Three-dimensional oil mist filtering material and preparation method thereof

Abstract

The invention provides a three-dimensional oil mist filtering material and a preparation method thereof. The three-dimensional oil mist filtering material comprises at least one of a hydrophilic and oleophylic filtering material and a hydrophobic and oleophobic filtering material, and the hydrophilic and oleophylic filtering material comprises a first foam base material and a hydrophilic and oleophylic polymer attached to the surface of the first foam base material. The hydrophobic and oleophobic filtering material comprises a second foam base material and a hydrophobic and oleophobic polymer grafted on the surface of the second foam base material through hydroxyl. The three-dimensional oil mist filtering material can efficiently filter oil mist such as oil smoke and the like, and can be effectively applied to gas purification in oil-containing and high-humidity environments and the like; the foam is used as a base material, so that a multi-dimensional filtering effect can be realized, meanwhile, the foam has good stability, and large-scale preparation and application are favorably realized; the pressure drop of the two filtering materials in the oil mist filtering process can be effectively reduced, so that the oil mist filtering resistance is reduced, and the filtering efficiency is favorably improved.

Description

Technical Field

[0001] This invention relates to the field of materials technology, specifically to three-dimensional oil mist filtration materials and their preparation methods. Background Technology

[0002] The main harmful components of cooking fumes include volatile oils, organic matter, and substances produced by their heating, decomposition, or cracking during cooking. Among these components, highly irritating substances such as acrolein and carcinogens cause serious harm to the human respiratory system. According to relevant statistics, the pollution level of cooking fumes to the atmosphere is not negligible; its harmfulness is no less than that of vehicle exhaust, and in some areas, it is even several times higher than the pollution level of vehicle exhaust.

[0003] Therefore, the treatment of oil fumes and other oil mists urgently needs to be addressed. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one object of this invention is to provide a three-dimensional oil mist filter material that can effectively filter oil mist and can be used for the purification of oily, high-humidity, and other gases.

[0005] In one aspect, the present invention provides a three-dimensional oil mist filter material. According to an embodiment of the present invention, the three-dimensional oil mist filter material includes at least one of a hydrophilic-oleophilic filter material and a hydrophobic-oleophobic filter material. The hydrophilic-oleophilic filter material includes a first foam substrate and a hydrophilic-oleophilic polymer attached to the surface of the first foam substrate. The hydrophobic-oleophobic filter material includes a second foam substrate and a hydrophobic-oleophobic polymer grafted onto the surface of the second foam substrate via hydroxyl groups. Thus, the above-mentioned three-dimensional oil mist filter material can efficiently filter oil mist such as fumes and can be effectively applied to gas purification in oily and high-humidity environments. Moreover, using foam as the substrate can achieve multi-dimensional filtration effects while also possessing good stability, which is conducive to large-scale preparation and application. Furthermore, selecting foam as the substrate for both the hydrophilic-oleophilic and hydrophobic-oleophobic filter materials can effectively reduce the pressure drop (pressure drop refers to the pressure difference before and after the filter material filters the oil mist) during the oil mist filtration process, thereby reducing the resistance to oil mist filtration and helping to improve filtration efficiency. Therefore, the hydrophilic-oleophilic and hydrophobic-oleophobic filter materials of the present invention can help realize a highly efficient and low-resistance three-dimensional oil mist filter material.

[0006] According to embodiments of the present invention, the hydrophilic-oleophilic polymer includes hydroxyl groups, and the hydrophobic-oleophilic polymer includes a perfluorocarbon chain.

[0007] According to embodiments of the present invention, the hydrophilic-oleophilic polymer includes at least one of polydopamine and polyvinyl alcohol, and the hydrophobic-oleophilic polymer includes at least one of a copolymer of tetraethyl orthosilicate and perfluorooctylsiloxane and a copolymer of tetraethyl orthosilicate and perfluorodecylsiloxane.

[0008] According to an embodiment of the present invention, at least one of the following conditions is met: the first foam substrate and the second foam substrate are respectively at least one of polystyrene foam, formaldehyde melamine foam and polyurethane foam; the pore density of the first foam substrate and the second foam substrate are respectively 10 to 100 ppi.

[0009] According to an embodiment of the present invention, the water contact angle of the hydrophilic-oleophilic filter material is 0° to 10°, and the oil contact angle of the hydrophilic-oleophilic filter material is 0° to 10°; and / or, the water contact angle of the hydrophobic-oleophobic filter material is greater than or equal to 140°, and the oil contact angle of the hydrophobic-oleophobic filter material is greater than or equal to 140°.

[0010] According to an embodiment of the present invention, in the oil mist filtration direction, the three-dimensional oil mist filter material includes the hydrophilic and oleophilic filter material and the hydrophobic and oleophobic filter material stacked together.

