Silicone oil has long held a unique and crucial position in the complex formulation system of shampoo and hair care products. As a type of polyorganosiloxane with varying degrees of polymerization and a chain - like structure, polydimethylsiloxane is the most common silicone oil component in hair care products. With stable chemical properties and excellent moisturizing effects, it has been applied in the shampoo product field for as long as 70 years since its introduction.
From the perspective of hair structure, its main component is keratin. The outermost layer is composed of 7 to 10 layers of dead cells, forming cuticles. These cuticles cover the hair surface like guardians, protecting the hair core. When the cuticles are healthy, intact, and smooth, the hair surface appears smooth and shiny. However, during daily shampooing, the oils that originally lubricate and protect the cuticles are washed away. When combing, the raised cuticles increase the friction between the hair strands, causing the hair to tangle and further damaging the cuticles. In the case of hair dyeing and perming, the cuticles open, leaving the hair dry and dull. Silicone oil can effectively address these issues. It can evenly distribute on the hair surface, firmly adhere to the cuticles, fill the unevenness on the cuticle surface, greatly reduce the friction between hair strands, making the hair easy to comb, smooth, and shiny, thus effectively alleviating hair damage. Meanwhile, silicone oil also excels in skin moisturization, forming a protective layer on the skin to prevent moisture loss, which makes it widely used in the field of moisturizers.
In terms of the market, the development of silicone oil in the shampoo and hair care industry has not been smooth. In previous years, rumors such as "silicone oil added to traditional shampoos can clog pores, cause hair loss, and even lead to cancer" spread widely, causing shampoos containing silicone oil to fall out of favor for a time. Silicone - free shampoos took this opportunity to quickly capture the market. Even though their prices were often 5 to 10 times higher than those of silicone - containing shampoos, they were still warmly welcomed by consumers. However, with the passage of time and the deepening of science popularization, consumers' understanding of silicone oil has gradually become more rational. As early as 2003, the Cosmetic Ingredient Review (CIR) Expert Panel in the United States evaluated the safety of silicone - based preparations. At that time, the concentration of silicone oil in most of the evaluated products was ≤15%. The panel concluded that due to the large molecular weight of silicone oil, it is not absorbed by the skin, and no carcinogenic, mutagenic, or teratogenic toxic reactions were found in animals or humans. In 2014, the CIR Expert Panel evaluated 62 cosmetics containing dimethicone cross - linked polymers and reaffirmed their safety, clearly stating that they are not carcinogenic. China's national standards for shampoo and hair cream, "GB/T29679 - 2013", also do not restrict the use of silicone oil. Many authoritative tests and standard settings have gradually reversed consumers' negative perception of silicone oil. Currently, when choosing shampoos, consumers no longer blindly reject silicone oil but make rational choices based on their hair quality. For people with dry scalps, low sebum secretion, rough hair, or hair damaged by long - term dyeing and perming, shampoos containing silicone oil are more suitable as they can make the hair smooth and easy to manage; while consumers with oily hair, sparse and thin hair tend to choose silicone - free shampoos for a voluminous effect.
From the perspective of technological innovation, the application of silicone oil in the shampoo and hair care industry is constantly evolving. In recent years, the silicone oil used in hair care products has been improved to have stronger water solubility. This improved silicone oil can adhere to the hair more efficiently during shampooing while reducing residue on the skin, further enhancing the safety and effectiveness of use. Some enterprises are also exploring the combination of silicone oil with other functional ingredients to develop new formulas with multiple functions. For example, combining silicone oil with plant extracts can not only make the hair smooth but also provide additional nutrition; or combining silicone oil with repair - effective ingredients can enhance the repair ability for damaged hair.
Looking to the future, silicone oil will continue to play an important role in the shampoo and hair care industry. With the increasing diversification and refinement of consumers' needs for hair health and care, the application technology of silicone oil is expected to continue to innovate. On the one hand, more precisely adapted silicone oil products will be developed for different hair qualities, degrees of damage, and scalp environments; on the other hand, against the backdrop of growing environmental awareness, the research and development of biodegradable, environmentally friendly silicone oil substitutes or improved silicone oils will also become an important development direction for the industry. In this way, silicone oil will not only meet consumers' demands for high - quality shampoo and hair care products but also achieve the sustainable development of the industry.