In the foaming water system, the addition of hydrophobic silica (ie, hydrophobic white carbon black) particles alone has a defoaming effect. The hydrophobic white carbon particles will attract the hydrophobic end of the surfactant on the surface of the bubbles. The hydrophobic particles become hydrophilic particles and enter the water phase, completing the defoaming effect. The solid particles of hydrophobic silica are generally white carbon black particles treated with methyl silicone oil, silazane or DMC.It is partially immersed on the surface of the bubble, so that the local surface tension of the bubble is reduced, and the role of solid particles is added. Insert bubbles like the tip of a needle and accelerate the bursting of bubbles. Therefore, the defoaming effect of defoamers containing hydrophobic silica is generally better.