[0011] In another aspect, the present invention provides a method for preparing the aforementioned three-dimensional oil mist filter material. According to an embodiment of the present invention, the method for preparing the three-dimensional oil mist filter material includes: immersing a foam substrate in a hydrophilic-oleophilic polymer solution for a first impregnation treatment; drying the impregnated foam substrate to obtain a hydrophilic-oleophilic filter material; immersing the hydrophilic-oleophilic filter material in a hydrophobic-oleophobic modified solution for a second impregnation treatment; and drying the impregnated hydrophilic-oleophilic filter material to obtain a hydrophobic-oleophobic filter material. Therefore, the three-dimensional oil mist filter material prepared by the above method can efficiently filter oil mist such as oil fumes and can be effectively applied to gas purification in oily and high-humidity environments; moreover, using foam as a substrate can achieve multi-dimensional filtration effects while also possessing good stability, which is conducive to large-scale preparation and application; furthermore, the above preparation method is simple and easy to implement, facilitating industrial mass production.

[0012] According to an embodiment of the present invention, the step of obtaining the hydrophilic and oleophilic filter material satisfies at least one of the following conditions: the polymer in the hydrophilic and oleophilic polymer solution includes at least one of polydopamine and polyvinyl alcohol; the mass concentration of the polymer in the hydrophilic and oleophilic polymer solution is 1 to 5 g / L; the first impregnation time is 12 to 60 h; and the first drying temperature is 50 to 80 °C.

[0013] According to embodiments of the present invention, the step of obtaining the hydrophobic and oleophobic filter material satisfies at least one of the following conditions: the hydrophobic and oleophobic modification solution comprises a polymeric monomer and an organic solvent, the polymeric monomer comprises perfluorosiloxane and tetraethyl orthosilicate, the perfluorosiloxane comprises at least one of perfluorooctylsiloxane and perfluorodecylsiloxane; the volume percentage of the perfluorosiloxane in the hydrophobic and oleophobic modification solution is 0.6-1.4%; the second impregnation time is 4-7 h; and the second drying temperature is 50-80 °C.

[0014] According to an embodiment of the present invention, the hydrophobic and oleophobic modified solution further includes an acid or an alkaline solution. Attached Figure Description

[0015] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0016] Figure 1 This is a schematic diagram of the structure of a three-dimensional oil mist filter material in one embodiment of the present invention;

[0017] Figure 2 These are contact angle test diagrams of the hydrophilic and oleophilic filter materials and the hydrophobic and oleophobic filter materials in Example 1;

[0018] Figure 3 These are scanning electron microscope images of the hydrophilic and oleophilic filter materials and the hydrophobic and oleophobic filter materials in Example 1;

[0019] Figure 4 This is a graph showing the test data for filtering oil mist using hydrophilic and oleophilic filter materials alone in Example 1.

[0020] Figure 5 This is a graph showing the test data for filtering oil mist using hydrophobic and oleophobic filter materials alone in Example 1.

[0021] Figure 6 This is a graph of test data from Example 1, which combines hydrophilic and oleophilic filter materials with hydrophobic and oleophobic filter materials.

[0022] Figure 7 This is a graph showing the test data from Example 1, which combines hydrophilic and oleophilic filter materials with hydrophobic and oleophobic filter materials. Detailed Implementation

[0023] The present invention will be explained below with reference to embodiments. Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be considered as limiting the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0024] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0025] In one aspect of the invention, a three-dimensional oil mist filter material is provided. According to an embodiment of the invention, the three-dimensional oil mist filter material includes at least one of a hydrophilic and oleophilic filter material and a hydrophobic and oleophobic filter material. The hydrophilic and oleophilic filter material includes a first foam substrate and a hydrophilic and oleophilic polymer attached to the surface of the first foam substrate. The hydrophobic and oleophobic filter material includes a second foam substrate and a hydrophobic and oleophobic polymer grafted onto the surface of the second foam substrate via hydroxyl groups. Therefore, both the hydrophilic and oleophilic polymers on the surface of the hydrophilic-oleophilic filter material and the hydrophobic and oleophobic polymers on the surface of the hydrophobic-oleophobic filter material enable the two filter materials to effectively filter oil mist. In other words, the aforementioned three-dimensional oil mist filter material can efficiently filter oil fumes and other oil mists, and can be effectively applied to gas purification in oily and high-humidity environments. Moreover, using foam as the substrate can achieve multi-dimensional filtration effects while also possessing good stability, which is conducive to large-scale preparation and application. Furthermore, choosing foam as the substrate for both the hydrophilic-oleophilic and hydrophobic-oleophobic filter materials can effectively reduce the pressure drop (pressure drop refers to the pressure difference before and after the filter material filters oil mist) during the oil mist filtration process, thereby reducing the resistance to oil mist filtration and helping to improve filtration efficiency. Therefore, the hydrophilic-oleophilic and hydrophobic-oleophobic filter materials of the present invention can help realize highly efficient and low-resistance three-dimensional oil mist filter materials.

[0026] According to embodiments of the present invention, in the hydrophilic-oleophilic filter material, since the surface of the first foam substrate has hydrophilic-oleophilic properties, oil droplets will directly adhere to its surface after colliding with the hydrophilic-oleophilic filter material, and will not diffuse backward with the airflow. Therefore, the oil droplet concentration in the downstream air is reduced after filtration by the hydrophilic-oleophilic filter material, achieving the effect of oil mist filtration. In the hydrophobic-oleophobic filter material, since the surface of the second foam substrate has hydrophobic-oleophobic properties, oil droplets will collide and bounce multiple times between the hydrophobic-oleophobic filter materials, and their kinetic energy will continuously decrease. Finally, they will be intercepted inside the hydrophobic-oleophobic filter material, and will not diffuse backward. Therefore, the oil droplet concentration in the downstream air is reduced after filtration by the hydrophobic-oleophobic filter material, achieving the effect of oil mist filtration.

