Silicone oil is now widely added to many skincare products. When many girls first see this ingredient, they tend to reject it. 
Basic information of silicone oil
Silicone oil is a special oily liquid mainly composed of silicon-carbon bonds and silicon-oxygen-silicon bonds. 
Structural diagram 
The silicon-carbon bond endows silicone oil with surface activity, hydrophobicity, defoaming property and demolding property. 
The silicon-oxygen silicon bond endows stable inertness and electrical properties. 
Silicone oil is divided into two types: 
Inert silicone oil, as an additive, we usually utilize its physical properties. Common types include: methyl silicone oil, phenyl silicone oil, and trifluoropropyl silicone oil. 
Reactive silicone oil, which participates in chemical reactions during use; Hydroxyl silicone oil, ethylene silicone oil, hydrogen-containing silicone oil, amino silicone oil, carboxyl silicone oil. 
The Application of Silicone Oil in Cosmetics
1. Advantages of Addition
1.1 It forms a layer on the skin surface, providing excellent waterproof and breathable protection, with a slight sheen. It can also be used for waterproofing in foundation liquids. 
2. Anti-ultraviolet property. It is often added to sunscreen to prevent it from oxidizing and deteriorating, thus avoiding any irritation to the skin due to ultraviolet rays. 
3. Excellent anti-static performance. After application on the skin surface, the static electricity disappears and the dust removal effect is excellent. 
4. It can be compatible with many components in cosmetics and can reduce stickiness. It can also be used as a co-solvent and solid dispersant. It can be added to清爽 type cream bases， facial cleansers， lotions， toners， and makeup products. 
5. It has the function of slow-release fragrance retention, extending the fragrance retention period. It is added to the perfume. 
The common silicon oils added in cosmetics include:
Polydimethylsiloxane - It has good combing properties and is mainly used in shampoo and conditioner products. 
------Surface tension, high surface activity, easy to spread out 
-- Hydrophobic property. A protective hydrophobic and breathable film forms on the skin surface, found in cosmetics with high water resistance. 
Poly methyl phenylsiloxane - Good compatibility, mainly used in moisturizing creams and lipsticks. 
Dimethylsiloxane ring - Good volatility, mainly used in antiperspirants and body deodorants. 
Polyether siloxane copolymer - Self-emulsifying, good hydrophilicity, mainly used in shampoos and conditioners. 
A large number of cosmetics contain it. It has been proven to be a non-corrosive, non-toxic and odorless safe substance.