Two-dimensional reticular hairline nanometer fiber material used for air filtration and preparation method of material

Abstract

The invention provides a two-dimensional reticular hairline nanometer fiber material used for air filtration and a preparation method of the material. The preparation method is characterized in that a high-molecular-weight polymer is selected, a polymer solution low in mass concentration is prepared, then in the electrostatic spraying process, a spinning nozzle is vibrated in situ by using external force, and the generation of charged droplets is promoted; meanwhile, by regulating the vapor concentration of a solvent in a closed spinning environment, the droplets form the two-dimensional reticular hairline nanometer fiber air filtration material on the surface of a receiving substrate after phase separation, wherein a punctiform adhesion structure is formed between the material and the substrate. The material is continuously and seamlessly stacked, the average diameter of the fibers in the net is 3-50 nm, meshes have a stable Steiner minimal-tree structure, the average mesh diameter is 10-500 nm, the porosity is equal to or larger than 75%, the filtering efficiency of the material to the particulate matter with the partical size of 0.01-5 micrometers is larger than 99.999%, and the resistance pressure drop is smaller than 50 Pa. the preparation process is simple, few materials are limited, and the reticular hairline nanometer fiber air filtration material has a tiny mesh structure and good channel connectivity, and shows a great application prospect in the field of air filtration.

Description

technical field [0001] The invention belongs to the field of nanofiber filter materials, and relates to an air filter material composed of two-dimensional network ultrafine nanofibers and a preparation method thereof. Background technique [0002] At present, with the continuous acceleration of industrialization and urbanization in our country, the problem of air pollution in our country is becoming more and more serious, especially in recent years, frequent smog pollution not only endangers human health but also seriously affects industrial production and daily life. Among the many haze pollution control methods, the filtration method has become the most widely used method because of its simplicity and economy. However, the existing air filter materials generally have the defects of low filtration efficiency and large resistance pressure drop, which cannot meet people's needs for high-efficiency and low-resistance air filter materials. Electrospun fibers are expected to bec...

AI Technical Summary

Problems solved by technology

However, the existing air filter materials generally have the defects of low filtration efficiency and large resistance pressure drop, which cannot meet people's needs for high-efficiency and low-resistance air filter materials. Electrospun fibers are expected to become ideal air filter material

The relevant published patents of electrospun fiber air filter materials include "A composite nanofiber air filter material and its preparation method" (CN201610034552.3), "An electrospun nanofiber air filter material and its preparation method" (CN201610381988.X), "A high-efficiency and low-resistance electrospinning nanofiber air filter material and its batch preparation method" (CN201610784058.9), etc., but the fiber diameter in the air filter material prepared by the above method is still relatively thick, and the pore size of the fiber membrane is large, resulting in a small material pair The filtration efficiency of particle size particles is low, and the resistance pressure drop is large

[0003] In order to further obtain high-efficiency and low-resistance electrospun air filter materials, the patent "A high-efficiency and low-resistance nanofiber air filter material for masks and its preparation method" (CN201510009971.7) reported a preparation of a three-dimensional cavity structure The method of high-efficiency and low-resistance air filter materials, but the beaded fibers used in this material have poor continuity and are easy to slip, and the cavity structure is easy to collapse, resulting in deformation of the pore structure, making the application performance of the material unstable

Another published patent "An Electrospinning Nanofiber Electret Filter Material and Its Preparation Method" (CN201410452788.X) reports a method for obtaining a high-efficiency and low-resistance filter material using the electrostatic electret method, but the material prepared by this method The medium electret charge is easy to dissipate, and after the charge is dissipated, the filtration efficiency of the material drops sharply, resulting in the safety of its use cannot be guaranteed. Therefore, an air filter material with a small diameter, small pore size, completely relying on physical interception and stable structure is constructed. It is expected to solve the above problems

[0004] The published patent "Preparation Method of Nano Cobweb / Nanofiber Composite Protective Material" (CN200910052163.3) reports a method for preparing composite protective material using nano spider web with fine diameter and small pore size, but the material prepared by this method contains a large amount of Conventional electrospun fiber scaffolds with large diameters, and the network structure is randomly and discontinuously distributed among ordinary electrospun fibers. There are a large number of gaps between the nets, the net coverage is low, and the integrity is poor, and material filtration is still not possible. The performance has been greatly improved, so there is an urgent need for a nanofiber air filter material with fine diameter, small pore size, no electrospun scaffold fibers, continuous stacking, and complete coverage

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