Silica Nanoparticles Applied to Substrate Surface Gives Superhydrophobic Properties
This transparent, durable ceramic coating can be applied to surfaces to supply superhydrophobic and self-cleaning properties. Superhydrophobic surfaces are those that have a water contact angle larger than 150 degrees. These types of surfaces, modeled after lotus plants, prevent liquid droplets from absorbing energy which prevents adhesion. Existing superhydrophobic coatings either need extreme processing conditions or have not been tested for durability and transparency. Researchers at the University of Florida have developed a superhydrophobic ceramic coating composed of silica nanoparticles that is transparent and durable and can be processed at room temperature. Superhydrophobic surfaces have many applications, such as in high voltage systems, microelectromechanical systems, and for anticorrosion of metal coatings. Other possible uses could be in biomedical applications or in photovoltaic devices.
Ceramic coating gives surfaces superhydrophobic properties while remaining transparent and durable
- Repels water and some other liquids, creating easy-to-clean surfaces
- Remains transparent, offering high visibility when applied to windshields, windows, and device displays
- Reduces rate of metal corrosion, increasing longevity of structures such as bridges
- Functions in extreme temperatures, extending performance of structures in snow, ice, or rain
This transparent, durable, superhydrophobic ceramic coating is created by randomly stacking silica nanoparticles on a surface to create a rough topography. The silica nanoparticles are sufficiently small, so most light transmits through the coating. The silica is then infused with a sol-gel glass matrix to ensure that the rough topography is retained. After curing, the surface is coated with a fluorinating agent to form a self-assembled monolayer. Controlling the particle size, stacking structure, and coating allows formation of a ceramic coating that is transparent and durable. The coating gives surfaces a contact angle of 150 degrees so water droplets cannot rest on the surface. The coating was tested to determine the transmittance and durability of the technology.