Capsule modification is a surface modification method in which a film of a uniform thickness and a film having a certain thickness is coated on the surface of the powder particles. Rong et al. encapsulated TiO2 composite particles coated with Al2O3 and SiO2 with polystyrene, which effectively improved the absorbance and stability of the material. Zhu Liqun and other methods used in-situ polymerization to prepare microcapsules with silicone resin and ceramic fiber as the core material, polyvinyl alcohol as the capsule material, silicone resin and fine powder mixture as the core material, and polyvinyl alcohol as the capsule material. . The microcapsules containing a silicone resin having liquid fluidity and good thermal stability are incorporated into the sol-gel film layer, and the sol-gel composite is improved by the action of the liquid repair microcracks in the microcapsules. The purpose of the film properties.

Second, high energy modification method
The high energy modification method is a method of initiating modification by initiating a polymerization reaction by plasma or radiation treatment. Studies have shown that low temperature plasma treatment has a certain effect on the performance of glass fiber-epoxy composites. When glass fiber is placed in the plasma generator, the quality loss of glass fiber is 0.28% with the extension of processing time. Increased to 0.82. This is due to the etching effect of the high energy ions in the plasma on the surface of the fiber. As the roughness increases, the new surface area increases, and some polar groups are better exposed, so the amount of adsorption to the coupling agent is greatly increased. This inevitably improves the wettability of the fiber and the epoxy resin, thereby improving the interface bonding and the mechanical properties of the composite. The surface modification of the powder by plasma has been applied to the oxidation treatment of carbon black. There have been many reports on the treatment of high polymers by plasma to change their surface properties, such as the treatment of polyethylene by helium plasma. Luo Shiyong uses hexamethyldisiloxane as a monomer to polymerize a silicone polymer coated film on the surface of ultrafine low-melting phosphate glass powder by high-frequency plasma. The change in contact angle between water and powder tableting characterizes the effect of plasma process parameters on the surface energy of the powder. The results show that the fineness, viscosity and rheological properties of the electronic slurry prepared by the modified powder are significantly improved. After modification, the surface energy of the ultrafine powder can be changed or controlled, thereby adjusting the rheology and printability of the electronic paste.

Third, precipitation reaction modification
In the precipitation reaction method, a precipitating agent is added to a solution containing the powder particles, or a substance which can initiate the formation of a precipitating agent in the reaction system is added, and the modified ions are precipitated and precipitated on the surface of the particles to coat the particles. The precipitation method can be mainly divided into a direct precipitation method, a uniform precipitation method, a non-uniform nucleation method, a coprecipitation method, a hydrolysis method, and the like. Liu Yongzhen et al. coated a layer of ZnS on the surface of the flake aluminum powder, and prepared the composite particles Al / ZnS to maintain the low infrared emissivity of the Al powder and at the same time cover the metallic luster, which is beneficial to the compatibility of visible light camouflage. Zhang Congrong et al. uniformly coated a layer of SiO2 on the surface of titanium hydride to prepare a composite foaming agent, which effectively delayed the hydrogen release time of the nuclear material.