Preparation And Disinfection Performance Of Polyacrylonitrile/polyaniline/silver Nanowire-Activated Carbon Fiber Cloth Nanofiber Composite Membrane

The removal and inactivation of waterborne pathogens from drinking water are important for human health.However,there are still a large number of people,particularly in developing and rural areas,lack adequate safe drinking water,where microbial contamination is a primary threat to unsafe drinking water.Due to insufficient funds,a centralized water supply is limited in dispersed rural areas.Additionally,owing to the ineffectiveness against resistant microorganisms and difficulty in managing equipment,conventional disinfection methods are not suitable for developing and rural areas that lack water utilities.Therefore,it is of great practical significance to develop new materials and new technologies for the disinfection of drinking water in rural areas.In this paper,a polyacrylonitrile/polyaniline/silver nanowires-carbon fiber cloth(PAN/PANI/AgNWs-CC)composite nanofiber membrane was fabricated using a simple and rapid co-electrospinning process.The characterization of PAN/PANI/AgNWs composite nanofibers by XRD,FTIR,FESEM,TEM and EDS showed that the composite nanofibers were uniform in diameter and had no obvious beads.And AgNWs were successfully embedded and distributed uniformly in the composite nanofibers.Furthermore,the analysis of GFAAS found that the silver release of PAN/PANI/AgNWs-CC is less than 15 ppb,indicating that the composite nanofiber structure can effectively avoid the impact of water flow,reduce the release of silver.And the release of silver is much lower than the international drinking water standards of 100 ppb,indicating that the amount of silver released in the safe range.The results of filtration experiment and static sterilization illustrated that the electrospun nanofibrous membrane is of great significance because it can act as an effective filter for the complete removal of Escherichia coli and Staphylococcus aureus.And for PAN/PANI/AgNWs-CC,the sieved bacteria were completely inactivated by the released silver within 8 h.But PAN-CC and PAN/PANI-CC did not exhibited antibacterial properties.The results of electrochemical disinfection experiments showed that PAN/PANI/AgNWs-CC can be well run in the electric field,and complete inactivation of the sieved bacteria was achieved within a few seconds by concurrent filtration and electrochemical disinfection under a voltage of 6 V.Increasing voltage and decreasing flow rate are conducive to enhancing the disinfection performance of PAN/PANI/AgNWs-CC nanocomposites.The physical destruction of the electric field and AgNWs is the main mechanism of the electrochemical disinfection of PAN/PANI/AgNWs-CC,and the physical destructive effect is mainly through the electroporation of AgNWs for micro-organisms.The higher voltage would lead to the stronger electroporation.Besides,the antimicrobial effect of silver ions and the oxidation of active chlorine are not the main mechanism of PAN/PANI/AgNWs-CC electrochemical disinfection,while the Ag+ and reactive oxygen species also make some contribution to the disinfection of PAN/PANI/AgNWs-CC in the low voltage.