Can liquid density-fluctuations near solid surface drive the motion of nanoscale droplets?

Abstract

We use thermodynamic models and molecular simulations to show that liquid-density fluctuations near solid surfaces can affect the driving force for capillary-motion under non-isothermal conditions. The above is possible for weakly attractive solid surfaces that show spatial variation of nanoscale roughness at large scales and chemical heterogeneities at small scales. Our model also indicates that the capillary-motion driven by interfacial fluctuations can improve the energy-efficiency of nano-fluidic devices. We have discussed the implications for two scenarios: 1) liquid inside a pore, and 2) an axisymmetric liquid droplet on a flat surface.