Structure and Kinetics of Fatty Acid Langmuir Monolayers on Zinc Salt Solutions
| Autor: | Michel Goldmann, Françoise Perrot, Marie-Claude Fauré, Sophie Cantin |
|---|---|
| Přispěvatelé: | CY Cergy Paris Université (CY), Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2013 |
| Předmět: |
inorganic chemicals
Langmuir Cations Divalent Iodide Inorganic chemistry chemistry.chemical_element 02 engineering and technology Zinc 010402 general chemistry 01 natural sciences chemistry.chemical_compound Adsorption X-Ray Diffraction Monolayer Materials Chemistry Qualitative inorganic analysis [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] Physical and Theoretical Chemistry ComputingMilieux_MISCELLANEOUS chemistry.chemical_classification Molecular Structure Fatty Acids Hydrogen-Ion Concentration 021001 nanoscience & nanotechnology 0104 chemical sciences Surfaces Coatings and Films Solutions [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry Kinetics chemistry Behenic acid Counterion 0210 nano-technology |
| Zdroj: | Journal of Physical Chemistry B Journal of Physical Chemistry B, American Chemical Society, 2013, 117 (50), pp.16275-16282. ⟨10.1021/jp407047a⟩ Journal of Physical Chemistry B, 2013, 117 (50), pp.16275-16282. ⟨10.1021/jp407047a⟩ |
| ISSN: | 1520-5207 1520-6106 |
| Popis: | International audience; The adsorption of zinc cations under behenic acid Langmuir monolayers was investigated by means of isotherm measurements, grazing incidence X-ray diffraction and Brewster angle microscopy. The structure of the films was characterized as a function of Zn2+ concentration, for three different counterions (chloride, iodide, bromide) and at two subphase pHs (5.5 and 7.5). At pH 5.5 and in the studied concentration range, Zn2+ adsorption leads to a condensation of the fatty acid monolayer with the same phase transitions as over pure water. In contrast, at higher pH the organic X-phase is evidenced immediately above a concentration threshold without any ion organization. Even though Cu2+ and Zn(2+)cations induce both the fatty acid X-phase, the kinetics of its formation appears strongly different. Indeed, as for Mg2+ and Cd2+, the intermediate new I-structure is evidenced in the course of Zn2+ adsorption although superstructures are observed only for Mg2+ and Cd2+. However, for Zn2+, the I-phase evolves to the final state through a new structure called X' and a continuous X'-X transition. Finally, any effect of the counterion is evidenced neither during the kinetic process nor in the final state. |
| Databáze: | OpenAIRE |
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