The particle size and uniformity of the emulsion have an important effect on the stability of the droplet, and further affect the application performance of the emulsion. Therefore, it is very important to understand the reasons that affect the stability of silicon emulsion.
Introduction of silicone oil
Siloxanes are a class of hybrid organic/inorganic linear and cyclic polymers that possess unusual structural characteristics and properties that make them different from other organic compounds.
The highly polarized Si-O-Si bonds have very large bond energies, making them thermodynamically more stable.
The free rotation of methyl groups and the relatively low intermolecular attraction give them structural flexibility, high permeability and high lubricity.
In addition, due to their low surface tension, they offer excellent wettability and film-forming properties, and are odorless, non-toxic, waterproof, and resistant to chemical and UV erosion.
Due to these excellent properties and performance, silicone oil is considered the ideal conditioner in hair and skin care products, making hair and skin feel smooth and silky.
In order to improve the stability of silicone oil emulsion, a large number of surfactants are used, including silicone surfactants, stabilizers, electrolysis suspending agents, etc. However, it has the following disadvantages:
The uniformity is still very poor, and it is difficult to solve the stability problem of the emulsion, resulting in a decline in product quality.
Excessive use of surfactants and stabilizers can cause irritation, dryness of skin and hair, inflammation, and allergic reactions.
In order to improve the performance of silicone emulsions, different thickeners/polymers were added into the shampoo and conditioner, but they were incompatible with the surfactant system, which led to the unsatisfactory coagulation effect of the shampoo and conditioner.
Excessive use of surfactants and/or thickeners can cause safety problems.
In recent years, in order to overcome the limitations of traditional formulations, the uniform and size controlled silicone oil emulsifier has become a promising system. They exhibit improved appearance, stability and application performance because they avoid the process of polymerization and Oswald ripening due to their narrow size distribution. Therefore, the use of surfactant can be greatly reduced and its safety can be improved.