An electrospun transparent honeycomb structure air filter material and its preparation method

Abstract

This invention discloses an electrospun transparent honeycomb structure air filter material and its preparation method, belonging to the technical field of air filter materials. The preparation of this material includes mixing barium titanate nanoparticles and a polar organic solvent, adding hexadecyltrimethylammonium bromide, and then adding polyvinylidene fluoride-hexafluoropropylene to obtain an electrospinning solution; cutting a stainless steel receiving plate to obtain a honeycomb structure stainless steel receiving plate; laying a substrate flat on the honeycomb structure stainless steel receiving plate; injecting the prepared electrospinning solution into a syringe; placing the syringe on an electrospinning machine for electrospinning to obtain a PVDF-HFP fiber membrane; and placing it on a stainless steel sterilization tray for drying to obtain the electrospun transparent honeycomb structure air filter material. This material has a transparent honeycomb structure, a filtration efficiency of over 98.51% for ultrafine particles of 100-1000 nm, and a pressure drop of up to 34 Pa.

Description

Technical Field

[0001] This invention relates to the field of air filtration materials technology, and in particular to an electrospun transparent honeycomb structure air filtration material and its preparation method. Background Technology

[0002] Existing air filtration materials mainly include non-woven fabrics, glass fibers, electret materials, and electrospun fiber membranes. Non-woven fabrics primarily refer to polyester or polypropylene fibers, which suffer from limited filtration efficiency, non-degradability, difficulty in recycling, moderate temperature resistance, and susceptibility to moisture. Glass fibers are characterized by brittleness, susceptibility to moisture, high air resistance, high cost, and easy shedding of fiber fragments. Electret materials mainly include electret fibers or electrostatic cotton, which are prone to static electricity decay, rapid loss of static electricity in high humidity environments, poor tolerance to high concentrations of pollutants, non-washability, and short lifespan. Electrospun fiber membranes mainly include PTFE and PVDF fiber membranes, which suffer from high resistance and low efficiency in intercepting large particles.

[0003] Spiderweb-like fiber air filter materials belong to the nanofiber network category and are prepared by electrospinning or electrostatic spraying techniques. However, the filtration efficiency of this material for ultrafine particles still needs improvement, and large-scale production is difficult. Transparent air filter materials are porous, membrane materials that combine air filtration and high light transmittance. These materials are mainly composed of nanofibers, transparent films, micromesh, and transparent electrets. Existing screen-type air filter materials mainly include household screens, dust screens, and anti-smog screens. These air filter materials mainly suffer from the contradiction between filtration efficiency and ventilation, and are prone to dust accumulation, clogging, short lifespan, lack of active adsorption capacity, and poor weather resistance. Therefore, developing a high-efficiency, low-resistance air filter material with hydrophobic and transparent properties has become a pressing technical problem that needs to be solved in the current technology field. Summary of the Invention

[0004] Based on the technical problems to be solved by the present invention, the nanofibers of the electrospun transparent honeycomb structure air filter material of the present invention are distributed in a concentrated and ordered, sparse and random manner, forming a transparent honeycomb structure; the transparent structure is based on the sparse and random distribution of barium titanate-functionalized polyvinylidene fluoride-hexafluoropropylene nanofibers in a hexagonal grid; the honeycomb structure is based on the concentrated and ordered distribution of barium titanate-functionalized polyvinylidene fluoride-hexafluoropropylene nanofibers on a hexagonal grid framework. Furthermore, an electrospun transparent honeycomb structure air filter material and its preparation method are proposed.

[0005] One objective of this invention is to provide a method for preparing an electrospun transparent honeycomb structure air filter material, comprising: S1. Mix barium titanate nanoparticles and polar organic solvent at a mass ratio of 0.10~0.12:1, stir, and obtain a fully mixed barium titanate-polar organic solvent mixture. S2. Thoroughly mix hexadecyltrimethylammonium bromide and the fully mixed barium titanate-polar organic solvent mixture, and stir to obtain a barium titanate-polar organic solvent-CTAB solution; S3. Mix polyvinylidene fluoride-hexafluoropropylene with the barium titanate-polar organic solvent-CTAB solution and stir to obtain an electrospinning solution; S4. Cut the stainless steel receiving plate to obtain a honeycomb structure stainless steel receiving plate. S5. Lay the substrate flat on the honeycomb structure stainless steel receiving plate, inject the prepared electrospinning solution into a syringe, and place the syringe on an electrospinning machine to perform electrospinning, obtaining... / PVDF-HFP fiber membrane; S6, the above The PVDF-HFP fiber membrane was placed on a stainless steel sterilization tray and dried to obtain the electrospun transparent honeycomb structure air filter material.

