Numerical study of mass transfer in drop and film systems using a regularized finite difference scheme in evaporative lithography

Mass transfer in drying drops and films is interesting with practical point of view, since it is used in problems of evaporative lithography. Compensatory flows arise when conditions of nonuniform evaporation from the surface of the liquid layer are created and move colloidal particles in the region of fast evaporation. This makes it possible to obtain micro- and nanostructures of the required shape on a solid surface. Nonstationary model of mass transfer in drops and films is described in this paper. Feature of the model is to jointly take into account viscous, gravitational and capillary forces. To solve the unstable discrete problem on drying drop (film), a regularized finite difference scheme is proposed. A computer algorithm is developed on the basis of this scheme. We present a way of obtaining ring structures by using evaporative lithography method that based on the results of the computational experiments.