Eco-friendly glass paint to keep metal roofs cool

Scientists have developed a glass paint that will keep metal cool in the harshest of summer days.

Scientists at Johns Hopkins University in the United States have developed environmentally friendly paint out of glass that bounces sunlight off metal surfaces, keeping them cool and durable. Senior scientist Jason Benkoski spearheaded the project aimed at protecting naval ships from the sun’s harsh rays.

“Most paints you use on your car or house are based on polymers, which degrade in the ultraviolet light rays of the sun,” says Benkoski. “So over time you’ll have chalking and yellowing. Polymers also tend to give off volatile organic compounds, which can harm the environment. That’s why I wanted to move away from traditional polymer coatings to inorganic glass ones.”

Glass, which is made out of silica, would be an ideal coating, but it’s not without its challenges. It’s hard, durable and has the right optical properties. But it’s very brittle, says Benkoski.

To overcome this, Benkoski modified one version of it, potassium silicate, that normally dissolves in water. His tweaks transformed the compound so that when it’s sprayed onto a surface and dries, it becomes water resistant.

The development is expected to have multiple commercial applications.

“You might want to paint something like this on your roof to keep heat out and lower your air conditioning bill in the summer,” says Benkoski. “It could even go on metal playground slides or bleachers.  And it would be affordable. The materials needed to make the coating are abundant and inexpensive.”

Benkoski presented his team’s work at the conference of the American Chemical Society in Boston earlier this month.