Numerical simulation of a drying colloidal suspension on a wettable substrate using the lattice Boltzmann method

[Display omitted] •A simulation model for a drying colloidal suspension was developed.•The present method is based on the lattice Boltzmann method.•Drying of a colloidal suspension on a wettable substrate was simulated.•The wettability of particles affects the arrangement process and the final structure. A computational method based on the lattice Boltzmann method (LBM) is developed to simulate a drying colloidal suspension on a wettable substrate. In this method, solid particles moving in the fluid are treated with an improved smoothed-profile LBM, and the liquid–vapor system is described by the free-energy LBM. To represent solvent evaporation dominated by density gradients, the density at the boundary of the simulation domain is specified to be lower than the equilibrium vapor density. We simulated the drying of a colloidal suspension on a wettable substrate and found that particles with higher wettability aggregated more slowly, but the aggregation proceeded more significantly. This result can be explained based on capillary interactions (i.e., capillary flotation force and capillary immersion force) between the particles. The proposed method can effectively simulate the particle arrangement process induced by the evaporation of the solvent from a colloidal suspension on a wettable substrate.