3M has developed an innovative product: roofing granules that suck smog from the atmosphere, reports Fast Company writer Eillie Anzilotti.
“Roofing granules have been a part of our business since the 1930s,” says Gayle Schueller, 3M’s chief sustainability officer. “This is not a new business to be in, and it’s not a new material for us.”
Traditionally, granules are used in construction to coat rooftops and provide an extra layer of protection from UV rays, which helps buildings remain cool and less dependent on air conditioning. They also make roofs more fire resistant. Around 10 years ago, 3M developed “cool roofing” granules that reflect sunlight and help buildings comply with roofing standards like the 2014 Los Angeles ordinance mandating new residential projects be built with additional rooftop insulation to keep them cool.
Instead of reflecting the sun, though, 3M’s new smog-reducing granules use it. The photocatalytic coating on these granules, designed for asphalt roofing, is activated by the sun’s UV rays. That generates radicals that bind with the chemical compounds in smoggy air, and transform them into water-soluble ions that eventually wash away.
Read more at Fast Company.
