Molecular mechanism for cavitation in water under tension
- Author(s)
- Georg Menzl, Miguel A. Gonzalez, Philipp Geiger, Frederic Caupin, Jose L. F. Abascal, Chantal Valeriani, Christoph Dellago
- Abstract
Despite its relevance in biology and engineering, the molecular mechanism driving cavitation in water remains unknown. Using computer simulations, we investigate the structure and dynamics of vapor bubbles emerging from metastable water at negative pressures. We find that in the early stages of cavitation, bubbles are irregularly shaped and become more spherical as they grow. Nevertheless, the free energy of bubble formation can be perfectly reproduced in the framework of classical nucleation theory (CNT) if the curvature dependence of the surface tension is taken into account. Comparison of the observed bubble dynamics to the predictions of the macroscopic Rayleigh-Plesset (RP) equation, augmented with thermal fluctuations, demonstrates that the growth of nanoscale bubbles is governed by viscous forces. Combining the dynamical prefactor determined from the RP equation with CNT based on the Kramers formalism yields an analytical expression for the cavitation rate that reproduces the simulation results very well over a wide range of pressures. Furthermore, our theoretical predictions are in excellent agreement with cavitation rates obtained from inclusion experiments. This suggests that homogeneous nucleation is observed in inclusions, whereas only heterogeneous nucleation on impurities or defects occurs in other experiments.
- Organisation(s)
- Computational and Soft Matter Physics, Department for Teacher Education
- External organisation(s)
- Imperial College London, Université Claude-Bernard-Lyon-I, Universidad Complutense De Madrid
- Journal
- Proceedings of the National Academy of Sciences of the United States of America (PNAS)
- Volume
- 113
- Pages
- 13582-13587
- No. of pages
- 6
- ISSN
- 0027-8424
- DOI
- https://doi.org/10.1073/pnas.1608421113
- Publication date
- 11-2016
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103015 Condensed matter, 103029 Statistical physics
- Keywords
- ASJC Scopus subject areas
- General
- Portal url
- https://ucris.univie.ac.at/portal/en/publications/molecular-mechanism-for-cavitation-in-water-under-tension(15d61b87-dd81-4980-97af-07c99bae825b).html