A molecular dynamics investigation of the surface tension of water nanodroplets and a new technique for local pressure determination through density correlation
by Leong, Kai-Yang; Wang, Feng
The surface tension of nanoscale droplets of water was studied with molecular dynamics simulations using the BLYPSP-4F water potential. The internal pressure of the droplet was measured using an empirical correlation between the pressure and density, established through a series of bulk simulations performed at pressures from 1 to 1000 bars. Such a procedure allows for reliable determination of internal pressure without the need to calculate the local virial. The surface tension, estimated with the Young-Laplace relation, shows good agreement with the Tolman equation with a Tolman length of -0.48 angstrom. The interface of a liquid water droplet is shown to be around 1.1-1.3 nm thick depending on radii. The fairly thick interface region puts a lower limit on the size of droplets that still have a bulk-like interior. Published by AIP Publishing.
- Journal
- Journal of Chemical Physics
- Volume
- 148
- Issue
- 14
- Year
- 2018
- URL
- https://dx.doi.org/10.1063/1.5004985
- ISBN/ISSN
- 1089-7690; 0021-9606
- DOI
- 10.1063/1.5004985