The steadily growing global trend of surfactants provides a favorable external environment for the development and expansion of the cosmetics industry, which in turn imposes increasingly higher demands on product structure, variety, performance, and technology. Therefore, it is imperative to systematically develop surfactants that are safe, mild, readily biodegradable, and endowed with special functions, thereby laying a theoretical foundation for the creation and application of new products. Priority should be given to developing glycoside-based surfactants, as well as diversifying polyol and alcohol-type surfactants; conducting systematic research into soybean phospholipid-derived surfactants; producing a range of sucrose fatty acid ester series; strengthening studies on compounding technologies; and broadening the scope of applications for existing products.
The phenomenon whereby water-insoluble substances become uniformly emulsified in water to form an emulsion is called emulsification. In cosmetics, emulsifiers are primarily used in the manufacture of creams and lotions. Common types such as powdery vanishing cream and “Zhongxing” vanishing cream are both O/W (oil-in-water) emulsions, which can be emulsified using anionic emulsifiers such as fatty acid soaps. Emulsification with soap makes it easier to obtain emulsions with low oil content, and the gelling effect of soap endows them with relatively high viscosity. For cold creams containing a large proportion of oil phase, the emulsions are mostly W/O (water-in-oil) type, for which natural lanolin—with its strong water-absorbing capacity and high viscosity—can be selected as the emulsifier. At present, nonionic emulsifiers are the most widely used, owing to their safety and low irritancy.
The phenomenon whereby the solubility of slightly soluble or insoluble substances is increased is termed solubilization. When surfactants are added to water, the surface tension of the water initially drops sharply, after which aggregates of surfactant molecules known as micelles begin to form. The concentration of surfactant at which micelle formation occurs is called the critical micelle concentration (CMC). Once the surfactant concentration reaches the CMC, the micelles can trap oil or solid particles at the hydrophobic ends of their molecules, thereby enhancing the solubility of poorly soluble or insoluble substances.
In cosmetics, solubilizers are mainly employed in the production of toners, hair oils, and hair growth and conditioning preparations. Because oily cosmetic ingredients—such as fragrances, fats, and oil-soluble vitamins—differ in structure and polarity, their modes of solubilization also vary; hence, suitable surfactants must be chosen as solubilizers. For instance, since toners solubilize fragrances, oils, and medicaments, alkyl polyoxyethylene ethers may be used for this purpose. Although alkylphenol polyoxyethylene ethers (OP-type, TX-type) possess strong solubilizing power, they are irritating to the eyes and thus generally avoided. Moreover, amphoteric derivatives based on castor oil exhibit excellent solubility for fragrance oils and vegetable oils, and being non-irritating to the eyes, they are suitable for preparing mild shampoos and other cosmetics.
Post time: Dec-05-2025