Detachment force of particles from fluid droplets

ETTELAIE, Rammile and LISHCHUK, Sergey (2015). Detachment force of particles from fluid droplets. Soft Matter, 11 (21), 4251-4265.

[img] PDF (Acceptance e-mail)
Lishchuk - 12852.pdf - Other
Restricted to Repository staff only

Download (108kB)
[img]
Preview
PDF (Created using the RSC template)
lishchuk - detachment force.pdf - Accepted Version
All rights reserved.

Download (628kB) | Preview
Official URL: http://pubs.rsc.org/en/Content/ArticleLanding/2015...
Link to published version:: https://doi.org/10.1039/c5sm00540j

Abstract

We calculate the deformation of a spherical droplet, resulting from the application of a pair of opposite forces to particles located diametrically opposite at the two ends of the droplet. The free-energy analysis is used to calculate the force–distance curves for the generated restoring forces, arising from the displacement of the particles relative to each other. While the logarithmic dependence of the “de Gennes–Hooke” constant on the particle to droplet size ratio, ν, is rather well known in the limit of very small ν, we find that for more realistic particle to droplet size ratios, i.e. ν = 0.001 to 0.01, the additional constant terms of O(1) constitute a significant correction to previously reported results. We derive the restoring force constant to be 2πγ[0.5 − ln(ν/2)]−1, in perfect agreement with the exact semi-numerical analysis of the same problem. The deviation from the linear force–displacement behaviour, occurring close to the point of detachment, is also investigated. A study of the energy dissipated shows it to be an increasingly dominant component of the work done during the detachment of the particles, as ν decreases. This indicates the existence of a significantly higher energy barrier to desorption of very small particles, compared to the one suggested by their adsorption energy alone. The influence of the line tension on the detachment force is also considered. It is shown that where line tension is important, the contact angle is no longer a constant but instead alters with the displacement of the particles from their equilibrium positions.

Item Type: Article
Research Institute, Centre or Group - Does NOT include content added after October 2018: Materials and Engineering Research Institute > Modelling Research Centre > Materials Modelling group
Identification Number: https://doi.org/10.1039/c5sm00540j
Page Range: 4251-4265
Depositing User: Sergey Lishchuk
Date Deposited: 12 Aug 2016 10:21
Last Modified: 18 Mar 2021 11:42
URI: https://shura.shu.ac.uk/id/eprint/12852

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year

View more statistics