Principle of defoamer
1. The partial surface tension of the foam is reduced, causing the bubble to burst.
The origin of this mechanism is to sprinkle higher alcohol or vegetable oil onto the foam, which, when dissolved in the foam, significantly reduces the surface tension there. Since these materials generally have a low solubility in water, the reduction in surface tension is limited to the local part of the foam, while the surface tension around the foam hardly changes. The portion where the surface tension is lowered is strongly pulled, extended, and finally broken.
2. Defoamer can destroy the elasticity of the film and cause the bubble to burst
The addition of the antifoaming agent to the foam system diffuses to the gas-liquid interface, making it difficult for the surfactant having a stabilizing effect to restore the elasticity of the film.
3. Defoamer can promote the liquid film to drain, thus causing the bubble to burst
The rate of foam drainage can reflect the stability of the foam, adding a substance that accelerates the discharge of the foam, and also acts as a defoaming effect.
4. Adding hydrophobic solid particles can cause bubbles to burst
Hydrophobic solid particles on the surface of the bubble attract the hydrophobic end of the surfactant, making the hydrophobic particles hydrophilic and entering the aqueous phase, thereby acting as a defoaming agent.
5. Solubilizing foaming surfactants can cause bubbles to burst
Certain low molecular substances that are sufficiently miscible with the solution can cause the bubble surfactant to be solubilized to reduce its effective concentration. Low molecular substances such as octanol, ethanol, propanol and the like can not only reduce the surfactant concentration of the surface layer, but also dissolve into the surfactant adsorption layer, reducing the tightness between the surfactant molecules. Degree, which reduces the stability of the foam.
6. The electrolyte disintegrates the surfactant double layer and causes the bubble to burst
For the interaction of the surfactant double layer by means of foam, a stable foaming liquid can be obtained by adding a common electrolyte to disintegrate the double layer of the surfactant to defoam.