Method for preparing nano microcapsule of shell-core structure from supercritical fluid

Abstract

The invention relates to a preparation method of a nano microcapsule of an energetic material by using supercritical CO2 as an anti-solvent, an atomizing medium and a drying medium. A series of problems that the cladding is not uniform, cladding particle sizes are too large, the distribution range of the particle sizes is wide, the process operation is complicated, the application is limited, the environment is polluted, and the like, and which exist in an existing technical method in which the micronization is carried out first and then the cladding is carried out are mainly solved. According to the method, by using the supercritical CO2 as the anti-solvent, the atomizing medium and the drying medium, and based on the supercritical principle that the atomization is carried out first and then the crystallization is carried out, after a solution is atomized through a spray nozzle, a crystal nucleus is formed and grows inside a fog drop; a molecular chain of a cladding material collapses towards the interior of the fog drop; as the sum of the nucleation and growth times of a crystal is less than the collapsing time of the molecular chain, the crystalline particle of the energetic material is tightly enwrapped by the cladding material; and the nano microcapsule of the shell-core structure is formed. By using the method, a micronization technique and a cladding technique are integrated; a preparation process is accomplished at one fling; the subsequent treatment is not needed; the production efficiency is high; the preparation quality of the microcapsule is good; and the sphericity of the particle is good.

Description

technical field [0001] The invention relates to a method for preparing nano-microcapsules with a "shell-core" structure from a supercritical fluid, in particular to a method using supercritical CO 2 Preparation method of nano-microcapsules of energetic material as anti-solvent, atomization medium and drying medium. Background technique [0002] Solid propellants play a very important role in the development of aerospace and missiles. Most of the high-energy energetic materials contained in solid propellants (such as HMX, CL-20, LLM-105, etc.) have high energy but high mechanical sensitivity, which brings great challenges to the development, use, storage, and transportation of propellants. Here comes the problem of unsafety and poor compatibility between propellant components. Therefore, high energy, low vulnerability, and insensitivity of energetic materials are one of the main goals to be achieved by solid propellants. [0003] At present, there are three main methods to...

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Problems solved by technology

[0005] The purpose of the present invention is to solve the problems of uneven coating, very large coating particle size, wide particle size distribution range, complicated operation process, limited application and pollution in the existing method of preparing energetic material nano-microcapsules by first thinning and then coating. To solve a series of problems such as the environment, provide a method for preparing nano-microcapsules with "shell-core" structure by supercritical fluid

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