Preparation And Properties Of Electrospun PA6 Dendritic Nanofiber Membranes

With the development of nanotechnology and nanomaterial,electrospun fibers had been widely used in energy,environment and electro-optic field.Recently,inspired by the nature,researchers focus their attention on fabricating novel nanofibers,such as helical,ribbon-like,beads-on-a-string,core-shell,multi-channel tubular,porous honeycomb,spider-wet et al and studying their applications in many areas.As is known,natural trees show hierarchical structures built up by many trunks and more branches.In this paper,a PA6 tree-like nanofiber membrane was fabricated by adding a certain amount of TBAC into spinning solution via one-step electrospinning.Then the tree-like nanofibers were modified by Ag NPs via in-situ reduction and impregnation method.And SEM,TEM,FT-IR and XPS were used to investigate the morphologies and structures of the as fabricated nanofiber membranes.The antibacterial properties and catalytic properties of the membranes were also investigated.The results showed that the adding of TBAC increase the electric conductivity of the solution,which could increase the electrostatic repulsion between macromolecule,leading to the splitting of jet.The membrane shows excellent tree-like structure when the concentration of PA6 is 14%,the adding of TBAC is 4%,the applied voltage is 45 kV,the collecting distance is 15 cm and the injection rate is 0.1 mL/h.The results showed that the tree-like structure improved the mechanical properties and hydrophilicity of the membrane while ensuring high specific surface area and small pore size(0.75 um).The inhibition zone radius of tree-like nanofiber membrane obtained from in-situ reduction are 17.34 mm(E.coli)and 30.2 mm(S.aureus),while the inhibition zone radius of normal Ag/PA6 nanofiber membrane are 14.03 mm(E.coli)and 25.93 mm(S.aureus),indicating that Ag/PA6 tree-like nanofiber membrane has a better antibacterial effect.The catalytic degradation rate of 0.1 g nanofiber membranes to 50 ml MB with initial concentration of 10 mg/L is 86%,while the degradation rate of membranes obtained from impregnation method is 98.13%.The nanofiber membrane can be easily recycled and exhibits good reusability.It retains a degradation rate for methylene blue of 83.5%after five consecutive cycles.Therefore,the tree-like nanofiber membranes show potential applications in antibacterial and catalytic areas.