Foam is a heterogeneous system of liquid-gas interface formed by the insoluble gas entering the liquid coating under the action of external force and being isolated by the liquid coating. Liquid coatings are subject to external forces during the production process, transportation process, and stirring during construction, which may generate air bubbles. The defoamer can penetrate into the foam system with fine particles, capture the hydrophobic chain ends of the foam surface after contacting the foam, spread rapidly, and form a very thin double film layer, and then further penetrate into the foam system . The defoamer with low surface tension always drives some liquid into the foam system with high surface tension, which makes the film wall gradually thinner and finally causes the bubble to burst.
