<The mechanism of action of organosilicon defoamers>         The ability of silicone to defoam or suppress foam is due to its very low surface tension. The organosilicon compound (silicone oil) interferes with the surface tension of the gas-liquid boundary, resulting in a defoaming effect.
When silicone is added to the foam medium, the small particles of silicone oil fall on the surface of the bubble, and at the same time effectively reduce the surface tension of the contact point, causing a weak point in the outer skin of the bubble, thereby causing the bubble to break.
        The best defoaming activity standard can be described as follows: The small particles of free silicone oil must be completely, as quickly and effectively as possible dispersed into the active area. Silicone oil is quickly dispersed with the help of a small proportion of SiO2 fillers with a large surface area added during production and processing, and causes demulsification and foam breaking outside the contact points of SiO2 particles. The squeezed foam is caused by the cracking of the adjacent foam. The unstable state accelerates the effect of causing continuous bubble breaking, and finally reaches a stable state. If it is an emulsion defoamer, if the emulsion is too stable, the defoaming effect will be reduced. When the stability is poor, there is greater activity. Therefore, it is necessary to balance between stability and activity, and to choose organosilicon compounds that have low solubility in water and oil phases and extremely high activity.
The function of defoamer is also defined according to the three mechanisms of foam breaking, defoaming and foam suppression.
        Bubble break: Compared with the foam, it enters the bubble from the air side and breaks the bubble together.
        Foam suppression: enter the bubble from the liquid side, and destroy the bubble together.
        Defoaming: Invade the bubble from the interface of the bubble, so that the bubble unites and rises to the surface of the liquid.