Influence of Nanoparticles on the Evaporation of a Nanodroplet from Solid Substrates: An Experimental and Molecular Dynamics Investigation

Abstract

Molecular Dynamic simulations and experiments have been performed to investigate the evaporative behavior of a liquid droplet in the presence of nanoparticles on a smooth, heated flat plate. Nanofluids of different volume fractions with CuO and Al2O3 nanoparticles were prepared to obtain liquid droplets. Experiments were conducted for droplets of both nanofluids and base fluid (DI water). The results showed that in the pinned region of evaporation, droplets of nanofluids with higher volume fractions of dense nanoparticles evaporated by keeping their base pinned at the triple point contact line. It is also observed that the evaporation rate of nanofluid droplets with nanoparticles having higher density is slower and promoted a typical pattern formation. Molecular Dynamic simulations were further performed to analyse the influence of various nanoparticle-liquid interaction strengths (εnp−l) on evaporative behavior. The simulation results suggest that in the pinned evaporation stage, for higher values of εnp−l, the droplet undergoes a delay on evaporation while subjected to higher heat flux on the substrate.