Linked Life Data

19759616

Source:http://linkedlifedata.com/resource/pubmed/id/19759616

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7262
pubmed:dateCreated
2009-9-17
pubmed:abstractText
Electric fields induce motion in many fluid systems, including polymer melts, surfactant micelles and colloidal suspensions. Likewise, electric fields can be used to move liquid drops. Electrically induced droplet motion manifests itself in processes as diverse as storm cloud formation, commercial ink-jet printing, petroleum and vegetable oil dehydration, electrospray ionization for use in mass spectrometry, electrowetting and lab-on-a-chip manipulations. An important issue in practical applications is the tendency for adjacent drops to coalesce, and oppositely charged drops have long been assumed to experience an attractive force that favours their coalescence. Here we report the existence of a critical field strength above which oppositely charged drops do not coalesce. We observe that appropriately positioned and oppositely charged drops migrate towards one another in an applied electric field; but whereas the drops coalesce as expected at low field strengths, they are repelled from one another after contact at higher field strengths. Qualitatively, the drops appear to 'bounce' off one another. We directly image the transient formation of a meniscus bridge between the bouncing drops, and propose that this temporary bridge is unstable with respect to capillary pressure when it forms in an electric field exceeding a critical strength. The observation of oppositely charged drops bouncing rather than coalescing in strong electric fields should affect our understanding of any process involving charged liquid drops, including de-emulsification, electrospray ionization and atmospheric conduction.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Sep
pubmed:issn
1476-4687
pubmed:author
pubmed:issnType
Electronic
pubmed:day
17
pubmed:volume
461
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
377-80
pubmed:year
2009
pubmed:articleTitle
Non-coalescence of oppositely charged drops.
pubmed:affiliation
Department of Chemical Engineering and Materials Science, University of California at Davis, 1 Shields Drive, Davis, California 95616, USA. wdristenpart@ucdavis.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't