1.2 Adsorption: An important role of gas phase white carbon black in defoaming agent is adsorption. Due to its small particle size, large specific surface area, high surface energy, and three-dimensional network structure, silica can form a huge force for adsorbing bubbles. Together with silicone oil, it forms a force to attack bubbles, that is, silica adsorbs and impacts. Bubbles create weak points, and the bubbles burst under the action of the low surface tension of silicone oil, leading to bubble breakage. Therefore, the fumed white carbon black is equivalent to the "needle point" in the defoaming agent, and the amount is small but the effect is huge. It and silicone oil are used as the active ingredients of high-efficiency defoaming agents, and they have compound high-efficiency and synergistic defoaming effects.

1.3 Thickening and anti-settling effect 　　 emulsion type silicone oil defoamer is an important indicator of the defoaming effect and storage stability, especially the silicone paste emulsion. There are many reasons that affect the stability of the emulsion, such as the particle size and viscosity of the emulsion. Emulsion particle size is the most important control index for emulsion type defoamers, and the particle size is generally required to be less than 10um. The particle size of the emulsion depends on the choice of emulsifier, the emulsification process and the size of the particles. The minimum particle size of the vapor phase silica can reach about 5um. The silicone oil emulsion particles containing this silica form a very small particle and a very large number of basic defoaming units in the foaming liquid, so that the defoaming agent can reach the best Defoaming effect. At the same time, due to the small particle size, large specific surface area, and stable hydrogen bond three-dimensional network structure, the silica particles can be uniformly and stably distributed in the entire system, making the system storage stable. Therefore, fumed silica is used as a very good thickening and anti-settling agent in defoaming agents. Generally, models with a specific surface area of 200-300m2/g should be selected. In summary, the vapor phase sili