[0006] Furthermore, the mass ratio of the hexadecyltrimethylammonium bromide to barium titanate-DMF mixture is 0.0020~0.0026:1.

[0007] Furthermore, the substrate is a polyvinyl chloride hexagonal mesh screen; the electrospinning scanning starting point is 3.5~4.5cm, the scanning speed is 400~600mm / min, the scanning stroke is 50~90mm, the receiving distance is 15~25cm, the adhesive pushing speed is 0.06~0.10mm / min, the spinning voltage is -5~-3KV for the negative electrode and 20~24KV for the positive electrode; the syringe is 5mL; the electrospinning needle is 18~20G, the spinning time is 60~80min, the spinning temperature is 20~25℃, and the humidity is 35~40%.

[0008] Furthermore, the stirring conditions for preparing the barium titanate-polar organic solvent mixture are room temperature, 400~800 rpm, 20~40 min; the stirring conditions for preparing the barium titanate-polar organic solvent-CTAB solution are room temperature, 400~800 rpm, 20~40 min; and the stirring conditions for preparing the electrospinning solution are 65~85℃, 400~800 rpm, 3~5 h.

[0009] Furthermore, the stainless steel receiving plate has a hexagonal grid structure; the side length of the hexagonal grid structure is 3.5~4.5mm, and the grid spacing is 0.4~0.6mm; the stainless steel receiving plate has a honeycomb structure; the length of the stainless steel receiving plate is 18~22cm, the width is 13~17cm, and the thickness is 0.8~1.2mm.

[0010] Furthermore, the polar organic solvent is N,N-dimethylformamide; the barium titanate has a purity of not less than 99.9% and a size of not more than 100 nm; the electrospinning machine is an SS-X3 electrospinning machine; and the stainless steel is SS316 stainless steel.

[0011] Furthermore, the drying is vacuum drying; the drying temperature is 50~60℃; and the holding time is 2~4h.

[0012] The second objective of this invention is to provide an electrospun transparent honeycomb structure air filter material, wherein the nanofibers of the air filter material are distributed in a concentrated and ordered manner and a sparse and random manner; the air filter material has a transparent structure; the transparent structure is based on barium titanate functionalized polyvinylidene fluoride-hexafluoropropylene nanofibers sparsely and randomly distributed in a hexagonal grid; the air filter material has a honeycomb structure; the honeycomb structure is based on barium titanate functionalized polyvinylidene fluoride-hexafluoropropylene nanofibers concentrated and orderedly distributed on a hexagonal grid framework.

[0013] Furthermore, the electrospun transparent honeycomb structure air filter material has a filtration efficiency of over 98.51% for ultrafine particles of 100~1000nm and a pressure drop of 34Pa.

[0014] The third objective of this invention is to provide an application of electrospun transparent honeycomb structure air filter material in the preparation of filter materials for building and home furnishing, medical protection, precision electronic manufacturing, or environmental protection.

[0015] Compared with existing technologies, this invention proposes an electrospun transparent honeycomb structure air filter material and its preparation method, which has the following beneficial effects: The air filter material prepared by this invention is mainly made of polyvinylidene fluoride cohexafluoropropylene. The transparent honeycomb structure air filter material prepared by electrospinning technology exhibits a dense and orderly orientation and a sparse and random distribution, which is beneficial to control the pore size and transparency of the transparent honeycomb structure air filter material. As a result, the transparent honeycomb structure air filter material has good transparency, high filtration efficiency and low air resistance.

