• Editors' Suggestion
  • Open Access

Contact-line deposits from multiple evaporating droplets

Alexander W. Wray, Patrick S. Wray, Brian R. Duffy, and Stephen K. Wilson
Phys. Rev. Fluids 6, 073604 – Published 22 July 2021

Abstract

Building on the recent theoretical work of Wray et al. [J. Fluid Mech. 884, A45 (2020)] concerning the competitive diffusion-limited evaporation of multiple thin sessile droplets in proximity to each other, we obtain theoretical predictions for the spatially nonuniform densities of the contact-line deposits (often referred to as “coffee stains” or “ring stains”) left on the substrate after such droplets containing suspended solid particles have completely evaporated. Neighboring droplets interact via their vapour fields, which results in a spatially nonuniform “shielding” effect. We give predictions for the deposits from a pair of identical droplets, which show that the deposit is reduced the most where the droplets are closest together, and demonstrate excellent quantitative agreement with experimental results of Pradhan and Panigrahi [Colloids Surf. A Physicochem. Eng. Asp. 482, 562 (2015)]. We also give corresponding predictions for a triplet of identical droplets arranged in an equilateral triangle, which show that the effect of shielding on the deposit is more subtle in this case.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 8 January 2021
  • Accepted 25 June 2021

DOI:https://doi.org/10.1103/PhysRevFluids.6.073604

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Published by the American Physical Society

Physics Subject Headings (PhySH)

Fluid Dynamics

Authors & Affiliations

Alexander W. Wray*

  • Department of Mathematics and Statistics, University of Strathclyde, Livingstone Tower, 26 Richmond Street, Glasgow, G1 1XH, United Kingdom

Patrick S. Wray

  • Drug Product Science and Technology, Bristol-Myers Squibb, Reeds Lane, Moreton, Wirral, CH46 1QW, United Kingdom

Brian R. Duffy and Stephen K. Wilson§

  • Department of Mathematics and Statistics, University of Strathclyde, Livingstone Tower, 26 Richmond Street, Glasgow, G1 1XH, United Kingdom

  • *alexander.wray@strath.ac.uk
  • patrick.wray@bms.com
  • b.r.duffy@strath.ac.uk
  • §Author for correspondence: s.k.wilson@strath.ac.uk

Article Text

Click to Expand

References

Click to Expand
Issue

Vol. 6, Iss. 7 — July 2021

Reuse & Permissions
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Fluids

Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

×

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×