Pure crystalline phase nano-sized magnesium titanate ceramic powder material
By performing liquid phase reaction and precipitation-dissolution-precipitation process in a mixed solvent of water and organic alcohol, combined with the action of surfactant and gaseous grinding treatment, magnesium titanate ceramic powder with a particle size of less than 100 nm and a pure crystal phase nano-size was successfully prepared, which solved the problems of large particle size and impure crystal phase in the prior art, and achieved high-quality nano-scale ceramic powder preparation.
Patent Information
- Application Number
- CN202510297874.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2021-12-22
- Publication Date
- 2025-05-13
AI Technical Summary
It is difficult to prepare magnesium titanate ceramic powders with a particle size of less than 100 nm and a pure crystal phase nano-size, and the products are prone to agglomeration and crystal phase impurity, which limits the development and application of materials.
In a mixed solvent of water and organic alcohol, a water-insoluble magnesium-containing compound precursor is used to react with titanium chloride for liquid phase. Through the complex process of precipitation-dissolution-precipitation, combined with the action of surfactant, a pure crystalline nano-sized magnesium titanate ceramic powder is prepared, and the particle size is further controlled by gaseous grinding treatment.
Magnesium titanate ceramic powder with a particle size of D50 less than 100nm and a pure crystal phase nano-sized one was successfully prepared. The particle dispersion is good, the particle size is uniform, and it has broad application prospects, especially in the field of ceramic device processing in the electronic information industry.
Smart Images
Figure CN119976944A_ABST
Abstract
Description
[0001] This application is a divisional application of application number: CN202111582128.X Application date: 20211222 Invention name: A pure crystalline nano-size magnesium titanate ceramic powder and its preparation method, applicant: Yuanjie New Materials Technology (Zhejiang) Co., Ltd. Technical Field
[0002] The invention belongs to the technical field of material preparation, and specifically relates to a magnesium titanate ceramic powder with a particle size D50 less than 100nm and pure crystal phase nano-size and a preparation method thereof. Background Art
[0003] Magnesium titanate-based ceramics are a common dielectric ceramic material with good application performance in daily life. They have relatively good dielectric stability and have been widely used in many fields such as electronic information, daily necessities, and biomedicine. However, with the expansion of application fields and the improvement of performance indicators, the performance requirements for magnesium titanate-based ceramic materials are becoming higher and higher. The performance of magnesium titanate ceramic powder is the fundamental factor that determines the filter dielectric ceramic products obtained by processing in the future. The preparation of magnesium titanate-based ceramic powder materials with special excellent performance has become a research hotspot in the materials industry. Controlling its crystal phase structure, size and morphology can improve its mechanical properties and thermal sintering properties. In the processing of dielectric filter ceramic devices, the purity, particle size, crystal phase, surface structure and morphology of magnesium titanate ceramic powder directly determine the yield rate of ceramic device processing and subsequent performance. The preparation of high-performance magnesium titanate nanoceramic powder is a current research hotspot and technical difficulty. However, the magnesium titanate ceramic powder particles obtained by the existing common preparation methods are often relatively large. Even if the particle size can reach the nanometer level, the product will always be severely agglomerated or have an impure crystal phase after drying, which greatly limits the development and application of magnesium titanate ceramic materials. The preparation of high-quality nano-scale magnesium titanate-based ceramic powders and their structural control are key technical problems that determine the application of magnesium titanate-based ceramics. Summary of the invention
[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a magnesium titanate ceramic powder material with a particle size D50 less than 100nm and pure crystal phase nano-size and a preparation method thereof.
[0005] The object of the present invention can be achieved by the following technical scheme: a pure crystalline nano-sized magnesium titanate-based powder material, characterized in that the material is a nano-sized magnesium titanate nano-ceramic powder with an irregular pure crystalline structure, the material particle size is 50-100nm, the particle size D50 is less than 100nm after drying and crushing, the D90 is less than 300nm, and the specific surface area is 3-10m 2 / g, apparent density is 3.0-4.0g / cm 3 .
