Preparation Of Silk Fibroin Composite Nanofiber Membrane By Electrospinning And Its Antibacterial Properties

In daily life,microorganisms such as bacteria and viruses pose a great threat to human health,so the development of materials with antibacterial properties has become an important task.Antibacterial materials have the advantages of wide antibacterial range,good antibacterial performance and simple operation,which have become the focus of current research.How to prepare antibacterial materials with large specific surface area,high porosity and excellent antibacterial properties has become a difficult research problem.The purpose of this paper is to prepare an antibacterial nanofiber film with silk fibroin as the composite nanofiber substrate material by electrospinning technology,and to study its morphology,structure and antibacterial properties.First,the cationic antibacterial agent chitosan quaternary ammonium salt and polyethylene oxide were introduced into the silk fibroin nanofibers by electrospinning technology to prepare silk fibroin composite nanofibers with excellent tensile and antibacterial properties.Different nanofiber films were obtained by changing the ratio of silk fibroin and chitosan quaternary ammonium salt;combined with SEM characterization,the effects of different ratios of silk fibroin and chitosan quaternary ammonium salt on silk fibroin nanofibers were studied.The tensile test results showed that after adding polyethylene oxide and chitosan quaternary ammonium salt to the silk fibroin fiber membrane,the fracture stress of the silk fibroin composite nanofiber membrane increased from 2 MPa to 6 MPa,which indicated that the silk fibroin Doping polyethylene oxide and chitosan quaternary ammonium salt in the fiber membrane can improve the tensile properties of nanofibers.Antibacterial tests were carried out on different fiber membranes,and the composite nanofiber membrane with the best antibacterial effect was selected.The experimental results prove that SH4 has the best antibacterial effect,and the antibacterial rate against Escherichia coli and Staphylococcus aureus reaches more than 98%.It can also be proved from the antibacterial curve that the composite nanofiber film has inhibitory effect on Gram-negative bacteria and Gram-positive bacteria.Secondly,the silk fibroin nanofiber membrane was reacted with tannic acid(TA)and silver nitrate sequentially by using layer-by-layer self-assembly technology to obtain a silk fibroin composite nanofiber membrane with excellent antibacterial properties.The structure and performance of the fiber membrane were studied by scanning electron microscope,X-ray diffraction and various performance analysis methods.It can be proved by SEM that after soaking in TA,the diameter of the fiber becomes larger,indicating that TA is successfully loaded on the surface of the fiber;after soaking in silver nitrate,the surface of the fiber can clearly see the uniform distribution of silver nano-ions.XRD and XPS can prove that the silver element is loaded on the fiber in the form of nano-silver.The results of antibacterial experiments showed that the higher the TA concentration and the longer the soaking time,the stronger the antibacterial performance of the fiber,and the antibacterial rate against Escherichia coli and Staphylococcus aureus was as high as 98%.