Phase separation of palmitic acid and perfluorooctadecanoic acid in mixed Langmuir-Blodgett monolayer films.
Deposition of mixtures of palmitic acid (C15H31COOH) and perfluorooctadecanoic acid (C17F35COOH) onto solid substrates gives rise to irregularly shaped, phase-separated domains under a variety of deposition conditions. The morphology and chemical composition of these phase-separated domains have been investigated using a combination of surface pressure-area isotherms, atomic force microscopy, X-ray photoemission electron microscopy, and confocal fluorescence microscopy imaging. While domain morphology and composition in 2D phase-separated mixed monolayer systems can typically be rationalized in terms of an interplay between line tension and dipole-dipole repulsion effects, it was found that for this system additional kinetic factors, including domain growth rates and the rate of dissolution of the fatty acid component into the aqueous subphase, also play a major role in controlling film properties. The potential importance of these effects for the controlled patterning of solid substrates is discussed.
Qaqish
Shatha E
SE
Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan, Canada S7N 5C9.
Urquhart
Stephen G
SG
Lanke
Uday
U
Brunet
Sophie M K
SM
Paige
Matthew F
MF