Air filtering material as well as preparation method and application thereof
By modifying the combined structure of the non-woven fabric layer and the electrospinning layer, and utilizing the hydrogen bonds between polyvinyl alcohol and polyvinylidene fluoride and the π-π stacking of carbon nanotubes, active oxygen and charge transfer complexes are generated, which solves the problem that existing air filter materials are difficult to simultaneously and efficiently remove particulate matter and harmful gases, and improves the filtration efficiency and mechanical properties of the material.
Patent Information
- Application Number
- CN202510871956.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-26
- Publication Date
- 2025-09-19
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing air filter materials are difficult to remove particulate matter and harmful gases efficiently at the same time, and have poor mechanical properties and a short service life.
A combined structure of a modified non-woven fabric layer and an electrospun layer is adopted, and the hydrogen bonds between polyvinyl alcohol and polyvinylidene fluoride, the π-π stacking of carbon nanotubes, the generation of reactive oxygen species and charge transfer complexes are utilized to form a high-efficiency filtration material. Through gradient filtration and the synergistic effect of multiple mechanisms, the removal of particulate matter and harmful gases is achieved.
It achieves the effect of efficiently filtering particulate matter and harmful gases, while improving the mechanical properties and service life of the material.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of filter materials, and in particular relates to an air filter material and a preparation method and application thereof. Background Art
[0002] With the rapid development of industry, some pollutants have gradually increased, leading to a certain degree of air pollution, such as high PM2.5 levels, which have adverse effects on people's health. After some interior decoration is completed, volatile organic gases will also be released into the air, which also has adverse effects on human health indoors.
[0003] Therefore, to improve air quality, there is a need for air filter materials that can effectively remove particulate matter and harmful gases from polluted air. However, existing air filter materials often struggle to simultaneously remove both particulate matter and harmful gases, or have low filtration efficiencies. Some air filter materials also have poor mechanical properties and a short service life.
[0004] Therefore, there is an urgent need to provide a new air filter material that has good filtration efficiency, good mechanical properties, and can remove particulate matter and harmful gases in the air. Summary of the Invention
[0005] The present invention aims to address at least one of the technical problems existing in the aforementioned prior art. To this end, the present invention provides an air filter material, a preparation method, and applications thereof. The air filter material of the present invention has good filtration efficiency and mechanical properties, while also being effective in removing particulate matter and harmful gases from the air.
[0006] A first aspect of the present invention provides an air filter material.
[0007] An air filter material comprises, from bottom to top, a modified non-woven fabric layer and an electrospun layer; The raw material components of the electrospinning layer include polyvinyl alcohol, polyvinylidene fluoride, carbon nanotubes, 4-[(2-chloro-4-nitrophenyl)azo]-N-ethyl-N-(2-phenoxyethyl)aniline, and N-ethyl-N-(2-hydroxyethyl)-4-(2-pyridylazo)aniline; The preparation process of the modified non-woven fabric layer includes: placing the non-woven fabric in a modification liquid, soaking, rolling, and drying to obtain the modified non-woven fabric; The components of the modified liquid include: activated carbon, diatomaceous earth, surfactant and water.
[0008] The air filter material of the present invention achieves the goals of efficient particulate matter interception, harmful gas removal and excellent mechanical properties through gradient filtration and multi-mechanism synergy. Specifically, in the electrospinning layer, the hydroxyl groups of polyvinyl alcohol (PVA) form strong hydrogen bonds with the fluorine atoms of polyvinylidene fluoride (PVDF), thereby improving the mechanical strength of the fiber. Carbon nanotubes (CNTs) are embedded in the PVDF molecular chain through π-π stacking to form a conductive pathway, while inducing the formation of the β phase of PVDF and promoting electron transfer. 4-[(2-chloro-4-nitrophenyl)azo]-N-ethyl-N-(2-phenoxyethyl)aniline and N-ethyl-N-(2-hydroxyethyl)-4-(2-pyridylazo)aniline generate active oxygen under visible light to decompose organic harmful gases. Their azo groups (-N=N-) form charge transfer complexes with the CF bonds of PVDF, thereby enhancing the efficiency of electron migration. Oxygen is adsorbed on the surface defect sites of carbon nanotubes to generate ·O2 - , synergistically with 4-[(2-chloro-4-nitrophenyl)azo]-N-ethyl-N-(2-phenoxyethyl)aniline and N-ethyl-N-(2-hydroxyethyl)-4-(2-pyridylazo)aniline to enhance the redox reaction rate. Hydroxyl groups on the activated carbon / diatomaceous earth surface neutralize formaldehyde, and the slightly alkaline environment of the diatomaceous earth further solidifies the acidic gas, thereby removing harmful organic gases.