[0006] The present invention proposes a method for preparing a pure crystalline nano-sized magnesium titanate ceramic powder material with a particle size D50 less than 100nm: firstly, a water-insoluble magnesium compound precursor and a certain amount of surfactant are dispersed in a mixed solution of water and organic alcohol, and a titanium chloride solution is slowly introduced into the mixed solution to carry out a liquid phase reaction process, and then a pure crystalline nano-sized magnesium titanate ceramic powder is obtained through subsequent centrifugation, washing, drying and roasting treatment, and then a pure crystalline nano-sized magnesium titanate ceramic powder material with a particle size D50 less than 100nm is obtained through gas grinding treatment. The specific steps are as follows:
[0007] (1) A certain amount of a water-insoluble magnesium compound precursor and a surfactant are dissolved in a mixed solvent of water and an organic alcohol (the volume ratio of water to the organic alcohol is 1:0.1-1), ultrasonically dispersed, and mechanically stirred to obtain a suspension, which is recorded as solution A.
[0008] (2) Weigh a certain amount of titanium chloride and dissolve it in a certain volume of deionized water solution, which is recorded as solution B.
[0009] (3) using a peristaltic pump to uniformly mix solution A and solution B in a forward addition, reverse addition or parallel flow manner, reacting at room temperature, and then continuing to stir for 1-2 days to obtain a white gel, centrifuging to obtain a precipitated product, washing, drying, and roasting, and finally subjecting the obtained solid powder sample to gas grinding treatment to obtain a pure crystalline nano-sized magnesium titanate ceramic powder material with a particle size D50 less than 100 nm.
[0010] In the present invention, the water-insoluble magnesium compound precursor is subjected to ultrasonic dispersion to form a suspension. Since titanium chloride can be violently hydrolyzed to produce highly acidic hydrogen chloride, it can effectively promote the dissolution of the magnesium-containing mixture to generate magnesium ions, and the titanic acid produced by the hydrolysis of titanium chloride can react with magnesium ions to undergo a precipitation reaction, resulting in a complex process of precipitation-dissolution-precipitation. The presence of a surfactant can weaken the interaction between sol particles and change the surface state of the corresponding precipitation, effectively preventing the occurrence of agglomeration between precipitation particles, and has an effective regulating effect on the magnesium titanate crystal phase. Therefore, a magnesium titanate ceramic powder material with a particle size D50 less than 100nm and a pure crystal phase nanometer size can be obtained through a relatively simple treatment process.
[0011] The concentration of the water-insoluble magnesium-containing compound precursor in the reaction system formed by solution A and solution B is 1-15wt%; the mass ratio of the water-insoluble magnesium-containing compound precursor to the titanium-containing chloride is 0.5-2.5:1; the reaction temperature can be controlled at room temperature, that is, in the range of 0-40°C as the seasons change.
[0012] The water-insoluble magnesium-containing compound precursor is an inorganic magnesium salt or an organic acid magnesium salt that is insoluble in water and organic alcohol; the magnesium salt precursor is one or more of magnesium carbonate, magnesium oxalate, magnesium citrate, magnesium tartrate, magnesium sulfite, and magnesium hydroxide;
[0013] The titanium chloride is one or more of titanium tetrachloride, titanium trichloride, and titanium oxychloride;
[0014] The surfactant is mainly a non-ionic high molecular polymer; the surfactant is one or more of polyethylene glycol, PVP, polyacrylic acid, polyether, and F127; the mass ratio of the magnesium compound precursor to the surfactant is 10:0.2-1.
[0015] The organic alcohol is a liquid straight-chain alkyl alcohol or an isomeric alcohol thereof; the organic alcohol is one or more of ethanol, methanol, propanol, isopropanol, n-butanol and benzyl alcohol.
[0016] The water is water obtained through water purification, wherein the heavy metal ions, iron, cobalt and nickel ions are below ppm.
