orthosilicigsäure

Orthosilicic acid is the simplest silicic acid with the chemical formula Si(OH)4. It is also known as silicic acid. In aqueous solutions, orthosilicic acid exists in equilibrium with dissolved silica. It is a colorless liquid and is highly soluble in water. The molecule is tetrahedral in structure, with a silicon atom at the center bonded to four hydroxyl groups.

Orthosilicic acid plays a crucial role in the biological world, particularly in plants. It is the primary form in which silicon is absorbed by plants from the soil. This absorbed silicon is then incorporated into cell walls, providing structural support, strengthening tissues against mechanical stress, and enhancing resistance to pests and diseases. For example, diatoms, a type of algae, construct their intricate cell walls, called frustules, from silica, which is derived from orthosilicic acid.

Industrially, orthosilicic acid is an intermediate in the production of silica gel and colloidal silica, materials used in a variety of applications such as desiccants, catalysts, and as reinforcing fillers in tires. It is also a precursor for the synthesis of silicones and other silicon-based materials. The concentration of orthosilicic acid in natural waters varies depending on factors like pH and temperature.