Composite porous ceramic, method for manufacturing the same, ceramic atomizing core, and atomizing device

Abstract

The application provides a composite porous ceramic and a preparation method thereof, a ceramic atomizing core and an atomizing device. The preparation method comprises the following steps: performing dip treatment on a porous ceramic blank by using a sol mixture to prepare a composite blank; and sequentially performing solidification treatment and sintering treatment on the composite blank; wherein the dip treatment time is 10s-40s, and the sintering treatment temperature is 800 DEG C-1700 DEG C. The above method has the advantages of simple process and low preparation cost.

Description

Technical Field

[0001] This application relates to the field of porous ceramics technology, and in particular to a composite porous ceramic and its preparation method, a ceramic atomizing core and an atomizing device. Background Technology

[0002] With the continuous development of modern society, people's health awareness is constantly improving, and higher demands are being placed on the safety of smoking, leading to the emergence of e-cigarettes. E-cigarettes, or electronic cigarettes, are electronic products that mimic traditional cigarettes, providing a similar smoke and sensory experience.

[0003] Porous ceramic atomizing cores play a role in transporting and storing e-liquid and generating atomization in electronic cigarette products. However, many existing ceramic atomizing cores suffer from powder and residue shedding. Summary of the Invention

[0004] Based on this, one or more embodiments of this application provide a composite porous ceramic that is not prone to powder shedding, has a long service life, and high strength.

[0005] According to a first aspect of the embodiments of this application, a method for preparing composite porous ceramics is provided, comprising the following steps:

[0006] Composite green bodies were prepared by impregnating porous ceramic green bodies with a sol-gel mixture.

[0007] The composite preform is subjected to curing and sintering treatments in sequence;

[0008] The impregnation treatment time is 10s~40s, and the sintering temperature is 800℃~1700℃.

[0009] In one embodiment, the method for preparing the sol mixture includes the following steps:

[0010] Polysiloxane sol is prepared by mixing silicon-based monomers, solvents, crosslinking agents, and catalysts.

[0011] The polysiloxane sol is mixed with a carbon source to prepare the sol mixture.

[0012] In one embodiment, the mass ratio of the carbon source, the silicon source monomer, the crosslinking agent, and the solvent is (1~2):(1~2):(0.1~0.5):(2~4).

[0013] In one embodiment, the silicon source monomer includes one or more of methyltrimethoxysilane, dimethyldimethoxysilane, tetramethoxysilane, tetraethoxysilane, and tetraethyl orthosilicate; and / or,

[0014] The carbon source includes one or more of carbon fibers, carbon black, activated carbon, graphene, and carbon nanotubes; and / or,

[0015] The crosslinking agent includes one or more of water and silane coupling agents; and / or,

[0016] The solvent includes one or more of methanol, anhydrous ethanol, and isopropanol; and / or,

[0017] The catalyst comprises one or more of hydrochloric acid and ammonia water; and / or,

[0018] The concentration of the catalyst is 0.01 mol / L to 0.1 mol / L.

[0019] In one embodiment, the curing temperature is 80°C to 100°C and the time is 3 hours to 12 hours.

[0020] In one embodiment, the sintering process includes: heating to the sintering temperature at a heating rate of 0.1°C / min to 5°C / min; and / or,

[0021] The atmospheric gas used in the sintering process includes one or more of nitrogen and argon.

[0022] In one embodiment, the porous ceramic preform includes one or more of silicon nitride porous ceramic preforms, silicon carbide porous ceramic preforms, zirconia porous ceramic preforms, and alumina porous ceramic preforms.

[0023] According to a second aspect of the embodiments of this application, a composite porous ceramic is provided, which is prepared by the above-described method for preparing composite porous ceramic.

[0024] According to a third aspect of the embodiments of this application, a ceramic atomizing core is provided, comprising the above-described composite porous ceramic.

[0025] According to a fourth aspect of the embodiments of this application, an atomizing device is provided, including the ceramic atomizing core described above.

