Study On The Novel Preparation Process Of Large Particle Size, High Concentration And Stable Silica Sol

A new preparation process of large particle size, high concentration and stable silica sol with good perspective and some value in production and application has been described. Combining ion exchange process and silicon hydrolyze process; Silicon dioxide (mother nuclide) with a specific particle size was prepared from sodium silicate through the dropwise technique, then the large particle size, high concentration and stable silica sol was prepared. The stability of silica sol also can be improved by enwrapping of macromolecule dispersant.The effects of multiple technical factors on the properties of products, including the concentrations of reactants, reaction temperature and time in this reaction system, particle size of mother nuclide on the average diameter etc, were investigated with the help of single-element method and orthogonal test method. Moreover, The optimum technological conditions of preparing large particle size, high concentration and stable silica sol have been given.The results of experiment show that there are two key conditions to synthesize highly uniform particle diameter and dispersive silica sol. One is the property of mother nuclide of silicon dioxide; the other is the hydrolyze conditions of silicon. Both of them influence the property of final product in the most.At the same time, the optimum macromolecule dispersant and the using mass have been investigated. The study shows that the macromolecule dispersant can improve the stability of silica sol only using a macromolecule dispersant with appropriate molecular weight and length of molecule chain.The structure and physical properties of products have been analyzed by SEM, IR etc. The experimental result shows that the silica sol with highly uniform particle diameter of more than 50 nanometers and the concentration of the silica sol can reach 40 percent prepared under the optimum technological conditions.