Preparation And Performance Study Of PVDF Nanofiber Filter Material For Air Purification

Air has always been a prerequisite for people to survive.However,with the development of China's industry and social progress,air pollution has recently become an important factor endangering people's health.The small-sized particles produced by the burning of kitchen fumes and fossil fuels have caused serious impacts on people's health and industrial production.In addition,in a closed and humid environment indoors,mites have become a means of spreading allergens,especially dust mites,which can easily cause some respiratory diseases such as bronchial asthma and inflammation of lung tissues.At present,indoor air purification is an effective way to control indoor air pollution.However,commercially available high-efficiency air filter materials mainly include melt-blown electret nonwoven materials and glass fiber filter materials.The melt-blown electret material has excellent air filtration ability due to electric field adsorption.However,its fiber diameter is in the range of micrometers and charge decay in the air is prone to cause the filtration efficiency to decrease,affecting the safety during use;the glass fiber material has a fine fiber diameter and a small pore size,which increases the physical interception ability of particulate matter and improves the filtration efficiency.However,the fiber is brittle and easy to fall off,which limits its wide use.The diameter of nanofibers prepared by electrospinning technology is mostly in the nanometer range,and has the advantages of small pore size,large specific surface area,high porosity and good connectivity,so it breaks the limitation of fiber refinement.Moreover,nanofiber filter materials have huge development prospects in high-efficiency air filter materials.However,most of the current air purification materials do not have the effect of removing allergens such as mites.Therefore,the development of an air purification material with anti-mite function is a major issue concerning human health.In order to realize the development of functional filter materials,In this experiment,the nanofiber air filtration membrane with excellent performance was prepared by electrospinning technology,using polyvinylidene fluoride(PVDF)as the polymer and N,N-dimethylformamide(DMF)as the solvent.We explored the effects of PVDF concentration and electrospinning voltage on fiber membrane structure and filtration performance.It is realized by scanning electron microscope,fiber strength tester,pore size analyzer and automatic filter tester.The results show that when the content of polyvinylidene fluoride is 18 wt%and the spinning voltage is 30 kV,the fiber diameter is evenly distributed,mainly concentrated in the range of 200~700 nm,and the fiber membrane shows good filtration performance.Secondly,in order to give the fiber membrane good anti-mite performance and improve the filtration effect of the fiber membrane,we prepared the PVDF/AMPs composite nanofiber membrane by introducing anti-mite nanoparticles(AMPs).Moreover,we explored the influence of the content of nanoparticles on the structure and comprehensive performance of the fiber membrane,and found that when the content of AMPs was2 wt%,the anti-mite performance and filtration performance of the fiber membrane reached the best.Finally,in order to better meet people's requirements for fiber membrane efficiency and resistance in actual use,we explored the effects of spinning time and air flow rate on fiber membrane filtration efficiency.The experiment found that the filtration performance of the fiber membrane increased with the increase of weight and declined with the increase of speed of airflow.Moreover,when the weight of the fiber membrane reaches 10.7 g/m~2 and the air flow rate is 32 L/min,the filtration efficiency of the fiber membrane reaches the best,99.919%,and the resistance is only 65 Pa.In addition,basing on the laboratory's control of polymer concentration,spinning parameters and anti-mite nanoparticle content,We use large-scale electrospinning equipment in the enterprise to complete the large-scale production of high-efficiency air filtration nanofiber membranes.And we innovatively combined the fiber membrane with the air-conditioning fan to design a simple air purifier,and evaluated the effect of the fiber membrane on air purification performance through practical tests.Compared to commercial filter materials,the study found that nanofiber membranes deliver more clean air in the same amount of time.Moreover,after a cycle of 10 test cycles,the filtration efficiency was reduced from 99.47%to 98.35%,only 1.12%.It provides new ideas for the application and large-scale production of nanofiber materials in the field of air purification.