Keeping Surfaces Cool with Colloidal Silica
Colloidal silica can increase dirt pickup resistance in architectural coatings and improve the durability of paint for heavy equipment.
Have you ever noticed that sunny days feel even warmer when you’re wearing black clothing? This isn’t your imagination—it’s called the albedo effect. Lighter colors have a high albedo rating, meaning they reflect light, while dark colors have a lower albedo rating, which means they absorb light. That absorbed light turns into heat energy, which is why you feel warmer.
This phenomenon is not limited to clothing. Architects, builders, and homeowners have used the albedo effect to their benefit in order to keep buildings cool. Roofs and walls that are black or gray have a low albedo rating—simply painting them white can reduce indoor temperatures in the summer by as much as 30%. This can help reduce the need for air-conditioning, leading to lower electricity costs and a smaller overall carbon footprint.
While these lighter surfaces have a remarkable cooling effect, they can be impacted by a simple problem: dirt. When dust and grime build up on these white surfaces, it darkens the color, so more of the sun’s energy is absorbed. And because dirt is more visible on a white surface than a darker surface, the original appearance is difficult to maintain, leaving the surface looking worn and messy.
How can coatings help combat dirt and keep temperatures down?
To improve dirt pickup resistance (DPUR) in architectural coatings, such as the type of paint used on buildings, consider a colloidal silica that can impart hardness at the nano level. “The combination of temperature and humidity softens the coating film, and dirt adheres to it more easily,” says Demetrius Michos, senior principal scientist at Grace. “Subsequent cooling results in entrapment of dirt particles, which cannot be dislodged by rain or washing. Colloidal silica particles work at the nano level to prevent dirt pickup.”
Dirt-resistant paint will stay white longer, so the albedo effect remains high and reduces heat absorption. Surfaces will also look fresher longer, cutting down on the need for cleaning and repainting. Consider a colloidal silica that delivers on both form and function, providing exceptional performance while keeping surfaces aesthetically pleasing.
Roofs and walls are not the only outdoor surfaces that require high-performance paint. Heavy equipment, like that used in farming, construction, and earthmoving, must maintain its coating despite intense wear and tear from the elements. Many coating formulators have encountered issues with durability, especially as they transition from solvent-based paints.
“By incorporating silica nanoparticles, we can enhance the hardness with no additional environmental impact,” Michos says. These coatings are more durable, so the paint lasts longer while maintaining its color. For manufacturers that use a distinctive color as part of their brand identity, they can rely on their paint to keep looking vibrant for years.
Premium silica additives for industrial coatings
Grace’s silica technology solutions can help solve a wide range of formulators paint and coatings challenges. Contact the team to learn more about our portfolio of architectural and industrial coatings.