[0009] Polyvinyl alcohol (PVA) and polyvinylidene fluoride (PVDF) are co-spun to form ultrafine fibers. Their high specific surface area and porosity allow them to efficiently intercept PM2.5. Carbon nanotube doping enhances fiber conductivity and strengthens the electrostatic adsorption effect, further improving the filtration efficiency of particulate matter. The modified non-woven fabric layer uses loaded activated carbon and diatomaceous earth to further intercept large particles through microporous physical adsorption, reducing the load on the electrospinning layer and extending its service life.
[0010] PVA provides flexibility, while PVDF imparts rigidity. The two are co-spun to form an interpenetrating network structure, which significantly improves the tensile strength.
[0011] Preferably, the surfactant includes sodium lauryl sulfate and polyoxyethylene ether. The surfactant improves the interfacial bonding strength between the modified non-woven fabric layer and the electrospinning layer.
[0012] Further preferably, in the surfactant, the weight ratio of sodium lauryl sulfate to polyoxyethylene ether is 1:(0.5-2).
[0013] Preferably, the components of the modifying liquid, calculated by weight, include: 10-15 parts of activated carbon, 1-8 parts of diatomaceous earth, 0.5-1 parts of surfactant, and 30-40 parts of water; further preferably, the components of the modifying liquid, calculated by weight, include: 12-14 parts of activated carbon, 2-6 parts of diatomaceous earth, 0.5-0.8 parts of surfactant, and 32-40 parts of water.
[0014] Preferably, the soaking temperature is 25-45° C., and the soaking time is 1-10 hours.
[0015] Preferably, the drying temperature is 90-100° C., and the drying time is 3-15 hours.
[0016] Preferably, the number of times of pressing the roller is 1-5 times.
[0017] Preferably, the mesh size of the activated carbon is 200-400 mesh, more preferably 300-400 mesh.
[0018] Preferably, the non-woven fabric is selected from one of PET (polyethylene terephthalate) melt-blown non-woven fabric and PP (polypropylene) melt-blown non-woven fabric.
[0019] Preferably, the thickness of the non-woven fabric is 0.1-0.3 mm.
[0020] Preferably, the weight of the nonwoven fabric is 5-20 g / m 2 , more preferably 8-12g / m 2 .
[0021] Preferably, the modified liquid further comprises nano-titanium dioxide. The addition of nano-titanium dioxide is beneficial for the air filter material to catalytically decompose the organic harmful gases under light conditions when absorbing the organic harmful gases, thereby achieving a better organic gas removal effect.
[0022] Preferably, the raw material components of the electrospinning layer further include a solvent.
[0023] Preferably, the solvent is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and tetrahydrofuran.
[0024] Preferably, the raw material components of the electrospinning layer include, by weight, 5-10 parts of polyvinyl alcohol, 8-15 parts of polyvinylidene fluoride, 0.1-0.5 parts of carbon nanotubes, 0.5-3 parts of 4-[(2-chloro-4-nitrophenyl)azo]-N-ethyl-N-(2-phenoxyethyl)aniline, and 0.5-6 parts of N-ethyl-N-(2-hydroxyethyl)-4-(2-pyridylazo)aniline.
[0025] Further preferably, the raw material components of the electrospinning layer include, by weight, 5-10 parts of polyvinyl alcohol, 8-15 parts of polyvinylidene fluoride, 0.1-0.5 parts of carbon nanotubes, 0.5-3 parts of 4-[(2-chloro-4-nitrophenyl)azo]-N-ethyl-N-(2-phenoxyethyl)aniline, 0.5-6 parts of N-ethyl-N-(2-hydroxyethyl)-4-(2-pyridylazo)aniline, and 65-90 parts of solvent.
[0026] Preferably, the components of the modified liquid include zeolite.
[0027] Preferably, the particle size of the zeolite is 1-10 μm, more preferably 3-10 μm.
