Marangoni instability of immiscible liquid–liquid stratified flow with a planar interface in the presence of interfacial mass transfer

•Marangoni instability of immiscible liquid–liquid stratified flow with interfacial mass transfer in either direction was investigated.•The effects of Marangoni number Ma, Reynolds number Re, viscosity ratio m, diffusion ratio, Schmidt number Sc and mass transfer direction on Marangoni instability were outlined.•Marangoni instability only happens at small Re number, where Marangoni instability induced by mass transfer plays the main roles.

Marangoni instability of immiscible liquid–liquid stratified flow with interfacial mass transfer was investigated. In this approach, a linear approximation relation of surface tension with solute concentration was assumed, and the stability of the flow was studied by small disturbance theory. Numerical results indicated that Marangoni instability occurs when Re number is very small (less than 1) and it should be considered in liquid–liquid stratified flows with interfacial mass transfer.