CN110745827B - Preparation method of two-dimensional flaky SiC material - Google Patents
Preparation method of two-dimensional flaky SiC material Download PDFInfo
- Publication number
- CN110745827B CN110745827B CN201810821990.3A CN201810821990A CN110745827B CN 110745827 B CN110745827 B CN 110745827B CN 201810821990 A CN201810821990 A CN 201810821990A CN 110745827 B CN110745827 B CN 110745827B
- Authority
- CN
- China
- Prior art keywords
- sic material
- preparation
- dimensional
- sic
- composite powder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000000463 material Substances 0.000 title claims abstract description 46
- 238000002360 preparation method Methods 0.000 title claims abstract description 23
- 239000003575 carbonaceous material Substances 0.000 claims abstract description 30
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 29
- 239000006185 dispersion Substances 0.000 claims abstract description 25
- 239000000843 powder Substances 0.000 claims abstract description 24
- 238000006243 chemical reaction Methods 0.000 claims abstract description 20
- 239000002131 composite material Substances 0.000 claims abstract description 20
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 19
- 239000002243 precursor Substances 0.000 claims abstract description 18
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 16
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 16
- 239000010703 silicon Substances 0.000 claims abstract description 16
- 238000001035 drying Methods 0.000 claims abstract description 14
- 238000005245 sintering Methods 0.000 claims abstract description 7
- 238000001879 gelation Methods 0.000 claims abstract description 6
- 230000003301 hydrolyzing effect Effects 0.000 claims abstract description 3
- 238000003756 stirring Methods 0.000 claims description 25
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 17
- 239000007788 liquid Substances 0.000 claims description 13
- 238000000034 method Methods 0.000 claims description 13
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 10
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 10
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 10
- 239000007800 oxidant agent Substances 0.000 claims description 10
- 230000008569 process Effects 0.000 claims description 10
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 claims description 9
- 238000009830 intercalation Methods 0.000 claims description 9
- 230000002687 intercalation Effects 0.000 claims description 9
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 8
- 239000006004 Quartz sand Substances 0.000 claims description 8
- 238000009768 microwave sintering Methods 0.000 claims description 8
- 238000002156 mixing Methods 0.000 claims description 8
- 229910017604 nitric acid Inorganic materials 0.000 claims description 8
- 230000001590 oxidative effect Effects 0.000 claims description 7
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Substances OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 7
- WFDIJRYMOXRFFG-UHFFFAOYSA-N Acetic anhydride Chemical compound CC(=O)OC(C)=O WFDIJRYMOXRFFG-UHFFFAOYSA-N 0.000 claims description 6
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 6
- 238000010438 heat treatment Methods 0.000 claims description 6
- 239000000138 intercalating agent Substances 0.000 claims description 6
- VLTRZXGMWDSKGL-UHFFFAOYSA-N perchloric acid Chemical compound OCl(=O)(=O)=O VLTRZXGMWDSKGL-UHFFFAOYSA-N 0.000 claims description 6
- KMUONIBRACKNSN-UHFFFAOYSA-N potassium dichromate Chemical compound [K+].[K+].[O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O KMUONIBRACKNSN-UHFFFAOYSA-N 0.000 claims description 6
- 239000012286 potassium permanganate Substances 0.000 claims description 4
- 239000002904 solvent Substances 0.000 claims description 4
- 229910021578 Iron(III) chloride Inorganic materials 0.000 claims description 3
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 3
- 239000003795 chemical substances by application Substances 0.000 claims description 3
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 claims description 3
- 235000006408 oxalic acid Nutrition 0.000 claims description 3
- 125000003158 alcohol group Chemical group 0.000 claims description 2
- 239000003054 catalyst Substances 0.000 claims description 2
- 230000015572 biosynthetic process Effects 0.000 abstract description 7
- 238000003786 synthesis reaction Methods 0.000 abstract description 7
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 abstract description 5
- 239000002245 particle Substances 0.000 abstract description 3
- 238000010304 firing Methods 0.000 abstract description 2
- 229910010271 silicon carbide Inorganic materials 0.000 description 43
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 42
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 10
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 9
- 239000013078 crystal Substances 0.000 description 8
