Method for preparing nanometer silicon dioxide

Abstract

The invention relates to a method for preparing nanometer SiO2. The method prepares the nanometer SiO2 by adopting composite shearing force field and comprises the following steps of: 1, using solution of sodium silicate as solution A, precipitator as solution B, mixed solution of surfactant and sodium chloride as solution C, and modifier as solution D; 2, pouring the prepared reaction solution A, B, C and D into a feed barrel at room temperature, introducing gas to the feed barrel, and controlling the pH value of a reaction system to perform reaction with stirring of a composite shearing force field; 3, precipitating ivory reaction solution, aging for 24 hours, filtering and washing till no chloridion, and drying to obtain silicon dioxide; and 4, grinding and sieving to obtain a sample. The method has the advantages of low cost of raw materials, simple structures of reaction devices, little investment, simple and feasible process, high yield and realization of large-batch production, can be performed at room temperature, can be widely used in plastic, rubber, adhesive, dope, ink and other products, and has extremely high practical value.

Description

technical field [0001] The invention relates to the preparation technology of silica powder, in particular to a method for preparing pure nano-silica or organically modified nano-silica with small and uniform particle size under a compound shear force field. Background technique [0002] nano-SiO 2 It is a non-toxic and non-polluting white powder. Due to its small particle size, large specific surface area and a large number of hydroxyl groups on the surface, it exhibits excellent reinforcement, stability, thickening and thixotropy. It is used in plastics, rubber, adhesives, Coatings and other fields have been widely used. At present, the preparation of nano-SiO 2 There are many methods, mainly dry and wet. The dry method includes gas phase decomposition method and arc method, and the wet method includes chemical precipitation method, microemulsion method, sol-gel method and vacuum condensation method. Nano-SiO prepared by dry method, microemulsion method and sol-gel met...

AI Technical Summary

Problems solved by technology

At present, most nano-SiO 2 The modification is to synthesize nano-SiO 2 , after modifying nano-SiO by dry or wet method 2 , dry modified nano-SiO 2 A large amount of modifier is required, and some modifiers are not grafted to nano-SiO 2 On the surface, it has adverse effects on the performance of the product, and wet modification of nano-SiO 2 A large amount of solvent is required, resulting in the production of nano-SiO 2 The cost increases, and the waste liquid needs to be treated, which is not suitable for the current environment-friendly and energy-saving requirements. Nano-SiO 2 Modification during synthesis can simplify the process and reduce production costs

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