Effects of fluid–fluid interfacial properties on the dynamics of bounded viscoelastic thin liquid films

The influence of fluid–fluid interfacial properties on the dynamics of viscoelastic thin liquid films bounded above by liquid–liquid interface and below by a horizontal solid plate is studied in this work. The present study allows for integration of both chemical and physical properties of the thin liquid film within the long wave approximation of the evolution equation for viscoelastic thin films. The effects of the contact angle, slippage and exposure time on interfacial film dynamics are verified. We demonstrate the importance of the interfacial tension due to surfactant concentration and the Marangoni number to responses of thin films to prescribed perturbations. The linear stability analysis shows that the rupture time is dependent on the initial tension, Marangoni number, slippage and contact angle, whereas the cut off wavenumber is only affected by the contact angle. Results of the numerical simulations of the nonlinear regime show that the film dynamics is faster with slippage and exposure time. We confirm that viscoelasticity increases the number of droplets formed after the film rupture. However, the linear relationship between interfacial tension and surfactant concentration fails to describe the thin film dynamics when the Weissenberg number exceeds the Reynolds number.