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 7
- 238000005265 energy consumption Methods 0.000 description 7
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 6
- 229910002804 graphite Inorganic materials 0.000 description 6
- 239000010439 graphite Substances 0.000 description 6
- 239000011259 mixed solution Substances 0.000 description 6
- 239000002135 nanosheet Substances 0.000 description 6
- 238000003825 pressing Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 239000000243 solution Substances 0.000 description 5
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 238000002441 X-ray diffraction Methods 0.000 description 3
- 239000003245 coal Substances 0.000 description 3
- 239000008367 deionised water Substances 0.000 description 3
- 229910021641 deionized water Inorganic materials 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 235000019441 ethanol Nutrition 0.000 description 3
- 238000000227 grinding Methods 0.000 description 3
- 239000002086 nanomaterial Substances 0.000 description 3
- 239000000523 sample Substances 0.000 description 3
- 238000001878 scanning electron micrograph Methods 0.000 description 3
- 238000002791 soaking Methods 0.000 description 3
- 239000010902 straw Substances 0.000 description 3
- 241000196324 Embryophyta Species 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 229910052681 coesite Inorganic materials 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 229910052906 cristobalite Inorganic materials 0.000 description 2
- 230000005284 excitation Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- -1 silicate ester Chemical class 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 229910052682 stishovite Inorganic materials 0.000 description 2
- 238000001308 synthesis method Methods 0.000 description 2
- 229910052905 tridymite Inorganic materials 0.000 description 2
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- 241000209140 Triticum Species 0.000 description 1
- 235000021307 Triticum Nutrition 0.000 description 1
- 229910021431 alpha silicon carbide Inorganic materials 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 235000013339 cereals Nutrition 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005485 electric heating Methods 0.000 description 1
- RSIHJDGMBDPTIM-UHFFFAOYSA-N ethoxy(trimethyl)silane Chemical compound CCO[Si](C)(C)C RSIHJDGMBDPTIM-UHFFFAOYSA-N 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 239000007952 growth promoter Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000005272 metallurgy Methods 0.000 description 1
- 239000002055 nanoplate Substances 0.000 description 1
- 239000002070 nanowire Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 230000001699 photocatalysis Effects 0.000 description 1
- 238000007146 photocatalysis Methods 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 239000012779 reinforcing material Substances 0.000 description 1
- 238000003980 solgel method Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- LFQCEHFDDXELDD-UHFFFAOYSA-N tetramethyl orthosilicate Chemical compound CO[Si](OC)(OC)OC LFQCEHFDDXELDD-UHFFFAOYSA-N 0.000 description 1
- 235000012431 wafers Nutrition 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/90—Carbides
- C01B32/914—Carbides of single elements
- C01B32/956—Silicon carbide
- C01B32/963—Preparation from compounds containing silicon
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/03—Particle morphology depicted by an image obtained by SEM
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/20—Particle morphology extending in two dimensions, e.g. plate-like
Abstract
The invention relates to a preparation method of a two-dimensional flaky SiC material, belonging to the technical field of microwave synthesis. The preparation method of the two-dimensional flaky SiC material comprises the following steps: 1) performing gelation treatment on a dispersion system mainly composed of sol and an expanded carbon material to obtain precursor gel; the sol is silica sol or is obtained by hydrolyzing and condensing a silicon source; 2) drying the obtained precursor gel to obtain composite powder; 3) and (3) reacting and sintering the obtained composite powder to obtain the composite powder. According to the preparation method of the two-dimensional flaky SiC material, the expanded carbon material is used as a carbon source, the silica sol particles in the dispersion system are distributed on the surface of the lamellar structure of the expanded carbon material and are also distributed in a flaky shape, the two-dimensional flaky SiC material with the nano flaky structure can be obtained after the firing reaction, the two-dimensional flaky SiC material has the advantages of larger specific surface area and easier dispersion, and the interface wettability of the two-dimensional flaky SiC material in the composite material can be improved by virtue of the lamellar structure.
