Dynamic stratification in drying films of colloidal mixtures
  In simulations and experiments, we study the drying of films containing mixtures of large and small colloidal particles in water. During drying, the mixture stratifies into a layer of the larger particles at the bottom with a layer of the smaller particles on top. We developed a model to show that a gradient in osmotic pressure, which develops dynamically during drying, is responsible for the segregation mechanism behind stratification. 
Andrea Fortini, Ignacio Mart\'in-Fabiani, Jennifer Lesage De La Haye,   Pierre-Yves Dugas, Muriel Lansalot, Franck D'Agosto,...
cond-mat.soft cond-mat.mtrl-sci cond-mat.stat-mech