[0026] Compared with traditional technologies, this application has the following advantages:

[0027] The method for preparing composite porous ceramics disclosed in this application involves impregnating a ceramic green body with a sol-gel mixture, followed by curing to form a uniform gel layer on the surface of the green body. The internal structure of the gel layer is a slender, elongated three-dimensional network structure, with the elongated strips bridging each other, thereby forming a structurally stable composite porous ceramic with high mechanical strength. This makes it less prone to powdering or slagging during use, resulting in a longer service life. The method described in this application also has the advantages of simple process and low preparation cost. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 This is an image showing the appearance of the silicon carbide ceramic preform after curing in Example 1 of this application;

[0030] Figure 2 This is an appearance diagram of the composite porous silicon carbide ceramic after sintering in Example 1 of this application;

[0031] Figure 3 This is a microstructure diagram of the composite porous silicon carbide ceramic prepared in Example 1 of this application;

[0032] Figure 4 This is an image showing the appearance of the silicon nitride ceramic preform after curing in Example 2 of this application;

[0033] Figure 5 This is an appearance diagram of the sintered composite porous silicon nitride ceramic in Example 2 of this application;

[0034] Figure 6 This is a microstructure diagram of the composite porous silicon nitride ceramic prepared in Example 2 of this application. Detailed Implementation

[0035] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, a detailed description of specific embodiments of this application is provided. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise specifically stated, all raw materials, reagents, instruments, and equipment used in this application are commercially available or can be prepared by existing methods.

[0037] The terms "and / or," "or / and," and "and / or" as used herein include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected by at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that in this application, the technical solution undoubtedly includes technical solutions connected by "logical AND," and also undoubtedly includes technical solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and A+B. For example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, a technical solution that is connected by "logical OR"), as well as any and all combinations of A, B, C, and D, that is, combinations of any two or three of A, B, C, and D, and also combinations of all four of A, B, C, and D (that is, a technical solution that is connected by "logical AND").

[0038] In this application, the terms "multiple", "various", "multiple times", "multi-dimensional", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0039] In this application, terms such as "further," "even further," and "particularly" are used to describe purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0040] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0041] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0042] In this application, numerical intervals (i.e., numerical ranges) are involved. Unless otherwise specified, the selected numerical distributions within the aforementioned numerical intervals are considered continuous and include the two endpoints (i.e., the minimum and maximum values) of the numerical range, as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints. In this document, this is equivalent to directly listing every integer. For example, if t is an integer selected from 1 to 10, it means that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Furthermore, when multiple ranges are provided to describe features or characteristics, these ranges can be merged. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0043] Some embodiments of this application provide a method for preparing composite porous ceramics, including steps S10 to S20:

[0044] S10: A composite green body is prepared by impregnating a porous ceramic green body with a sol mixture;

[0045] S20: The composite preform is subjected to curing and sintering treatments in sequence;

[0046] The impregnation treatment time is 10s~30s, and the sintering temperature is 800℃~1700℃.

[0047] The above-mentioned method for preparing composite porous ceramics involves impregnating a ceramic blank with a sol mixture and then curing it to form a uniform gel layer on the surface of the ceramic blank. The gel layer contains a three-dimensional network structure of slender strips, which bridge each other to form a composite porous ceramic with a stable structure and high mechanical strength. This makes it less prone to powdering or slagging during use and results in a longer service life.

[0048] This application employs a sol-gel method, in which a porous ceramic preform is immersed in a sol mixture. The sol fills the surface and pores of the preform through capillary action, and after curing and sintering, the sol transforms into a gel, ultimately forming a coating. Compared with the traditional chemical vapor deposition method, the sol-gel method has advantages such as simple process, low cost, and no need for secondary sintering. In some embodiments, the preparation method of the above-mentioned composite porous ceramic consists of steps S10 and S20.

