The principle of defoaming agent

The stable existence of foam in liquids has troubled many companies. Some companies use physical watering to defoam, and some companies use the chemical method of adding defoamer to defoam. Each has its own advantages, but the method of adding defoamer is It is a more convenient and quick defoaming method. Today, the editor of Xinwancheng will show you the principle of defoaming agent.

Principle 1: Reducing the surface tension of the foam causes the foam to burst

Add oil-based defoaming agent to the foaming liquid. This type of defoaming agent is not easily soluble in water and enters the inside of the foam, reducing the surface tension of the foam. Since the surface tension around the foam is almost not reduced, a pressure difference is formed, causing the surface to decrease. Parts are pulled and stretched around, eventually causing the bubble to burst.

Principle 2: Destroy the elasticity of the foam film and cause the foam to burst.

Adding a defoaming agent to the foaming system will disperse it and prevent the surfactant from stabilizing the elasticity of the foam film, thereby destroying the elasticity of the foam film and causing the foam to burst.

Principle 3: Promote liquid membrane drainage

Adding defoaming agent to the liquid can promote liquid film drainage, causing the foam to burst. However, the stability of the foam can be seen from the rate of liquid drainage. Fast liquid drainage indicates that the foam is not stable enough, so we can also add acceleration Foam draining chemicals to assist defoaming..

Principle 4: Hydrophobic substances can cause foam to burst

When hydrophobic substances are added to the foaming liquid, the hydrophobic substances will be attracted by the hydrophobic end of the surfactant, causing the hydrophobic substances to become hydrophilic and enter the water phase, thus playing a defoaming effect.

Principle 5: Compatibilized surfactants cause foam to burst

Since surfactants can stabilize the existence of foam, we can add some low molecular substances that can be fully mixed with the solution, such as ethanol, propanol, octanol and other low molecular substances, which can not only solubilize the bubble surfactant and thereby Reducing the effective concentration can also reduce the closeness between surfactant molecules, thereby weakening the stability of the foam and ultimately achieving the defoaming effect.

Principle 6: Electrolyte disintegrates the surfactant double layer

For some foaming liquids, the stable existence of foam is due to the interaction of the double electric layer of the surfactant in the foam. At this time, we can add ordinary electrolytes to collapse the double electric layer of the surfactant, thereby defoaming. Effect.

Through the above summary, I believe that you have a grasp of the principles of defoaming agents, and you will not blindly add defoaming agents when using them.