The Study On The Application Of Poly(Lactic Acid)/poly(Caprolactone) Nanofiber Membrane As Mask Filter Material

At present,the worsening environment is hindering human health and economic and social development The development and application of air filter materials has become a research hotspot.By the end of 2019,the outbreak of New Coronavirus（COVID-19）has attracted worldwide attention.This highly pathogenic virus is wantonly endangering our lives.People with COVID-19 mainly suffer from lung lesions,leading to severe damage to alveolar cells,resulting in gas exchange blockage.Wearing masks is an effective strategy widely adopted.The high demand and functional modification of masks have become the focus of attention in recent years.Based on the above research hotspots,the purpose of this experiment is to develop a functional air filter material to make it have the ability to filter PM0.3 and excellent antibacterial activity.Firstly,polylactic acid（PLA）/polycaprolactone（PCL）electrospun fiber membrane was prepared by electrospinning.PLA/PCL composite fiber membrane had smooth fiber surface and no bead structure.Doping of PCL fiber affected the porosity and bulk density of the fiber membrane to a certain extent.When the PLA/PCL jet ratio was2/1,the capture efficiency of fine particles by the composite fiber membrane could reach98.51%Then we used magnetron sputtering technology to modify the cotton fabric and prepare silver zinc composite cotton fabric(as S_Ag/ZnC).Magnetron sputtering of cotton fabric did not affect its original physical and mechanical properties.And it would impart asymmetric wettability to the fabric,which was conducive to the unidirectional transmission of moisture.S_Ag/ZnC fabric had obvious antibacterial activity against Escherichia coli and Staphylococcus aureus,and had no effect on the proliferation and differentiation of fibroblasts,indicating that the metabolism of fibroblasts was not affected by the released silver ions and zinc ions,and that the released metal ions were not cytotoxic and showed good biocompatibility.Finally,we used the S_Ag/ZnC fabric as the base fabric to construct a double-layer composite PLA/PCL@S_Ag/ZnC fiber fabric,which could effectively and conveniently utilize the surrounding water vapor and achieved wet electroactive antibacterial.Compared with the common mask filter layer on the market,PLA/PCL@S_Ag/ZnC exhibited excellent filtration efficiency for PM0.3.The results of bioaerosol filtration also showed that the retention rate of PLA/PCL@S_Ag/ZnC fabric for Escherichia coli and Staphylococcus aureus could reach 99.33%and 99.19%,showing that the composite fabric has excellent bacterial retention.It can be used as the sterilization intermediate layer of mask to intercept and effectively kill bacteria in polluted air.The three-dimensional structure of electrospun PLA/PCL nanofiber membrane as a filter medium had a great impact on air permeability,filtration efficiency and pressure drop.Magnetron sputtered cotton fabric as the underlying support structure had skin affinity and excellent antibacterial properties.Taking advantage of these advantages,it was proved that the double-layer fabric can effectively capture PM0.3 in the air and kill pathogenic pollutants.This fibrous medium was expected to be used as the core filter medium of mask,protect people from the air polluted by pathogens in a green,efficient and concise way,and provide a new research direction for the development of high-performance filter media for personal protection.