A kind of preparation method of boron nitride nanotube

Abstract

The invention relates to a preparation method of a boron nitride nano tube. The method comprises the steps of carrying out ball milling on metal magnesium powder and low-cost boron oxide as a boron source instead of B to prepare a precursor; preparing the pure-phase boron nitride nano tube with a high length-diameter ratio in high-temperature ammonia gas atmosphere in a vertical induction heating furnace. According to the invention, used raw materials are boron oxide powder and metal magnesium powder which both belong to ordinary chemical raw materials which are industrially produced, are low and easily available and non-toxic; the synthesized boron nitride nano tube is high in purity, large in length-diameter ratio, little in defect and uniform in morphology; the method is non-toxic, reliable and suitable for synthesis on large scale; the prepared boron nitride nano tube can be applied to the fields of nanoelectronics, electronic heat dissipation elements, solid / liquid lubricants, nano composite materials, high-temperature structure members and the like.

Description

technical field

[0001] The technical solution of the invention relates to the technical synthesis field of hexagonal boron nitride nanomaterials, specifically a method for synthesizing hexagonal boron nitride nanotubes with a pure phase and high aspect ratio. Background technique

[0002] The molecular formula of hexagonal boron nitride crystal is BN, which is a graphite-like layered structure material composed of nitrogen (N) atoms and boron (B) atoms. It has excellent electrical insulation, high temperature resistance, oxidation resistance, and chemical resistance. Corrosion and high thermal conductivity are widely used in high-tech fields such as machinery, metallurgy, electronics, and aerospace.

[0003] Boron nitride nanotubes have a one-dimensional nano-hollow structure similar to carbon nanotubes, and are formed by curling one or more layers of hexagonal boron nitride layered structures. Boron nitride nanotubes have mechanical properties and thermal conductivity comp...

Examples

Embodiment 1

[0028] (1) Mix boron oxide and metal magnesium powder according to the molar ratio of 1:1, put them in an agate jar, adopt the method of alternating forward and reverse operation, ball mill for 48 hours, take out, and obtain a uniformly mixed solid powder with a particle size of about 2 -5 microns;

[0029] (2) The solid powder obtained in step (1) was placed in a vertical vacuum radio frequency induction heating furnace, and the temperature was raised in an argon atmosphere at a heating rate of 50° C. per minute, and a gas flow rate of 200 ml / min. When the temperature rose to 1350° C., feed 300 ml / min of ammonia gas, keep warm for 3 hours, and naturally cool down to room temperature in an argon atmosphere with an air velocity of 200 ml / min to obtain a white solid.

[0030] (3) The white solid obtained in step (2) was soaked in 0.1N nitric acid aqueous solution for 5 hours, and then washed 5 times with deionized water.

[0031] (4) Put the white solid obtained in step (4) int...

Embodiment 2

[0034] Change the reaction temperature of step (2) in Example 1 to 1500°C, and other operations are the same as in Example 1 to obtain boron nitride nanotubes. SEM analysis shows that the diameter of the obtained boron nitride nanotubes is about 80-100 nanometers, about 10 microns in length, and about 100 aspect ratios.

Embodiment 3

[0036] Change the reaction temperature of step (2) in Example 1 to 1600 ° C, and other operations are the same as in Example 1 to obtain boron nitride nanotubes. SEM analysis shows that the obtained boron nitride nanotubes have a diameter of about 100 nanometers, about 10 microns in length, and an aspect ratio of about 100.

technical field

[0001] The technical solution of the invention relates to the technical synthesis field of hexagonal boron nitride nanomaterials, specifically a method for synthesizing hexagonal boron nitride nanotubes with a pure phase and high aspect ratio. Background technique

[0002] The molecular formula of hexagonal boron nitride crystal is BN, which is a graphite-like layered structure material composed of nitrogen (N) atoms and boron (B) atoms. It has excellent electrical insulation, high temperature resistance, oxidation resistance, and chemical resistance. Corrosion and high thermal conductivity are widely used in high-tech fields such as machinery, metallurgy, electronics, and aerospace.

[0003] Boron nitride nanotubes have a one-dimensional nano-hollow structure similar to carbon nanotubes, and are formed by curling one or more layers of hexagonal boron nitride layered structures. Boron nitride nanotubes have mechanical properties and thermal conductivity comp...

Examples

Embodiment 1

[0028] (1) Mix boron oxide and metal magnesium powder according to the molar ratio of 1:1, put them in an agate jar, adopt the method of alternating forward and reverse operation, ball mill for 48 hours, take out, and obtain a uniformly mixed solid powder with a particle size of about 2 -5 microns;

[0029] (2) The solid powder obtained in step (1) was placed in a vertical vacuum radio frequency induction heating furnace, and the temperature was raised in an argon atmosphere at a heating rate of 50° C. per minute, and a gas flow rate of 200 ml / min. When the temperature rose to 1350° C., feed 300 ml / min of ammonia gas, keep warm for 3 hours, and naturally cool down to room temperature in an argon atmosphere with an air velocity of 200 ml / min to obtain a white solid.

[0030] (3) The white solid obtained in step (2) was soaked in 0.1N nitric acid aqueous solution for 5 hours, and then washed 5 times with deionized water.

[0031] (4) Put the white solid obtained in step (4) int...

Embodiment 2

[0034] Change the reaction temperature of step (2) in Example 1 to 1500°C, and other operations are the same as in Example 1 to obtain boron nitride nanotubes. SEM analysis shows that the diameter of the obtained boron nitride nanotubes is about 80-100 nanometers, about 10 microns in length, and about 100 aspect ratios.

Embodiment 3

[0036] Change the reaction temperature of step (2) in Example 1 to 1600 ° C, and other operations are the same as in Example 1 to obtain boron nitride nanotubes. SEM analysis shows that the obtained boron nitride nanotubes have a diameter of about 100 nanometers, about 10 microns in length, and an aspect ratio of about 100.

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