A metal organic framework-based coating modified difficult-to-sinter ceramic powder, a preparation method and application thereof

Abstract

The application belongs to the technical field of additive manufacturing photocuring forming, and relates to a metal organic framework coating modified difficult-to-cure ceramic powder and a preparation method and application thereof, and comprises the following preparation steps: metal salt and organic ligand are added to a solvent, and after being fully mixed, the mixture is added to a reaction container to react to obtain a metal organic framework material; the metal organic framework material is fully mixed with activated ceramic powder to coat the metal organic framework material on the surface of the ceramic powder, to obtain a composite ceramic powder coated and modified by the metal organic framework, and the composite ceramic powder is mixed with a sintering aid, resin, a photoinitiator and a dispersant to obtain a ceramic slurry, increase a curing depth, and prepare a ceramic slurry meeting photocuring forming conditions, which can be widely applied to the field of photocuring ceramic additive manufacturing.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of additive manufacturing photocuring forming technology, and particularly relates to a metal organic framework coated modified difficult-to-cure ceramic powder and a preparation method and application thereof. BACKGROUND

[0002] Ceramic materials are inorganic non-metallic compounds prepared by liquid phase reaction and solid phase sintering of natural or synthetic compounds, and have many unique properties. Ceramics are widely used in national defense, aerospace, machinery, electronics, biomedicine and other fields. With the gradual increase of production and application requirements, the shape and performance requirements of ceramic parts are also increasing. Additive manufacturing technology is an advanced manufacturing technology for manufacturing ceramic parts by layer-by-layer stacking of materials. Compared with traditional ceramic processing methods, it does not require molds and has high material utilization, higher freedom and plasticity, and can manufacture complex-shaped ceramics. Among them, the photocuring forming technology has the characteristics of fast forming speed, high forming precision and low material loss, and has broad prospects for forming complex structure ceramics using photocuring forming technology.

[0003] There are many studies on photocuring forming technology for preparing ceramics, such as alumina, zirconia, and silicon oxide. The ultraviolet absorbance and refractive index of difficult-to-cure ceramic powders (silicon nitride, silicon carbide, PZT, etc.) are relatively high, resulting in low solidification depth of ceramic slurry and difficulty in photocuring forming (J. Asian Ceram. Soc., 2022, 10(1), 69-82.; J. Eur. Ceram. Soc., 2021, 41(4), 2386-2394.). It is found that by reducing the absorbance of ceramic powder and reducing the refractive index difference between the photocuring resin, the solidification depth of the ceramic slurry can be increased, the solidification performance of the ceramic slurry can be improved, and the photocuring forming is facilitated. It is found that surface oxidation can significantly reduce the ultraviolet absorbance of difficult-to-cure ceramic powder and increase the solidification depth, but the introduction of low-strength oxides will reduce the mechanical properties of non-oxide ceramics; sintering aid coated modification of difficult-to-cure ceramic powder can improve the solidification properties of ceramic slurry, but this method is complex and requires high-temperature pretreatment, increasing the complexity and cost of the ceramic manufacturing process. Therefore, selecting an appropriate method to reduce the ultraviolet absorbance of difficult-to-cure ceramic powder, reduce the refractive index difference between the photocuring resin, increase the solidification depth, and prepare ceramic slurry that meets the photocuring forming conditions is a key scientific problem to be solved for photocuring forming technology for preparing difficult-to-cure ceramics. SUMMARY

[0004] In view of the defects of the prior art, the application provides a metal organic framework coated modified difficult-to-cure ceramic powder and a preparation method and application thereof, which aims to solve the technical problems of low photocuring depth and difficulty in photocuring forming of the prior art difficult-to-cure ceramic powder.

[0005] According to a first aspect of the present application, a preparation method of ceramic powder coated and modified based on metal organic framework is provided, comprising the following steps:

[0006] (1) adding metal salt and organic ligand into solvent, mixing thoroughly, and then adding into reaction container to react to obtain metal organic framework material;

[0007] (2) mixing the metal organic framework material with ceramic powder to coat the metal organic framework material on the surface of the ceramic powder, to obtain composite ceramic powder coated and modified based on metal organic framework.

