Tools don't make for brainy birds

Abstract

From non-stick pans to waterproof jackets, water-repellent materials are in high demand. But many of the processes used to deposit hydrophobic coatings are expensive and complicated. Yong-Lai Zhang at Jilin University in Changchun and Feng-Shou Xiao at Zhejiang University in Hangzhou, both in China, and their colleagues have created a hydrophobic chalk made of nanoporous polydivinylbenzene that can be easily wiped or painted onto surfaces. The porous structure renders the material's surface rough and reduces its contact with water droplets, making the material hydrophobic. The team tested their coating by applying the fine powder to paper, a piece of silicone and human skin. Fingers smeared in the chalk and dipped in water remained dry. The group speculates that the substance could be used by swimmers to reduce drag or for various industrial applications.