News Picks : Silica nanoparticles turn water into moldable substance
New Scientist: Coating water droplets with hydrophobic powder creates opaque, liquid marbles. Now a team led by Xiaoguang Li of Tongji University in Shanghai, China, has extended that technique by replacing the hydrophobic powder with 20-nm silica particles. Because of the thinness of the silica layer, the water droplets remain transparent. And unexpectedly, the silica particles have the ability to jam together, which allows the researchers to mold the water droplets into almost any shape. They have demonstrated how the new material can be sliced like Play-Doh, formed into words, and even used as a convex lens. Further, the researchers discovered that chemicals added to the water diffused slower than normal, suggesting that the droplets might server as miniature test tubes.