[0008] Preferably, the metal salt is selected from one or more of aluminum nitrate, aluminum chloride, magnesium nitrate, magnesium chloride, zirconium nitrate or zirconium chloride;

[0009] Preferably, the organic ligand is selected from one or more of terephthalic acid, 2-amino terephthalic acid, trans-1,5-cyclohexane dicarboxylic acid, trimesic acid, 1,2-cyclohexane dicarboxylic acid, 1,2,4-benzene tricarboxylic acid, 1,4-naphthalene dicarboxylic acid, 2,2'-bipyridine-4,4'-dicarboxylic acid, 2,2'-bipyridine-5,5'-dicarboxylic acid or 2,5-dihydroxy terephthalic acid;

[0010] Preferably, the solvent is selected from one or more of water, ethanol, methanol, N,N-dimethylformamide, chloroform or tetrahydrofuran;

[0011] Preferably, the ceramic powder is selected from one or more of silicon nitride, silicon carbide, zirconium oxide, lead oxide or titanium oxide.

[0012] Preferably, the mass ratio of the metal organic framework material to the ceramic powder is 1:99-50:50.

[0013] Preferably, the reaction temperature of step (1) is 100-240℃, and the reaction time is 12-100h.

[0014] Preferably, in step (2), before mixing with the metal organic framework material, the ceramic powder is further subjected to activation treatment; the specific steps of the activation treatment are: alkali washing the ceramic powder, and then filtering, washing and drying.

[0015] According to another aspect of the present application, a composite ceramic powder prepared by the preparation method of ceramic powder coated and modified based on metal organic framework is provided.

[0016] According to another aspect of the present application, a ceramic slurry is provided, comprising the composite ceramic powder, and further comprising sintering aid, resin, photoinitiator and dispersant.

[0017] Preferably, the sintering aid is selected from one or more of yttrium oxide, magnesium oxide or aluminum oxide;

[0018] Preferably, the resin is selected from one or more of trimethylolpropane triacrylate (TMPTA), 1,6-hexanediol diacrylate (HDDA), bis-pentaerythritol hexaacrylate (DPHA), ethoxylated pentaerythritol tetraacrylate (PPTTA), ethoxylated trimethylolpropane triacrylate (TMP3EOTA), isobornyl acrylate (IBOA), acryloyl morpholine (ACMO), polyethylene glycol (400) diacrylate (PEG400), trimethylolpropane trimethacrylate (TMPTMA);

[0019] Preferably, the photoinitiator is selected from one or more of (2,4,6-trimethylbenzoyl) diphenylphosphine oxide (TPO), hydroxycyclohexane phenyl ketone (184);

[0020] Preferably, the dispersant is selected from one or more of polyacrylate, sodium dodecyl benzene sulfonate, polyvinyl acetate, vinyl bis stearyl amide.

[0021] Preferably, the mass ratio of the composite ceramic powder, sintering aid, resin, photoinitiator and dispersant is 100:5:20:1:1 to 100:50:150:30:15.

[0022] According to another aspect of the present application, the application provides a use of the ceramic slurry for photocuring ceramic additive manufacturing.

[0023] Overall, compared with the prior art, the above technical solutions conceived by the present application mainly have the following technical advantages:

[0024] (1) The present application uses metal organic framework materials for the coating modification of difficult-to-solidify ceramic powder, which can significantly reduce the ultraviolet absorbance of difficult-to-solidify ceramic powder, improve the photocuring depth of difficult-to-solidify ceramic powder, and is conducive to the photocuring forming of difficult-to-solidify ceramic. Ultimately, the photocuring forming technology can be used to prepare ceramic. This method has the advantages of simple preparation and greatly improved photocuring efficiency of difficult-to-form ceramic, and provides a new idea for preparing photocuring difficult-to-solidify ceramic powder.