[0028] Preferably, the pores of the zeolite are smaller than 50 nm, for example, 1-2 nm, 5-20 nm.
[0029] Preferably, the raw material components of the electrospinning layer also include silver ions. The silver ions can be provided by silver salts, such as silver nitrate, silver sulfate, etc. The introduction of silver ions is beneficial to improving the sterilization effect of the air filter material.
[0030] A second aspect of the present invention provides a method for preparing an air filter material.
[0031] A method for preparing an air filter material comprises the following steps: The raw material components of the electrospinning layer are mixed to form an electrospinning solution, and electrospinning is performed on the modified non-woven fabric layer, followed by drying to obtain the air filter material.
[0032] Preferably, during the electrospinning process, the flow rate of the electrospinning solution is 1-2 mL / h, the electrode spacing is 12-18 cm, and the voltage difference is 25-30 KV.
[0033] Preferably, the inner diameter of the spinning needle is 0.5-0.8 mm.
[0034] Preferably, the electrospinning time is 0.8-3 h.
[0035] A third aspect of the present invention provides an application of an air filter material.
[0036] An air filtering device comprises the above-mentioned air filtering material.
[0037] Preferably, the air filtering device includes an air purifier.
[0038] Compared with the prior art, the present invention has the following beneficial effects: The air filter material of this invention achieves efficient particle interception, harmful gas removal, and excellent mechanical properties through gradient filtration and multi-mechanical synergy. Through the specific selection of raw material components for the electrospinning layer and the modification of the non-woven fabric, the air filter material of this invention achieves excellent filtration efficiency, good mechanical properties, and the ability to remove both particulate matter and harmful gases from the air. DETAILED DESCRIPTION
[0039] In order to make the technical solution of the present invention more clearly understood by those skilled in the art, the following examples are given for illustration. It should be noted that the following examples do not limit the scope of protection claimed by the present invention.
[0040] Unless otherwise specified, the raw materials, reagents, or devices used in the following examples can be obtained from conventional commercial sources or by existing known methods.
[0041] Example 1 An air filter material comprises, from bottom to top, a modified non-woven fabric layer and an electrospun layer; The raw material components of the electrospinning layer include 6 parts of polyvinyl alcohol, 10 parts of polyvinylidene fluoride, 0.2 parts of carbon nanotubes, 1 part of 4-[(2-chloro-4-nitrophenyl)azo]-N-ethyl-N-(2-phenoxyethyl)aniline, 1 part of N-ethyl-N-(2-hydroxyethyl)-4-(2-pyridylazo)aniline, and 90 parts of N,N-dimethylformamide; The preparation process of the modified non-woven fabric layer includes: PET melt-blown non-woven fabric (thickness 0.2mm, gram weight 20g / m 2 ) was placed in the modification liquid, soaked at 25°C for 2 hours, rolled 4 times, and dried at 80°C for 6 hours to obtain a modified non-woven fabric; The components of the modification liquid, calculated by weight, include: 12 parts of activated carbon (the mesh number of the activated carbon is 300 mesh), 4 parts of diatomaceous earth (the mesh number of the diatomaceous earth is 200 mesh), 0.8 parts of surfactant (the surfactant is composed of sodium lauryl sulfate and polyoxyethylene ether in a weight ratio of 1:1), and 35 parts of water.
[0042] A method for preparing an air filter material comprises the following steps: The raw material components of the electrospinning layer are mixed to form an electrospinning solution, and electrospinning is performed on the modified non-woven fabric layer. During the electrospinning process, the flow rate of the electrospinning solution is 1.5 mL / h, the electrode spacing is 12 cm, the voltage difference is 30 KV, the inner diameter of the spinning needle is 0.7 mm, the electrospinning time is 2.5 h, and the air filter material is dried.
