Silica hollow microspheres, as an inorganic material, possess narrow particle size distribution, good dispersion, stability, high melting point, and large specific surface area, offering a broad development prospect in fields such as biotechnology, optics, catalysis, and composite materials. Their primary functions include: micro-storage devices, where various loads are placed inside the hollow spheres as carriers for optimal utilization; micro-reactors, confining reactions within the spheres, such as photocatalytic reactions, with each hollow sphere serving as a reactor that enhances light pathways and significantly boosts reaction efficiency; micro-separators, which adsorb various harmful substances to achieve purification goals, such as modified hollow silica spheres adsorbing toxic organic compounds for separation and purification purposes; and micro-structural units, acting as additives for various materials to enhance their properties.
In the photonic field: Stacking hollow microspheres into a three-dimensionally periodic latticelike structure, the photons and photonic band gaps within this structure do not propagate in any direction, achieving the effect of altering the path of light and thus inhibiting spontaneous light propagation. Layer-by-layer self-assembly of silicon dioxide hollow microsphere particles onto mica and glass yields an antireflection coating. Optimizing the antireflection performance between 300-650nm results in a monolithic antireflection coating, capable of reducing reflectivity from 7% to 0% near the target wavelength, while increasing transmission from 92% to 97%.
2. In the light industry sector: Leveraging the advantages of hollow silicon dioxide, such as good thermal stability and a large specific surface area, it can be used for essential oil loading to extend the release time of the fragrance. For instance, when using mesoporous silicon dioxide to coat hydrophilic essential oils, the loading rate is high, effectively reducing the volatility of easily volatile substances in the essential oils and enhancing their stability. By encapsulating aromatic compounds containing unsaturated fatty acids like lavender, eucalyptus, thyme, balm, rosemary, sage, mint, basil, oregano, lavender seed oil, evening primrose oil, and ginger with hollow silicon dioxide, it can effectively prevent the reaction of unsaturated fatty acids with oxygen in the air during storage. This effectively improves the sustained-release effect of aromatic substances.
3. As a filler in structural materials or coatings: In lightweight ablation materials used for TPS, silicon dioxide hollow microspheres are a crucial filler. The addition of silicon dioxide hollow microspheres not only enhances the mechanical and mechanical properties of the resin matrix but also significantly reduces the density of the structural material, thereby decreasing its weight, playing a decisive role in the development and application of the aerospace field. Additionally, in coatings applied to friction devices (such as drills, bearings), the inclusion of silicon dioxide hollow microspheres can act as a lubricant, extending their service life.