[0025] (2) The metal organic framework material of the present application is self-assembled from metal ions and organic ligands through coordination bonds. By changing the type of organic ligand, adjusting the synthesis reaction temperature, and adjusting the reaction time, the size and optical properties of the metal organic framework material can be adjusted. By changing the type of organic ligand and the synthesis conditions, the light absorption and emission of the metal organic framework material can be controlled, and a metal organic framework material with low ultraviolet absorption can be prepared. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is the ultraviolet absorption spectrum of the silicon nitride ceramic powder before and after the metal organic framework coating modification in example 1.

[0027] Figure 2 is the single layer curing depth comparison chart of the silicon nitride ceramic slurry before and after the metal organic framework coating modification in example 1.

[0028] Figure 3 is the ultraviolet absorption spectrum of the silicon nitride ceramic powder before and after the metal organic framework coating modification in example 2.

[0029] Figure 4 is the single layer curing depth comparison chart of the silicon nitride ceramic slurry before and after the metal organic framework coating modification in example 2.

[0030] Figure 5 is the ultraviolet absorption spectrum of the silicon carbide ceramic powder before and after the metal organic framework coating modification in example 3.

[0031] Figure 6 is the single layer curing depth comparison chart of the silicon carbide ceramic slurry before and after the metal organic framework coating modification in example 3. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0033] Example 1

[0034] First step: 22.075g of aluminum nitrate, 4.881g of terephthalic acid are added to 100mL of deionized water, after ultrasonic mixing, put into the reaction kettle, react at 180℃ for 72 hours. Cool to room temperature, after a series of filtration, washing, drying and other operations, MOF-1 material is obtained.

[0035] Second step: 100g of silicon nitride ceramic powder is placed in 1mol / L sodium hydroxide solution for a period of time, then filtered, washed and dried to obtain activated silicon nitride ceramic powder. Then the MOF-1 material prepared in the first step and the activated silicon nitride ceramic powder are added to ethanol, ball milled for a period of time, then filtered and dried to obtain MOF-1 coated modified silicon nitride ceramic powder.

[0036] Third step: the MOF-1@ silicon nitride ceramic powder prepared in the second step is mixed with the sintering aid yttrium oxide, the resin trimethylolpropane triacrylate (TMPTA), acryloyl morpholine (ACMO), bis-quintisyl hexaacrylate (DPHA), a photoinitiator (2,4,6-trimethylbenzoyl) diphenyl phosphine oxide (TPO), and a dispersant polyacrylate, and is placed in a vacuum defoaming machine, and finally a silicon nitride ceramic slurry is obtained, and the single-layer curing depth of the silicon nitride ceramic slurry is tested.

[0037] The ultraviolet absorption spectra of the MOF-1 coated modified silicon nitride ceramic powder before and after modification are shown in FIG. 2. Figure 1 As can be seen from the ultraviolet absorption spectrum, at a wavelength of 355 nm, the ultraviolet absorbance of the MOF-1 material is significantly lower than that of the silicon nitride ceramic powder. The absorbance of the MOF-1 coated modified silicon nitride ceramic powder is significantly lower than that of the original silicon nitride ceramic powder, indicating that coating with the MOF-1 material can significantly reduce the ultraviolet absorbance of the silicon nitride ceramic powder. The single-layer curing depth of the silicon nitride ceramic slurry before and after modification by the MOF-1 is shown in FIG. 3. Figure 2 As can be seen, the single-layer curing depth of the silicon nitride ceramic slurry before modification is 24 μm, and the curing depth of the MOF-1 coated modified silicon nitride ceramic slurry is 59 μm. The MOF-1 coating can greatly increase the single-layer curing depth of the silicon nitride ceramic slurry and improve the curing performance of the silicon nitride ceramic slurry. Finally, a silicon nitride ceramic is photo-cured. Therefore, the MOF-1 material can be used to coat and modify the silicon nitride ceramic powder for photo-cured forming.

[0038] Example 2

[0039] First step: 11 g of aluminum nitrate and 7.4 g of pyrazole dicarboxylic acid are added to 300 mL of deionized water, and after ultrasonic mixing, the reaction is carried out at 100°C for 24 hours. After cooling to room temperature, a series of filtration, washing, and drying operations are performed to obtain the MOF-2 material.

