Loading…
Motions of droplets on hydrophobic model surfaces induced by thermal gradients
We have studied experimentally the motions of liquid droplets deposited on nonwettable surfaces (silanized silicon wafers) submitted to horizontal thermal gradients partial differential T. Systematic measurements of the drift velocity V for different droplet radii R show the following: (i) the dropl...
Saved in:
Published in: | Langmuir 1993-08, Vol.9 (8), p.2220-2224 |
---|---|
Main Authors: | , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | We have studied experimentally the motions of liquid droplets deposited on nonwettable surfaces (silanized silicon wafers) submitted to horizontal thermal gradients partial differential T. Systematic measurements of the drift velocity V for different droplet radii R show the following: (i) the droplets move only above a critical radius R sub(c) which depends on contact angle hysteresis and is inversely proportional to partial differential T; (ii) above R sub(c), V increases linearly with R and partial differential T; (iii) for large radii R (droplets flattened by gravity), V reaches a saturation value. The droplet contour is no longer circular, but presents two straight-line segments in the direction of partial differential T. The flow patterns at the free surface of the droplets have been monitored by video recording the displacement of floating particles. |
---|---|
ISSN: | 0743-7463 1520-5827 |
DOI: | 10.1021/la00032a052 |