Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10377940 | Journal of Colloid and Interface Science | 2005 | 7 Pages |
Abstract
We studied interfacial properties of a series of methyl and ethyl esters of enantioenriched syn-2,3-dihydroxy fatty acids with different chain lengths at the air-water interface, using a Langmuir type film balance and a Brewster angle microscope (BAM). After analyzing their surface pressure (Î )-area (A) isotherms, we inferred that these molecules existed as an E conformation in the liquid-expanded (LE) phase of monolayers, and the E conformation of molecules changed into a Z conformation during the LE-LC transition in a monolayer. BAM images evidenced the formation of elongated LC aggregates. This is possibly induced by the intermolecular hydrogen bonds, leading to the anisotropic growth of LC domains, on the basis of the FT-IR spectroscopy data. The enthalpy change of the LE-LC phase transition is considered to result from the three types of intermolecular interactions at the air-water interface during compression of these amphiphiles. These findings are discussed in terms of various physical factors that influenced intermolecular interactions and macroscopic aggregations of these amphiphiles.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Colloid and Surface Chemistry
Authors
Liyan Wang, Sandra Jacobi, Jing Sun, Michael Overs, Harald Fuchs, Hans Juergen Schaefer, Xi Zhang, Jiacong Shen, Lifeng Chi,