[0027] According to some embodiments of the present invention, with reference to Figure 1 In the oil mist filtration direction, the three-dimensional oil mist filter material includes a layered arrangement of hydrophilic and oleophilic filter material 10 and hydrophobic and oleophobic filter material 20. In some specific embodiments, such as Figure 1In (a) of the embodiment, in the filtration direction of the oil mist, the hydrophilic and oleophilic filter material 10 is in front, and the hydrophobic and oleophobic filter material 20 is behind, that is, the oil mist first passes through the hydrophilic and oleophilic filter material 10 and then through the hydrophobic and oleophobic filter material 20; in other embodiments, such as Figure 1 In (b) of the diagram, the hydrophobic and oleophobic filter material 20 is placed in front of the hydrophilic and oleophilic filter material 10 in the filtration direction of the oil mist. That is, the oil mist first passes through the hydrophobic and oleophobic filter material 20 and then through the hydrophilic and oleophilic filter material 10. Both of these configurations can effectively filter the oil mist and have a good filtration effect.

[0028] According to some embodiments of the present invention, the first foam substrate is at least one selected from polystyrene foam, formaldehyde melamine foam, and polyurethane foam, and the pore density of the first foam substrate is 10-100 ppi, such as 10 ppi, 20 ppi, 30 ppi, 40 ppi, 50 ppi, 60 ppi, 70 ppi, 80 ppi, 90 ppi, 100 ppi, etc. Thus, the foam substrate under the above conditions has a three-dimensional structure and a suitable pore density, which can effectively filter oil fumes and other oil mists. In some specific embodiments, the pore density of the first foam substrate is 70-90 ppi.

[0029] According to some embodiments of the present invention, the second foam substrate is at least one selected from polystyrene foam, formaldehyde melamine foam, and polyurethane foam, and the pore density of the second foam substrate is 10-100 ppi, such as 10 ppi, 20 ppi, 30 ppi, 40 ppi, 50 ppi, 60 ppi, 70 ppi, 80 ppi, 90 ppi, 100 ppi, etc. Thus, the foam substrate under the above conditions has a three-dimensional structure and a suitable pore density, which can effectively filter oil fumes and other oil mists. In some specific embodiments, the pore density of the second foam substrate is 70-90 ppi.

[0030] In some embodiments, there are no special requirements for the specific shape of the foam substrate. Those skilled in the art can design it flexibly according to actual needs. For example, the shape of the foam substrate includes, but is not limited to, cylindrical, cubic, spherical, and other shapes.

[0031] According to some embodiments of the present invention, the hydrophilic-oleophilic polymer includes hydroxyl groups, and the hydrophobic-oleophobic polymer includes perfluorocarbon chains. Thus, the hydrophilic-oleophilic filter material has good hydrophilic-oleophilic properties, and the hydrophobic-oleophobic filter material has good hydrophobic-oleophobic properties, thereby enabling both the hydrophilic-oleophilic filter material and the hydrophobic-oleophobic filter material to have good oil mist filtering performance.

[0032] According to some embodiments of the present invention, the hydrophilic-lipophilic polymer includes at least one of polydopamine and polyvinyl alcohol. This hydrophilic-lipophilic polymer has a large number of hydroxyl groups, which can effectively improve the oil mist filtering performance of the hydrophilic-lipophilic filter material. Furthermore, polydopamine and polyvinyl alcohol can adhere well to the surface of the foam substrate; that is, the above-mentioned polymers have good adhesion to the surface of the foam substrate and are not easily detached during drying and other processes, thereby helping to improve the stability and service life of the hydrophilic-lipophilic filter material.

[0033] According to some embodiments of the present invention, the hydrophobic and oleophobic polymer includes at least one of a copolymer of tetraethyl orthosilicate and perfluorooctylsiloxane and a copolymer of tetraethyl orthosilicate and perfluorodecylsiloxane. The above copolymers exhibit excellent hydrophobic and oleophobic properties, which can significantly improve the oil mist filtering performance of hydrophobic and oleophobic filter materials. Furthermore, the above copolymers can be effectively grafted onto the surface of the foam substrate via hydroxyl groups, and the two have good bonding strength, thereby contributing to improving the stability and service life of the hydrophobic and oleophobic filter material.

[0034] According to some embodiments of the present invention, the water contact angle of the hydrophilic-oleophilic filter material is 0° to 10° (e.g., water contact angles of 0°, 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, etc.), and the oil contact angle of the hydrophilic-oleophilic filter material is 0° to 10° (e.g., oil contact angles of 0°, 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, etc.). Therefore, the hydrophilic-oleophilic filter material of the present invention has excellent hydrophilic and oleophilic properties, can effectively adhere oil droplets to its surface, prevent them from diffusing backward with the airflow, and thus can better improve its oil mist filtering efficiency.

