High-viscosity silica sol and preparation method thereof

Abstract

The invention discloses a preparation method of a high-viscosity silica sol. The method comprises the following steps: S01. preparing a humic acid solution, and regulating the pH value to 6-8 with an acid or alkali; S02. dropwisely adding the humic acid solution obtained in the S01 into the silica sol solution, and stirring and mixing to form a humic acid / silica sol mixed system; and S03. filtering the humic acid / silica sol mixed system obtained in the S02, washing with anhydrous ethanol, and finally, dispersing the filtered mixture into a hydroxyethyl cellulose solution to obtain the high-viscosity silica sol. The viscosity of the silica sol is greatly enhanced; the SiO2 particles are uniformly dispersed in the polymer emulsion; and the product has the characteristics of cost saving and environment friendliness.

Description

technical field [0001] The invention relates to a high-viscosity silica sol and a preparation method thereof, belonging to the technical field of nanometer materials. Background technique [0002] Silica sol is a dispersion of nano-scale silica particles in water or solvents. It has the characteristics of large specific surface area, high temperature resistance, and oxidation resistance. It is an ideal polymer emulsion enhancer. [0003] strong material. Due to the nano-SiO in silica sol 2 There are a large number of hydroxyl groups on the surface of the particles, which need to be hydrophobically modified to make SiO 2 The particles can be uniformly dispersed in the polymer emulsion. So far, the main modifiers mainly include organic modifiers and metal modifiers. Organic modifiers are mainly silane coupling agents, but silane coupling agents will undergo severe hydrolysis and condensation reactions in water, resulting in gel formation; metal modifiers are commonly used ...

AI Technical Summary

Problems solved by technology

Organic modifiers are mainly silane coupling agents, but silane coupling agents will undergo severe hydrolysis and condensation reactions in water, resulting in gel formation; metal modifiers are commonly used aluminum, tin, zinc and lead, but metal modifiers The cost of neutralizing agents is higher, and in addition, it will cause problems such as heavy metal pollution

In addition, the viscosity of ordinary silica sol is not too high, which often limits the application range of silica sol