Chemical Instability-Induced Wettability Patterns on Superhydrophobic Surfaces
Chemical instability of liquid-repellent surfaces is one of the nontrivial hurdles that hinders their real-world applications. Although much effort has been made to prepare chemically durable liquid-repellent surfaces, little attention has been paid to exploit the instability for versatile use. Here...
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| Format: | Article |
| Language: | English |
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MDPI AG
2024-02-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/15/3/329 |
| _version_ | 1797239997426827264 |
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| author | Tianchen Chen Faze Chen |
| author_facet | Tianchen Chen Faze Chen |
| author_sort | Tianchen Chen |
| collection | DOAJ |
| description | Chemical instability of liquid-repellent surfaces is one of the nontrivial hurdles that hinders their real-world applications. Although much effort has been made to prepare chemically durable liquid-repellent surfaces, little attention has been paid to exploit the instability for versatile use. Herein, we propose to create hydrophilic patterns on a superhydrophobic surface by taking advantage of its chemical instability induced by acid solution treatment. A superhydrophobic Cu(OH)<sub>2</sub> nanoneedle-covered Cu plate that shows poor stability towards HCl solution (1.0 M) is taken as an example. The results show that 2.5 min of HCl solution exposure leads to the etching of Cu(OH)<sub>2</sub> nanoneedles and the partial removal of the self-assembled fluoroalkyl silane molecular layer, resulting in the wettability transition from superhydrophobocity to hydrophilicity, and the water contact angle decreases from ~160° to ~30°. Hydrophilic dimples with different diameters are then created on the superhydrophobic surfaces by depositing HCl droplets with different volumes. Afterwards, the hydrophilic dimple-patterned superhydrophobic surfaces are used for water droplet manipulations, including controlled transfer, merging, and nanoliter droplet deposition. The results thereby verify the feasibility of creating wettability patterns on superhydrophobic surfaces by using their chemical instability towards corrosive solutions, which broadens the fabrication methods and applications of functional liquid-repellent surfaces. |
| first_indexed | 2024-04-24T18:00:25Z |
| format | Article |
| id | doaj.art-6203d5fbf959453da50e80a1778f14ae |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-04-24T18:00:25Z |
| publishDate | 2024-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-6203d5fbf959453da50e80a1778f14ae2024-03-27T13:55:03ZengMDPI AGMicromachines2072-666X2024-02-0115332910.3390/mi15030329Chemical Instability-Induced Wettability Patterns on Superhydrophobic SurfacesTianchen Chen0Faze Chen1School of Mechanical Engineering, Tianjin University, Tianjin 300350, ChinaSchool of Mechanical Engineering, Tianjin University, Tianjin 300350, ChinaChemical instability of liquid-repellent surfaces is one of the nontrivial hurdles that hinders their real-world applications. Although much effort has been made to prepare chemically durable liquid-repellent surfaces, little attention has been paid to exploit the instability for versatile use. Herein, we propose to create hydrophilic patterns on a superhydrophobic surface by taking advantage of its chemical instability induced by acid solution treatment. A superhydrophobic Cu(OH)<sub>2</sub> nanoneedle-covered Cu plate that shows poor stability towards HCl solution (1.0 M) is taken as an example. The results show that 2.5 min of HCl solution exposure leads to the etching of Cu(OH)<sub>2</sub> nanoneedles and the partial removal of the self-assembled fluoroalkyl silane molecular layer, resulting in the wettability transition from superhydrophobocity to hydrophilicity, and the water contact angle decreases from ~160° to ~30°. Hydrophilic dimples with different diameters are then created on the superhydrophobic surfaces by depositing HCl droplets with different volumes. Afterwards, the hydrophilic dimple-patterned superhydrophobic surfaces are used for water droplet manipulations, including controlled transfer, merging, and nanoliter droplet deposition. The results thereby verify the feasibility of creating wettability patterns on superhydrophobic surfaces by using their chemical instability towards corrosive solutions, which broadens the fabrication methods and applications of functional liquid-repellent surfaces.https://www.mdpi.com/2072-666X/15/3/329superhydrophobic surfacechemical instabilitywettability patterndroplet manipulation |
| spellingShingle | Tianchen Chen Faze Chen Chemical Instability-Induced Wettability Patterns on Superhydrophobic Surfaces Micromachines superhydrophobic surface chemical instability wettability pattern droplet manipulation |
| title | Chemical Instability-Induced Wettability Patterns on Superhydrophobic Surfaces |
| title_full | Chemical Instability-Induced Wettability Patterns on Superhydrophobic Surfaces |
| title_fullStr | Chemical Instability-Induced Wettability Patterns on Superhydrophobic Surfaces |
| title_full_unstemmed | Chemical Instability-Induced Wettability Patterns on Superhydrophobic Surfaces |
| title_short | Chemical Instability-Induced Wettability Patterns on Superhydrophobic Surfaces |
| title_sort | chemical instability induced wettability patterns on superhydrophobic surfaces |
| topic | superhydrophobic surface chemical instability wettability pattern droplet manipulation |
| url | https://www.mdpi.com/2072-666X/15/3/329 |
| work_keys_str_mv | AT tianchenchen chemicalinstabilityinducedwettabilitypatternsonsuperhydrophobicsurfaces AT fazechen chemicalinstabilityinducedwettabilitypatternsonsuperhydrophobicsurfaces |