Structural Design And Preparation Of Structure-enhanced Electrospinning Environmental Purification Membranes

The nanofiber membrane prepared by the electrospinning method has a wide range of applications in related fields such as air purification,multiphase catalysis,tissue scaffolds,and battery electrodes due to its unique nanostructure,high specific surface area,and porous structure.However,since the electrospinning fiber membrane is obtained by stacking the electrospinning fiber layer by layer,the fibers are liable to slip fracture and drift,which results in the poor strength.Therefore,it is necessary to improve the mechanical properties of the electrospinning membrane in order to improve its stability,durability and recyclability in the application process,and broaden its application and development in related fields.Aiming at the above problems,this paper improves the mechanical strength of the fiber membrane by introducing cross-linking points in the organic and inorganic fiber membranes.And based on the advantages of electrospinning fibers and the characteristics of LDHs,realize the effective load of inorganic powder materials on organic fibers and inorganic fibers and broaden the application of electrospinning fiber membranes in the fields of air purification and water pollution treatment.The specific research contents and results are as follows:1.For the cross-linking of organic fiber membranes,a combination of electrospinning and electrostatic spraying was used to uniformly introduce PCL electrostatic spray particles inside the PAN electrospinning fibers,followed by heat treatment of the fiber membranes in order to promote the melting of the PCL particles to introduce the cross-linking points for connecting the fibers to reduce the slippage of the fibers,and improve the mechanical strength of the fiber membrane.At the same time,combined with the characteristics of LDHs that can electrostatically adsorb fine particles easily,LDHs is incorporated into the electrospinning fiber as an electret.By improving the strength of the fiber membrane,the fiber membrane can be applied to the purification of fine particles under high pressure and high wind speed environment.2.For the cross-linking of inorganic fiber membranes,cross-linking the inorganic silica fibers by adding the hydrolysate dropwise and then calcining after some attempts such as heat-melt cross-linking and incomplete solvent volatilization cross-linking.Fiber slip is restricted and the mechanical strength of the fiber membrane is improved by introducing cross-linking points in the fibers.Then the method of "Seeds Embedded Epitaxial Growth" was used to grow LDHs on the silica fibers,and combined with the ability of LDHs to adsorb Congo red dye molecules,applied it in the purification process of Congo red dye wastewater.Combined with the "Calcination-rehydration" characteristics of LDHs and the high temperature resistance of silica fibers,the MgAl-LDH@SiO2 composite fiber membrane with dye molecules adsorbed can be roasted at high temperature,and the dye molecules adsorbed on LDHs can be roasted at high temperature.It can form gas molecules such as carbon dioxide,realize the complete removal of organic dyes and the reuse of composite fiber membranes,reduce the generation of solid waste.