[0017] The containers and reaction containers for solution A and solution B are glass containers, organic plastic containers or ceramic enamel containers, including one or more of glass flasks, glass beakers, watch glasses, conical flasks, wide-mouth bottles, weighing bottles, test tubes, measuring cups, plastic beakers, ceramic reactors, enamel reactors, and centrifuge tubes.
[0018] The centrifugal speed of the centrifugal separation in step (3) is 4000-10000 rpm, and the centrifugal time each time is 5-10 minutes.
[0019] The solvent used for washing in step (3) is one or more of water, methanol, ethanol and isopropanol.
[0020] The temperature range selected for the drying treatment in step (3) is 70-120°C; the temperature range selected for the roasting treatment is 700-1200°C, the roasting time is 3-10h, the atmosphere used is air atmosphere, and an air compressor is required to continuously blow in air.
[0021] The equipment selected for gaseous grinding of solid powder samples is a jet mill with a power of 5KW. The powder products are collected by a cyclone separator. The air compressor has a power of 80KW and provides 10.0Mpa compressed air for grinding.
[0022] Compared with the prior art, the present invention uses a magnesium compound precursor that is insoluble in water in a mixed solvent of water and organic alcohol to undergo violent hydrolysis with titanium chloride to produce highly acidic hydrogen chloride for reaction, and then undergoes precipitation reaction with titanic acid, resulting in a complex process of precipitation-dissolution-precipitation. In this reaction system, organic alcohol plays a vital role. Its presence can not only weaken the interaction between sol particles, but also change the surface state of the corresponding oxalic acid precipitate, thereby preventing the occurrence of agglomeration between precipitated particles. In addition, the crystal phase structure of magnesium titanate is effectively regulated, and the subsequent gaseous pulverization technology can effectively remove the agglomeration of particles in the product and effectively control the particle size distribution in the product. Compared with the traditional magnesium titanate ceramic powder synthesis method, the invention method has strong controllability, simple process, convenient operation and low cost. Moreover, the entire preparation reaction process is carried out under static conditions at room temperature, and the energy-saving and environmentally friendly pure crystal phase nano-sized magnesium titanate ceramic powder has irregular particle morphology, uneven surface, good particle dispersibility, uniform particle size, and small particle size, and has broad application prospects, especially in the field of ceramic device processing in the electronic information industry. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 The characteristic transmission electron microscope (TEM) image of the magnesium titanate ceramic powder with a particle size D50 less than 100 nm and pure crystal phase nanometer size obtained by the preparation method is obtained by Example 1.
[0024] Figure 2 The characteristic high-angle X-ray spectrum of monodisperse magnesium titanate ceramic powder with a particle size D50 less than 100 nm and pure crystal phase nano-size is prepared by Example 1. DETAILED DESCRIPTION
[0025] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.
[0026] Example 1
[0027] Dissolve 10g magnesium carbonate and 1.0g PEG-10000 in 500ml water and ethanol mixed solvent (volume ratio of water to organic alcohol is 1:0.1), stir for half an hour, add 100ml of titanium tetrachloride solution containing 40g into the above solution through a peristaltic pump, stir for 12h, centrifuge the resulting gel solution product at 11000rpm for 5 minutes to separate the gel, then wash twice with water and ethanol, dry at 80℃ in air for 12h, calcine at 1100℃ for 4 hours, and then process it in a gaseous pulverizer with a gas pressure of 8.0MPa. The powder sample collected by the cyclone separator can obtain a pure crystal phase nano-sized magnesium titanate ceramic powder with a D50 of 80nm. Its morphology and characteristics are shown in Figure 1-Figure 2 shown.
[0028] Example 2
[0029] 10g magnesium oxalate and 1.0g PEG-40000 were dissolved in 500ml of a mixed solvent of water and ethanol (the volume ratio of water to organic alcohol was 1:0.1). After stirring for half an hour, 100ml of an aqueous solution containing 50g of titanium oxychloride was added to the above solution through a peristaltic pump. After stirring for 12 hours, the generated gel solution product was centrifuged at 11000rpm for 5 minutes to separate the gel. The gel was then washed twice with water and ethanol respectively, dried at 110°C in air for 12 hours, and calcined at 900°C for 4 hours to obtain a pure crystalline nano-sized magnesium titanate ceramic powder with a D50 of 100nm.