[0049] In some embodiments, in S10, the method for preparing the sol mixture includes the following steps S11 to S12:

[0050] S11: Prepare polysiloxane sol by mixing silicon source monomer, solvent, crosslinking agent and catalyst;

[0051] S12: Mix polysiloxane sol with a carbon source to prepare a sol mixture.

[0052] Understandably, in S11, after the silicon source monomer, solvent, crosslinking agent and catalyst are mixed, a hydrolysis reaction can occur after stirring at room temperature for several hours to generate silanol (Si-OH). The silanol further condenses to form Si-O-Si bonds, generating polysiloxane sol.

[0053] In some embodiments, in S10, the mass ratio of carbon source, silicon source monomer, crosslinking agent and solvent is (1~2):(1~2):(0.1~0.5):(2~4).

[0054] In some embodiments, in S10, the mass ratio of carbon source, silicon source monomer, crosslinking agent and solvent is 1:1:0.2:2.

[0055] In some embodiments, the immersion treatment time in S10 is 10s to 40s. As an example, the immersion treatment time can be 10s, 11s, 12s, 13s, 14s, 15s, 16s, 17s, 18s, 19s, 20s, 21s, 22s, 23s, 24s, 25s, 26s, 27s, 28s, 29s, 30s, 31s, 32s, 33s, 34s, 35s, 36s, 37s, 38s, 39s, 40s, or any value within the range formed by any two of the above point values.

[0056] Furthermore, the immersion treatment time is 10s~30s.

[0057] Furthermore, the immersion treatment time is 20s~30s.

[0058] In some embodiments, the immersion temperature is at room temperature; further, the immersion temperature is 22°C to 30°C; and even further, the immersion temperature is 25°C.

[0059] It is understandable that by controlling the impregnation time within the above range, the thickness of the gel layer of the final porous composite ceramic is 0.1 mm to 1 mm.

[0060] In some embodiments, in S30, the curing temperature is 80°C to 100°C and the time is 3h to 12h.

[0061] As an example, the curing temperature can be 80℃, 81℃, 82℃, 83℃, 84℃, 85℃, 86℃, 87℃, 88℃, 89℃, 90℃, 91℃, 92℃, 93℃, 94℃, 95℃, 96℃, 97℃, 98℃, 99℃, or 100℃, or any value within the range formed by any two of the above values. The curing time can be 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, or 12h, or any value within the range formed by any two of the above values.

[0062] After the porous ceramic preform is impregnated with a sol mixture, it is cured under the aforementioned specific temperature conditions, which allows the sol mixture to gel, forming a gel layer on the surface of the ceramic preform. The slender carbon fibers in the gel layer bridge each other, forming a structurally stable outer layer, thereby improving the mechanical strength of the composite porous ceramic and reducing powder and slag shedding.

[0063] In some embodiments, in S30, the sintering process includes heating to the sintering temperature at a heating rate of 0.1°C / min to 5°C / min.

[0064] As an example, the heating rate of the sintering process can be 0.1℃ / min, 0.2℃ / min, 0.3℃ / min, 0.4℃ / min, 0.5℃ / min, 0.6℃ / min, 0.7℃ / min, 0.8℃ / min, 0.9℃ / min, 1℃ / min, 2℃ / min, 3℃ / min, 4℃ / min, 5℃ / min, or any value within the range formed by any two of the above points.

[0065] As an example, in S30, the sintering temperature can be, but is not limited to, 800℃, 850℃, 900℃, 950℃, 1000℃, 1050℃, 1100℃, 1150℃, 1200℃, 1250℃, 1300℃, 1350℃, 1400℃, 1450℃, 1500℃, 1550℃, 1600℃, 1650℃, 1700℃, or any value within the range formed by any two of the above points.

[0066] It should be noted that when the porous ceramic green body is a silicon carbide ceramic green body, the sintering temperature is 800℃~1250℃; when the porous ceramic green body is a silicon nitride ceramic green body, the sintering temperature is 1250℃~1700℃.

[0067] In some embodiments, the sintering process takes 2 to 3 hours.

