Classification and core application analysis of silicone oil in cosmetics
Silicone oil, as an essential functional ingredient in cosmetics, is endowed with unique lubricity, film-forming properties, and chemical stability due to the silicon oxygen bond in its molecular structure. According to their chemical structure and functional characteristics, cosmetic silicone oils can be classified into the following categories and play key roles in different products.


1、 Classification of Silicone Oil in Cosmetics
Polydimethylsiloxane (PDMS)
PDMS is the most common type of silicone oil in cosmetics, which can be adapted to different product requirements by adjusting viscosity (0.6-1000cSt). Low viscosity PDMS (such as 5cSt) is used for essence water to achieve "second absorption" effect, while high viscosity PDMS (such as 1000cSt) gives face cream "silk touch". Its molecular chains can penetrate into the gaps between the stratum corneum, forming a breathable protective film that combines UV resistance, moisturizing, and smooth skin feel.
polymethylphenylsiloxane
This type of silicone oil significantly improves the glossiness of the product by introducing phenyl groups to increase the refractive index (1.54). Its high compatibility with oils makes it an ideal additive for moisturizers and lipsticks, while the UV absorption ability of phenyl groups can enhance the stability of sunscreen products.
Cyclic siloxanes (such as cyclic pentadimethylsiloxane)
The circular structure endows it with low volatility and high lubricity, allowing it to quickly penetrate hair in hair care essential oils, forming a lightweight protective layer. Its characteristic of no cold sensation or residue when evaporated makes it the core component of refreshing cream.
Polyether modified silicone oil
By introducing polyether segments, this type of silicone oil combines hydrophilicity and surface activity, and can significantly improve dry and wet combing in shampoo, preventing hair tangling. Its emulsifying ability makes it a stabilizer for water-based cosmetics, such as being used as an moisturizer in skincare water.
amino silicone oil
Silicone oil containing amino functional groups has excellent adhesion to hair and can form a protective film with a thickness of 3nm in hair conditioners, reducing the friction coefficient to 0.12. Its cationic properties make it outstanding in repairing damaged hair and improving electrostatic control time.
Phenyl Silicone Oil
Its high refractive index (1.54) endows it with the title of "optical magic hand", which can achieve the visual effect of "drilling light muscle" in high-end anti-aging facial cream. Its low volatility and good skin feel make it a hero behind the makeup foundation make-up. For example, one day, the makeup foundation make-up can achieve a 16 hour zero powder feeling by adding phenyl silicone oil.
2、 Core applications of silicone oil in cosmetics
Skincare category
PDMS forms a breathable protective film in lotion and face cream to prevent moisture loss; Polyether modified silicone oil as an emulsifier enhances product stability; Phenyl silicone oil adjusts skin texture and gloss through refractive index. For example, Kerun Moisturizing&Nourishing cream achieves long-term moisturizing through PDMS, and Elizabeth Arden products use polydimethylsiloxane alcohol to improve skin smoothness.
Makeup category
Amino silicone oil can enhance concealer effect and makeup retention in liquid foundation, and long-chain alkyl modified silicone oil can achieve uniform spreading by improving organic compatibility. For example, COVER FX Long lasting Mist liquid foundation uses alkyl silicone oil to improve the makeup durability, and Anresa Sunscreen Gel uses phenyl silicone oil to enhance UV protection.
Hair care category
Amino silicone oil repairs hair scales in hair conditioners, while cyclic silicone oil quickly penetrates into hair care essential oils. For example, a salon grade hair mask achieves 30 second combing and knotting through amino silicone oil and cationic technology, while a certain type of hair mask improves repair efficiency by precisely controlling the molecular weight of silicone oil (500-800Da).
Sunscreen category
The combination of cyclic siloxane and zinc oxide can weaken the stickiness, while phenyl silicone oil enhances the sun protection effect through its UV absorption ability. For example, a certain sun protection flagship product reduces the stickiness of zinc oxide by 80% by adding cyclopentasiloxane, while enhancing the lightness of SPF50+products.