Dissolvent hot liquid state phase-change method for synthesizing superhard micro nano material

Abstract

The invention discloses a solvent hot-liquid phase transforming method to synthesize superhard micro-nanometer material in the chemical and new material domain, which comprises the following steps: dispersing hexagonal boron nitride, graphite mold carbon nitride or graphite powder solid particle in the liquid dielectric organic solvent, proceeding ultrasonic dispersing disposal for suspension liquid, adding fitful addictive to reduce phase-transforming needed temperature and pressure, changing boundary energy condition between solid particle and liquid dielectric, accelerating the solid particle to change to needed material.

Description

technical field [0001] The invention relates to a solvothermal liquid phase transition method for controllably synthesizing superhard micro-nano materials under mild conditions, belonging to the technical fields of chemical industry and new materials. Background technique [0002] Cubic boron nitride and diamond not only have high hardness, but also have excellent thermal conductivity and good stability. In addition, they are also ideal wide-bandgap high-temperature semiconductor materials. It has been widely used in the development of power and short-wavelength semiconductor devices and in the defense industry. On the other hand, theoretical calculations show that: carbon atoms in sp 3 C that is hybridized and bonded to a nitrogen atom 3 N 4 It has a hardness very similar to that of diamond, and has the characteristics of high resistivity, high thermal conductivity and wide energy gap. As with diamond and cubic boron nitride, it is expected that C 3 N 4 The material h...

AI Technical Summary

Problems solved by technology

The direct consequence of this phenomenon is that the input-output ratio is too high, and the product price has been high, which limits the application of these superhard materials.

[0004] In addition to the disadvantages of high input and low output caused by the use of extreme conditions, there are also the following disadvantages when using high temperature and high pressure methods to synthesize superhard materials: first, the uniformity of the reaction system is poor, resulting in poor particle size uniformity of the product; second, It is difficult to regulate the average particle size of the product in a wide range, so that the product variety is single, and it is difficult to adapt to the needs of different occasions, especially it is difficult to prepare the urgently needed superhard nanomaterials; thirdly, it is difficult to monitor the parameters of the phase transition process in real time. It leads to poor consistency of product performance; Fourth, excessive temperature and pressure accelerate the diffusion of impurity atoms, and the product is easy to be polluted

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