1106.4645v1.pdf (3.39 MB)
Nucleation of liquid droplets in a fluid with competing interactions
journal contribution
posted on 2014-10-06, 14:52 authored by Andrew ArcherAndrew Archer, Robert EvansUsing a simple density functional theory (DFT) the height of the free energy barrier for forming a droplet of the liquid phase from the metastable gas phase is determined for a model colloidal fluid exhibiting competing interactions. The pair potential has a hard core of diameter σ, is attractive Yukawa at intermediate separations, and is repulsive Yukawa at large separations. It is found that even a very weak long-range repulsive tail in the pair potential has a profound effect on nucleation: increasing the amplitude of the repulsive Yukawa tail reduces significantly the free energy barrier height and therefore increases the liquid droplet nucleation rate. The method introduced for calculating the droplet density profile and free energy employs a fictitious external potential to stabilize a liquid droplet of the desired size, i.e. with a given excess number of particles. For the critical droplet, corresponding to an extremum of the grand potential, this fictitious potential is everywhere zero. The decay of the droplet density profiles into the bulk gas is examined. For a range of nucleation state points the DFT predicts exponentially damped, long wavelength oscillatory decay for systems exhibiting long-range repulsion, contrasting sharply with the monotonic decay found when the pair potential has only an attractive Yukawa piece. The changes in nucleation properties found for small amplitudes of the repulsive Yukawa tail reflect the propensity of the fluid to form modulated structures such as clusters or stripes
History
School
- Science
Department
- Mathematical Sciences
Published in
MOLECULAR PHYSICSVolume
109Issue
23-24Pages
2711 - 2722 (12)Citation
ARCHER, A.J. and EVANS, R., 2011. Nucleation of liquid droplets in a fluid with competing interactions. Molecular Physics, 109 (23-24), pp. 2711 - 2722.Publisher
© Taylor and FrancisVersion
- AM (Accepted Manuscript)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Publication date
2011Notes
This is an Accepted Manuscript of an article published in Molecular Physics on 27 July 2011, available online: http://www.tandfonline.com/10.1080/00268976.2011.597356ISSN
0026-8976Publisher version
Language
- en