The advantages of organosilicon defoamers
(1) Wide application: Due to the special chemical structure of silicone oil, it is neither miscible with water or substances containing polar groups, nor with hydrocarbons or organic compounds containing hydrocarbon groups. Due to the insolubility of silicone oil in various substances, it has a wide range of applications, both in water-based defoaming systems and in oil-based systems.
(2) Low surface tension: The surface tension of silicone oil is generally 20-21 dyne/cm, which is lower than that of water (72 dyne/cm) and general foaming solutions, resulting in good defoaming performance.
(3) Good thermal stability: Taking the commonly used dimethyl silicone oil as an example, it can withstand temperatures of 150℃ for a long time and over 300℃ for a short time, and its Si-O bond does not decompose. This ensures that silicone defoamers can be used in a wide range of temperatures.
(4) Good chemical stability: Due to the relatively stable Si-O bond, silicone oil has high chemical stability and is difficult to react with other substances. Therefore, as long as the formulation is reasonable, silicone defoamers are allowed to be used in systems containing acids, alkalis, and salts.
(5) Physiological inertia: Silicone oil has been proven to be non-toxic to humans and animals, with a median lethal dose greater than 34 grams/kilogram. Therefore, silicone defoamers (when combined with suitable non-toxic emulsifiers) can be safely used in industries such as food, medical, pharmaceutical, and cosmetics.
(6) Strong defoaming power: silicone defoamer can not only effectively break the generated foam, but also significantly inhibit foam and prevent the formation of foam. Its usage is very small, as long as one millionth (1ppm) of the weight of the foaming medium is added, it can produce a defoaming effect. Its commonly used range is 1 to 100ppm. Not only is it cost-effective, but it also does not pollute the defoaming material.