[0035] According to some embodiments of the present invention, the water contact angle of the hydrophobic and oleophobic filter material is greater than or equal to 140° (e.g., water contact angles of 140°, 142°, 145°, 147°, 149°, 150°, 152°, 154°, 155°, 156°, 158°, 160°, etc.), and the oil contact angle of the hydrophobic and oleophobic filter material is greater than or equal to 140° (e.g., oil contact angles of 140°, 142°, 145°, 147°, 149°, 150°, 152°, 154°, 155°, 156°, 158°, 160°, etc.). Therefore, the hydrophobic and oleophobic filter material of the present invention has excellent hydrophobic and oleophobic properties, allowing oil droplets to collide and bounce repeatedly on its surface, thereby continuously reducing their kinetic energy and ultimately trapping them inside the hydrophobic and oleophobic filter material without spreading backward, thus better improving its oil mist filtering efficiency.

[0036] In another aspect, the present invention provides a method for preparing the aforementioned three-dimensional oil mist filter material. According to an embodiment of the present invention, the method for preparing the three-dimensional oil mist filter material includes:

[0037] S100: The foam substrate is impregnated in a hydrophilic and oleophilic polymer solution for a first impregnation treatment. During the first impregnation treatment, a large amount of hydrophilic and oleophilic polymer adheres to the surface of the foam substrate, resulting in a large number of hydrophilic and oleophilic groups on the surface of the obtained hydrophilic and oleophilic filter material, such as a large number of hydroxyl groups.

[0038] According to some embodiments of the present invention, the foam substrate can be pre-cleaned before impregnation, for example, by using ethanol and / or acetone to clean the foam substrate, specifically by ultrasonic cleaning.

[0039] According to some embodiments of the present invention, the foam substrate is at least one selected from polystyrene foam, formaldehyde melamine foam, and polyurethane foam, and the pore density of the foam substrate is 10-100 ppi, such as 10 ppi, 20 ppi, 30 ppi, 40 ppi, 50 ppi, 60 ppi, 70 ppi, 80 ppi, 90 ppi, 100 ppi, etc. Therefore, the foam substrate under the above conditions has a three-dimensional structure and a suitable pore density, which can effectively filter oil fumes and other oil mists. In some specific embodiments, the pore density of the foam substrate is 70-90 ppi.

[0040] According to some embodiments of the present invention, the polymer in the hydrophilic-lipophilic polymer solution includes at least one of polydopamine and polyvinyl alcohol. Polydopamine and polyvinyl alcohol contain a large number of hydroxyl groups, which can effectively improve the oil mist filtering performance of the hydrophilic-lipophilic filter material. Furthermore, polydopamine and polyvinyl alcohol can adhere well to the surface of the foam substrate; that is, the above-mentioned polymers have good adhesion to the surface of the foam substrate and are not easily detached during drying and other processes, thereby helping to improve the stability and service life of the hydrophilic-lipophilic filter material.

[0041] According to some embodiments of the present invention, the mass concentration of the polymer in the hydrophilic-lipophilic polymer solution is 1–5 g / L, such as 1 g / L, 2 g / L, 3 g / L, 4 g / L, 5 g / L, etc. The above concentrations can effectively achieve a large amount of adhesion to the surface of the foam substrate without wasting raw materials. The solvent for the hydrophilic-lipophilic polymer solution can be water.

[0042] According to some embodiments of the present invention, a hydrophilic and lipophilic polymer solution can be prepared by the following steps: at room temperature, an appropriate amount of water, polymer monomer, and polymerization accelerator are added to a container, and the mixture is stirred to obtain a homogeneous solution. Under the action of the polymerization accelerator, the polymer monomer undergoes a polymerization reaction to obtain a polymer solution. In some specific embodiments, taking a polydopamine solution as an example, the preparation method of the polydopamine solution includes: adding an appropriate amount of water, dopamine hydrochloride, and tris(hydroxymethyl)aminomethane solution to a container, stirring to obtain a homogeneous solution, and adjusting the pH of the mixed solution to about 8.5 using tris(hydroxymethyl)aminomethane (polymerization accelerator). This can effectively promote the polymerization reaction of the monomer dopamine hydrochloride to obtain a polydopamine solution.

[0043] According to some embodiments of the present invention, the first impregnation time is 12 to 60 hours, such as 12 hours, 15 hours, 20 hours, 25 hours, 30 hours, 35 hours, 40 hours, 45 hours, 50 hours, 55 hours, 60 hours, etc., so that the polymer can be sufficiently adhered to the surface of the foam substrate.

[0044] S200: The impregnated foam substrate is dried first to obtain a hydrophilic and oleophilic filter material.

[0045] According to an embodiment of the present invention, the first drying temperature is 50-80°C, for example, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, etc. Drying can be performed quickly at the above temperatures.

[0046] S300: The hydrophilic-oleophilic filter material is impregnated in a hydrophobic-oleophilic modification solution for a second impregnation treatment, that is, a hydrophobic-oleophilic filter material is further prepared based on the prepared hydrophilic-oleophilic filter material. During the second impregnation treatment, the hydrophobic-oleophilic polymer in the hydrophobic-oleophilic modification solution is grafted onto the surface of the hydrophilic-oleophilic filter material through hydrophilic-oleophilic groups (such as hydroxyl groups) on the surface of the hydrophilic-oleophilic filter material, thereby obtaining a hydrophobic-oleophilic filter material with hydrophobic-oleophilic groups on the surface.