[0043] Example 2 An air filter material comprises, from bottom to top, a modified non-woven fabric layer and an electrospun layer; The raw material components of the electrospinning layer include 8 parts of polyvinyl alcohol, 12 parts of polyvinylidene fluoride, 0.1 parts of carbon nanotubes, 1.2 parts of 4-[(2-chloro-4-nitrophenyl)azo]-N-ethyl-N-(2-phenoxyethyl)aniline, 1.1 parts of N-ethyl-N-(2-hydroxyethyl)-4-(2-pyridylazo)aniline, and 90 parts of N,N-dimethylformamide; The preparation process of the modified non-woven fabric layer includes: PET melt-blown non-woven fabric (thickness 0.2mm, gram weight 20g / m 2 ) was placed in the modification liquid, soaked at a temperature of 25° C. for 1.5 hours, rolled 3 times, and dried at 80° C. for 6 hours to obtain a modified non-woven fabric; The components of the modification liquid, calculated by weight, include: 10 parts of activated carbon (the mesh number of the activated carbon is 400 mesh), 2 parts of diatomaceous earth (the mesh number of the diatomaceous earth is 200 mesh), 0.5 parts of surfactant (the surfactant is composed of sodium lauryl sulfate and polyoxyethylene ether in a weight ratio of 1:0.8), and 35 parts of water.
[0044] A method for preparing an air filter material comprises the following steps: The raw material components of the electrospinning layer are mixed to form an electrospinning solution, and electrospinning is performed on the modified non-woven fabric layer. During the electrospinning process, the flow rate of the electrospinning solution is 2 mL / h, the electrode spacing is 12 cm, the voltage difference is 25 KV, the inner diameter of the spinning needle is 0.7 mm, the electrospinning time is 2.2 h, and the air filter material is dried.
[0045] Example 3 An air filter material comprises, from bottom to top, a modified non-woven fabric layer and an electrospun layer; The raw material components of the electrospinning layer include 6 parts of polyvinyl alcohol, 10 parts of polyvinylidene fluoride, 0.2 parts of carbon nanotubes, 1 part of 4-[(2-chloro-4-nitrophenyl)azo]-N-ethyl-N-(2-phenoxyethyl)aniline, 1 part of N-ethyl-N-(2-hydroxyethyl)-4-(2-pyridylazo)aniline, and 90 parts of N,N-dimethylformamide; The preparation process of the modified non-woven fabric layer includes: PET melt-blown non-woven fabric (thickness 0.2mm, gram weight 20g / m 2 ) was placed in the modification liquid, soaked at a temperature of 25° C. for 1 hour, rolled 4 times, and dried at 80° C. for 6 hours to obtain a modified non-woven fabric; The components of the modification liquid, calculated by weight, include: 12 parts of activated carbon (the mesh number of the activated carbon is 300 mesh), 4 parts of diatomaceous earth (the mesh number of the diatomaceous earth is 200 mesh), 0.8 parts of surfactant (the surfactant is composed of sodium lauryl sulfate and polyoxyethylene ether in a weight ratio of 1:1), zeolite (the particle size of the zeolite is 2±1 μm, and the pore size of the zeolite is 20±2 nm), and 35 parts of water.
[0046] A method for preparing an air filter material comprises the following steps: The raw material components of the electrospinning layer are mixed to form an electrospinning solution, and electrospinning is performed on the modified non-woven fabric layer. During the electrospinning process, the flow rate of the electrospinning solution is 1.5 mL / h, the electrode spacing is 12 cm, the voltage difference is 30 KV, the inner diameter of the spinning needle is 0.7 mm, the electrospinning time is 2.5 h, and the air filter material is dried.
[0047] Comparative Example 1 Compared with Example 1, the only difference in Comparative Example 1 is that an equal amount of 2-[[4-[(2-chloro-4-nitrophenyl)azo]phenyl]ethylamino]ethanol is used to replace the N-ethyl-N-(2-hydroxyethyl)-4-(2-pyridylazo)aniline in Example 1. The other components and preparation process are the same as those in Example 1.
[0048] Comparative Example 2 Compared with Example 1, the only difference in Comparative Example 2 is that an equal amount of polyvinyl alcohol is used to replace the polyvinylidene fluoride in Example 1. Other components and preparation processes are the same as those in Example 1.
[0049] Comparative Example 3 Compared with Example 1, the only difference of Comparative Example 3 is that the diatomaceous earth in Example 1 is replaced by an equal amount of activated carbon, and the other components and preparation process are the same as those in Example 1.
[0050] Product effect testing 1. Filtration resistance and efficiency test The air filter materials prepared in Examples 1-3 and Comparative Example 3 were tested for resistance and efficiency according to GB / T6165-2008. The results are shown in Table 1.
