Study on the adsorption mechanism of droplets on parallel flow interfaces in U-shaped microchannels

The adsorption process of deionized water droplets on the parallel flow interface between ionic liquid [BMIM][PF6] and mineral oil is investigated in U-shaped microchannels. Three flow patterns of the efficient adsorption, moderate adsorption, and inefficient adsorption based on the adsorption efficiency were observed. The dimensionless droplet length D / W > 0.72 is conducive to efficient adsorption of droplets. When droplet shape factor β > 1, the lubrication pressure generated within the curved liquid film has a more significant hindrance on the adsorption process, and the reverse lubrication pressure at the outlet of the liquid film is the main reason for the rupture of the liquid film. An increase in the velocity of phase interface A-B movement can lead to an increase in lubrication pressure. A correlation model is established between the dimensionless adsorption length L * and the dimensionless adsorption time t *, and the influence of Laplace pressure is analyzed.