Silicic acid for sale in stock CAS 7699-41-4

Chemical Composition: Hydrated silica has the chemical formula SiO2·nH2O, where "n" represents the number of water molecules associated with each silicon dioxide unit. The presence of water molecules distinguishes it from anhydrous silica, which lacks water.

Natural Occurrence: Hydrated silica is found abundantly in nature in various forms, including as opal, chalcedony, and certain types of volcanic glasses. It can also be found in mineral deposits, sedimentary rocks, and as an amorphous component of soils.

Synthesis: Hydrated silica can be produced synthetically through various methods, including the hydrolysis and precipitation of silicon compounds such as sodium silicate (water glass) or the sol-gel process, which involves the controlled polymerization of silicate precursors in the presence of water.

Physical Properties:

• Appearance: Hydrated silica can occur in various physical forms, including powders, gels, beads, and colloidal dispersions.
• Texture: It often has a soft, powdery texture, although gels may exhibit a smooth or gelatinous consistency.
• Porosity: Hydrated silica can possess high porosity, with pore sizes ranging from nanometers to micrometers, depending on its structure and production method.
• Surface Area: It may have a large surface area due to its porous structure, making it useful in adsorption and catalysis applications.

Applications:

• Abrasives: Hydrated silica is used as an abrasive agent in toothpaste, cleansers, and polishing compounds due to its gentle abrasive properties, which help remove plaque, stains, and surface imperfections without damaging tooth enamel or delicate surfaces.
• Thickeners and Stabilizers: In food and cosmetic formulations, hydrated silica is employed as a thickening agent, stabilizer, and viscosity modifier. It enhances texture, suspension, and mouthfeel in products such as sauces, beverages, lotions, and creams.
• Absorbents and Desiccants: Hydrated silica's porous structure allows it to absorb and retain moisture, making it useful as a desiccant in packaging materials to prevent moisture-related degradation of products.
• Matting Agents: In paints, coatings, and plastics, hydrated silica is used as a matting agent to impart a matte or dull finish by scattering light and reducing glossiness.
• Pharmaceutical Excipients: Hydrated silica is utilized as an excipient in pharmaceutical formulations to improve flow properties, disintegration, and dissolution rates of tablets and capsules.
• Catalyst Supports: Its high surface area and porosity make hydrated silica suitable as a support material for catalysts in various chemical reactions, such as heterogeneous catalysis and enzyme immobilization.

Safety Considerations:

• Hydrated silica is generally regarded as safe for its intended applications in food, cosmetics, and pharmaceuticals when used in accordance with regulatory guidelines and good manufacturing practices.
• Inhalation of fine silica dust may pose respiratory hazards, especially in occupational settings such as mining or manufacturing. Proper ventilation and personal protective equipment should be used to minimize exposure.