Research On The Structure Regulation Of Electrospun Nanofibrous Membranes Based On Pan And Its Application In Air Filtration

In recent years,as the development of science and technology,the problem of air pollution is more and more serious,which is harmful to the social production and people's health,so it is very urgent to improve air quality.Electrospinning nanofiber membrane has a small fiber diameter,large specific surface area and high porosity,which can be used as a kind of fiber filtration material effectively to remove the fine particles in the air.In this paper,in order to obtain a filter with high filtration efficiency and low resistance,a variety of composite nanofiber membranes with different microstructure based on polyacrylonitrile(PAN)were prepared by electrospinning technique.The main research contents are as follows:(1)PAN nanofiber membrane was prepared by electrospinning technology supported on PP non-woven fabric.The results shown that when the concentration of PAN spinning solution was 12 wt% and the voltage was 20 k V,the well-distributed nanofibers with mean diameter of 230 nm could be formed.The pressure drop increased from 121.93 Pa to 591.75 Pa when membrane thickness increased from 18 ?m to 35 ?m,whereas the filtration efficiency of aerosol particle sized 0.33 ?m raised from 81.78% to99.24%.Besides,mechanical properties and pore size distribution determined by the PAN fiber diameter with the better filtration efficiency were tested.Results revealed that its tensile fracture stress was 0.78 MPa and the average pore size tested by bubble pressure method was 2.0643 ?m.(2)PAN/PES nanofiber composite membrane with groove structure was prepared by using the solubility of the solvent.PAN/PES nanofiber membrane was supported on PP non-woven fabric layer with the average diameter of 142 nm.TG characterization showed that the weightlessness temperature of PAN/PES nanofiber membrane is between two monomers.PAN/PES nanofiber composite membrane with groove structure was obtained by soaking in chloroform,extending the retention time of fine particles on the surface of fiber and improving the filtering efficiency.(3)Supported by PP non-woven fabric layer,PAN/PES/Attapulgite(ATP)nanofiber composite membrane was fibric by adding ATP to PAN/PES spinning solution to increase the roughness of fiber surface and enlarge the fiber interlayer spacing,resulting in the higher filtration efficiency and lower resistance.This paper studied the filtration performance of PAN/PES/ATP nanofiber composite membranes under different surface density,fine particle size,flow velocity,and the filtration performance at loading time mode.Under the 32L/min flow velocity,the efficiency of PAN/PES/ATP nanofiber membrane to filter0.33 ?m DOP aerosol particles is as high as 97.14%,and the pressure drop is only64.80 Pa,which has a promissing filtration performance.