Electrowetting-Dominated Instability of Cassie Droplets on Superlyophobic Pillared Surfaces
| Autor: | Yu-Chung Chen, Kenichi Morimoto, Yuji Suzuki |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
02 engineering and technology Surfaces and Interfaces Dielectric Edge (geometry) 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Instability 0104 chemical sciences Contact angle Electric field Electrochemistry Electrowetting General Materials Science Composite material 0210 nano-technology Electrical conductor Spectroscopy Voltage |
| Zdroj: | Langmuir : the ACS journal of surfaces and colloids. 35(6) |
| ISSN: | 1520-5827 |
| Popis: | The liquid–air interface of Cassie droplets on superhydrophobic/superlyophobic surfaces has been directly captured with a high-precision laser displacement meter. The measured profile of the interface shape and the critical voltage with which the Cassie-to-Wenzel transition occurs are compared against those from numerical simulations of the electric field coupled with the interface shape. Under the applied voltage, the collapsing behavior of water, glycerol, and hexadecane droplets on SU-8, CYTOP, and overhanging Si/SiO2 pillars has been uniquely identified depending on the liquid properties, the pillar geometry, and the pillar material. It is shown that, with increasing voltage, the contact angle at the three-phase contact line approaches the maximum advancing angle along the pillar sidewalls, above which the depinning from the pillar edge leads to a slide-down motion. The slide-down instability is dominant over the pull-in instability both on dielectric pillars and conductive overhanging pillars examine... |
| Databáze: | OpenAIRE |
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