D. Vollhardt, V. Fainerman
Jan 8, 2004
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0
Influential Citations
14
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Journal
Journal of Physical Chemistry B
Abstract
Surface pressure−area per molecule (Π−A) isotherms and lattice structures of n-hydroxyoctadecanoic acid monolayers with n = 2, 9, 11, and 12 are experimentally studied to obtain information on the effect of the hydroxyl group position on the phase behavior and properties of the monolayers. Striking differences exist between the monolayers of 2-hydroxyoctadecanoic acid and hydroxyoctadecanoic acids with n = 9−12. Theoretical calculations of the Π−A isotherms are performed to explain the strong effect of the position of the OH-substitution on the thermodynamic properties of the monolayers. The calculations provide reasonable agreement between the theoretical predictions and the experimental Π−A isotherms are obtained as well as between the parameters calculated from the theoretical model and those obtained from the GIXD measurements. The combination with the experimental GIXD data allows conclusions on the orientation of the molecules in the different monolayer states and their changes at the main phase tra...