Fingering instabilities in dewetting nanofluids

Pauliac-Vaujour E., Stannard A., Martin C.P., Blunt M.O., Notingher I., Moriarty P.J., Vancea I., Thiele U.

Abstract

The growth of fingering patterns in dewetting nanofluids (colloidal solutions of thiol-passivated gold nanoparticles) has been followed in real time using contrast-enhanced video microscopy. The fingering instability on which we focus here arises from evaporatively driven nucleation and growth in a nanoscopically thin precursor solvent film behind the macroscopic contact line. We find that well-developed isotropic fingering structures only form for a narrow range of experimental parameters. Numerical simulations, based on a modification of the MonteCarlo approach introduced by Rabani etal., reproduce the patterns we observe experimentally. © 2008 The American Physical Society.