[0051] Table 1
[0052] As can be seen from Table 1, the air filter material prepared in the embodiment of the present invention has relatively low air resistance and high filtration efficiency, taking into account both resistance and efficiency. Comparative Example 3, based on Example 1, modified some technical features, resulting in a corresponding increase in resistance but a decrease in efficiency. This shows that the technical solution of the present invention can simultaneously take into account both resistance and efficiency.
[0053] 2. Mechanical strength test The air filter materials prepared in Example 1 and Comparative Example 2 were tested for transverse tensile strength and longitudinal tensile strength in accordance with GB / T 13554-2020. The results are shown in Table 2.
[0054] Table 2
[0055] It can be seen from Table 2 that the air filter material prepared in Example 1 of the present invention has good mechanical properties. It can also be further seen that in the technical solution of the present invention, the coordinated use of polyvinyl alcohol and polyvinylidene fluoride helps to improve the mechanical properties of the air filter material.
[0056] 3.PM2.5 and TVOC (total volatile organic compounds) testing In the atmosphere, PM2.5 is 250±20μg / m 3 In the time period, under the external environment of temperature of 1-10°C and relative humidity of 30-40%, the air filter materials prepared in Example 1, Example 3, Comparative Example 1 and Comparative Example 3 were used to filter the atmosphere, and the air filtration rate was 80 L / min. The results of PM2.5 and TVOC in the gas after purification by the above air filter materials are shown in Table 3.
[0057] Table 3
[0058] It can be seen from Table 3 that the air filter material prepared in the embodiment of the present invention has a good removal effect on PM2.5 and TVOC.
Claims
1. An air filter material, characterized in that: From bottom to top, it includes a modified non-woven fabric layer and an electrospinning layer; The raw material components of the electrospinning layer include polyvinyl alcohol, polyvinylidene fluoride, carbon nanotubes, 4-[(2-chloro-4-nitrophenyl)azo]-N-ethyl-N-(2-phenoxyethyl)aniline, and N-ethyl-N-(2-hydroxyethyl)-4-(2-pyridylazo)aniline; The preparation process of the modified non-woven fabric layer includes: placing the non-woven fabric in a modification liquid, soaking, rolling, and drying to obtain the modified non-woven fabric; The components of the modified liquid include: activated carbon, diatomaceous earth, surfactant and water.
2. The air filter material according to claim 1, characterized in that The surfactant includes sodium lauryl sulfate and polyoxyethylene ether.
3. The air filter material according to claim 1, characterized in that The components of the modified liquid include, by weight, 10-15 parts of activated carbon, 1-8 parts of diatomaceous earth, 0.5-1 part of surfactant, and 30-40 parts of water.
4. The air filter material according to claim 1, characterized in that The soaking temperature is 25-45°C, and the soaking time is 4-10 hours; and / or, the drying temperature is 90-100°C, and the drying time is 3-15 hours; and / or, the number of pressing rollers is 1-5 times; and / or, the mesh size of the activated carbon is 200-400 mesh; and / or, the non-woven fabric is selected from one of PET melt-blown non-woven fabric and PP melt-blown non-woven fabric.
5. The air filter material according to claim 1, characterized in that The raw material components of the electrospinning layer further include a solvent, and the solvent is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and tetrahydrofuran.
6. The air filter material according to claim 1, characterized in that The raw material components of the electrospinning layer include, by weight, 5-10 parts of polyvinyl alcohol, 8-15 parts of polyvinylidene fluoride, 0.1-0.5 parts of carbon nanotubes, 0.5-3 parts of 4-[(2-chloro-4-nitrophenyl)azo]-N-ethyl-N-(2-phenoxyethyl)aniline, and 0.5-6 parts of N-ethyl-N-(2-hydroxyethyl)-4-(2-pyridylazo)aniline.
7. The air filter material according to claim 1, characterized in that The raw material components of the electrospinning layer also include silver ions.
8. The method for preparing the air filter material according to any one of claims 1 to 7, characterized in that: The following steps are involved: The raw material components of the electrospinning layer are mixed to form an electrospinning solution, and electrospinning is performed on the modified non-woven fabric layer, followed by drying to obtain the air filter material.
9. The preparation method according to claim 8, characterized in that During the electrospinning process, the flow rate of the electrospinning solution is 1-2 mL / h, the electrode spacing is 12-18 cm, and the voltage difference is 25-30 KV.
10. An air filtering device, characterized in that: The invention comprises the air filter material according to any one of claims 1 to 7.