The Structure and Phase Diagram of Langmuir Films of Alcohols on Mercury
Autor: | Eli Sloutskin, H. Kraack, L. Tamam, Moshe Deutsch, Peter S. Pershan, B. M. Ocko |
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Rok vydání: | 2004 |
Předmět: |
Langmuir
Analytical chemistry chemistry.chemical_element Alcohol Phase Transition chemistry.chemical_compound Adsorption Molecular film Electrochemistry Surface Tension Organic chemistry Molecule General Materials Science Spectroscopy Alkyl Phase diagram chemistry.chemical_classification Chemistry X-Rays Temperature Mercury Surfaces and Interfaces Condensed Matter Physics Mercury (element) Alcohols |
Zdroj: | Langmuir. 20:5386-5395 |
ISSN: | 1520-5827 0743-7463 |
DOI: | 10.1021/la0497954 |
Popis: | The coverage-dependent phase behavior of molecular films of alcohols (CH3(CH2)n-2CH2OH, denoted as CnOH) on mercury was studied for chain lengths 8or = nor = 28, using surface tensiometry and surface specific X-ray methods. Phases with surface-normal-oriented molecules are found at high coverage, showing the CS, S, and LS phases found also on water. Phases comprising surface parallel molecules, which do not exist on water, are found here at low coverage. For the lowest coverage a two-dimensional gas phase is found, followed, upon increasing the coverage, by an n-dependent sequence of condensed phases of up to four layers of surface-parallel molecules before converting to the surface-normal phases. In contrast with the surface-normal phases, all of the surface-parallel phases are found to lack long-range order in the surface-parallel direction. Adsorption energies are derived from the phase diagram for the alkyl chain and the alcohol headgroup. |
Databáze: | OpenAIRE |
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