Description
Technical Field
The invention relates to a preparation method of a two-dimensional flaky SiC material, belonging to the technical field of microwave synthesis.
Background
SiC has high strength, high hardness, high elastic modulus and good chemical stability, and is widely used as a reinforcing material for abrasive tools, refractory materials, metallurgy, high-temperature structural ceramics and composite materials. The SiC has excellent high-temperature electrical property and can be used as an electric heating body material of high-temperature equipment. Low dimensional SiC such as nanoplates, nanowires, and wafers can be used in the fields of photocatalysis, field effect transistors, atom probes, and high-end military.
At present, the most common SiC synthesis methods are still based on the carbothermic reduction principle proposed by Acheson in 1893, namely: heating by graphite resistance at 1400-2700 deg.C to obtain SiO2Reacts with C to generate SiC crystal. The crystal synthesis method has high energy consumption and long period, and moreover, an open-air production mode is adopted, so that the pollution is serious; the obtained SiC has low purity, the crystal form distribution is complicated along with the change of the synthesis temperature, and the application is limited.
In the prior art, Chinese patent application with application publication No. CN1401828A discloses a preparation method of silicon carbide flaky crystal, which is to use SiO2The powder and the C powder are mixed according to the proportion of (1-3) to (3-1), the heat preservation is carried out for 1-2 h at the temperature of 1400-2000 ℃, the beta-SiC crystal whisker is synthesized, and then the crystal whisker and SiO are mixed2The powder, the C powder and the growth promoter are mixed according to the proportion of (5-10): (10-30): (5-10): 0.1-2.0), and the mixture is kept at 1900-2250 ℃ for 1-2 hours to synthesize alpha-SiC flaky crystals; the SiC crystal grains prepared by the method are flaky, have good dispersibility and more regular shapes, but need two times of high-temperature treatment, and still have the problems of complex process and high energy consumption.
Disclosure of Invention
The invention aims to provide a preparation method of a two-dimensional flaky SiC material with simple process and low energy consumption.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
a preparation method of a two-dimensional flaky SiC material comprises the following steps: 1) performing gelation treatment on a dispersion system mainly composed of sol and an expanded carbon material to obtain precursor gel; the sol is silica sol or is obtained by hydrolyzing and condensing a silicon source; 2) drying the obtained precursor gel to obtain composite powder; 3) and (3) reacting and sintering the obtained composite powder to obtain the composite powder.
The preparation method of the two-dimensional flaky SiC material has the advantages of simple process and low energy consumption, the expanded carbon material is used as a carbon source, the silica sol particles in a dispersion system are distributed on the surface of the lamellar structure of the expanded carbon material and are also distributed in a flaky shape, and the two-dimensional flaky SiC material can be obtained after sintering reaction, has a nano lamellar structure, is larger in specific surface area and easier to disperse, and can reduce the degree of overall toughness reduction of the material in the composite material due to the lamellar structure. In addition, in the abrasive grinding process, the SiC nano sheets with the sheet structures can reduce damage of edges and corners of the SiC nano sheets to workpieces, and the grinding luminosity and the flatness of the SiC nano sheets are enhanced. The two-dimensional sheet SiC prepared by the preparation method is especially suitable for environments with special requirements on performance, such as the fields of high-end grinding materials and functional ceramics, and therefore has wide market application prospect.
Preferably, the silicon source is at least one of silicate ester, polysiloxane and silsesquioxane. More preferably, the silicate is at least one of ethyl orthosilicate, methyl orthosilicate and trimethylethoxysilane.
Preferably, the expanded carbon material is expanded graphite.
Preferably, the method for producing an expanded carbon material includes: and (3) carrying out intercalation treatment on the carbon source, and then heating and expanding by microwave to obtain the carbon source. The carbon source comprises at least one of graphite, activated carbon, coal and plant straws.