[0016] Furthermore, the inorganic salts in the air filter material of the present invention This technology can introduce a transparent honeycomb structure into air filter materials. The transparent honeycomb structure air filter material has the characteristics of fine fiber diameter and small pore size. The nanofibers are distributed in a concentrated and ordered and sparse and random manner, presenting a typical honeycomb structure, which further improves the conductivity of the spinning solution.

[0017] Furthermore, this invention employs fiber laser cutting of SS316 stainless steel to control the mesh size of the stainless steel receiving plate, effectively improving the variation of the electric field intensity on the receiving plate and the distribution of fibers on the receiving plate. Moreover, the air filter material described in this invention has hydrophobic properties, effectively removing ultrafine particles such as… Its filtration efficiency can reach over 98.51%, and its pressure drop is as low as 34 Pa, making it a promising candidate for applications in air filtration and medical and health fields. Attached Figure Description

[0018] Figure 1 A stereo electron microscope image of an electrospun transparent honeycomb structure air filter material according to an embodiment of the present invention is shown. Figure 2 A stereo electron microscope image of another electrospun transparent honeycomb structure air filter material according to an embodiment of the present invention is shown; Figure 3 A stereo electron microscope image of an air filter material according to the present invention is shown as a comparative example. Figure 4 The diagram shows a comparison of the filtration performance of an air filter material according to an embodiment and a comparative example of the present invention; wherein, (a) is a filtration efficiency-pressure drop diagram; and (b) is a quality factor line graph. Detailed Implementation

[0019] Exemplary embodiments of the present application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0020] Unless otherwise specified, the technical means used in the following embodiments are conventional means well known to those skilled in the art, and the reagents and materials in this invention are obtained from the market or other public channels.

[0021] This invention proposes an electrospun transparent honeycomb structure air filter material and its preparation method. The preparation of the electrospun transparent honeycomb structure air filter material includes mixing barium titanate nanoparticles and a polar organic solvent, adding hexadecyltrimethylammonium bromide and mixing thoroughly, adding polyvinylidene fluoride-hexafluoropropylene and mixing thoroughly to obtain an electrospinning solution; cutting a stainless steel receiving plate to obtain a honeycomb structure stainless steel receiving plate; laying a substrate flat on the honeycomb structure stainless steel receiving plate; injecting the prepared electrospinning solution into a syringe; and placing the syringe on an electrospinning machine for electrospinning to obtain... / PVDF-HFP fiber membrane; the fiber membrane is placed on a stainless steel sterilization tray and dried to obtain an electrospun transparent honeycomb structure air filter material. This material has a transparent honeycomb structure, a filtration efficiency of over 99% for ultrafine particles of 100~1000nm, and a pressure drop of no more than 35Pa.

[0022] The stainless steel receiving plates with different hexagonal grid sizes used in this invention are all obtained by fiber laser cutting.

[0023] Based on the above principles, this invention proposes an electrospun transparent honeycomb structure air filter material and its preparation method, comprising: Step 1: Mix barium titanate nanoparticles and polar organic solvent at a mass ratio of 0.11:1, stir, and obtain a fully mixed barium titanate-polar organic solvent mixture; wherein, the stirring speed is 350~450 rpm.

[0024] Step 2: Thoroughly mix hexadecyltrimethylammonium bromide and the fully mixed barium titanate-polar organic solvent mixture, and stir to obtain a barium titanate-polar organic solvent-CTAB solution; wherein the stirring speed is 350~450 rpm.

[0025] Step 3: Mix polyvinylidene fluoride-hexafluoropropylene with the barium titanate-polar organic solvent-CTAB solution and stir to obtain an electrospinning solution; wherein the stirring speed is 350~450 rpm and the stirring temperature is 70~80℃.

[0026] Step 4: Cut the stainless steel receiving plate to obtain a honeycomb structure stainless steel receiving plate.

