Formation of ring structures in a drying under the mask film of colloidal solution

The author offers a method of formation of concentric ring structures out of micro- and nanoparticles on impermeable surfaces as a result of evaporation of the film of colloidal solution under a special mold. The above mentioned method is studied theoretically. A mathematical model of initial stage of process is solved numerically. The model includes the continuity equation, the motion equation and the convection-diffusion equation for the case of a system with a variable mass. Results of calculations have shown that mass fraction of particles transferred by the radial flow increases considerably in the areas set by the mask. To confirm the feasibility of the method a full-scale experiment should be carried out.