Compression of langmuir films composed of fine particles: Collapse mechanism and wettability

Sándor Bordács, Attila Agod, Zoltán Hórvölgyi

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36 Citations (Scopus)

Abstract

The collapse mechanism of microparticulate Langmuir films was studied experimentally in the present work. Using a Wilhelmy film balance, surface pressure vs area isotherms were determined, and the particle removal during the compression was examined by video-microscope and by naked eye. Upon compressing partially wettable 75 μm diameter surface modified glass beads at liquid (water or aqueous surfactant solution)-air (or n-octane) interfaces, different collapse mechanisms were visualized depending on the wettability of the particles. At low contact angles (below 40°) irreversible particle removal was observed as a consequence of a paniculate line-by-line collapse mechanism. At higher contact angles a buckling-type collapse mechanism was revealed without particle removal from the liquid interface. In the case of irreversible particle removal we assessed the contact angles from the nondissipative part of the isotherm. These values were found to be in reasonable agreement with those determined directly on the beads.

Original languageEnglish
Pages (from-to)6944-6950
Number of pages7
JournalLangmuir
Volume22
Issue number16
DOIs
Publication statusPublished - Aug 1 2006

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ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Spectroscopy
  • Electrochemistry

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