[0068] As an example, the sintering time can be, but is not limited to, 2h, 2.1h, 2.2h, 2.3h, 2.4h, 2.5h, 2.6h, 2.7h, 2.8h, 2.9h, 3h, or any value within the range formed by any two of the above points.

[0069] In some embodiments, during S30, the atmosphere gas in the sintering process includes one or more of nitrogen and argon.

[0070] In some embodiments, the porous ceramic preform includes one or more of silicon nitride porous ceramic preforms, silicon carbide porous ceramic preforms, zirconia porous ceramic preforms, and alumina porous ceramic preforms.

[0071] Understandably, when the ceramic body is silicon nitride, nitrogen can be used as a reactive gas source to participate in the reaction, and the gel layer and the ceramic body are intertwined, making the two more tightly bonded.

[0072] In some examples, the atmospheric gas used in the sintering process is argon. Understandably, argon serves as a protective atmosphere and does not participate in the reaction.

[0073] In some examples, the method for preparing porous ceramic preforms includes steps a through c.

[0074] Step a: Provide the raw materials, mix and melt them to obtain a mixture;

[0075] Step b: Press the mixture into shape to obtain a preform;

[0076] Step c: The preform is heat-insulated to obtain a porous ceramic blank.

[0077] Optionally, in step a, when the porous ceramic body is a silicon nitride porous ceramic body, the raw materials include 40% silicon nitride powder, 10% glass powder, 20% pore-forming agent, 20% paraffin wax and 10% beeswax by mass percentage.

[0078] Optionally, in step b, the pressing method includes hot die casting.

[0079] Optionally, in step c, the heat preservation treatment includes the following steps: heating from room temperature to 200℃ at a rate of 0.5℃ / min, heating from 200℃ to 600℃ at a rate of 0.25℃ / min to 0.5℃ / min, and holding at that temperature for 3 hours. Understandably, the heat preservation treatment achieves degreasing of the porous ceramic body.

[0080] In some embodiments, the silicon source monomer includes one or more of methyltrimethoxysilane, dimethyldimethoxysilane, tetramethoxysilane, tetraethoxysilane, and tetraethyl orthosilicate.

[0081] In some embodiments, the carbon source includes one or more of carbon fibers, carbon black, activated carbon, graphene, and carbon nanotubes.

[0082] In some examples, the carbon source is carbon fiber; furthermore, the length of the carbon fiber is 1mm to 2mm; even further, the length of the carbon fiber is 1mm.

[0083] In some embodiments, the crosslinking agent includes one or more of water and silane coupling agents.

[0084] In some examples, the crosslinking agent is selected from water.

[0085] In some embodiments, the solvent includes one or more of methanol, anhydrous ethanol, and isopropanol.

[0086] In some examples, the solvent is selected from anhydrous ethanol.

[0087] This application improves the problem of porous ceramics easily shedding powder and slag by coating the outer periphery of the porous ceramic body with a layer of gel, thereby greatly reducing the probability of harmful substances being inhaled during the use of electronic cigarettes.

[0088] The preparation method described in this application can produce composite porous ceramics through a single high-temperature sintering process, which has the advantages of simple process and low preparation cost.

[0089] Some embodiments of this application also provide a composite porous ceramic, which is prepared by the above-described method for preparing composite porous ceramics.

[0090] Some embodiments of this application also provide a ceramic atomizing core, comprising the aforementioned composite porous ceramic.

[0091] In some embodiments, the method for preparing the above-mentioned ceramic atomizing core includes the following steps:

[0092] A heating layer is formed on a composite porous ceramic to obtain a ceramic atomizing core.

[0093] Optionally, the method of forming the heating layer includes one or more of the following: printing resistive paste, sputtering resistive layer and attaching heating mesh.

[0094] Some embodiments of this application also provide an atomizing device, including the ceramic atomizing core described above.

[0095] In some of these embodiments, the atomizing device includes an electronic cigarette.