[0040] Second step: 100 g of silicon nitride ceramic powder is placed in a 1 mol / L sodium hydroxide solution for a period of time, and then filtered, washed, and dried to obtain activated silicon nitride ceramic powder. Then the MOF-2 material prepared in the first step and the activated silicon nitride ceramic powder are added to ethanol, ball-milled for a period of time, filtered, and dried to obtain MOF-2 coated modified silicon nitride ceramic powder.

[0041] Third step: the MOF-2@ silicon nitride ceramic powder prepared in the second step is mixed with the sintering aid yttrium oxide, the resin TMPTA, 1,6-hexanediol diacrylate (HDDA), ACMO, a photoinitiator TPO, and a dispersant sodium dodecylbenzenesulfonate, and is placed in a vacuum defoaming machine, and finally a silicon nitride ceramic slurry is obtained, and the single-layer curing depth of the silicon nitride ceramic slurry is tested.

[0042] The UV absorption spectra of the silicon nitride ceramic powder before and after MOF-2 coating modification are shown in FIG. 2. Figure 3 As can be seen from the UV absorption spectrum, the UV absorbance of the MOF-2 material is significantly lower than that of the silicon nitride ceramic powder at a wavelength of 355 nm. The absorbance of the MOF-2 coated modified silicon nitride ceramic powder is significantly lower than that of the original silicon nitride ceramic powder, indicating that coating with MOF-2 material can significantly reduce the UV absorbance of the silicon nitride ceramic powder. The single layer curing depth of the silicon nitride ceramic slurry before and after MOF-2 coating modification is shown in FIG. 3. Figure 4 As can be seen, the single layer curing depth of the silicon nitride ceramic slurry before coating modification is 24 μm, and the curing depth of the MOF-1 coated modified silicon nitride ceramic slurry is 53 μm. MOF-1 coating can greatly increase the single layer curing depth of the silicon nitride ceramic slurry and improve the curing performance of the silicon nitride ceramic slurry. Finally, the silicon nitride ceramic is light cured. Therefore, the MOF-1 material can be used to coat and modify the silicon nitride ceramic powder for light curing forming.

[0043] Example 3

[0044] First step: 22.075 g of aluminum nitrate and 4.881 g of terephthalic acid were added to 100 mL of deionized water, ultrasonically mixed, and then placed in a reaction kettle and reacted at 180°C for 72 hours. After cooling to room temperature, a series of filtration, washing, drying and other operations were performed to obtain the MOF-1 material.

[0045] Second step: 100 g of silicon carbide ceramic powder was placed in a 1 mol / L sodium hydroxide solution for a period of time, then filtered, washed and dried to obtain activated silicon carbide ceramic powder. Then the MOF-1 material prepared in the first step and the activated silicon carbide ceramic powder were added to ethanol, ball milled for a period of time, then filtered and dried to obtain MOF-1 coated modified silicon carbide ceramic powder.

[0046] Third step: The MOF-1@silicon carbide ceramic powder prepared in the second step was placed in a vacuum defoaming machine together with the sintering aid yttrium oxide, the resins TMPTA, HDDA, ACMO, the photoinitiator TPO and the dispersant vinyl bis stearyl amide, and finally the silicon carbide ceramic slurry was obtained. The single layer curing depth of the silicon carbide ceramic slurry was tested.

