This April, when the spring breeze carried the formal acceptance notice of our paper by the Journal of the American Chemical Society to my desk, my thoughts instantly drifted back to the late Phil Geissler. A legendary physical chemist and the original spark for this research, Geissler had once obse rved a baffling phenomenon: When the hairy, flexible ligands passivating a nanoparticle's surface spontaneously order themselves into crystalline patterns, a massive, seemingly magical attractive force suddenly erupts between the particles. ...read more read less