[0047] According to some embodiments of the present invention, the hydrophobic and oleophobic modification solution comprises a polymeric monomer and an organic solvent. The polymeric monomer comprises a perfluorosiloxane and tetraethyl orthosilicate, and the perfluorosiloxane comprises at least one of perfluorooctylsiloxane and perfluorodecylsiloxane. That is, in some embodiments, the hydrophobic and oleophobic modification solution comprises perfluorooctylsiloxane, tetraethyl orthosilicate, and an organic solvent; in other embodiments, the hydrophobic and oleophobic modification solution comprises perfluorodecylsiloxane, tetraethyl orthosilicate, and an organic solvent; and in still other embodiments, the hydrophobic and oleophobic modification solution comprises perfluorooctylsiloxane, perfluorodecylsiloxane, tetraethyl orthosilicate, and an organic solvent. Thus, in the hydrophobic and oleophobic modification solution, perfluorosiloxane and tetraethyl orthosilicate copolymerize to obtain a hydrophobic and oleophobic polymer containing a perfluorocarbon chain.

[0048] According to some embodiments of the present invention, the hydrophobic and oleophobic modification solution further includes an acid or an alkaline solution. Thus, the acid can provide hydrogen ions to the hydrophobic and oleophobic modification solution, and the alkaline solution can provide hydroxide ions. Under the action of hydrogen ions or hydroxide ions, the copolymerization reaction of perfluorosiloxane and tetraethyl orthosilicate can be effectively promoted.

[0049] In some embodiments, the organic solvents mentioned above include, but are not limited to, organic solvents such as methanol and ethanol; in other embodiments, the alkaline solutions mentioned above include, but are not limited to, alkaline solutions such as sodium hydroxide and ammonia; in still other embodiments, the acid solutions mentioned above include, but are not limited to, acid solutions such as acetic acid, acetic acid, formic acid, hydrochloric acid, and sulfuric acid.

[0050] According to some embodiments of the present invention, the volume percentage of perfluorosiloxane in the hydrophobic and oleophobic modified solution is 0.6-1.4%, such as 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, etc.

[0051] According to some embodiments of the present invention, the second impregnation time is 4 to 7 hours, for example, 4 hours, 5 hours, 6 hours, 7 hours, etc. This allows the hydrophobic and oleophobic polymer to be sufficiently grafted onto the foam substrate via hydroxyl groups.

[0052] S400: The impregnated hydrophilic and oleophilic filter material is dried in a second process to obtain a hydrophobic and oleophobic filter material.

[0053] According to some embodiments of the present invention, the second drying temperature is 50–80°C, such as 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, etc. Drying can be performed quickly at these temperatures without negatively impacting the resulting filter material.

[0054] According to embodiments of the present invention, the three-dimensional oil mist filter material prepared by the above method can efficiently filter oil mist such as oil fumes, and can be effectively applied to gas purification in oily and high-humidity environments. Furthermore, using foam as a substrate allows for multi-dimensional filtration effects while exhibiting good stability, facilitating large-scale preparation and application. Additionally, the above preparation method is simple and easy to implement, facilitating industrial mass production and contributing to large-scale preparation and enhancing the development potential of filter material applications. Furthermore, selecting foam as the substrate for both hydrophilic and oleophilic filter materials and hydrophobic and oleophobic filter materials can effectively reduce the pressure drop (pressure drop refers to the pressure difference before and after oil mist filtration) between the two filter materials, thereby reducing the resistance to oil mist filtration and improving filtration efficiency. Therefore, the hydrophilic and oleophilic filter materials and hydrophobic and oleophobic filter materials prepared by the above method of the present invention can help achieve highly efficient and low-resistance three-dimensional oil mist filter materials.

[0055] Example

[0056] Example 1

[0057] The preparation methods of three-dimensional oil mist filter materials include:

[0058] (1) Immerse a cylindrical formaldehyde melamine foam with a bottom radius of 2cm, a height of 3.5cm, and a pore density of 80ppi in ethanol and ultrasonically clean it for 15 minutes, then air dry it at room temperature.

[0059] (2) At room temperature, add 95 ml of water, 0.2 g of dopamine hydrochloride and 5 mL of 120 g / L tris(hydroxymethyl)aminomethane solution to a 100 mL beaker and stir to dissolve to obtain a homogeneous mixed solution; in the mixed solution, dopamine hydrochloride polymerizes to obtain polydopamine with a concentration of 2 g / L, and a hydrophilic and lipophilic polymer solution is obtained.