Preferably, the microwave heating temperature is 600-1000 ℃ and the time is 30-120 s. The intercalation process and the microwave rapid expansion enable the carbon source to form a lamellar structure.
Preferably, the intercalation treatment is to soak the carbon source in a solution containing an oxidant and/or an intercalating agent for 1-10 min.
Preferably, the oxidizing agent is a strong oxidizing agent. The oxidant is one or a combination of more of potassium permanganate, potassium dichromate, perchloric acid and concentrated nitric acid.
Preferably, the intercalation agent is one or a mixture of more of concentrated sulfuric acid, concentrated nitric acid, phosphoric acid, acetic anhydride, oxalic acid and ferric chloride.
For the concentrated nitric acid which can be used as an intercalating agent and an oxidizing agent, the carbon source is only required to be soaked in the concentrated nitric acid when the intercalation treatment is carried out.
Preferably, when the carbon source contains plant straws, the intercalation agent at least comprises concentrated sulfuric acid.
Preferably, the molar ratio of C to Si in the precursor gel is 2-6: 1. The excessive C can ensure that the silica sol can be attached to the surface of the carbon source and distributed in a sheet shape in the sol-gel process.
The preparation method of the dispersion system comprises the following steps: mixing the expanded carbon material with a solvent, water and a catalyst to obtain a dispersion liquid, adding a silicon source into the dispersion liquid under the condition of continuous stirring, and continuously stirring until the silicon source becomes sol to obtain the silicon-based carbon material sol. After the silicon source is added into the dispersion system, the silicon source is continuously hydrolyzed and condensed, and the sol particles are polymerized.
Preferably, the solvent is an alcohol. Further preferably, the alcohol is at least one of ethanol and methanol.
The gelation treatment is to stir the dispersion system under heating condition, then add ammonia water, and continue stirring. And in the gelation treatment process, adding ammonia water until the pH value of the system is 8-11, and then continuously stirring.
Preferably, the total stirring time after the silicon source is added and before the ammonia water is added is 2-7 hours.
The mass fraction of the ammonia water is 5-28%.
Preferably, the temperature of the system is kept at 35-60 ℃ in the process of adding the silicon source. Preferably, the temperature of the system is kept at 35-60 ℃ during the stirring process after the silicon source is added into the dispersion system.
Preferably, the time for continuously stirring after adding the ammonia water is 50-70 min.
Preferably, the drying temperature is 50-120 ℃. The drying time is 5-60 min.
Further preferably, the drying is microwave drying.
The reaction sintering is carried out under the anaerobic condition. Preferably, the reactive firing is microwave sintering. The microwave sintering utilizes the rapid integral heat effect of the microwave integral field to realize the rapid synthesis and the directional growth of the SiC nano-sheets.
Preferably, the temperature of the microwave sintering is 950-1350 ℃, and the time is 10-60 min.
More preferably, the reactive sintering is performed by pressing the composite powder into a green compact, embedding the green compact into quartz sand, and performing microwave sintering. As only the material can be coupled with the microwave, a gradient temperature field with the temperature decreasing and with the sample as the high-temperature center and the heat radiated outwards is formed in the microwave sintering reaction zone in the whole reaction process. In the gradient temperature field, the quartz sand close to the material approaches or exceeds the melting point thereof, and softening and flowing occur to form a closed environment around the sample area. The closed environment is beneficial to the uniformity of a material thermal field and the excitation of a microwave plasma effect, and the time for synthesizing the SiC nano-sheets can be reduced to a great extent. The quartz sand adopted during microwave sintering has high purity, and the high-purity quartz sand has good microwave permeability.
The pressing pressure is 4-10 MPa. And the pressure maintaining time of the pressing is 30-120 s.
Drawings
FIG. 1 is an SEM image of a two-dimensional sheet-like SiC material of example 1;
FIG. 2 is an XRD pattern of the two-dimensional plate-like SiC material of example 1;
FIG. 3 is an SEM image of a two-dimensional sheet-like SiC material of example 2;
FIG. 4 is an XRD pattern of the two-dimensional plate-like SiC material of example 2;
FIG. 5 is an SEM image of a two-dimensional sheet-like SiC material of example 3;
figure 6 is an XRD pattern of the two-dimensional plate-like SiC material of example 3.
