Superspreading - Has the mystery been unraveled?

摘要: Abstract Superspreading is a fascinating phenomenon first observed about 30 years ago with dilute solutions of trisiloxane surfactants on hydrophobic substrates. Although many groups all over the world have contributed considerably to solve scientific challenges involved, reasons why only some promote superspreading, whereas others similar chemical structure behave more like ordinary surfactants, has remained mystery up now. A number original papers and reviews superspreading been published in recent years. The driving force still proposed today most often Marangoni flow. This is, however, contradiction results showing that starts after surface tension gradient between apex leading edge eliminated. From foam film experiments unrelated wetting, there evidence for “dangling” bilayers attached air/water interface case surfactants. By combining this other experimental findings, new hypothesis mode action put forward: Advancing by “rolling action” at edge, supply surfactant “unzippering” dangling drop; even fulfills basic thermodynamic requirements.