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The effect and influencing factors of surface modification of synthetic nano-barium sulfate
- 2020-02-17-

The effect and influencing factors of surface modification of synthetic nano-barium sulfate

In the process of preparing nano-barium sulfate by wet process, the surface of barium sulfate contains a lot of water. During the drying process, the non-bridging hydroxyl (-OH) between nano-barium sulfate particles is transformed into ether bond (-O-), and sulfuric acid The disadvantages of high surface energy and high mechanical instability of barium lead to hard agglomeration and serious agglomeration of nano-barium sulfate, which loses the advantage of nano-level.

Nano barium sulfate modifier

Therefore, the key lies in the selection of a suitable powder modifier during the wet process. After the surface modifier is applied to the nano-barium sulfate, it is physically or chemically adsorbed on the surface of the nano-barium sulfate to make the modified nano-barium sulfate hydrophobic At the same time, it is well compatible with the organic matrix, taking advantage of the small particle size and large specific surface area of ​​nano barium sulfate. So what factors are related to the modification of the surface of nano-barium sulfate by the powder modifier?

1. The relationship between the particle size of nano barium sulfate and the modification effect

The smaller the particle size of barium sulfate, the better the performance (optical performance, good adsorption, strong aging resistance, good stability), and the higher the thermodynamic performance of the powder, the greater the degree of agglomeration, the more difficult it is to disperse, so it needs to pass Powder surface modifier, improve the activation degree of barium sulfate particles, the better the dispersion effect, of course, not the more the addition, the better, choose the appropriate addition, the higher the activation degree of the barium sulfate powder, the better the effect , The greater the role played by downstream products.

2. The relationship between the temperature resistance of the powder modifier and the surface modification of nano-barium sulfate

Barium sulfate modifier

The surface of barium sulfate particles is modified by the powder modifier to achieve high dispersibility and high activation. However, depending on the application field of barium sulfate, the temperature resistance of the powder modifier needs to be considered, such as In the field of automotive paint, the temperature resistance is required to reach about 350 degrees. If the temperature resistance of the coating layer on the barium sulfate surface cannot reach the temperature, yellowing will occur, which will seriously affect the gloss of the paint film.

In addition, the influencing factors of barium sulfate surface modification are also related to the operation process (wet method and dry method), the time of high-speed stirring and dispersion, the pH value of the solution, etc., no matter which method, the final goal is to use the powder surface Modifier, complete surface coating modification of nano barium sulfate, achieve uniform dispersion and high activation effect, exert the performance of downstream products, and reduce enterprise production costs.