[0096] The present application will be further described below with reference to specific embodiments and comparative examples, but these should not be construed as limiting the scope of protection of the present application. Unless otherwise specified, the raw materials involved in the following specific embodiments are all commercially available, the instruments used are all commercially available, and the processes involved are conventionally selected by those skilled in the art unless otherwise specified.

[0097] Example 1

[0098] (1) Preparation of silicon carbide ceramic blank: 40% silicon carbide powder, 10% glass powder, 20% pore-forming agent, 20% paraffin wax and 10% beeswax are melted and hot-pressed to prepare porous ceramic blank. The ceramic blank is placed in a sintering furnace and heated from room temperature to 200℃ at a heating rate of 5℃ / min. Then it is heated from 200℃ to 600℃ at a heating rate of 0.25℃ / min. It is held at 600℃ for 3 hours and then cooled to room temperature before being taken out.

[0099] (2) Preparation of sol mixture: 1 part by mass of tetramethoxysilane, 0.2 parts by mass of water, 2 parts by mass of anhydrous ethanol and catalyst with a concentration of 0.05 mol / L are provided and stirred to prepare polysiloxane sol; the above polysiloxane sol is mixed with 1 part by mass of carbon fiber so that the surface of carbon fiber is covered with polysiloxane sol to prepare sol mixture.

[0100] (3) Dipping and curing treatment: Dip the silicon carbide ceramic blank into the sol mixture. The silicon carbide ceramic is completely immersed in the sol for 10 seconds. Then place it in an oven at 100°C and let it stand for 10 hours to gel. Figure 1 This is a view of the cured silicon carbide ceramic preform.

[0101] (4) Sintering treatment: The gelled green body is placed in a sintering furnace and argon gas is introduced. The temperature is increased from room temperature to 800℃ at a heating rate of 1℃ / min, and then increased from 800℃ to 1250℃ at a heating rate of 3℃ / min. The temperature is held for 3 hours and then cooled to room temperature to obtain composite porous ceramic. Figure 2 This is an image of the sintered composite porous silicon carbide ceramic. Figure 3 This is a microstructure diagram of composite porous silicon carbide ceramics, in which long strip three-dimensional network structures bridge each other to form a structurally stable gel layer.

[0102] (5) A heating layer is formed on the surface of the composite porous ceramic to obtain the atomizing core.

[0103] Example 2

[0104] (1) Preparation of silicon nitride ceramic blank: 40% silicon nitride powder, 10% glass powder, 20% pore-forming agent, 20% paraffin wax and 10% beeswax were mixed and melted by mass percentage, and a porous ceramic blank was prepared by hot pressing. The ceramic blank was placed in a sintering furnace. The temperature was raised from room temperature to 200℃ at a heating rate of 0.5℃ / min, and then raised from 200℃ to 600℃ at a heating rate of 0.25℃ / min. The temperature was held at 600℃ for 3 hours, and then cooled to room temperature before being taken out to obtain the silicon nitride ceramic blank.

[0105] (2) Preparation of sol mixture: 1 part by mass of tetramethoxysilane, 0.2 parts by mass of water, 2 parts by mass of anhydrous ethanol, and a catalyst with a concentration of 0.05 mol / L were provided and stirred to obtain a polysiloxane sol; the above polysiloxane sol was mixed with 1 part by mass of carbon fiber to make the surface of the carbon fiber coated with polysiloxane sol, thus preparing a sol mixture. That is, the mass ratio of carbon source, silicon source monomer, crosslinking agent, and solvent is 1:1:0.2:2.

[0106] (3) Curing treatment: The silicon nitride ceramic blank is dipped into the sol mixture and then placed in an oven at 80°C for 8 hours to gel. Figure 4 This is a schematic diagram of the appearance of the cured silicon nitride ceramic preform.

[0107] (4) Degreasing: The solidified silicon nitride ceramic blank is placed in a sintering furnace and heated from room temperature to 200°C at a heating rate of 1°C / min, and then heated from 200°C to 600°C at a heating rate of 2°C / min. The blank is then held at 600°C for 5 hours to degrease.

