Method for preparing Al2O3 composite powder with uniformly dispersed carbon nanotubes by in-situ synthesis process

Abstract

The invention discloses a method for preparing Al2O3 composite powder with uniformly dispersed carbon nanotubes by an in-situ synthesis process, which comprises the following steps: proportionally preparing aluminum nitrate, nickelous nitrate and citric acid into a solution, and heating and calcining the obtained solution to initiate the combustion reaction, thereby obtaining the NiAlxO3x+1 solid solution catalyst precursor powder; and putting the obtained solid solution in a pipe furnace, introducing a gas mixture containing methane, hydrogen and nitrogen, heating to reaction temperature, reacting for some time, and cooling to obtain the Al2O3 composite powder with uniformly dispersed carbon nanotubes. The content of the catalyst nickel is controlled to control the content of the carbon nanotubes; and meanwhile, the invention solves the problem that the carbon nanotubes can not be easily dispersed in the ceramic matrix, so that the nanotubes are uniformly dispersed in the product.

Description

technical field

[0001] The invention relates to a method for preparing carbon nanotubes uniformly dispersed Al by using an in-situ synthesis method 2 o 3 The method for composite powder belongs to carbon nanotube synthesis and composite powder preparation technology. Background technique

[0002] Carbon nanotubes have attracted the attention of the scientific community since they were discovered, and the carbon-carbon sp 2 Hybridization is one of the strongest chemical bonds in nature, so CNTs have high strength and toughness. The Young's modulus of single-walled carbon nanotubes is theoretically estimated to be as high as 5TPa. The average Young's modulus of multi-walled carbon nanotubes measured by scientists is 1.8TPa, the bending strength is 14.2GPa, and the tensile strength is 100 times that of steel. The density is only 1 / 6 of that of steel, and it may be the material with the highest specific strength and specific stiffness at present. Therefore, it has great appl...

Examples

Embodiment 1

[0037] A method of in situ synthesis to prepare carbon nanotubes uniformly dispersed Al 2 o 3 The method for compound powder, comprises the following steps:

[0038] 1) According to Ni 2+ with Al 3+ The mol ratio is 1: 2, put 11.6316g of nickel nitrate hexahydrate and 30.0104g of aluminum nitrate nonahydrate into 200ml distilled water, then follow the method of citric acid monohydrate and metal ion (Ni 2+ with Al 3+ The molar ratio of the total) is 1:2, 12.6084g of citric acid monohydrate is added to the solution, and fully dissolved under the condition of a magnetic stirrer; then the resulting solution is poured into a corundum crucible and heated in a muffle furnace to Calcining at 950°C for 1 hour, the heating rate of the furnace is 10°C / min, after the calcination is completed, cool to room temperature and grind to obtain NiAl 2 o 4 Solid solution catalyst precursor powder;

[0039] 2) Take the NiAl obtained in step 1 2 o 4 The solid solution catalyst precursor pow...

Embodiment 2

[0042] The specific method and steps are the same as in Example 1, the different conditions are that the holding time of step 2) is 30min, and the final carbon nanotube content is 11.17% and uniformly dispersed Al 2 o 3 Composite powder.

[0043] pass image 3 It can be seen that the carbon nanotubes are uniformly dispersed in the matrix.

Embodiment 3

[0045] The specific method and steps are the same as in Example 1. The different conditions are that the molar ratio of the added citric acid to the metal ion is 1:1 (25.2168g), the holding time of step 2) is 30min, and finally the carbon nanotube content is 8.68% and homogeneously dispersed Al 2 o 3 Composite powder.

[0046] pass Figure 4 It can be seen that the carbon nanotubes are uniformly dispersed in the matrix, but the content of the carbon nanotubes is reduced compared with the examples 1 and 2 due to the variation of the experimental parameters.

technical field

[0001] The invention relates to a method for preparing carbon nanotubes uniformly dispersed Al by using an in-situ synthesis method 2 o 3 The method for composite powder belongs to carbon nanotube synthesis and composite powder preparation technology. Background technique

[0002] Carbon nanotubes have attracted the attention of the scientific community since they were discovered, and the carbon-carbon sp 2 Hybridization is one of the strongest chemical bonds in nature, so CNTs have high strength and toughness. The Young's modulus of single-walled carbon nanotubes is theoretically estimated to be as high as 5TPa. The average Young's modulus of multi-walled carbon nanotubes measured by scientists is 1.8TPa, the bending strength is 14.2GPa, and the tensile strength is 100 times that of steel. The density is only 1 / 6 of that of steel, and it may be the material with the highest specific strength and specific stiffness at present. Therefore, it has great appl...

Examples

Embodiment 1

[0037] A method of in situ synthesis to prepare carbon nanotubes uniformly dispersed Al 2 o 3 The method for compound powder, comprises the following steps:

[0038] 1) According to Ni 2+ with Al 3+ The mol ratio is 1: 2, put 11.6316g of nickel nitrate hexahydrate and 30.0104g of aluminum nitrate nonahydrate into 200ml distilled water, then follow the method of citric acid monohydrate and metal ion (Ni 2+ with Al 3+ The molar ratio of the total) is 1:2, 12.6084g of citric acid monohydrate is added to the solution, and fully dissolved under the condition of a magnetic stirrer; then the resulting solution is poured into a corundum crucible and heated in a muffle furnace to Calcining at 950°C for 1 hour, the heating rate of the furnace is 10°C / min, after the calcination is completed, cool to room temperature and grind to obtain NiAl 2 o 4 Solid solution catalyst precursor powder;

[0039] 2) Take the NiAl obtained in step 1 2 o 4 The solid solution catalyst precursor pow...

Embodiment 2

[0042] The specific method and steps are the same as in Example 1, the different conditions are that the holding time of step 2) is 30min, and the final carbon nanotube content is 11.17% and uniformly dispersed Al 2 o 3 Composite powder.

[0043] pass image 3 It can be seen that the carbon nanotubes are uniformly dispersed in the matrix.

Embodiment 3

[0045] The specific method and steps are the same as in Example 1. The different conditions are that the molar ratio of the added citric acid to the metal ion is 1:1 (25.2168g), the holding time of step 2) is 30min, and finally the carbon nanotube content is 8.68% and homogeneously dispersed Al 2 o 3 Composite powder.

[0046] pass Figure 4 It can be seen that the carbon nanotubes are uniformly dispersed in the matrix, but the content of the carbon nanotubes is reduced compared with the examples 1 and 2 due to the variation of the experimental parameters.

Images