[0047] The UV absorption spectra of the silicon nitride ceramic powder before and after MOF-2 coating modification are shown in FIG. 2. Figure 5The UV absorption spectrum of the MOF-1 material is shown in Figure 6. It can be seen from the UV absorption spectrum that the UV absorbance of the MOF-1 material is significantly lower than that of the silicon carbide ceramic powder at a wavelength of 405 nm. The absorbance of the silicon carbide ceramic powder coated with the MOF-1 material is significantly lower than that of the original silicon carbide ceramic powder, indicating that coating with the MOF-1 material can significantly reduce the UV absorbance of the silicon carbide ceramic powder. The single-layer curing depth of the silicon carbide ceramic slurry before and after coating with the MOF-1 material is shown in Figure 7. Figure 6 It can be seen that the single-layer curing depth of the silicon carbide ceramic slurry before coating with the MOF-1 material is 21 μm, and the curing depth of the silicon carbide ceramic slurry coated with the MOF-1 material is 47 μm. Coating with the MOF-1 material can greatly increase the single-layer curing depth of the silicon carbide ceramic slurry and improve the curing performance of the silicon carbide ceramic slurry. Finally, the silicon carbide ceramic is photo-cured. Therefore, the MOF-1 material can be used to coat and modify the silicon carbide ceramic powder for photo-curing forming.

[0048] Those skilled in the art will readily understand that the above description is only preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A photocurable ceramic slurry, characterized by, The application relates to a kind of metal organic framework-based coated modified difficult-to-sinter ceramic powder, further comprising a sintering aid, a resin, a photoinitiator and a dispersant; the metal organic framework-based coated modified difficult-to-sinter ceramic powder is prepared by the following method, specifically comprising the following steps: (1) adding metal salt and organic ligand to solvent, mixing thoroughly, then adding to a reaction vessel, and reacting at a temperature of 100-240 DEG C for 12-100 hours to obtain metal organic framework material; (2) mixing the metal organic framework material with ceramic powder to coat the metal organic framework material on the surface of the ceramic powder, and obtaining metal organic framework coated modified difficult-to-sinter ceramic powder; the metal salt is selected from one or more of aluminum nitrate, aluminum chloride, magnesium nitrate, magnesium chloride, zirconium nitrate and zirconium chloride; the organic ligand is selected from one or more of terephthalic acid, 2-amino terephthalic acid, trans-1,5-cyclohexane dicarboxylic acid, trimesic acid, 1,2-cyclohexane dicarboxylic acid, 1,2,4-benzene tricarboxylic acid, 1,4-naphthalene dicarboxylic acid, 2,2'-bipyridine-4,4'-dicarboxylic acid, 2,2'-bipyridine-5,5'-dicarboxylic acid and 2,5-dihydroxy terephthalic acid.

2. The photocurable ceramic slurry according to claim 1, characterized in that the solvent is selected from one or more of water, ethanol, methanol, N,N-dimethylformamide, chloroform and tetrahydrofuran; the ceramic powder is selected from one or more of silicon nitride, silicon carbide, zirconium oxide, lead oxide and titanium oxide.

3. The photocurable ceramic slurry of claim 1, wherein, The mass ratio of the metal organic framework material to the ceramic powder is 1:99-50:

50.

4. The photocurable ceramic slurry of claim 1, wherein, In step (2), the ceramic powder is further subjected to activation treatment before being mixed with the metal organic framework material; the specific steps of the activation treatment are as follows: the ceramic powder is subjected to alkali washing, and then is filtered, washed and dried.

5. The photocurable ceramic slurry of claim 1, wherein, the sintering aid is selected from one or more of yttrium oxide, magnesium oxide and aluminum oxide; the resin is selected from one or more of trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, bis-quintis hexaacrylate, ethoxylated pentaerythritol tetraacrylate, ethoxylated trimethylolpropane triacrylate, isobornyl acrylate, acryloyl morpholine, polyethylene glycol, diacrylate and trimethylolpropane trimethacrylate; the photoinitiator is selected from one or more of (2,4,6-trimethylbenzoyl) diphenyl phosphine oxide and hydroxycyclohexane phenone; the dispersant is selected from one or more of polyacrylate, sodium dodecyl benzene sulfonate, polyvinyl acetate and vinyl bis stearyl amide.

6. The photocurable ceramic slurry of claim 1, wherein, The mass ratio of the metal organic framework coated modified difficult-to-sinter ceramic powder, the sintering aid, the resin, the photoinitiator and the dispersant is 100:5:20:1:1-100:50:150:30:

15.

7. Use of a photocurable ceramic slurry according to any one of claims 1 to 6, characterized in that, It is used for photocurable ceramic additive manufacturing.

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