Evaporating droplets of mixed liquids form distinct patterns | Science News

As a drop of isopropanol mixed with ethylene glycol pools on a surface, the ethylene glycol builds up at the puddle’s edge and splits into a crown of fingerlike protrusions, as seen in the first clip. Thanks to their relatively high surface tension, these ethylene glycol “fingers” can drag fluid out from the puddle’s center, coating the surface in an ethylene glycol film that gets left behind as the evaporating isopropanol recedes. The second clips shows how, in a drop of dodecane-laced isopropanol, dodecan