Detailed Description
The technical solution of the present invention will be further described with reference to the following embodiments.
In each example, the mass fraction of the concentrated sulfuric acid is 98%, and the mass fraction of the concentrated nitric acid is 98%.
Example 1
The preparation method of the two-dimensional sheet-shaped SiC material of the embodiment includes the following steps:
1) mixing graphite and coal according to the mass ratio of 3:1 to obtain a carbon source; mixing 5g of potassium permanganate, 50mL of concentrated sulfuric acid, 50mL of 36% acetic acid and 6g of oxalic acid to obtain a mixed solution of a strong oxidant and an intercalating agent;
then adding a carbon source into the mixed solution and soaking for 1min to obtain an expandable carbon material;
2) putting the expandable carbon material obtained in the step 1) into an industrial microwave oven, and treating for 30s at 1000 ℃ to obtain an expanded carbon material;
3) placing the reaction vessel in a constant-temperature water bath kettle at 35 ℃, and then adding 4.8g of an expanded carbon material, 100mL of deionized water, 70mL of absolute ethyl alcohol and 6g of citric acid into the reaction vessel and stirring for 30min to obtain a dispersion liquid; taking 46mL of tetraethoxysilane according to the molar ratio of C in the expanded carbon material to Si in the tetraethoxysilane being 2:1, adding the tetraethoxysilane into the dispersion liquid in a reaction container (placed in a 35 ℃ constant-temperature water bath kettle) while continuously stirring the dispersion liquid, continuously stirring for 7 hours, then adding ammonia water with the mass fraction of 28% into the reaction container (placed in the 35 ℃ constant-temperature water bath kettle) to adjust the pH value of the solution to 11, and continuously stirring for 60 minutes to obtain precursor gel;
4) taking out the precursor gel from a constant-temperature water bath kettle at 35 ℃, placing the precursor gel in a microwave drying box, and drying for 60min at 80 ℃ to obtain composite powder;
5) pressing the composite powder obtained in the step 4) for 120s under the pressure of 4MPa by using a powder tablet press to obtain a green body F;
6) and burying the green body F in quartz sand, and burying and burning in an industrial microwave oven at 1150 ℃ for 20min to obtain the two-dimensional flaky SiC material.
The two-dimensional sheet-like SiC material obtained in this example was subjected to SEM test and XRD test, and the results are shown in fig. 1 and fig. 2, respectively. As can be seen from fig. 1 and 2, the two-dimensional sheet-like SiC material prepared by the preparation method of this example has a two-dimensional sheet-like nanostructure.
Example 2
The preparation method of the two-dimensional sheet-shaped SiC material of the embodiment includes the following steps:
1) mixing coal and wheat straws according to the mass ratio of 3:1 to obtain a carbon source; mixing 5g of potassium dichromate, 50mL of concentrated nitric acid, 50mL of 72% perchloric acid, 50mL of concentrated sulfuric acid and 6g of phosphoric acid to obtain a mixed solution of a strong oxidant and an intercalating agent;
then adding a carbon source into the mixed solution and soaking for 5min to obtain an expandable carbon material;
2) putting the expandable carbon material obtained in the step 1) into an industrial microwave oven, and treating for 120s at 600 ℃ to obtain an expanded carbon material;
3) placing the reaction vessel in a constant-temperature water bath kettle at 60 ℃, and then adding 14.4g of an expanded carbon material, 100mL of deionized water, 70mL of absolute ethyl alcohol and 6g of citric acid into the reaction vessel and stirring for 30min to obtain a dispersion liquid; taking 46mL of tetraethoxysilane according to the molar ratio of C in the expanded carbon material to Si in the tetraethoxysilane being 6:1, adding the tetraethoxysilane into the dispersion liquid in a reaction container (placed in a constant-temperature water bath kettle at 60 ℃) while continuously stirring the dispersion liquid, continuously stirring for 3 hours, then adding ammonia water with the mass fraction of 20 percent into the reaction container (placed in the constant-temperature water bath kettle at 60 ℃) to adjust the pH value of the solution to 10, and continuously stirring for 70 minutes to obtain precursor gel;
4) taking out the precursor gel and the reaction container from a constant-temperature water bath kettle at 60 ℃, placing the precursor gel and the reaction container in a microwave drying box, and drying at 120 ℃ for 5min to obtain composite powder;
5) pressing the composite powder obtained in the step 4) for 30s under the pressure of 10MPa by using a powder tablet press to obtain a green body F;
6) burying the green body F in quartz sand, and burying and burning for 60min at 950 ℃ in an industrial microwave oven to obtain the two-dimensional flaky SiC material.
