The Application Fields and Detailed Introduction of Aqueous Hydrophilic Fumed Silica with a Specific Surface Area of 50 m²/g

1. Basic Characteristics

- Preparation Method: It is generated by the high-temperature hydrolysis of silicon tetrachloride in a hydrogen-oxygen flame, forming amorphous silica at the nanoscale.

- Specific Surface Area: 50 m²/g (relatively low-end, with larger particles or a more compact structure).

- Surface Properties: Hydrophilic (rich in hydroxyl groups on the surface, which is easy to disperse in polar systems).

- Particle Size: Usually within the range of 5-50 nm, but due to the relatively low specific surface area, some may agglomerate into secondary particles.

2. Core Application Fields

(1) Coatings and Inks

- Function: Rheological control, anti-sedimentation, matting.

- Mechanism: A network structure is formed through hydrogen bonds to prevent the precipitation of pigments; the low specific surface area provides mild thickening, which is suitable for water-based coatings that require low viscosity.

- Case: Used in architectural water-based coatings, it improves the storage stability and avoids excessive thickening affecting the construction performance at the same time.

(2) Adhesives and Sealants

- Function: Thickening, thixotropy, reinforcement.

- Advantage: The hydrophilic property has good compatibility with water-based systems, and it is suitable for environmentally friendly adhesives (such as white glue), preventing the sedimentation of fillers and improving the construction accuracy.

(3) Plastics and Rubbers

- Function: Semi-reinforcing filler, processing aid.

- Application: In silicone rubber, it can replace part of the products with high specific surface area, reducing costs while maintaining certain mechanical properties; in plastics (such as PE), it improves the melt strength and reduces processing defects.

(4) Cosmetics

- Purpose: Viscosity adjustment, oil absorption, skin feel improvement.

- Example: Used in sunscreen products, it balances the fluidity of the emulsion, avoids the "whitening" phenomenon, and adsorbs excess oil at the same time, enhancing the refreshing feeling.

(5) Pharmaceuticals and Foods

- Role: Glidant, disintegrant, carrier.

- Details: As a glidant for tablets (such as vitamin C tablets), it improves the fluidity during tableting; the low specific surface area reduces hygroscopicity and prolongs the stability of drugs.

(6) Electronic Materials

- Application: Encapsulation materials, thermal conductive fillers.

- Function: In epoxy resin encapsulation adhesives, it adjusts the leveling property and prevents glue overflow; when filling thermal conductive silicone grease, it balances the thermal conductivity and extrudability.

3. Analysis of Performance Advantages

- Dispersibility: The relatively low specific surface area reduces the inter-particle forces, making it easier to disperse in water/polar solvents and saving energy consumption.

- Cost-effectiveness: It is cheaper than the fumed silica products with high specific surface area, and is suitable for scenarios where the reinforcement requirements are not strict.

- Compatibility: The hydrophilic surface is suitable for water-based systems, which is in line with the environmental protection trend (such as replacing organic thickeners).

4. Precautions

- Reinforcement Limitation: It is not suitable for rubber products with high mechanical property requirements (such as tire treads).

- Dry Storage: Due to its strong hydrophilicity, it needs to be protected from moisture to avoid caking and affecting the dispersion.

- Alternative Selection: When high thickening is required (such as in gel coatings), products with a specific surface area greater than 200 m²/g need to be replaced.

5. Examples of Market Products

- Similar Models: Although the specific surface area of the mainstream fumed silica (such as AEROSIL 200) is relatively high, customized or classified products can reach 50 m²/g (such as the "ZLSIL-A50" model of Zhonglian Chemical Co., Ltd. and some other manufacturers).

- Application Adaptation: It is often used in fields where fine adjustment of rheological properties is required, such as high-end electronic adhesives or medical-grade gels.

6. Future Trends

- Greenization: In line with the development of water-based systems, it replaces traditional solvent-based additives.

- Functionalization: Surface modification (such as grafting polymers) expands its application in smart materials, such as temperature-sensitive drug carriers.

Through the above analysis, the aqueous hydrophilic fumed silica with a specific surface area of 50 m²/g plays an important role in multiple industrial fields by virtue of its balanced performance parameters, especially in scenarios where processing performance and cost control are emphasized.