[0108] (5) Sintering treatment: After cooling, take it out and place it in a 100-2 type multi-functional vertical carbon tube furnace. Protect it with nitrogen and heat it to 1700℃ at a heating rate of 5℃ / min. Hold it for 1 hour and then cool it to room temperature to obtain composite porous ceramics. Figure 5 This is an image of the sintered composite porous silicon nitride ceramic. Figure 6 The microstructure diagram of the composite porous silicon nitride ceramic is shown. (6) A heating layer is formed on the surface of the composite porous ceramic to obtain the atomizing core.

[0109] Example 3

[0110] The process is essentially the same as in Example 1, except that the immersion time of the ceramic blank in the sol mixture is different. Specifically, in Example 3, the silicon carbide ceramic is completely immersed in the sol for 20 seconds.

[0111] Example 4

[0112] The process is essentially the same as in Example 1, except that the immersion time of the ceramic blank in the sol mixture is different. Specifically, in Example 4, the silicon carbide ceramic is completely immersed in the sol for 30 seconds.

[0113] Example 5

[0114] The process is essentially the same as in Example 1, except that the immersion time of the ceramic blank in the sol mixture is different. Specifically, in Example 5, the silicon carbide ceramic is completely immersed in the sol for 40 seconds.

[0115] Example 6

[0116] The method is basically the same as in Example 1, except that the mass ratio of carbon source, silicon source monomer, crosslinking agent and solvent is different. Specifically, the mass ratio of carbon source, silicon source monomer, crosslinking agent and solvent is 1:2:2:20.

[0117] Comparative Example 1

[0118] By mass percentage, 40% silicon nitride powder, 10% glass powder, 20% pore-forming agent, 20% paraffin wax, and 10% beeswax are mixed and melted. A porous ceramic green body is prepared by hot pressing. The ceramic green body is placed in a sintering furnace. The temperature is increased from room temperature to 200℃ at a heating rate of 0.5℃ / min, and then increased from 200℃ to 600℃ at a heating rate of 0.25℃ / min. The temperature is held at 600℃ for 3 hours, and then cooled to room temperature to obtain silicon nitride ceramic.

[0119] A heating layer is formed on the surface of silicon nitride ceramic to obtain an atomizing core.

[0120] Comparative Example 2

[0121] (1) Preparation of sol mixture: Carbon fiber, siloxane, water and anhydrous ethanol are mixed in a mass ratio of 1:1:0.2:2 and stirred for 1 hour to make the carbon fiber uniformly dispersed in the crosslinking agent to obtain sol mixture.

[0122] (2) Place the sol mixture in an oven, heat it to 100°C, and keep it warm for 4 hours to allow it to solidify.

[0123] (3) The solidified carbon fiber sol was placed in a sintering furnace, heated to 1700°C, and argon gas was introduced for heat preservation for 4 hours. The gel was decomposed to generate SiC nanowires. The furnace was cooled to room temperature to form an intermediate structure of SiC nanowires / carbon fiber skeleton.

[0124] (4) Heat the intermediate structure to 700°C and keep it warm for 2 hours to obtain silicon carbide aerogel; form a heating layer on the aerogel to obtain the aerogel atomizing core.

[0125] Performance testing:

[0126] The porosity test method refers to the national standard JIS R1634-1998, which determines the porosity of the composite porous ceramic according to Archimedes' water displacement method; referring to the national standard GB / T 1041-2008, the compressive stress-strain curve of the composite porous ceramic is measured using a mechanical testing machine, and the maximum force of the aerogel atomizing core is calculated; the lifespan tested in this application refers to the total number of puffs tested when the composite porous ceramic with a heating element is combined with an electronic cigarette for simulated inhalation; whether powder is shed is determined by visually inspecting the surface of the composite porous ceramic for dispersed powder particles, either with the naked eye or under a magnifying glass.

[0127] The performance test results of the atomizing cores prepared in the above embodiments and comparative examples are shown in the table below.

