Dynamics of an impacting emulsion droplet.
Name
sciadv.abl7160.pdf
Description
Published version
Size
2.23 MB
Format
Adobe PDF
Checksum (MD5)
74fec26c36f8f8dd5719fc3ad4283f0c
Author(s)
Damak, Maher
de Ruiter, Jolet
Panat, Sreedath
Varanasi, Kripa K
Date Issued
March 18, 2022
Journal
Sci Adv
Citation
Damak, Maher, de Ruiter, Jolet, Panat, Sreedath and Varanasi, Kripa K. 2022. "Dynamics of an impacting emulsion droplet.." Sci Adv, 8 (11).
Version
Final published version
Abstract
Emulsions are widely used in agriculture where oil-based pesticides are sprayed as an emulsion. However, emulsion droplets can bounce off hydrophobic plant surfaces, leading to major health and environmental issues as pesticides pollute water sources and soils. Here, we report an unexpected transition from bouncing to sticking to bouncing as the droplet impact speed increases. We show that the physics are governed by an in situ, self-generated lubrication of the surface leading to a suction force from the nascent oil layer around the droplet. We demonstrate that this phenomenon can be controlled by a careful balance of three time scales: the contact time of the droplet, the impregnation time scale of the oil, and the oil ridge formation time scale. We lastly build a design map to precisely control the bouncing of droplets and the oil coverage of the target surface. These insights have broad applicability in agriculture, cooling sprays, combustion, and additive manufacturing.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Terms of Use
Creative Commons Attribution NonCommercial License 4.0
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1126/sciadv.abl7160
