Silica sol, also known as silica sol or silica hydrosol, is a colloidal solution composed of colloidal particles of silica dispersed in water. It is odorless, non-toxic, and usually appears milky white or light blue transparent. The concentration range is generally between 10% and 35%, and can reach 50% in extreme cases. The particles of silica sol are extremely small, with a particle size between 5-100 nanometers and a specific surface area of up to 50-400 square meters/gram. These unique properties make it uniquely competitive in a variety of applications.
There are various preparation processes for silica sol, including ion exchange resin method, sulfuric acid neutralization method, electrolysis electrodialysis method, and one-step hydrolysis of silicon powder. Among them, the ion exchange resin method is one of the most commonly used and mature methods. This method uses ion exchange resin to treat a dilute sodium silicate solution to obtain silica sol by removing sodium ions from the solution. The sulfuric acid neutralization method uses sulfuric acid to neutralize a dilute water glass solution and prepares silica sol by strictly controlling pH value, temperature and other conditions. Electrolysis and electrodialysis method prepares silica sol through electrochemical process, with high product purity and stability.
Silica sol is widely used in many fields due to its excellent performance. In the field of casting, the stability of silica sol makes the metal and silica sol more closely combined, thereby improving the strength of casting parts and reducing casting defects. In addition, silica sol is also commonly used in the coating industry, which can significantly improve the coating's firmness, anti-fouling and dust-proof, aging resistance and fire resistance. In thin shell precision casting, silica sol can make the shell mold strong and the casting finish high. Its modeling quality is better than that of water glass, and it can reduce costs and improve operating conditions.
In addition to the casting and coating industries, silica sol is also widely used in other fields. For example, in the papermaking industry, silica sol can be used as a cellophane anti-adhesive agent, a photographic paper pre-treatment agent, and a cement bag anti-slip agent. In the textile industry, silica sol can be used as a sizing agent, and used in combination with oil agents to treat wool, rabbit hair and other fibers to improve spinnability and reduce breakage. In addition, silica sol is also commonly used to prepare inorganic polymer coatings, catalyst carriers, and silicon steel sheet treatment agents.
It is worth noting that the performance characteristics of silica sol are closely related to its application fields. Silica sol has excellent properties such as large specific surface, high adsorption, high dispersion, and excellent fire resistance and thermal insulation. These properties enable silica sol to perform excellent performance in many fields.
With the continuous development of science and technology, the application field of silica sol will continue to expand. In the future, silica sol is expected to be used in more fields and make greater contributions to the development of modern industry. At the same time, the research on silica sol will be more in-depth to further improve its performance and expand its application field.
In summary, silica sol, as an important fine chemical product, plays a vital role in modern industry. Its excellent performance and wide application fields make silica sol one of the most popular materials.