The two-dimensional sheet-like SiC material obtained in this example was subjected to SEM test and XRD test, and the results are shown in fig. 3 and fig. 4, respectively. As can be seen from fig. 3 and 4, the two-dimensional sheet-like SiC material prepared by the preparation method of this example has a two-dimensional sheet-like nanostructure.
Example 3
The preparation method of the two-dimensional sheet-shaped SiC material of the embodiment includes the following steps:
1) mixing graphite and activated carbon according to the mass ratio of 3:1 to obtain a carbon source; mixing 5g of potassium permanganate, 50mL of concentrated sulfuric acid, 50mL of 36% acetic acid and 6g of ferric chloride to obtain a mixed solution of a strong oxidant and an intercalating agent;
then adding a carbon source into the mixed solution and soaking for 10min to obtain an expandable carbon material;
2) putting the expandable carbon material obtained in the step 1) into an industrial microwave oven, and treating for 40s at 900 ℃ to obtain an expanded carbon material;
3) placing the reaction vessel in a constant-temperature water bath kettle at 55 ℃, and then adding 7.2g of an expanded carbon material, 100mL of deionized water, 70mL of absolute ethyl alcohol and 6g of citric acid into the reaction vessel and stirring for 30min to obtain a dispersion liquid; taking 46mL of tetraethoxysilane according to the molar ratio of C in the expanded carbon material to Si in the tetraethoxysilane being 3:1, adding the tetraethoxysilane into the dispersion liquid in the reaction container (placed in a 55 ℃ constant-temperature water bath kettle) while continuously stirring the dispersion liquid, continuously stirring for 2 hours, then adding ammonia water with the mass fraction of 5% into the reaction container (placed in the 55 ℃ constant-temperature water bath kettle) to adjust the pH value of the solution to 8, and continuously stirring for 50 minutes to obtain precursor gel;
4) taking out the precursor gel from a constant-temperature water bath kettle at 55 ℃, placing the precursor gel in a microwave drying box, and drying the precursor gel for 30min at 110 ℃ to obtain composite powder;
5) pressing the composite powder obtained in the step 4) for 80s under the pressure of 6MPa by using a powder tablet press to obtain a green body F;
6) burying the green body F in quartz sand, and burying and burning for 10min at 1350 ℃ in an industrial microwave oven to obtain the two-dimensional flaky SiC material.
The two-dimensional sheet-like SiC material obtained in this example was subjected to SEM test and XRD test, and the results are shown in fig. 5 and fig. 6, respectively. As can be seen from fig. 5 and 6, the two-dimensional sheet-like SiC material prepared by the preparation method of this example has a two-dimensional sheet-like nanostructure.
