Welcome Guest to Coatings World    Login || Register
Last Updated Wednesday, October 7 2015

Researchers from Chinese Academy of Sciences develop a reflective coating

Published April 1, 2011
Scientists in China have made a reflective coating with a structure that mimics the underside of a poplar tree leaf. The coating could be used on the outside of buildings to counteract the heating effect of carbon dioxide emissions, reducing the energy needed to cool the building from the inside.

Yanlin Song and colleagues from the Chinese Academy of Sciences, Beijing, mimicked the structure of the leaf’s lower surface using polymers spun into reflective films consisting of long, hollow uniform fibers.

The underside of the poplar leaf is better at reflecting light than the top. This is because of the ‘cool roof’ effect, in which a layer of hairs on the underside reflects the light, so that less heat penetrates the leaf. The leaf turns over in strong sunlight to reveal the underside and as the light is being reflected rather than absorbed, the leaf appears white. “Normally, the poplar tree looks green, but sometimes in the summer, the tree shows a white cast,” said Song.

The team discovered that controlling the film thickness and making the cross section of the fibers as similar to the leaf hair as possible is the key to high reflectivity. They tested their films by coating them onto the compound diarylethene, which changes from red to colorless in the presence of visible light—the structure changes from a closed ring to an open ring. They found that the coating stopped the diarylethene changing color, and had the additional benefit of being hydrophobic.

“The reflectance and waterproof nature of the coatings make them ideal candidates for a number of building situations,” said Robert Lamb, an expert on surface science. “Improving the
durability of such delicate interfaces with the environment will be the major hurdle.”

Song says that his team will continue to develop highly reflective materials, widening the wavelength at which they function, to eventually be used to improve the efficiency of lighting. 

blog comments powered by Disqus

Receive free Coatings World emails
Sign up now to receive the weekly newsletter, and more!

Enter your email address:
Company Spotlight
Houchi Chemical Co., Ltd
No.56, Fu Chow Street
Taipei, Taipei, 100
View Profile
Micro Powders, Inc.
580 White Plains Rd.
Tarrytown, NY, 10591
View Profile
Siltech Corporation
225 Wicksteed Avenue
Toronto, ON, M4H 1G5
View Profile
Sunin Machine Co., Ltd.
No.96, Chiao Ho Rd ,Chungho Dist
New Taipei City, Taiwan , 235
Taiwan Roc
View Profile
18F, No.85, Sec. 1, Chung-Shiao E. Rd.
Taipei, Taiwan, 100
View Profile
BASF Corporation
100 Campus Drive
Florham Park, NJ, 07932
View Profile
AZ Electronic Materials Co., Ltd.
No. 458-6, Sinsing Road Hu Kou Township Hsinchu Country 303, Taiwan
Hsinchu Country, Taiwan, 303
View Profile
Follow Coatings World On