Wetting Transition from the Cassie–Baxter State to the Wenzel State on Regularly Nanostructured Surfaces Induced by an Electric Field
| Autor: | Shuo-Lin Wang, Xiao-Dong Wang, Ben-Xi Zhang |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Condensed matter physics 02 engineering and technology Surfaces and Interfaces State (functional analysis) 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 0104 chemical sciences Wetting transition Electric field Electrochemistry General Materials Science Wetting 0210 nano-technology Spectroscopy |
| Zdroj: | Langmuir. 35:662-670 |
| ISSN: | 1520-5827 0743-7463 |
| Popis: | When droplets are placed on hydrophobic textured surfaces, different wetting states Cassie-Baxter (CB) state or Wenzel (W) state may occur depending on materials and structures of surfaces, types and sizes of droplets, thermal fluctuations, and external stimuli. The wetting transition from the CB to the W state and the opposite process have attracted a great deal of attention because of their primary importance for designing and fabricating textured surfaces. In this work, molecular dynamics (MD) simulations are employed to understand the mechanism behind the CB-to-W transition for a nanoscale water film placed on a surface decorated with a single nanogroove when an external electric field is applied. The free energy variation during the transition process is computed on the basis of the restrained MD simulations. Water intrusion into the groove is observed by simulation snapshots, which provides direct evidence for the electric field-induced CB-to-W transition. In the previous experiments, however, only a sharp reduction in the apparent contact angle is employed to judge whether the transition takes place. The free energy curves reveal that there are two energy barriers separating the CB and W states (Δ E |
| Databáze: | OpenAIRE |
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