Dynamical Self-assembly during Colloidal Droplet Evaporation Studied by   in situ Small Angle X-ray Scattering
  The nucleation and growth kinetics of highly ordered nanocrystal superlattices during the evaporation of nanocrystal colloidal droplets was elucidated by in situ time resolved small-angle x-ray scattering. We demonstrated for the first time that evaporation kinetics can affect the dimensionality of the superlattices. The formation of two-dimensional nanocrystal superlattices at the liquid-air interface of the droplet has an exponential growth kinetics that originates from interface "crushing". 
Suresh Narayanan, Jin Wang, Xiao-Min Lin