[0128] Table 1

[0129]

[0130] As shown in the table above, the silicon carbide and silicon nitride composite porous ceramics prepared in Examples 1 and 2 using the same method showed little difference in their properties. Compared to Examples 3, 4, and 5, with the same sol concentration but different ceramic body immersion times, the surface sol thickness varied; longer immersion times resulted in thicker surface sol. In Example 5, the ceramic body immersion time was 40 seconds, and its porosity was lower than in Examples 3 and 4, indicating that a longer immersion time is not necessarily better. This may be because a longer immersion time leads to more sol entering the ceramic body, thus clogging the pores of the porous ceramic itself. In Example 6, the crosslinking agent was increased, resulting in a higher sol concentration. Under the same immersion time, the surface sol of the ceramic body became thicker, thus increasing the mechanical strength of the composite, but decreasing the porosity, thereby affecting the amount of smoke generated and the taste.

[0131] Comparative Example 1 is a pure porous ceramic without a sol layer on its surface. The maximum force it can withstand is greater than that of the composite porous ceramic. However, the lifespan of the electronic cigarette made by combining the pure porous ceramic with the heating element is shorter than that of the composite ceramic, and it is prone to shedding powder and residue, which has an impact on human health. Comparative Example 2 is a pure aerogel atomizing core with the same concentration as in Example 1. It is thin, has low strength, and a short lifespan.

[0132] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0133] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for preparing composite porous ceramics, characterized in that, Includes the following steps: Composite green bodies were prepared by impregnating porous ceramic green bodies with a sol-gel mixture. The composite preform is subjected to curing and sintering treatments in sequence; The impregnation treatment time is 10s~40s, and the sintering temperature is 800℃~1700℃.

2. The method for preparing composite porous ceramics according to claim 1, characterized in that, The method for preparing the sol mixture includes the following steps: Polysiloxane sol is prepared by mixing silicon-based monomers, solvents, crosslinking agents, and catalysts. The polysiloxane sol is mixed with a carbon source to prepare the sol mixture.

3. The method for preparing composite porous ceramics according to claim 2, characterized in that, The mass ratio of the carbon source, the silicon source monomer, the crosslinking agent, and the solvent is (1~2):(1~2):(0.1~0.5):(2~4).

4. The method for preparing composite porous ceramics according to claim 2, characterized in that, The silicon source monomer includes one or more of methyltrimethoxysilane, dimethyldimethoxysilane, tetramethoxysilane, tetraethoxysilane, and tetraethyl orthosilicate; and / or, The carbon source includes one or more of carbon fibers, carbon black, activated carbon, graphene, and carbon nanotubes; and / or, The crosslinking agent includes one or more of water and silane coupling agents; and / or, The solvent includes one or more of methanol, anhydrous ethanol, and isopropanol; and / or, The catalyst comprises one or more of hydrochloric acid and ammonia water; and / or, The concentration of the catalyst is 0.01 mol / L to 0.1 mol / L.

5. The method for preparing composite porous ceramics according to any one of claims 1 to 4, characterized in that, The curing temperature is 80℃~100℃, and the time is 3h~12h.

6. The method for preparing composite porous ceramics according to any one of claims 1 to 4, characterized in that, The sintering process includes: heating to the sintering temperature at a heating rate of 0.1℃ / min to 5℃ / min; and / or, The atmospheric gas used in the sintering process includes one or more of nitrogen and argon.

7. The method for preparing composite porous ceramics according to any one of claims 1 to 4, characterized in that, The porous ceramic preform includes one or more of silicon nitride porous ceramic preforms, silicon carbide porous ceramic preforms, zirconia porous ceramic preforms, and alumina porous ceramic preforms.

8. A composite porous ceramic, characterized in that, The composite porous ceramic was prepared using the method described in any one of claims 1 to 7.

9. A ceramic atomizing core, characterized in that, Including the composite porous ceramic as described in claim 8.

10. An atomizing device, characterized in that, Includes the ceramic atomizing core as described in claim 9.

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