Credit: Image courtesy of Lawrence Berkeley National Laboratory
Paralleling your favorite oil-based salad dressing, combining nanoparticles and a soap-like material (surfactant) goes one step further—tunable channels are stabilized in the mixture. Left: A water droplet with a trapped, a.k.a. jammed, nanoparticle-surfactant assembly at its surface. Withdrawing the “water-liking” phase caused the single layer of assemblies to compress. The visible wrinkles developed immediately, suggesting a “solid-like” nature of the squeezed assemblies. And, the process is reversible. Right: A confocal fluorescence image shows the bicontinuous structure of the nanoparticle-surfactant mixtures.