[0030] Example 3
[0031] 10g of magnesium carbonate and 1.0g of PEG-10000 were dissolved in 500ml of a mixed solvent of water and ethanol (the volume ratio of water to organic alcohol was 1:0.2). After stirring for half an hour, the above solution was slowly added dropwise to 400ml of an aqueous solution containing 80g of titanium trichloride using a peristaltic pump. After stirring for 12 hours, the generated gel solution product was centrifuged at 8000rpm for 5 minutes to separate the gel, which was then washed twice with water and ethanol respectively, dried at 100°C in air for 12 hours, calcined at 1000°C for 4 hours, and then treated with a gaseous pulverizer with a gas pressure of 1.0MPa. The powder sample obtained by collecting the powder sample with a cyclone separator can obtain a magnesium titanate ceramic powder with a D50 of 95nm and a pure crystalline nano-size.
[0032] Example 4
[0033] 10g magnesium carbonate and 2.0g P123 were dissolved in 500ml water and ethanol mixed solvent (the volume ratio of water to organic alcohol was 1:0.1), and after stirring for half an hour, the above solution was slowly added dropwise to 400ml of 60g titanium trichloride aqueous solution using a peristaltic pump. After stirring for 12 hours, the generated gel solution product was centrifuged at 8000rpm for 5 minutes to separate the gel, and then washed twice with water and ethanol respectively, dried at 100°C in air for 12 hours, calcined at 1000°C for 4 hours, and then treated with a gaseous pulverizer with a gas pressure of 1.0MPa. The powder sample collected by the cyclone separator can obtain a pure crystalline nano-sized magnesium titanate ceramic powder with a D50 of 105nm.
[0034] Example 5
[0035] A method for preparing pure crystal phase nano-sized magnesium titanate ceramic powder with a particle size D50 less than 100 nm has the following specific steps:
[0036] (1) A certain amount of magnesium salt precursor magnesium carbonate and surfactant PVP are dissolved in a mixed solvent of water and organic alcohol ethanol (the volume ratio of water to organic alcohol is 1:0.1), and a suspension is obtained under mechanical stirring. This solution is recorded as solution A.
[0037] (2) Weigh a certain amount of titanium trichloride aqueous solution and record it as solution B. The mass ratio of magnesium salt precursor to titanium trichloride aqueous solution is 0.8:2;
[0038] (3) A peristaltic pump is used to uniformly mix solution A and solution B in a forward addition, reverse addition or parallel flow mode, and a reaction occurs at room temperature. The concentration of the magnesium salt precursor in the reaction system formed is 1wt%, and then stirring is continued for 1 day to obtain a gel solution, and a precipitate product is obtained by centrifugal separation. The centrifugal speed of the centrifugal separation is 5000rpm, and the centrifugal time is 10min each time. The solid powder sample is washed with water, dried at 120°C, and roasted at 1100°C for 3h. Finally, the solid powder sample is subjected to gaseous grinding treatment to obtain a pure crystal phase nano-sized magnesium titanate ceramic powder material with a particle size D50 less than 100nm. The equipment selected for the gaseous grinding treatment of the solid powder sample is a gas flow mill with a power of 5KW. The powder product is collected through a cyclone separator. The air compressor has a power of 80KW and provides 10.0Mpa compressed air for grinding.
