Investigation of the detachment of oil droplets driven by water shear field on solid surfaces with different wettabilities

The movement and detachment of tiny oil droplets in water on a substrate is the key technology to strengthen oil–water separation by using corrugated plate oil–water separation technology. Here, the detachment behaviors of oil droplets adhered to substrates with different wettabilities in a laminar flow field are studied experimentally and theoretically. The morphologic changes of mother and daughter oil droplets are obtained when the adhered oil droplets are continuously separated. The shedding mechanism of oil droplets is analyzed in detail, and the critical condition for the effective detachment of oil droplets is obtained, which can be used to guide the design of the surface wettability and water flow velocity in the actual production of oil–water separation.