Preparation And Antibacterial Properties Of Electrospun Cellulose Acetate Composite Nanofiber Membrane

In recent years,with the outbreak of the new coronavirus epidemic,viruses and bacterial microorganisms in the living environment attracted great attention.In order to cut off the transmission routes of bacteria and viruses and reduce the diseases caused by bacteria and viruses invading the human body,new antibacterial materials have attracted much attention of researchers.Electrospinning technology is an excellent method for preparing nanofiber membranes.The nanofiber membranes prepared by using polymer solution as spinning precursor solution can be repeatedly bent and have good flexibility.At the same time,the nanofiber membrane has the advantages of high porosity,large specific surface area,good air permeability,and easy functionalization,which is a good choice for the preparation of antibacterial materials.In this paper,organic antibacterial agents and sterile antibacterial agents were added to cellulose acetate nanofibers at the same time,and natural antibacterial agents and p H-responsive copolymers were combined with cellulose acetate to blend.Two types of antibacterial nanofibers based on cellulose acetate were prepared and their antibacterial properties were studied.Based electrospinning technology,cellulose acetate composite nanofiber membranes were prepared by introducing antibacterial agents Ag NPs and cetylpyridinium bromide(CPB)into cellulose acetate(CA)nanofibers.The obtained nanofiber membrane was characterized,and it was found that after adding CPB,the spun fibers were refined,the surface wettability of the fiber membrane was improved,the tensile force of the fiber membrane was increased,and the Ag NPs in the fiber were uniformly distributed.Taking Escherichia coli and Staphylococcus aureus as examples to conduct antibacterial experiments on the composite nanofiber membrane.The results show that the coexistence of Ag NPs and CPB achieved a synergistic antibacterial effect,enhanced the antibacterial performance,prolonged the antibacterial time,and improved the broad applicability of the antibacterial nanofibrous membrane.In order to reduce the toxicity of antibacterial agents,poly(acrylic acid-acrylamide)(P(AA-AM))copolymers were further prepared by aqueous solution copolymerization.Natural and harmless gallic acid(GA)was introduced into cellulose acetate nanofibers as an antibacterial agent,and CA/P(AA-AM)/GA antibacterial nanofiber membranes were successfully prepared.The obtained nanofibrous membranes were characterized,and it was found that the addition of antibacterial agent gallic acid caused the thermal stability of the nanofibrous membranes to weaken.The addition of P(AA-AM)induced fiber coarsening and enhanced the surface wettability of the nanofibrous membranes.Partial cross-linking of the fiber membrane after high temperature treatment improved the mechanical properties of the nanofiber membrane.The prepared CA/P(AA-AM)/GA nanofibrous membrane had a certain p H response effect,and the release degree of gallic acid was different when the fiber membrane was immersed in different p H solutions.The cellulose acetate spun nanofiber structure formed by gallic acid under the wrapping of P(AA-AM)also prolonged the release process of gallic acid and improved the antibacterial time-efficiency of the nanofibrous membrane.Taking Escherichia coli and Staphylococcus aureus as examples to conduct antibacterial experiments on the composite nanofiber membrane,the study found that the spun nanofiber membrane containing gallic acid had excellent antibacterial activity,and the higher the content of gallic acid,the better the antibacterial performance.