1.1 Introduction to white carbon black

Silica is a general term for white powdered X-ray amorphous silicic acid and silicate products. It mainly refers to precipitated silica, fumed silica and ultrafine silica gel, as well as powdered synthetic silicic acid. Aluminum and calcium silicate. Silica is a porous substance whose composition can be represented by SiO2·nH2O, wherein nH2O exists in the form of a surface hydroxyl group. Soluble in caustic and hydrofluoric acid, insoluble in water, solvents and acids (except hydrofluoric acid). High temperature resistance, non-combustible, odorless, odorless, and has good electrical insulation.

1.2 Structure and properties of white carbon black

The particle size of white carbon black is very small, the primary particle size is about 0.01~1μm, and there are a large number of hydroxyl groups on the surface of the microparticles. It has been confirmed by research that there are three types of surface hydroxyl groups of white carbon black: one is isolated and undisturbed. The hydroxyl group is isolated; the second is a bi-hydroxy group attached to a Si atom; and the third is an adjacent hydroxyl group which forms a hydrogen bond with each other. The presence of a hydroxyl group makes it highly hydrophilic. At the same time, there is a relatively active Si-OH bond on the surface of the particle, which is easy to bond with other ions to enhance the effect. The surface of the silica also has a uniform layer of siloxane and silanol groups which have a strong water absorption. Moreover, the silanol is easily reacted to make it easy to be modified.