ABSTRACT
We summarize our recent studies on solid–fluid interfaces using a mean-field free-energy lattice Boltzmann scheme. Results show that contact angles on smooth and heterogeneous surfaces are determined by the surface properties near the contact point and not those between the solid–liquid interface. This finding implies the invalidity of Cassie's equation in macroscopic contact angle measurements. Apparent liquid slip was also observed over a no-slip solid fluid interface due to specific solid–fluid interactions: the weaker the interactions, the larger the contact angle and slip magnitude. These simulations have demonstrated the potential of this mean-field free-energy lattice Boltzmann model in fluid interfacial studies.