Entrapment and Dissolution of Microbubbles Inside Microwells

Xiaolai Li, Yuliang Wang* (Corresponding Author), Binglin Zeng, Yanshen Li, Huanshu Tan, Harold J.W. Zandvliet, Xuehua Zhang, Detlef Lohse

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

7 Citations (Scopus)
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Abstract

The formation and evolution of immersed surface micro- and nanobubbles are essential in various practical applications, such as the usage of superhydrophobic materials, drug delivery, and mineral flotation. In this work, we investigate the entrapment of microbubbles on a hydrophobic surface, structured with microwells, when water flow passes along, and the subsequent microbubble dissolution. At entrapment, the microbubble is initially pinned at the edge of the microwell. At some point, the three-phase contact line detaches from one side of the edge and separates from the wall, after which it further recedes. We systematically investigate the evolution of the footprint diameter and the contact angle of the entrapped microbubbles, which reveals that the dissolution process is in the constant contact angle mode. By varying the gas undersaturation level, we quantify how a high gas undersaturation enhances the dissolution process, and compare with simplified theoretical predictions for dissolving bubbles on a plane surface. We find that geometric partial blockage effects of the diffusive flux out of the microbubble trapped in the microwell lead to reduced dissolution rates.

Original languageEnglish
Pages (from-to)10659-10667
Number of pages9
JournalLangmuir
Volume34
Issue number36
DOIs
Publication statusPublished - 11 Sep 2018

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Keywords

  • UT-Hybrid-D

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