[0060] (3) Immerse the formaldehyde melamine foam obtained in step (1) in the hydrophilic and lipophilic polymer solution obtained in step (2) for 48 hours;

[0061] (4) After removing the formaldehyde melamine foam impregnated in step (3), dry it at 60°C to obtain a hydrophilic and oleophilic filter material;

[0062] (5) Add 80 mL of ethanol, 1.0 mL of tetraethyl orthosilicate, 1.0 mL of perfluorooctyltrimethoxysilane and 18 mL of ammonia to a 100 mL beaker and mix to obtain a hydrophobic and oleophobic modified solution; in this hydrophobic and oleophobic modified solution, the volume percentage concentration of perfluorooctyltrimethoxysilane is 1.0%, and tetraethyl orthosilicate and perfluorooctyltrimethoxysilane undergo a copolymerization reaction to obtain a hydrophobic and oleophobic polymer;

[0063] (6) Immerse the hydrophilic and oleophilic filter material obtained in step (4) in the hydrophobic and oleophobic modified solution obtained in step (5) for 6 hours;

[0064] (7) After removing the hydrophilic and oleophilic filter material impregnated in step (6), dry it at 60°C to obtain a hydrophobic and oleophilic filter material.

[0065] The contact angle of the filter material was tested, and the test results are as follows: Figure 2 As shown, Figure 2 As shown in (a), the water contact angle (WCA) of the hydrophilic-oleophilic filter material is 0°, and the oil contact angle (OCA) is 0°; Figure 2 As shown in (b), the water contact angle (WCA) of the hydrophobic and oleophobic filter material is 155.0° and the oil contact angle (OCA) is 150.1°.

[0066] The filter material was subjected to scanning electron microscopy (SEM) testing, and the results are as follows: Figure 3As shown, SEM images of the hydrophilic-oleophilic filter material and the hydrophobic-oleophilic filter material are respectively shown in [reference 1]. Figure 3 (a) and (b) in the example.

[0067] The oil mist filtration performance of the filter material was tested. The oil mist consisted of edible corn oil and was generated by an air compressor connected to an aerosol generator. The principle was that the air compressor sent air into the aerosol generator, and the air was injected into the edible corn oil to form bubbles, causing the oil to form an oil mist that was carried out by the airflow. The test results are as follows:

[0068] Using hydrophilic and oleophilic filter materials alone to filter oil mist, such as Figure 4 As shown, when using this hydrophilic and oleophilic filter material alone, the oil mist filtration efficiency is 91.43% and the pressure drop is 0.063 kPa;

[0069] Using hydrophobic and oleophobic filter materials alone to filter oil mist, such as Figure 5 As shown, when this hydrophobic and oleophobic filter material is used alone, the oil mist filtration efficiency is 84.76% and the pressure drop is 0.043 kPa;

[0070] Combining hydrophilic and oleophilic filter materials with hydrophobic and oleophobic filter materials: a combination where the hydrophilic and oleophilic filter material is used first, followed by the hydrophobic and oleophobic filter material, such as... Figure 1 (a) in the example Figure 6 As shown, its oil mist filtration efficiency is 96.16%, and the pressure drop is 0.048 kPa; the combination of hydrophobic and oleophobic filter material in front and hydrophilic and oleophilic filter material in the back, as shown... Figure 1 (b) in the example Figure 7 As shown, its oil mist filtration efficiency is 89.46% and its pressure drop is 0.047 kPa.

[0071] Example 2

[0072] The preparation methods of three-dimensional oil mist filter materials include:

[0073] (1) Immerse a cylindrical formaldehyde melamine foam with a bottom radius of 2cm, a height of 1.5cm, and a pore density of 80ppi in ethanol and ultrasonically clean it for 15 minutes, then air dry it at room temperature.

[0074] (2) At room temperature, add 95 ml of water, 0.2 g of dopamine hydrochloride and 5 mL of 120 g / L tris(hydroxymethyl)aminomethane solution to a 100 mL beaker and stir to dissolve to obtain a homogeneous mixed solution; in the mixed solution, dopamine hydrochloride polymerizes to obtain polydopamine with a concentration of 2 g / L, and a hydrophilic and lipophilic polymer solution is obtained.

[0075] (3) Immerse the formaldehyde melamine foam obtained in step (1) in the hydrophilic and lipophilic polymer solution obtained in step (2) for 48 hours;

[0076] (4) After removing the formaldehyde melamine foam impregnated in step (3), dry it at 60°C to obtain a hydrophilic and oleophilic filter material;

[0077] (5) Add 80 mL of ethanol, 1.0 mL of tetraethyl orthosilicate, 1.0 mL of perfluorooctyltrimethoxysilane and 18 mL of ammonia to a 100 mL beaker and mix to obtain a hydrophobic and oleophobic modified solution; in this hydrophobic and oleophobic modified solution, the volume percentage concentration of perfluorooctyltrimethoxysilane is 1.0%, and tetraethyl orthosilicate and perfluorooctyltrimethoxysilane undergo a copolymerization reaction to obtain a hydrophobic and oleophobic polymer;

[0078] (6) Immerse the hydrophilic and oleophilic filter material obtained in step (4) in the hydrophobic and oleophobic modified solution obtained in step (5) for 6 hours;

[0079] (7) After removing the hydrophilic and oleophilic filter material impregnated in step (6), dry it at 60°C to obtain a hydrophobic and oleophilic filter material.

