Silica for toothpaste is usually precipitated silica, also known as hydrated silica or amorphous silica. It is generally synthesized by precipitation method using sodium silicate and sulfuric acid as raw materials, and has the characteristics of good chemical stability, compatibility and adjustable friction value.

The structural characteristics of precipitated silica make it suitable for toothpaste. It can be highly dispersed in aqueous solution and convert a large amount of free water into bound water in the network structure. When damaged by external force, its network structure can quickly become a low-viscosity suspension, and can return to a homogeneous plastic state after the external force disappears. This characteristic gives toothpaste good pseudoplasticity and thixotropy, making it difficult to fall off during use, and can improve the stability and gloss of the paste.

In addition, silica for toothpaste can also be divided into different types such as friction type, mixed type, thickening type, etc. to meet the needs of different toothpaste formulas. When choosing silica for toothpaste, it is necessary to consider its quality indicators such as particle size, specific surface area, oil absorption value, light transmittance, as well as compatibility and stability with other ingredients.