bacteria by sieving mechanism. Concomitant electrolysis in the course of filtration results in significantly increased inactivation of sieved bacteria. Application of 3.0 V leads to complete (5 log) inactivation of bacteria within 20 min. 5-cycle experiments, membrane flux and shake flask tests prove that composite restrict the excessive release of SWNTs retaining the long-lasting antibacterial properties of SPTP membrane. At 1.0 and 2.0 V, electrolyte concentration and composition is irrelevant to electrochemical inactivation consistent with oxidation of SPTP filter. Bacterial reactive oxygen species (ROSs) also support an oxidation mechanism. At 3.0 V, electrochemical disinfection mainly relies on indirect oxidation.