Dynamic equilibrium Mechanism for Surface Nanobubble Stabilization

Overview

Authors: Michael P. Brenner & Detlef Lohse

Source: arXiv:0810.4715v1

Soft matter key words: nanobubbles, Laplace pressure, hydrophobic surface

Abstract

Recent experiments have convincingly demonstrated the existence of surface nanobubbles on submerged hydrophobic surfaces. However, classical theory dictates that small gaseous bubbles quickly dissolve because their large Laplace pressure causes a diffusive outflux of gas. Here we suggest that the bubbles are stabilized by a continuous influx of gas near the contact line, due to the gas attraction towards hydrophobic walls (Dammer & Lohse, PRL96, 206101 (2006); Zhang et al., PRL98, 136101 (2007); Mezger et al., J. Chem. Phys. 128, 244705 (2008)). This influx balances the outflux and allows for a meta-stable equilibrium, which however vanishes in thermodynamic equilibrium. Our theory predicts the equilibrium radius of the surface nanobubbles, as well as the threshold for surface nanobubble formation as a function of hydrophobicity and gas concentration.

Soft Matter Snippet

Fig.1 : M.P.Brenner & D.Lohse

Fig.2 : M.P.Brenner & D.Lohse

Fig.3 : M.P.Brenner & D.Lohse