Dewetting of a Stratified Two-Component Liquid Film on a Solid Substrate

Dissipative particle dynamics simulations for the dewetting of a stratified thin film, composed of two immiscible fluids of different viscosity, reveal a nontrivial dewetting kinetics depending on the location of the more viscous liquid with respect to the solid substrate. Our simulations show that when the layer of higher viscosity is in contact with the substrate, the energy loss through viscous dissipation is concentrated near the contact line. The kinetics of dewetting is then inversely proportional to the viscosity of the lower layer eta(A) (with respect to eta(B) for the upper layer). However, when the liquid of higher viscosity is on the upper layer, a new dynamics appears with a dewetting velocity V similar to eta(-0.44)(B)eta(-0.56)(A). The difference between these two scenarios lies in the different routes through which the interfacial energy is converted into heat by viscous dissipation in the rim.