Lattice Boltzmann simulation of capillary interactions among colloidal particles

We present a numerical model for dynamic simulation of colloidal particles attached to a fluid interface. A new coupling method is proposed for combining Newtonian dynamics for colloidal particles and the lattice Boltzmann method for fluid phases so as to account for the wetting properties of particle surfaces. With this feature, capillary interaction of colloidal particles, in addition to electrostatic and hydrodynamic interactions, can be simulated. For the validation of the proposed model, we perform numerical simulations of the steady flow around a square array of cylinders, the transient dynamics of a moving particle in the quiescent solvent, as well as the contact angle of a colloidal particle attached to the multi-component fluid interface. Further, we apply the current model to simulate capillary interactions between two colloidal particles at a fluid interface. Effects of the relevant physical parameters on the dynamics of the particles, in particular, wettability and gravity, are investigated.