(Nature Publishing Group, 2013) Jung, Hyun Young; Chun, Hyunkyung; Park, Sora; Kang, Seoung-Hun; Ahn, Chi Won; Kwon, Young-Kyun; Upmanyu, Moneesh; Ajayan, Pulickel M.; Jung, Yung Joon
Here we report direct observations of spatial movements of nanodroplets of Pb metal trapped inside sealed
carbon nanocontainers. We find drastic changes in the mobility of the liquid droplets as the particle size
increases from a few to a few ten nanometers. In open containers the droplet becomes immobile and readily
evaporates to the vacuum environment. The particle mobility strongly depends on confinement, particle
size, and wetting on the enclosed surface. The collisions between droplets increase mobility but the tendency
is reversed if collisions lead to droplet coalescence. The dynamics of confined nanodroplets could provide
new insights into the activity of nanostructures in spatially constrained geometries.