As a high-performance nanomaterial, fumed silica has shown significant advantages in the field of reinforcement. Its core functions are reflected in improving the mechanical properties of the material, optimizing the processing characteristics and enhancing the durability.The following analysis is carried out from the specific functional mechanism：


1. The microscopic mechanism of enhancing mechanical properties
The original particle size of fumed silica is 7-80nm, and the specific surface area exceeds 100㎡/G. This nanoscale structure enables it to form a three-dimensional network structure during the reinforcement process.When added to a rubber or resin matrix, the surface silicon hydroxyl group and the polymer chain form a crosslinking point through physical adsorption or chemical bonding, which significantly improves the tensile strength and tear strength of the material.


For example, after adding fumed silica to silicone rubber, the tensile strength can be increased by 10-20 times and the tear strength can be increased by more than 40 times.Its high surface energy characteristics can also promote the interfacial binding of the filler and the matrix, reduce the stress concentration point, and thereby improve the elongation at break of the material.


2. Optimize the rheological regulation of processing characteristics
The thixotropic and thickening properties of fumed silica make it play a key role in the processing process.In a liquid system, its nano-particles form a reversible mesh structure through hydrogen bonding, giving the material shear thinning properties.


This characteristic is particularly important in the fields of coatings, adhesives, etc.: When stirring or coating, the viscosity of the system is reduced to facilitate construction; after standing, the viscosity is restored to prevent sedimentation and sagging.In rubber mixing, fumed silica can adjust the Mooney viscosity of the rubber material, improve the dispersion of the filler, reduce the energy consumption of the mixing, and improve the surface finish of the extruded product.


3. Multi-dimensional protection to improve durability
Fumed silica enhances the durability of the material in multiple ways.Its high specific surface area gives the material excellent ULTRAVIOLET reflection ability, which can reduce the performance attenuation caused by photoaging in outdoor applications.


For example, adding fumed silica to outdoor rubber products can extend the service life by more than 30%.Its nano-scale pore structure can also absorb moisture and impurities, inhibit electrochemical corrosion, and improve the moisture and heat resistance of the material.


In addition, the synergistic effect of fumed silica and flame retardant can enhance the flame retardant and smoke suppression properties of the material, form a dense carbon layer during combustion, and reduce heat release and toxic gas generation.


4. Differentiated adaptation of application scenarios
According to the characteristics of different substrates, the functional table of fumed silica is still different.In silicone rubber, its reinforcing effect is better than that of precipitated silica, and it can prepare highly transparent and high-strength medical catheters and seals; in thermoplastics, a small amount of addition can improve rigidity and heat resistance while maintaining impact strength.；


In coatings, the matting effect is uniform, and high-grade matte coatings can be prepared.Through surface modification (such as silane coupling agent treatment), its compatibility with the substrate can be further adjusted and the application field can be expanded.