Organic-inorganic composite coated metal wave-absorbing filler and preparation method thereof

Abstract

The invention belongs to the technical field of electromagnetic absorbers, and particularly relates to an organic-inorganic composite coated metal wave-absorbing filler and a preparation method thereof. According to the preparation method, a sol-gel method is utilized, micron-sized flaky carbonyl iron powder subjected to surface activation is used as a core, ammonia water is used as a catalyst, and an organic-inorganic hybrid coating layer with a nanoscale thickness is formed on the surface of the powder through hydrolysis and copolycondensation of tetraethoxysilane (TEOS) and perfluorooctyltriethoxysilane (PC 9757). Wherein the coating layer is connected with the surface of the powder by generating Si-O-Fe bonds, and Si-O-Si bonds in the hybrid coating layer and perfluorooctyl chains areinterwoven in a three-dimensional space to form a network structure. The hybrid coating layer is uniform and compact and has a good physical barrier effect, the heat resistance, the electrochemical corrosion resistance, the acid resistance and the hydrophobicity of the coated powder are obviously improved, and meanwhile good magnetic performance is achieved. The invention provides a basis for application and development of the high-performance flaky modified carbonyl iron powder.

Description

technical field [0001] The invention belongs to the technical field of electromagnetic absorbers, and relates to a magnetic metal wave-absorbing filler, in particular to an organic-inorganic composite coated metal wave-absorbing filler and a preparation method thereof, which is a development and application of high-performance modified flake carbonyl iron powder. Applications provide the basis. Background technique [0002] Modern stealth technology refers to the technology that effectively suppresses the characteristic signal of a specific target in a certain detection environment, making it difficult to be accurately detected in a certain spectral frequency range. With the development of advanced detection technology, the stealth capabilities of aircraft, missiles, ships, armor and other large military equipment need to be improved urgently. In terms of anti-radar, stealth materials usually refer to the use of coatings that can absorb radar waves, so that most of the dete...

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Problems solved by technology

In previous studies, many scholars used tetraethoxysilane (TEOS) as a single silicon source, and coated SiO on the surface of carbonyl iron powder particles. 2 , to obtain uniform and dense SiO 2 layer, but purely inorganic SiO 2 The thickness of the layer is often 50-80nm to achieve good corrosion resistance, and the thicker modified layer will greatly reduce the magnetic properties, and the inorganic SiO 2 The hydrophobicity of the coating layer is poor, and the stability in acidic solution is not good

[0007] In the current research, the heat resistance of the pure organic modification layer such as resin, rubber or conductive polymer is poor, and the thermal stability of carbonyl iron powder is not significantly improved, and the modification process conditions are relatively harsh. The application of powder modification is greatly restricted

In terms of organic-inorganic hybrid coating modification, tetraethoxysilane (TEOS) and 3-aminopropyltriethoxysilane (APTES) or other organic substances are commonly used for hybrid coating of iron powder, but the common organic The influence of the inorganic hybrid coating modification layer on the magnetic properties of carbonyl iron powder is generally more obvious

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