Coalescence of electrically charged liquid marbles

Binks, Bernard P.; Fu, Xiangyu; Liu, Zhou; Shum, Ho Cheung

Abstract

© The Royal Society of Chemistry. In this work, we investigated the coalescence of liquid water marbles driven by a DC electric field. We have found that two contacting liquid marbles can be forced to coalesce when they are charged by a sufficiently high voltage. The threshold voltage leading to the electro-coalescence sensitively depends on the stabilizing particles as well as the surface tension of the aqueous phase. By evaluating the electric stress and surface tension effect, we attribute such coalescence to the formation of a connecting bridge driven by the electric stress. This liquid bridge subsequently grows and leads to the merging of the marbles. Our interpretation is confirmed by the scaling relation between the electric stress and the restoring capillary pressure. In addition, multiple marbles in a chain can be driven to coalesce by a sufficiently high threshold voltage that increases linearly with the number of the marbles. We have further proposed a simple model to predict the relationship between the threshold voltage and the number of liquid marbles, which agrees well with the experimental results. The concept of electro-coalescence of liquid marbles can be potentially useful in their use as containers for chemical and biomedical reactions involving multiple reagents.

Citation

Binks, B. P., Fu, X., Liu, Z., & Shum, H. C. (2017). Coalescence of electrically charged liquid marbles. Soft matter, 13(1), 119-124. https://doi.org/10.1039/c6sm00883f

• Journal Article Type: Article
• Acceptance Date: May 4, 2016
• Publication Date: 2017-02
• Deposit Date: May 5, 2016
• Publicly Available Date: Feb 6, 2017
• Journal: Soft matter
• Print ISSN: 1744-683X
• Electronic ISSN: 1744-6848
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 13
• Issue: 1
• Pages: 119-124
• DOI: https://doi.org/10.1039/c6sm00883f
• Keywords: Liquid marbles
• Public URL: https://hull-repository.worktribe.com/output/437734
• Publisher URL: http://pubs.rsc.org/en/content/articlelanding/2016/sm/c6sm00883f#!divAbstract
• Additional Information: Authors' accepted manuscript of article published in: Soft matter, 2017, v.13.