Article ID Journal Published Year Pages File Type
148524 Chemical Engineering Journal 2013 7 Pages PDF
Abstract

In addition to the generation of micrometer scaled droplets, microchannel device can also serve as unique platform to control microdroplet coalescence. In this study, a cross-shaped microchannel junction is designed to realize head-on microdroplet coalescence without strict control of droplet synchronism. The flow characters of contacting microdroplets in confined microchannels are carefully examined and a critical capillary number (Ca∗ ≈ 0.005) for the occurrence of coalescence is identified for different working systems. Experimental analysis on the film drainage time and the droplet contact time are carefully discussed and a comparison between microdroplet coalescences in confined and free flowing spaces are taken for the in-depth understanding of microdroplet coalescence process.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Head-on microdroplet coalescence is obtained without synchronism control. ► The critical Ca for microdroplet coalescence is identified as 0.005. ► The critical Ca is larger in confined microchannel than in free flowing space.

Related Topics
Physical Sciences and Engineering Chemical Engineering Chemical Engineering (General)
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