Drying Simulation of Nanoparticle Suspension Film on Substrate

Drying simulations of nanoparticle suspension films on a substrate are carried out by a threedimensional simulator developed. The motion of nanoparticles in the suspension films is modeled by Langevin equation, in which forces exerted on each nanoparticle consist of contact force, capillary force, Brownian force, van der Waals force, electrostatic force and fluid drag force. The drying of suspension films is described as a variation of interface between gas and liquid with time. The present simulator is applied to drying processes of suspension films on a flat substrate, so that self-organized monolayer or multilayer structures of nanoparticles are formed after drying up depending on concentration of the suspension films. The structure formations are visualized with time, and planar structures of nanoparticles are evaluated temporally and quantitatively. The results indicate mechanisms of monolayer and multilayer structure formations of nanoparticles in the suspension films during drying.