In the preparation method of the two-dimensional flaky SiC material in the specific embodiment, a microwave rapid expansion technology, a microwave rapid drying technology and a microwave rapid synthesis technology are adopted, the excellent microwave coupling capacity (the relative dielectric constants of graphite and silicon carbide are 14 and 10.9 respectively) of raw materials and products and the plasma excitation effect of an intermediate gas product are combined, the microwave characteristics (coupling thermal effect and plasma thermal effect) are fully utilized, the microwave rapid synthesis is carried out, the rapid synthesis and preparation of SiC nanosheets are realized, the production flow of the two-dimensional flaky SiC material is greatly simplified, the production period is shortened, the energy consumption is greatly reduced (the energy consumption is reduced by more than 80% compared with the traditional industrial energy consumption), and the pollution to the environment is reduced; in addition, the process flow is simple and clear, and the method is very suitable for large-scale industrial automatic control and rapid production.
Claims (6)
1. A preparation method of a two-dimensional flaky SiC material is characterized by comprising the following steps: the method comprises the following steps:
1) performing gelation treatment on a dispersion system mainly composed of sol and an expanded carbon material to obtain precursor gel; the sol is obtained by hydrolyzing and condensing a silicon source; the molar ratio of C to Si in the precursor gel is 2-6: 1;
2) drying the obtained precursor gel to obtain composite powder;
3) reacting and sintering the obtained composite powder to obtain the composite powder; the reaction sintering is to press the composite powder into a green body and embed the green body into quartz sand for microwave sintering; the expanded carbon material is a sheet material, and the preparation method of the expanded carbon material comprises the following steps: carrying out intercalation treatment on a carbon source, and then heating and expanding by microwave to obtain the carbon source; the temperature of the microwave sintering is 950-1350 ℃, and the time is 10-60 min.
2. The method for producing a two-dimensional sheet-like SiC material according to claim 1, characterized in that: the intercalation treatment is to soak a carbon source in a solution containing an oxidant and/or an intercalating agent for 1-10 min; the oxidant is one or a combination of more of potassium permanganate, potassium dichromate, perchloric acid and concentrated nitric acid; the intercalation agent is one or a combination of more of concentrated sulfuric acid, concentrated nitric acid, phosphoric acid, acetic anhydride, oxalic acid and ferric chloride.
3. The method for producing a two-dimensional sheet-like SiC material according to claim 1, characterized in that: the preparation method of the dispersion system comprises the following steps: mixing the expanded carbon material with a solvent, water and a catalyst to obtain a dispersion liquid, adding a silicon source into the dispersion liquid under the condition of continuous stirring, and continuously stirring until the silicon source becomes sol to obtain the silicon-based carbon material; the solvent is an alcohol.
4. A method for producing a two-dimensional sheet-like SiC material according to claim 3, characterized in that: the gelation treatment is to stir the dispersion system under heating condition, then add ammonia water, and continue stirring.
5. The method for producing a two-dimensional sheet-like SiC material according to claim 3 or 4, characterized in that: and in the process of adding the silicon source, keeping the temperature of the system at 35-60 ℃.
6. The method for producing a two-dimensional sheet-like SiC material according to claim 4, characterized in that: and adding ammonia water and then continuing stirring for 50-70 min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810821990.3A CN110745827B (en) | 2018-07-24 | 2018-07-24 | Preparation method of two-dimensional flaky SiC material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810821990.3A CN110745827B (en) | 2018-07-24 | 2018-07-24 | Preparation method of two-dimensional flaky SiC material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110745827A CN110745827A (en) | 2020-02-04 |
| CN110745827B true CN110745827B (en) | 2022-02-15 |
Family
ID=69275587
