Coalescence of Spreading Droplets on a Wettable Substrate
- 7 August 2006
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review Letters
- Vol. 97 (6), 064501
- https://doi.org/10.1103/physrevlett.97.064501
Abstract
We investigate experimentally and theoretically the coalescence dynamics of two spreading droplets on a highly wettable substrate. Upon contact, surface tension drives a rapid motion perpendicular to the line of centers that joins the drops and lowers the total surface area. We find that the width of the growing meniscus bridge between the two droplets exhibits power-law behavior, growing at early times as . Moreover, the growth rate is highly sensitive to both the radii and heights of the droplets at contact, scaling as . This size dependence differs significantly from the behavior of freely suspended droplets, in which the coalescence growth rate depends only weakly on the droplet size. We demonstrate that the scaling behavior is consistent with a model in which the growth of the meniscus bridge is governed by the viscously hindered flux from the droplets.
Keywords
This publication has 19 references indexed in Scilit:
- Hydrodynamics of Droplet CoalescencePhysical Review Letters, 2005
- Reflectivity-based evaluation of the coalescence of two condensing drops and shape evolution of the coalesced dropPhysical Review E, 2004
- Contact Line Dynamics in Drop Coalescence and SpreadingLangmuir, 2004
- A Microfluidic System for Controlling Reaction Networks in TimeAngewandte Chemie-International Edition, 2003
- Coalescence of sessile dropsJournal of Fluid Mechanics, 2002
- Coalescence of liquid dropsJournal of Fluid Mechanics, 1999
- Kinetic spray coatingsSurface and Coatings Technology, 1999
- Effect of droplet size and carrier volume on performance of foliage-applied herbicidesCrop Protection, 1994
- Solidification of droplets on a cold surfaceInternational Journal of Heat and Mass Transfer, 1976
- The Leaching of Substances from PlantsAnnual Review of Plant Physiology, 1970