Preparation Of Electrically Charged Electrospun PVDF Membranes Doped With Inorganic Particles And Their Applications In PM2.5 Resistance

In recent years,the emission source treatment and protection means of PM2.5 has become a new research hotspot to solve the problem of air pollution.However,when the PM2.5 in the air exceeds a certain range,it can cause serious damage to the health of the human body,causing various respiratory diseases;In addition,some of the PM2.5 particles have a certain corrosive effect on the insulating materials on the electric power transmission equipment,and the materials are exposed to severe smog environment for a long time,which has a significant impact on the performance of the PM2.5.Currently,materials mainly used for air filtration are electret nonwovens and electrospun nanofiber membrane.Howeve,the nanofiber membrane prepared by electrospinning has the advantages of small pore size,high porosity and light weight.In this paper,I use inorganic electret materials to prepare nanofiber membranes by electrospinning technology.Thereafter,the nanofiber membranes are charged by corona charging to prepare high-efficiency and low-resistance air filter materials.Nanofiber membranes with different doping amounts were prepared by electrospinning using polyvinylidene fluoride with long-term charge storage capacity as raw material,N,N-dimethylformamide as solvent,inorganic nanoparticles.The properties of the nanofiber membrane were characterized using a scanning electron microscope,a water contact angle meter,a force tester,a electrostatic tester,a filtration device,and so on.The optimum doping amount of PVDF-TiO2 nanofiber membrane was 5%and the optimum content of Si3N4 in PVDF-TiO₂/Si₃N₄ nanofiber membrane was 20%.We investigated the effects of inorganic nanoparticles on the fiber morphology,pore structure,surface hydrophobicity,mechanical properties,surface potential,and filtration properties of PVDF nanofiber membranes.When the doping amount of TiO2 is 5%,the water contact angle is at most 122.3°,and the surface potential is at most-9 kV.At a flow rate of 85 L/min,the filtration efficiency of the fiber membrane was98.627%,and the filtration resistance was 88 Pa.Under the condition that the doping amount of the inorganic nanoparticles is 5%,of which the content of Si₃N₄ is 20%,the water contact angle of the fiber film is at most 128.7°,and the surface potential reaches about 10 kV.The filtration efficiency of the PVDF-TiO2/Si3N4 nanofiber membrane was 99.024%,and the filtration resistance was 90 Pa.In addition,this experiment further analyzes the effect of gram weight on the filtration performance of nanofiber membranes.We determined that the best filtration weight of PVDF-TiO₂ nanofiber membrane is about 2.2g/m².We determined that the best filtration weight of PVDF-TiO₂/Si₃N₄ nanofiber membrane is about 2.67g/m².The filtration efficiency of the fiber membrane was 99.724%,and the filtration resistance was 92 Pa.