Surface modification method of silicon micro powder

In the process of application, silicon micro powder is mainly composed of functional fillers with organic polymer polymers, thereby improving the overall performance of composite materials. Silicon micro powder itself is a substance of polarity and hydrophilicity. It is different from the interface attributes of the matrix matrix of the polymer polymer and is poorly compatible. It is often difficult to disperse in the base material. Therefore, the surface modification of silicon micro powder is usually required. Depending on the needs of the application, the physical and chemical properties of the silicon micr -powder surface are changed, thereby improving the compatibility of its organic polymer materials, and meeting the decentralization and liquidity needs of polymer materials.

Silicon micro -powder ingredients quality, modification process, surface modification method and modified agent, modifier dosage, modified process conditions (modifier temperature, time, pH, and mixing speed) and other factors all affect the surface modification effect of silicon microfanten surface. The surface modification method and modifier are the main factor affecting the modified effect.

1. Silicon microfin raw material quality

The types, particle size, surface area, and surface -oriented group of silicon powder directly affect the combination of its surface modifiers. Different types of silicon micro -powder modification effects are also different. Among them, spherical silicon micro powder has good liquidity. It is easy to combine with the modifier during the modification process. And the performance of density, hardness, and dielectric constant is significantly better than that of corner silicon microfim.

Generally, the smaller the particle size of the silicon microfanten, the larger the surface area, the more the number of active sites on the surface, and the increase in the amount of the modifier. In addition, in the process of application of silicon microfimmes of different granularity, it also has a certain impact on the performance of downstream products. For example, in the process of mixed with resin mixing with resin, the particle size distribution should be strictly controlled. It should not be too large or too small. The size of the size is too large. Essence

2. Surface modification method and modified agent

At present, the surface modification method of silicon micro powder is mainly organic modification, inorganic modification, and mechanical chemical modification. The most commonly used method is organic modification. When a single modification effect is poor

(1) Organic modification
Organic modification is a method of physical adsorption, chemical adsorption, and chemical reactions on the surface of silicon microfilling on the surface of silicon micro -powder to change the surface properties of silicon microfan. At present, the most commonly used organic modified agent is a sibidine coupling agent, which mainly includes amino, epoxy, ethylene, sulfur, and other types. The modification effect is usually good, but the price is expensive. Some researchers use aluminate, titanate, and hard fatty acid to make silicon microfimmeter with relatively low prices, but the modification effect is often not as good as the silicane coupling agent. Two or more surfactants are compounded to the silicon microfimmeter, and the modified effect is often more ideal than that of a single modifier.

(2) Inorganic modification
Inorganic modification refers to a new function of materials to give materials on the surface of silicon microfimy or composite metal, inorganic oxides, hydroxide, etc. For example, Oyama and others use precipitation methods to cover AL (OH) 3 on the surface of the SIO2, and then use the SiO2 after the polyethylene -based phenylphenylene wrapping, which can meet some special application needs.

(3) Mechanical chemical modification
Mechanical chemical modification refers to the first use of ultra -fine crushing and other strong mechanical power to activate the surface of the powder particles to increase the active point or active group on the surface of the silicon microfan, and then combine the modified agent to achieve the compound modification of silicon microfan.