Preparation And Performance Study Of Charge Self-recovery Melt-blown Electrospinning Air Filtration Membran

The health problems cause by air pollution have attracted more and more attention.People hope to minimize the harm of pollutants to the respiratory tract and the cardiovascular and cerebrovascular.At the same time,the complex air pollution situation also requires filters to have versatility.Therefore,the preparation of fibrous filter material with high filtration efficiency,low pressure drop resistance,and antibacterial function that can satisfy people’s long-term use has become a top priority.The electret material can improve the filtration efficiency through electrostatic effect without increasing the pressure drop,and the filter membrane after finishing with carboxymethyl chitosan has excellent antibacterial properties.In our study,a self-recoverable charge self-recovering meltblown electrospun air filtration membrane with antibacterial properties and excellent comprehensive filtration performance was prepared by combining a meltblown membrane and an electrospun membrane.The main research contents are as follows:First,polytetrafluoroethylene（PTFE）electret powder was introduced into polypropylene（PP）to construct a PTFE/PP melt-blown micron membrane,which made it have excellent self-recovery properties of charge and refines the fiber diameter.Then,the PTFE/PEO was successfully loaded onto the PTFE/PP meltblown membrane in the form of a nanomembrane by electrostatic spinning process.Four PTFE/PP@PTFE micro-nano composite membranes with different PTFE contents were obtained,which’s performance and principles were analyzed.Among them,the surface potential of the composite membrane with 0.5%PTFE can reach-1123.2 V after corona charging,the charge can still be restored to 92.72%after five washing-drying,and the filtration efficiency and quality factor reached 95.39%and 0.0358 Pa^-1.To further improve the comprehensive filtration performance of the composite membrane,three high-dielectric polycarbonate（PC）with different melt indexes as electrets and dispersants were introduced into PP for melt-blown.And the PTFE/PEO electrospun layer was combined with meltblown membrane,a batch of Mx PPCy@PTFE composite membranes with excellent performance were obtained,and their performance and mechanism were discussed separately.The initial potential of the M22PPC5@PTFE composite membrane after corona was-1994 V,and the charge can be restored to 95.7%after five washings-drying.The filtration efficiency and quality factor were 95.78%and 0.0377 Pa^-1.Finally,to enrich the functionality of the filter membrane,carboxymethyl chitosan（CMCS）was used to construct composite membrane the M22PPC5@PTFE composite membrane,and three CMCS/PPC@PTFE antibacterial micro-nano air filtration composite membranes were prepared.The effects of CMCS concentration on filtration performance and antibacterial activity were discussed.5%CMCS/PPC@PTFE composite membrane had good antibacterial properties,and the antibacterial rates against Staphylococcus aureus and Escherichia coli reached 81.54%and 86.10%,respectively.In addition,the initial surface potential of the composite membrane was as high as-2190.0 V and the charge can be recovered by 83.8%.The filtration efficiency was 97.31%,and the quality factor was 0.0312 Pa^-1.In summary,a composite membrane was prepared with both antibacterial properties and high-efficiency and low-resistance filtration performance.After five washings-drying,it still has a high surface potential value.This method can provide new ideas for the later development of the preparation of recyclable high-efficiency low-resistance air filter materials and broaden the direction for improving the performance of air filter materials.