Nano-silica has become one of the most widely used nanomaterials in optical coatings and functional thin films. Its chemical stability, optical transparency, and surface modification potential make it suitable for anti-reflective coatings, wear resistance, and easy-clean surfaces. As waterborne coating systems continue to grow in importance, waterborne nano-silica solutions are becoming a practical choice for formulators.
This article discusses a typical waterborne hollow nano-silica solution, N-1160-70W, and reviews its technical characteristics and application potential.
What Is Hollow Nano-Silica?
Conventional solid nano-silica particles have a refractive index of about 1.46. Hollow nano-silica particles, by contrast, contain an internal void surrounded by a silica shell. The void is usually filled with air, which has a refractive index of about 1.0. This shell-and-void structure gives the particle a lower effective refractive index than solid silica.
A lower refractive index is useful in anti-reflective coatings. When applied to glass or other optical substrates, a low-index coating can reduce interfacial reflection and increase light transmission. This is relevant for photovoltaic modules, display panels, optical lenses, and other applications where light transmission matters.
Key Features of N-1160-70W
N-1160-70W is a waterborne hollow nano-silica solution. Its typical properties include:
| Property | Typical Value |
|---|---|
| Appearance | Semi-transparent liquid |
| Nano-silica content | 20 wt% |
| Viscosity at 25°C | 100–300 mPa·s |
| pH | 8–9 |
| Relative density | 1.02 |
| Nanoparticle size | 70 nm |
Several features make this type of product suitable for coating formulations.
Low refractive index. The hollow structure contributes to a lower effective refractive index, which can help formulators adjust the optical properties of anti-reflective and interference coatings.
High transparency. The nano-scale particle size supports good transparency in the visible range. Coatings made with this material can maintain the original optical appearance of the substrate, which is important for optical films and display applications.
Waterborne compatibility. The product is water-based and shows compatibility with common waterborne monomers. It is also miscible with alcohols and alcohol ethers. This makes it easier to incorporate into existing waterborne coating systems without major changes to the solvent balance.
Dispersion stability. Dispersion stability is a key factor for waterborne nano-silica. A stable dispersion helps prevent agglomeration during storage and use. N-1160-70W is designed to provide good storage stability in waterborne systems.
Main Application Areas
Photovoltaic glass anti-reflective coatings. Reflection from the glass cover is one source of optical loss in photovoltaic modules. Anti-reflective coatings containing hollow silica can help reduce reflection and increase light transmission. This can support the overall optical efficiency of the module.
Optical films and electronic thin films. In display panels, touch modules, and other electronic optical devices, low-index coatings are often used as anti-reflective layers or to adjust optical interference. Hollow nano-silica solutions are suitable as functional additives for these coatings.
Automotive and architectural glass. Automotive windshields and architectural glass require high light transmission and visual clarity. Adding waterborne nano-silica to a coating formulation can help achieve anti-reflective effects while maintaining appearance. The chemical inertness of silica may also contribute to weatherability.
General waterborne coatings. Beyond optical applications, nano-silica is often used to improve the mechanical properties of waterborne coatings. When added at an appropriate level, nano-silica dispersions can increase surface hydrophobicity, abrasion resistance, and scratch resistance. N-1160-70W can also be used as a functional additive in such systems.
Usage Considerations
When using waterborne nano-silica solutions, formulators should consider the following:
Calculate the addition level based on the target refractive index and coating thickness.
Run a compatibility test with other components in the formula before scaling up.
Avoid prolonged high-temperature or freezing conditions during storage to maintain dispersion stability.
Refer to the product MSDS and application literature for specific handling and safety information.
Summary
Waterborne hollow nano-silica solutions combine the chemical stability of nano-silica with the low refractive index provided by a hollow structure. N-1160-70W is a 70 nm, 20 wt% waterborne product with good compatibility and dispersion stability in waterborne systems. It is suitable for anti-reflective and functional coatings in photovoltaic glass, optical films, automotive glass, and general waterborne coating applications. As demand for high-performance optical coatings continues to grow, waterborne nano-silica materials are likely to see further application development.