Claims
1. A pure crystalline nano-sized magnesium titanate ceramic powder material, characterized in that: The material is a nano-sized magnesium titanate ceramic powder with an irregular pure crystal structure. The particle size of the material is 50-100nm. After dry gaseous pulverization, the particle size D50 is less than 100nm, and the specific surface area is 2-20m 2 / g, apparent density is 3.0-4.0g / cm 3 ; The preparation method comprises the following steps: (1) A certain amount of a water-insoluble magnesium compound precursor and a surfactant are dissolved in a mixed solvent of water and an organic alcohol, and a suspension is obtained under ultrasonic treatment and mechanical stirring. This solution is recorded as solution A. (2) Weigh a certain amount of a solution containing titanium chloride and record it as solution B. (3) using a peristaltic pump to uniformly mix solution A and solution B in a forward addition, reverse addition or parallel flow manner, reacting at room temperature, and then continuing to stir for 1-2 days to obtain a gel solution, centrifuging to obtain a precipitated product, washing, drying, and roasting, and finally subjecting the obtained solid powder sample to gas grinding treatment to obtain a pure crystalline nano-sized magnesium titanate ceramic powder material with a particle size D50 less than 100 nm.
2. The pure crystalline nano-sized magnesium titanate ceramic powder material according to claim 1, characterized in that: The mass concentration of the water-insoluble magnesium-containing compound precursor in the reaction system formed by solution A and solution B is 1-15wt%; the mass ratio of the water-insoluble magnesium-containing compound precursor to the titanium-containing chloride is 0.5-2.5:1; and the reaction temperature range is 0-40°C.
3. The pure crystalline nano-sized magnesium titanate ceramic powder material according to claim 1, characterized in that: The magnesium-containing compound precursor is an inorganic magnesium salt, an organic acid magnesium salt or a magnesium-containing hydroxide that is insoluble in water and organic alcohol, such as magnesium carbonate, magnesium oxalate, magnesium citrate, etc.; The surfactant is mainly a non-ionic high molecular polymer; The titanium-containing chloride is mainly titanium tetrachloride, titanium oxychloride or titanium trichloride; The organic alcohol is a liquid straight-chain alkyl alcohol or an isomeric alcohol thereof; The water is water obtained through water purification, wherein the heavy metal ions, iron, cobalt and nickel ions are less than 10 ppm.
4. The pure crystalline nano-sized magnesium titanate ceramic powder material according to claim 3, characterized in that: The magnesium salt precursor is one or more of magnesium carbonate, magnesium oxalate, magnesium citrate, magnesium tartrate, magnesium sulfite, and magnesium hydroxide; The titanium chloride is one or more of titanium tetrachloride, titanium trichloride, and titanium oxychloride; The surfactant is one or more of polyethylene glycol, PVP, polyacrylic acid, polyether, and F127; The organic alcohol is one or more of ethanol, methanol, propanol, isopropanol, n-butanol and benzyl alcohol.
5. The pure crystalline nano-sized magnesium titanate ceramic powder material according to claim 1, characterized in that: The containers and reaction containers for solution A and solution B are glass containers, organic plastic containers or ceramic enamel containers, including one or more of glass flasks, glass beakers, watch glasses, conical flasks, wide-mouth bottles, weighing bottles, test tubes, measuring cups, plastic beakers, ceramic reactors, enamel reactors, and centrifuge tubes.
6. The pure crystalline nano-sized magnesium titanate ceramic powder material according to claim 1, characterized in that: The centrifugal speed of the centrifugal separation in step (3) is 4000-10000 rpm, and the centrifugal time each time is 5-10 minutes.
7. The pure crystalline nano-sized magnesium titanate ceramic powder material according to claim 1, characterized in that: The solvent used for washing in step (3) is one or more of water, methanol, ethanol and isopropanol.
8. The pure crystalline nano-sized magnesium titanate ceramic powder material according to claim 1, characterized in that: The temperature range selected for the drying treatment in step (3) is 70-120°C; the temperature range selected for the roasting treatment is 700-1200°C, the roasting time is 3h-10h, and the roasting adopts an air atmosphere, which requires an air compressor to continuously blow in air.
9. The pure crystalline nano-sized magnesium titanate ceramic powder material according to claim 1, characterized in that: The equipment selected for gaseous grinding of solid powder samples is a jet mill with a power of 5KW. The powder products are collected by a cyclone separator. The air compressor has a power of 80KW and provides 10.0Mpa compressed air for grinding.