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810821990.3A Active CN110745827B (en) | 2018-07-24 | 2018-07-24 | Preparation method of two-dimensional flaky SiC material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110745827B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113439869A (en) * | 2020-03-26 | 2021-09-28 | 深圳市合元科技有限公司 | Aerosol-generating article for use with an aerosol-generating device |
| CN111441087B (en) * | 2020-04-02 | 2021-05-25 | 吉林大学 | Preparation method of 6H-silicon carbide two-dimensional single crystal nanosheet |
| CN111424312B (en) * | 2020-04-03 | 2021-08-03 | 吉林大学 | Preparation method of 3C-silicon carbide two-dimensional single crystal nanosheet |
| CN112062573B (en) * | 2020-09-11 | 2022-09-06 | 郑州大学 | Sheet SiC-SiO2 composite material and preparation method thereof |
| CN114477185B (en) * | 2020-10-28 | 2023-07-07 | 中国科学院理化技术研究所 | beta-SiC with lamellar structure and preparation method thereof |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1131343C (en) * | 2001-08-24 | 2003-12-17 | 中国科学院金属研究所 | Method for mfg. plate crystal of silicon carbide |
| CN101077776B (en) * | 2007-03-26 | 2010-12-08 | 武汉工程大学 | Method for preparing silicon carbide products from expanded graphite or flexible graphite paper |
| CN102730687B (en) * | 2012-07-05 | 2014-04-16 | 浙江理工大学 | Preparation method of SiC nanowire with expandable graphite as carbon source |
| JP6078330B2 (en) * | 2012-12-21 | 2017-02-08 | 昭和電工株式会社 | Silicon carbide single crystal manufacturing crucible, silicon carbide single crystal manufacturing apparatus, and silicon carbide single crystal manufacturing method |
| CN104328478B (en) * | 2014-08-14 | 2016-08-31 | 郑州航空工业管理学院 | A kind of preparation method of SiC whisker |
| CN105777124B (en) * | 2016-02-29 | 2018-03-30 | 中原工学院 | A kind of preparation method of graphene growth in situ silicon carbide nano material |
-
2018
- 2018-07-24 CN CN201810821990.3A patent/CN110745827B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110745827A (en) | 2020-02-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110745827B (en) | Preparation method of two-dimensional flaky SiC material | |
| US10364193B2 (en) | Method for synthesizing high-purity ultrafine ZrC—SiC composite powder | |
| CN104556022A (en) | Method for preparing expanded microcrystal graphite material from microcrystal graphite | |
| CN113718370B (en) | Preparation method of hollow silicon carbide fiber | |
| CN104387073B (en) | The method of ultra-fine high tenacity thyrite is manufactured based on reaction sintering | |
| CN108033801A (en) | Silicon nitride nanowire reinforced porous silicon nitride composite material and preparation method thereof | |
| CN107721429A (en) | Zirconium carbide silicon carbide composite powder body material and preparation method thereof | |
| CN103979507A (en) | Method for preparing spherical aluminum nitride powder under assistance of high atmospheric pressure and fluoride additive | |
| CN106629732A (en) | Preparation method of nano ZrC-SiC composite powder | |
| CN107697916B (en) | Preparation method of metal-silicon-carbon compound nano powder | |
| CN111762785A (en) | Method for preparing granular silicon carbide by double-frequency microwave | |
| CN105000562A (en) | Preparation method of silicon carbide hollow sphere | |
| CN106542829B (en) | A kind of preparation and application of silicon carbide whisker/silicon-carbide particle composite granule | |
| CN107311177B (en) | A kind of carbide-graphite alkene composite granule and preparation method thereof | |
| CN112142020B (en) | Method for preparing aluminum nitride fiber by carbothermic reduction | |
| CN113264774A (en) | SiC crystal synthesized by seed induced microwave and preparation method thereof | |
| CN114685170B (en) | Method for synthesizing silicon carbide by microwave flash firing | |
| CN110791810B (en) | Preparation method of silicon carbide crystal | |
| CN114477184B (en) | Preparation method of silicon carbide powder | |
| CN112694336B (en) | Preparation method of high-purity alpha-phase silicon nitride fibrofelt | |
| CN103570359A (en) | Production process for submicron silicon nitride (Si3N4) ceramic powder | |
| CN114408910A (en) | Preparation method of graphene anti-skid wear-resistant modified novel material | |
| CN107188181A (en) | A kind of low temperature synthesizes the method and silicon carbide products of high-specific-surface mesoporous carborundum | |
| CN112759401A (en) | Method for preparing high-entropy boron ceramic surface material by microwave sintering | |
| CN112607715B (en) | Preparation method of high-purity alpha-phase silicon nitride nanowire |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |