Precipitated Hydrate Silica is a form of synthetic amorphous silicon dioxide (silica). It is derived from quartz sand and is obtained by the precipitation, drying, and grinding of silica.
The name describes the structure of the molecule:
- "Precipitated": This refers to a substance that has been formed from a solution or a suspension due to a chemical reaction or a change in conditions (like temperature or pressure). The substance is typically solid and separates out from the rest of the mixture.
- "Hydrated": This refers to a compound that has water molecules bound to it.
- "Silica": This is a common name for silicon dioxide (SiO2), a compound consisting of one silicon atom and two oxygen atoms. It's a hard, unreactive, colorless compound that occurs as the mineral quartz and as a principal constituent of sandstone and other rocks.
The synthesis process takes place in different steps:
- Sulfuric acid is added to quartz sand to create silicon tetrachloride (SiCl4).
- The silicon tetrachloride is then hydrolyzed to create a silica gel.
- The silica gel is precipitated, washed, and then dried to create precipitated silica.
- The precipitated silica is then hydrated, meaning water is added to it, to create precipitated hydrated silica.
It appears in the form of a white powder.
Precipitated silica is a versatile material with a wide range of applications.
Fharmaceutical applications
- Flow Agent. Precipitated hydrated silica is used as a flow agent in pharmaceuticals. It improves the flow properties of powders in the production of tablets and capsules.
- Filler. Precipitated hydrated silica can be used as a filler in tablets. It increases the volume of the tablets, making them easier to handle and swallow.
- Disintegrant. Precipitated hydrated silica can act as a disintegrant, absorbing water and helping tablets to break apart and release the active ingredient.
- Stabilizer. Precipitated hydrated silica can be used to stabilize pharmaceutical formulations, preventing the degradation of active ingredients.
Rubber and Tires. Precipitated silica is used as a reinforcing filler in tires and other rubber products to improve durability and energy efficiency.
Food and Animal Feed. It's used as an anti-caking agent in food and animal feed to prevent clumping. It's also used as a carrier for flavors and vitamins.
Toothpaste. Precipitated silica serves as a mild abrasive in toothpaste, helping to remove plaque and other debris from the teeth.
Plastics. In plastics, precipitated silica is used as an anti-blocking agent, helping to prevent sheets of plastic from sticking together.
Paints and Coatings. It's used in paints and coatings to control rheological characteristics and to provide anti-settling, thickening, and anti-sagging properties.
Paper. Precipitated silica is used in the paper industry as a filler and to improve printability.
Agriculture. It's used in slow-release fertilizer formulations to improve the efficiency of nutrient delivery.
Cosmetics. Precipitated silica is used in a variety of health and beauty products, including skin and hair care products, where it serves as a thickening, suspending and anti-caking agent.
Pharmaceuticals. In pharmaceuticals, it's used as a desiccant (to control humidity), as an anti-caking agent, and as a drug carrier in certain formulations.
Defoamers. Precipitated silica is used in defoamers for both its adsorbent properties and as a carrier for the active defoaming agent.