[0080] The contact angles of the filter materials were tested. The water contact angle (WCA) of the hydrophilic and oleophilic filter materials was 0° and the oil contact angle (OCA) was 0°. The water contact angle (WCA) of the hydrophobic and oleophobic filter materials was 154.5° and the oil contact angle (OCA) was 148.8°.

[0081] The oil mist filtration performance of the filter material was tested. The composition and testing method of the oil mist were the same as in Example 1. The test results are as follows:

[0082] When this hydrophilic and oleophilic filter material is used alone, the oil mist filtration efficiency is 79.33% and the pressure drop is 0.043 kPa;

[0083] When this hydrophobic and oleophobic filter material is used alone, the oil mist filtration efficiency is 82.07% and the pressure drop is 0.045 kPa;

[0084] Combining hydrophilic and oleophilic filter materials with hydrophobic and oleophobic filter materials: the combination of hydrophilic and oleophilic filter material first and hydrophobic and oleophobic filter material last has an oil mist filtration efficiency of 72.41% and a pressure drop of 0.033 kPa; the combination of hydrophobic and oleophobic filter material first and hydrophilic and oleophilic filter material last has an oil mist filtration efficiency of 80.44% and a pressure drop of 0.055 kPa.

[0085] Compared with Example 1, Example 2 uses formaldehyde melamine foam with a smaller height, which shortens the oil mist filtration path and reduces the chance of oil mist colliding inside the filter material. Therefore, compared with Example 1, the oil mist filtration efficiency of the filter material in this example is relatively lower.

[0086] Example 3

[0087] The preparation methods of three-dimensional oil mist filter materials include:

[0088] (1) Immerse a cylindrical formaldehyde melamine foam with a bottom radius of 2cm, a height of 3.5cm, and a pore density of 80ppi in ethanol and ultrasonically clean it for 15 minutes, then air dry it at room temperature.

[0089] (2) At room temperature, add 95 ml of water, 0.2 g of dopamine hydrochloride and 5 mL of 120 g / L tris(hydroxymethyl)aminomethane solution to a 100 mL beaker and stir to dissolve to obtain a homogeneous mixed solution; in the mixed solution, dopamine hydrochloride polymerizes to obtain polydopamine with a concentration of 2 g / L, and a hydrophilic and lipophilic polymer solution is obtained.

[0090] (3) Immerse the formaldehyde melamine foam obtained in step (1) in the hydrophilic and lipophilic polymer solution obtained in step (2) for 48 hours;

[0091] (4) After removing the formaldehyde melamine foam impregnated in step (3), dry it at 60°C to obtain a hydrophilic and oleophilic filter material;

[0092] (5) Add 80 mL of ethanol, 0.8 mL of tetraethyl orthosilicate, 1.2 mL of perfluorooctyltrimethoxysilane and 18 mL of ammonia to a 100 mL beaker and mix to obtain a hydrophobic and oleophobic modified solution; in this hydrophobic and oleophobic modified solution, the volume percentage concentration of perfluorooctyltrimethoxysilane is 1.2%, and tetraethyl orthosilicate and perfluorooctyltrimethoxysilane undergo a copolymerization reaction to obtain a hydrophobic and oleophobic polymer;

[0093] (6) Immerse the hydrophilic and oleophilic filter material obtained in step (4) in the hydrophobic and oleophobic modified solution obtained in step (5) for 6 hours;

[0094] (7) After removing the hydrophilic and oleophilic filter material impregnated in step (6), dry it at 60°C to obtain a hydrophobic and oleophilic filter material.

[0095] The contact angles of the filter materials were tested. The water contact angle (WCA) of the hydrophilic and oleophilic filter materials was 0° and the oil contact angle (OCA) was 0°. The water contact angle (WCA) of the hydrophobic and oleophobic filter materials was 148.2° and the oil contact angle (OCA) was 145.3°.

[0096] Example 4

[0097] The preparation methods of three-dimensional oil mist filter materials include:

[0098] (1) Immerse a cylindrical formaldehyde melamine foam with a bottom radius of 2cm, a height of 3.5cm, and a pore density of 80ppi in ethanol and ultrasonically clean it for 15 minutes, then air dry it at room temperature.

[0099] (2) At room temperature, add 95 ml of water, 0.2 g of dopamine hydrochloride and 5 mL of 120 g / L tris(hydroxymethyl)aminomethane solution to a 100 mL beaker and stir to dissolve to obtain a homogeneous mixed solution; in the mixed solution, dopamine hydrochloride polymerizes to obtain polydopamine with a concentration of 2 g / L, and a hydrophilic and lipophilic polymer solution is obtained.

[0100] (3) Immerse the formaldehyde melamine foam obtained in step (1) in the hydrophilic and lipophilic polymer solution obtained in step (2) for 48 hours;

[0101] (4) After removing the formaldehyde melamine foam impregnated in step (3), dry it at 60°C to obtain a hydrophilic and oleophilic filter material;

[0102] (5) Add 80 mL of ethanol, 1.2 mL of tetraethyl orthosilicate, 0.8 mL of perfluorooctyltrimethoxysilane and 18 mL of ammonia to a 100 mL beaker and mix to obtain a hydrophobic and oleophobic modified solution; in this hydrophobic and oleophobic modified solution, the volume percentage concentration of perfluorooctyltrimethoxysilane is 0.8%, and tetraethyl orthosilicate and perfluorooctyltrimethoxysilane undergo a copolymerization reaction to obtain a hydrophobic and oleophobic polymer;

[0103] (6) Immerse the hydrophilic and oleophilic filter material obtained in step (4) in the hydrophobic and oleophobic modified solution obtained in step (5) for 6 hours;

[0104] (7) After removing the hydrophilic and oleophilic filter material impregnated in step (6), dry it at 60°C to obtain a hydrophobic and oleophilic filter material.

