Definition and Essence: A Nanoscale Form of Inorganic Silica
Organosilicon silica is not a traditional organosilicon compound. It is essentially a nanoscale silica (SiO₂) powder, named for its white appearance and high carbon black reinforcement. Its chemical structure consists of a three-dimensional network of silicon-oxygen tetrahedra (Si-O-Si). Its surface is rich in hydroxyl groups (-OH), creating a porous structure with a specific surface area of 100-600 m²/g. These properties give it excellent adsorption, dispersibility, and chemical inertness, making it a key medium connecting the inorganic materials and silicone industries.

Classification and Preparation: A Technical Comparison Between Fumed and Precipitation Methods
Based on the preparation process, silica is divided into two categories: fumed and precipitation methods.
Fumed silica: Using silicon tetrachloride (SiCl₄) as the raw material, it undergoes a vapor-phase hydrolysis reaction with hydrogen and oxygen at 1800°C, producing ultrafine particles with a size of 5-50 nm. Companies like Wacker in Germany and Cabot in the United States have achieved large-scale production using chemical vapor deposition (CVD) technology, achieving product purity exceeding 99.8%. These products are widely used in silicone rubber, coatings, and other fields.
Precipitated silica: Made from sodium silicate (Na₂SiO₃), it is produced through acidification, precipitation, washing, and drying. Its particle size typically ranges from 100 to 300 nm. Companies like Jiangsu Xinxing and Hesheng Silicon Industry in China use continuous production processes, which reduce costs by 40% compared to vapor phase processes. They have a dominant position in bulk markets such as tires and footwear.

Application Scenario: From Industrial Reinforcement to High-End Manufacturing
As a core reinforcing agent in the silicone industry chain, silica is used in three major areas:
Rubber Industry: Replacing 30%-50% of carbon black in tire formulations can reduce rolling resistance by 20% and improve fuel economy by 5%. Michelin, Bridgestone, and other companies have used nanocomposite technology to combine fumed silica with silane coupling agents to develop green tires with Class A wet-skid resistance.
New Energy Materials: In lithium-ion batteries, silica, as a conductive agent and separator coating, can increase battery cycle life by 30%. CATL, LG Chem, and other companies use fumed silica to modify polyvinylidene fluoride (PVDF) binders, enhancing electrode adhesion by 50%.
Biomedicine: Silica nanoparticles modified with amino groups can serve as drug carriers for targeted delivery. SiO₂@DOX nanoparticles developed by a Fudan University team have demonstrated over 90% drug loading and controlled release properties in tumor treatment.

Industry Trends: Green Manufacturing and Functional Upgrades
With the advancement of the "Dual Carbon" goals, the silica industry is exhibiting two major trends:
Clean Production: Using hydrogen chloride recycling technology, the chlorine recovery rate in the fumed process is increased to 99.5%, reducing energy consumption per ton of product by 15%. Functional Modification: Fluorosilicone segments are grafted onto silica surfaces via a sol-gel method to develop a superhydrophobic material with a hydrophobicity angle of up to 165°, suitable for self-cleaning coatings in aerospace applications.
From inorganic silica to organosilicon functional materials, silica is continuously expanding its application in high-end manufacturing, green energy, and other fields through the integration of nanotechnology and interfacial chemistry.