Antibacterial And Tensile Properties Of PAN/Graphene Composite Nanofiltration Membrane

At present,environmental pollution has become increasingly serious,especially air pollution caused by haze which has attracted worldwide attention.The most effective method for purifying air is filtration,so the research and development of air filtration materials is becoming a focus of research.The traditional air filtration material can only effectively filter the particle size larger than 0.3 ?m,and it is almost ineffective for particles with smaller particle size and pathogens.In fiber preparation,electrospinning technology has attracted wide attention.With the advantages of small diameter,small size,high porosity and good uniformity of fiber,the electrospun fiber has a great application prospect in the field of filtration and protection.In this paper,graphene is added to the electrospinning film,which has a good filtering effect and also a certain performance of graphene.Firstly,graphene oxide was synthesized by an improved Hummer method and reduced graphene oxide was prepared using ascorbic acid as a reducing agent,polyacrylonitrile/graphene(PAN/graphene)nanocomposite films were prepared by electrospinning technique.Field emission scanning electron microscopy,infrared spectroscopy,X-ray diffraction,and thermal gravimetric analysis were used on the preparation of graphene oxide and reducing oxide grapheme to characterize the morphology,structure and thermal performance.The successful preparation of the graphene oxide and reducing the graphene oxide lays a foundation for application in filtration and antibacterial.Secondly,GO/PAN and rGO/PAN composite membranes were prepared by adding different amount of GO and rGO to spinning solution.The viscosity and conductivity of spinning solution were measured and SEM,pore size,thickness,filtration and other tests were taken to characterize nanombranes.The results showed that graphene had no significant effect on viscosity and conductivity while changed the property of PAN nanofibers.when the amount of GO added up to0.3 wt%,the property of the GO/PAN nanofibers was good for making fiber and filtering performance.When the amount of GO and rGO added up to 0.3 wt%,the property of the GO/PAN nanofibers was better for making fiber,nanofiber was finest,distribution was most even,the filtering performance was the best,the aperture distribution was between 1.3 ~1.7 ?m.Andnanocomposites filtration efficiency decreased with the increase of the gas flow rate.Thirdly,tensile properties were mearesured on PAN nanomembranes with different contents GO and rGO.The experimental results showed that GO was added,the tensile properties of PAN nanofibers increased,when the amount of GO added up to 0.3 wt%,the tensile properties of the composites were improved and the tensile strength increasing by 42.4% and the elongation increasing by 32.5% compared with the neat PAN membrane.When the amount of GO was over0.3 wt%,the composite membrane performance became deteriorate.When the amounts of GO and rGO were 0.3 wt%,the tensile properties of GO/PAN composite were better than rGO/PAN composite,while the tensile properties of rGO/PAN composite were worse than PAN composite.Finally,when the amounts of GO and rGO were 0.3 wt%,the antibacterial performance about qualitative and quantitative tests had carried on the rGO/PAN and GO/PAN composite materials.The qualitative experiment results showed that the escherichia coli and staphylococcus aureus antibacterial effects of rGO/PAN and GO/PAN composite materials were limited.The quantitative test results showed that the GO/PAN and rGO/PAN nanocomposite bacteriostatic rate of e.coli were 32.4% and 40.5% respectively,the inhibition rate of staphylococcus aureus were45.8% and 56.7% respectively.Reduced grapheme oxide was better than graphene oxide on the antibacterial effection.