[0105] The contact angles of the filter materials were tested. The water contact angle (WCA) of the hydrophilic and oleophilic filter materials was 0° and the oil contact angle (OCA) was 0°. The water contact angle (WCA) of the hydrophobic and oleophobic filter materials was 147.5° and the oil contact angle (OCA) was 146.4°.

[0106] As can be seen from the test data of the above embodiments, the hydrophilic and oleophilic filter materials of the present invention have good hydrophilic and oleophilic properties, which gives them a better oil mist filtration effect and a better filtration efficiency; the hydrophobic and oleophobic filter materials have good hydrophobic and oleophobic properties, which gives them a better oil mist filtration effect and a better filtration efficiency.

[0107] The terms "first" and "second" used in this document are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature marked "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0108] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0109] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A three-dimensional oil mist filter material, characterized in that, The filter material includes at least one of hydrophilic and oleophilic filter materials and hydrophobic and oleophobic filter materials. The hydrophilic and oleophilic filter material includes a first foam substrate and a hydrophilic and oleophilic polymer attached to the surface of the first foam substrate. The hydrophobic and oleophobic filter material includes a second foam substrate and a hydrophobic and oleophobic polymer grafted onto the surface of the second foam substrate by hydroxyl groups.

2. The three-dimensional oil mist filter material according to claim 1, characterized in that, Hydrophilic and oleophilic polymers include hydroxyl groups, while hydrophobic and oleophobic polymers include perfluorocarbon chains.

3. The three-dimensional oil mist filter material according to claim 2, characterized in that, The hydrophilic and oleophilic polymers include at least one of polydopamine and polyvinyl alcohol, and the hydrophobic and oleophilic polymers include at least one of a copolymer of tetraethyl orthosilicate and perfluorooctylsiloxane and a copolymer of tetraethyl orthosilicate and perfluorodecylsiloxane.

4. The three-dimensional oil mist filter material according to any one of claims 1 to 3, characterized in that, At least one of the following conditions must be met: The first foam substrate and the second foam substrate are at least one of polystyrene foam, formaldehyde melamine foam and polyurethane foam, respectively. The pore densities of the first foam substrate and the second foam substrate are 10 to 100 ppi, respectively.

5. The three-dimensional oil mist filter material according to any one of claims 1 to 3, characterized in that, The water contact angle of the hydrophilic-oleophilic filter material is 0° to 10°, and the oil contact angle of the hydrophilic-oleophilic filter material is 0° to 10°; and / or, The water contact angle of the hydrophobic and oleophobic filter material is greater than or equal to 140°, and the oil contact angle of the hydrophobic and oleophobic filter material is greater than or equal to 140°.

6. The three-dimensional oil mist filter material according to any one of claims 1 to 3, characterized in that, In the direction of oil mist filtration, the three-dimensional oil mist filter material includes the hydrophilic and oleophilic filter material and the hydrophobic and oleophobic filter material stacked together.

7. A method for preparing the three-dimensional oil mist filter material according to any one of claims 1 to 6, characterized in that, include: The foam substrate is immersed in a hydrophilic and oleophilic polymer solution for the first immersion treatment. The impregnated foam substrate is dried first to obtain a hydrophilic and oleophilic filter material. The hydrophilic and oleophilic filter material is immersed in a hydrophobic and oleophobic modified solution for a second immersion treatment. The impregnated hydrophilic and oleophilic filter material is dried in a second process to obtain a hydrophobic and oleophobic filter material.

8. The method according to claim 7, characterized in that, The steps for obtaining the hydrophilic and oleophilic filter material satisfy at least one of the following conditions: The polymer in the hydrophilic and lipophilic polymer solution includes at least one of polydopamine and polyvinyl alcohol; The mass concentration of the polymer in the hydrophilic-lipophilic polymer solution is 1-5 g / L; The first immersion time is 12 to 60 hours; The temperature of the first drying process is 50–80°C.

9. The method according to claim 7, characterized in that, The steps for obtaining the hydrophobic and oleophobic filter material satisfy at least one of the following conditions: The hydrophobic and oleophobic modified solution comprises a polymeric monomer and an organic solvent, wherein the polymeric monomer comprises perfluorosiloxane and tetraethyl orthosilicate, and the perfluorosiloxane comprises at least one of perfluorooctylsiloxane and perfluorodecylsiloxane. The volume percentage of the perfluorosiloxane in the hydrophobic and oleophobic modified solution is 0.6-1.4%; The second immersion time is 4 to 7 hours; The second drying temperature is 50-80℃.

10. The method according to claim 7, characterized in that, The hydrophobic and oleophobic modified solution also includes an acid or an alkaline solution.

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