[0027] Step 5: Lay the substrate flat on the honeycomb structure stainless steel receiving plate, inject the prepared electrospinning solution into a syringe, place the syringe on an electrospinning machine to perform electrospinning, and obtain... / PVDF-HFP fiber membrane; wherein, the substrate is a polyvinyl chloride hexagonal mesh screen; the electrospinning scanning starting point is 4cm, the scanning speed is 500mm / min, the scanning stroke is 70mm, the receiving distance is 20cm, the adhesive pushing speed is 0.08mm / min, the spinning voltage is -4KV and 22KV; the syringe specification is 5mL; the spinning needle is 19G, the spinning time is 70min; the spinning temperature is 20~25℃, and the humidity is 35~40%.

[0028] Step 6, the above The PVDF-HFP fiber membrane was placed on a stainless steel sterilization tray and dried to obtain the electrospun transparent honeycomb structure air filter material; wherein the drying temperature was 55℃ and the heat preservation time was 3h.

[0029] Example 1 This embodiment proposes a method for preparing an electrospun transparent honeycomb structure air filter material, including the following steps: Step 1: Using a 10mL graduated cylinder, weigh 17mL of N,N-dimethylformamide (DMF) solvent in two portions and pour it into a 20mL solution bottle. The total weight of the DMF solvent is 15.4700g.

[0030] Step 2: Weigh 1.6936g of barium titanate nanoparticles using a balance and add them to a solution bottle containing DMF solution to obtain a barium titanate-DMF mixture.

[0031] Step 3: Place the barium titanate-DMF mixture on a magnetic stirrer and stir at 600 rpm for 30 min at room temperature to obtain a well mixed barium titanate-DMF solution.

[0032] Step 4: Weigh 0.0397g of cetyltrimethylammonium bromide (CTAB) powder using a balance and add it to the above-mentioned fully mixed barium titanate-DMF solution. Then place the solution in a magnetic stirrer and stir at 600rpm for 30min at room temperature to obtain barium titanate-DMF-CTAB solution.

[0033] Step 5: After stirring, weigh 3.9667g of polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) particles and add them to the above barium titanate-DMF-CTAB solution. Stir continuously at 400rpm for 4h at 75℃ to obtain a milky white spinning solution with a PVDF-HFP mass fraction of about 20wt%.

[0034] Step 6: Using a fiber laser, cut SS316 stainless steel (20cm long, 15cm wide, approximately 1mm thick) to obtain a honeycomb structure SS316 stainless steel receiving plate. The side length of each hexagonal grid on the stainless steel receiving plate is 4mm, and the spacing between the hexagonal grids is 0.5mm. Then, install the cut honeycomb structure stainless steel receiving plate on an SS-X3 electrospinning machine (Beijing Yongkang Leyue Technology Development Co., Ltd.). 3mL of spinning solution is placed in a 5mL syringe. After attaching a 19G spinning needle to the syringe, place the syringe in the SS-X3 electrospinning machine. Set the scanning starting point to 40mm, the scanning speed to 500mm / min, the scanning stroke to 70mm, the receiving distance to 20cm, the adhesive pushing speed to 0.08mm / min, the receiving substrate to a PVC hexagonal mesh screen, the spinning voltage to -4KV and 22KV, the spinning temperature to 20~25℃, and the humidity to 35~40%. The resulting product... / PVDF-HFP fiber membrane.

[0035] Step 7: Place the above The PVDF-HFP fiber membrane is placed in a stainless steel sterilization tray, and then the stainless steel sterilization tray is placed in a vacuum drying oven and kept at 55°C for 3 hours to obtain an electrospun transparent honeycomb structure air filter material.

[0036] result: See Figure 1 The electrospun transparent honeycomb structure air filter material prepared in this embodiment exhibits a typical honeycomb structure, with nanofiber diameters ranging from 50 to 140 nm. This air filter material... The filtration efficiency is 98.51%, the pressure drop is 34 Pa, and the quality factor is approximately 0.12. .

[0037] Example 2 This embodiment is the same as Embodiment 1, except that the side length of the hexagonal grid on the stainless steel receiving plate is 2mm.

[0038] result: See Figure 2 In this embodiment, the electrospun transparent honeycomb air filter material has a smaller honeycomb structure, with nanofiber diameters ranging from 40 to 160 nm. This air filter material... The filtration efficiency is 99.02%, the pressure drop is 73 Pa, and the quality factor is approximately 0.06. .

