Characterization of anomalous flow and phase behavior in a Langmuir monolayer of 2-hydroxy-tetracosanoic acid.
Langmuir monolayers of long-chain fatty acids display a wide range of interesting flow and phase behaviors, but the correlation between these behaviors varies. In this paper, we report two interesting behaviors in a Langmuir monolayer of 2-hydroxy-tetracosanoic acid: phase coexistence between the L(2h) and L(2)' phases over a large pressure range and a peak in the viscosity and elastic modulus of the material as a function of pressure. The two behaviors are confirmed over a range of temperatures for which the location of the undistorted lattice appears to vary relative to the range of coexistence for the two phases. Evidence for a correlation between the phase behavior and the peak in the mechanical properties is presented.
Twardos
Michael
M
Department of Physics and Astronomy and Institute for Interfacial and Surface Science, University of California at Irvine, Irvine, California 92697-4575, USA.
Dennin
Michael
M
Brezesinski
Gerald
G