The amount of hydroxyl groups on the surface of silica also has a large effect on the performance of silica. The amount of hydroxyl groups is too small, the agglomerates formed are less rigid, and the reinforcing effect on rubber is lowered. On the contrary, the amount of hydroxyl groups is too high, resulting in an increase in the viscosity of the rubber compound, and even a structuring phenomenon, which is not conducive to processing. In general, the amount of hydroxyl groups on the surface of silica is rich. The surface modification of the fumed silica is to select a suitable surface treatment agent to react with the hydroxyl groups on the surface of the silica through a certain process to reduce and adjust the amount of surface silicon hydroxyl groups to achieve the best use effect.

The surface of the unmodified fumed silica is acidic, and the vulcanization system has a strong adsorption effect in the rubber compound, and the vulcanization system is delayed. It is often necessary to add an active agent to the rubber compound to adjust the vulcanization rate. In addition, the content of impurities in the fumed silica also affects the use of the effect, such as high iron content, will accelerate the aging of the vulcanizate.

The fumed silica has an excellent reinforcing effect on rubber, but it is only used for silicone rubber and special rubber in the rubber industry due to its high price, which limits its use to some extent. With the rise of the domestic fumed silica industry, the continuous expansion of production capacity and the increasingly reasonable price of products, it is possible to broaden its application fields. Guangzhou Ji Bi Shi Technology Industrial Co., Ltd. has developed a process for the production of fumed silica by using organosilicon by-products, which greatly reduces the production cost. The products have partially replaced imports and achieved good economic and social benefits. The development of the silicon industry and related industries has played a huge role in promoting.