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Sessile multidroplets and salt droplets under high tangential electric fields
Guoxin Xie1, Feng He1, Xiang Liu1
1State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China.
Scientific Reports
|April 29, 2016
Summary
High voltage applied to sessile droplets causes polarity-dependent discharge and coalescence. Droplet merging is driven by pressure differences, not temperature, influenced by salt ionization and electrode reactions.
Area of Science:
- Physics
- Chemistry
- Materials Science
Background:
- Understanding sessile droplet interactions under high voltage is crucial for microfluidics and outdoor high-power applications.
- Droplet behavior impacts device reliability and longevity, necessitating detailed study.
Purpose of the Study:
- Investigate droplet coalescence, discharge activity, and thermal response of sessile multidroplets and salt droplets under high tangential electric fields.
- Analyze polarity effects and the influence of salt ionization and electrode reactions on droplet behavior.
Main Methods:
- Infrared thermography for surface thermal distribution.
- High-speed photography for droplet dynamics and coalescence.
- Pulse current measurement for discharge activity.
Main Results:
- Observed polarity effects on discharge path direction and initial temperature changes due to anodic dissolution.
- Discharge path influenced initial droplet coalescence location in aligned multidroplets.
- Droplet merging driven by internal pressure differences, not asymmetric temperature changes.
- Discharge inception voltages and temperature variations correlated with salt ionization and interfacial electrochemical reactions.
Conclusions:
- High voltage induces complex interactions in sessile droplets, including polarity-dependent discharge and coalescence.
- Electrochemical reactions and salt properties significantly influence electrical discharge and thermal behavior.
- Pressure-driven coalescence is the primary mechanism for droplet merging in this configuration.
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