[0039] Comparative Example This comparative example is the same as Example 1, except that the stainless steel receiving plate is a solid plate and does not contain a hexagonal network.

[0040] result: Please see Figure 3 The air filter material prepared in this comparative example is an opaque, randomly distributed fiber membrane with nanofibers ranging from 30 to 200 nm in diameter. This air filter material... The filtration efficiency is 99.84%, the pressure drop is 148 Pa, and the quality factor is approximately 0.04. .

[0041] Examples 1 and 2 of this invention and the comparative examples all used the SX-L1056R1 mask filtration performance testing platform manufactured by Suzhou Suxin Environmental Technology Co., Ltd. to test the filtration performance of the prepared electrospun transparent honeycomb structure air filter material. The effective test area of ​​the air filter material was 100. The wind speed was set to 32 L / min; the surface morphology of the prepared electrospun transparent honeycomb air filter material was analyzed using stereo electron microscopy.

[0042] result: Please see Figure 4(a) It can be seen that PHB-8-L (Example 1), PHB-8-M (Example 2) and PHB-8-Z (Comparative Example) all have good filtration efficiency (see Table 1) and all belong to the high-efficiency filtration level; while the pressure drop of Example 1 is significantly lower than that of Example 2 and the comparative example. In particular, the wind resistance of Example 1 is 1 / 5 of that of the comparative example. High wind resistance will lead to poor ventilation, high noise and high energy consumption, which also indirectly reflects the significant structural advantages of the electrospun transparent honeycomb structure air filter material prepared by the present invention.

[0043] Table 1. List of filtration performance and pressure drop of filter materials prepared in the embodiments and comparative examples of the present invention. Please see Figure 4 (b) The quality factor of the present invention is based on In this table, QF represents the quality factor; η represents the filtration efficiency; and ΔP represents the pressure drop. A higher QF value indicates significantly superior overall performance of the material. Therefore, Example 1 has the best quality factor (see Table 2), followed by Example 2, while the comparative example shows a significant decrease. Example 1's PHB-8-L embodies the structure with the best overall performance among the three, achieving near 100% filtration efficiency while minimizing air resistance. It is best suited for applications such as transparent window screens, low-resistance masks, and fresh air filters in building and home furnishings, medical protection, precision electronic manufacturing, or environmental governance. The comparative example, PHB-8-Z, has the worst overall performance due to excessively high air resistance.

[0044] Table 2. List of quality factors of the filter materials prepared in the embodiments and comparative examples of the present invention. In summary, this invention proposes an electrospun transparent honeycomb structure air filter material and its preparation method. This material is prepared based on polyvinylidene fluoride cohexafluoropropylene, barium titanate nanoparticles, and hexadecyltrimethylammonium bromide. The barium titanate nanoparticles are successfully introduced into the honeycomb structure air filter material, which features fine fiber diameters and small pore sizes. Furthermore, the nanofibers are distributed in a concentrated and ordered, sparse and random manner, exhibiting a typical honeycomb structure. Further, this invention utilizes fiber laser cutting of SS316 stainless steel to control the grid size of the stainless steel receiving plate, effectively improving the variation of the electric field intensity on the receiving plate and the distribution of fibers on the receiving plate. Furthermore, the transparent honeycomb structure air filter material prepared by this invention has hydrophobic properties, effectively filtering ultrafine particles such as… Its filtration efficiency can reach over 98.51%, and its pressure drop is as low as 34 Pa, making it a promising candidate for application in air filtration.

[0045] It should be noted that the term "comprising," or any other variation thereof, is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0046] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for preparing an electrospun transparent honeycomb structure air filter material, characterized in that, include: S1. Mix barium titanate nanoparticles and polar organic solvent at a mass ratio of 0.10~0.12:1, stir, and obtain a fully mixed barium titanate-polar organic solvent mixture. S2. Thoroughly mix hexadecyltrimethylammonium bromide and the fully mixed barium titanate-polar organic solvent mixture, and stir to obtain a barium titanate-polar organic solvent-CTAB solution; S3. Mix polyvinylidene fluoride-hexafluoropropylene with the barium titanate-polar organic solvent-CTAB solution and stir to obtain an electrospinning solution; S4. Cut the stainless steel receiving plate to obtain a honeycomb structure stainless steel receiving plate. S5. Lay the substrate flat on the honeycomb structure stainless steel receiving plate, inject the prepared electrospinning solution into a syringe, and place the syringe on an electrospinning machine to perform electrospinning, obtaining... / PVDF-HFP fiber membrane; S6, the above The PVDF-HFP fiber membrane was placed on a stainless steel sterilization tray and dried to obtain the electrospun transparent honeycomb structure air filter material.

