If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.



Colorful paints could keep buildings cool

Paintable polymers help surfaces reflect sunlight

by Katherine Bourzac
May 2, 2020 | A version of this story appeared in Volume 98, Issue 17


Photo of heat-reflecting coatings with different finishes.
Credit: Sci. Adv.
Heat-reflecting paints can be finished with a matte or shiny top coat.

About 15% of household electricity in the US goes to keeping buildings cool. Materials that reflect heat to passively cool buildings could save some of that energy. Yuan Yang, a materials scientist at Columbia University, wanted to make an inexpensive and practical coating to do that efficiently. Two years ago, his group developed a paintable, snow-white polymer with randomly shaped pores that are the right size to reflect visible and infrared light (Science 2018, DOI: 10.1126/science.aat9513). Half the energy in sunlight is in the infrared part of the spectrum, so a material that reflects those wavelengths can keep things cool even if it still absorbs some visible light. The group has now added color, which should make the coatings more attractive to homeowners and vehicle makers. The team showed that a double-layer coating of the porous polymer and regular paint is still a highly effective passive cooler—and coating the polymer with dyes that absorb only specific wavelengths is even more effective, as commercial paints typically absorb some infrared light. Their vividly colored coatings reduce surface temperatures by 5–10 °C in full sun (Sci. Adv. 2020, DOI: 10.1126/sciadv.aaz5413).


This article has been sent to the following recipient:

Chemistry matters. Join us to get the news you need.