Extraordinarily Rapid Rise of Tiny Bubbles Sliding beneath Superhydrophobic Surfaces

Tiny bubbles readily stick onto substrates owing to contact angle hysteresis (CAH). Nevertheless, they can slide slowly on a tilted surface with ultralow CAH because capillarity is overcome by buoyancy. It is surprising to observe experimentally that bubbles of 3-15 μL (diameter 1.79-3.06 mm) slide...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 33(2017), 5 vom: 07. Feb., Seite 1326-1331
1. Verfasser: Wu, Cyuan-Jhang (VerfasserIn)
Weitere Verfasser: Chang, Cheng-Chung, Sheng, Yu-Jane, Tsao, Heng-Kwong
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2017
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article Research Support, Non-U.S. Gov't
Beschreibung
Zusammenfassung:Tiny bubbles readily stick onto substrates owing to contact angle hysteresis (CAH). Nevertheless, they can slide slowly on a tilted surface with ultralow CAH because capillarity is overcome by buoyancy. It is surprising to observe experimentally that bubbles of 3-15 μL (diameter 1.79-3.06 mm) slide beneath a tilted superhydrophobic surface at a vertical ascent rate faster than that of freely rising ones of high Reynold numbers ≈O(102). As the tilting angle increases, the drag coefficient remains essentially the same as that of a freely rising bubble, but the frontal area of the flat bubble rises monotonically. Nonetheless, the frontal area of the sliding bubble always stays much smaller than that of a freely rising bubble. Consequently, the small drag force associated with the sliding bubbles is attributed to their substantially small frontal areas on superhydrophobic surfaces
Beschreibung:Date Completed 18.04.2018
Date Revised 18.04.2018
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1520-5827
DOI:10.1021/acs.langmuir.6b04645