2. The method for preparing the electrospun transparent honeycomb structure air filter material according to claim 1, characterized in that, The mass ratio of the hexadecyltrimethylammonium bromide to barium titanate-DMF mixture is 0.0020~0.0026:

1.

3. The method for preparing the electrospun transparent honeycomb structure air filter material according to claim 1, characterized in that, The substrate is a polyvinyl chloride hexagonal mesh screen. The electrospinning scanning starting point is 3.5~4.5cm, the scanning speed is 400~600mm / min, the scanning stroke is 50~90mm, the receiving distance is 15~25cm, the adhesive pushing speed is 0.06~0.10mm / min, and the spinning voltage is -5~-3KV for the negative electrode and 20~24KV for the positive electrode. The syringe has a capacity of 5 mL; The electrospinning needle is 18~20G, the spinning time is 60~80min, the spinning temperature is 20~25℃, and the humidity is 35~40%.

4. The method for preparing the electrospun transparent honeycomb structure air filter material according to claim 1, characterized in that, The stirring conditions for preparing the barium titanate-polar organic solvent mixture are room temperature, 400~800 rpm, 20~40 min; The stirring conditions for preparing the barium titanate-polar organic solvent-CTAB solution were room temperature, 400~800 rpm, 20~40 min; The stirring conditions for preparing the electrospinning solution are 65~85℃, 400~800rpm, and 3~5h.

5. The method for preparing the electrospun transparent honeycomb structure air filter material according to claim 1, characterized in that, The stainless steel receiving plate has a hexagonal mesh structure; the side length of the hexagonal mesh structure is 3.5~4.5mm, and the mesh spacing is 0.4~0.6mm; The stainless steel receiving plate has a honeycomb structure; The stainless steel receiving plate has a length of 18-22cm, a width of 13-17cm, and a thickness of 0.8-1.2mm.

6. The method for preparing the electrospun transparent honeycomb structure air filter material according to claim 1, characterized in that, The polar organic solvent is N,N-dimethylformamide; The barium titanate has a purity of not less than 99.9% and a size of not more than 100 nm; The electrospinning machine is an SS-X3 electrospinning machine; The stainless steel is SS316 stainless steel.

7. The method for preparing the electrospun transparent honeycomb structure air filter material according to claim 1, characterized in that, The drying process is vacuum drying; The drying temperature is 50~60℃; the heat preservation time is 2~4h.

8. An electrospun transparent honeycomb structure air filter material prepared by the preparation method according to any one of claims 1 to 7, characterized in that, The nanofibers of the air filter material are distributed in a concentrated, ordered, and sparse, random manner; The air filter material has a transparent structure; the transparent structure is based on barium titanate-functionalized polyvinylidene fluoride-hexafluoropropylene nanofibers sparsely and randomly distributed in a hexagonal grid. The air filter material has a honeycomb structure; the honeycomb structure is based on barium titanate functionalized polyvinylidene fluoride-hexafluoropropylene nanofibers that are concentrated and orderly distributed on a hexagonal grid framework.

9. The electrospun transparent honeycomb structure air filter material according to claim 8, characterized in that, The electrospun transparent honeycomb structure air filter material has a filtration efficiency of over 98.51% for ultrafine particles of 100~1000nm and a pressure drop of 34Pa.

10. The application of an electrospun transparent honeycomb structure air filter material prepared by the preparation method according to any one of claims 1 to 7, or according to any one of claims 8 to 9, in the preparation of filter materials for building and home furnishing, medical protection, electronic precision manufacturing, or environmental protection.

Images