Structure and Kinetics of Fatty Acid Langmuir Mono layers on Zinc Salt Solutions - Archive ouverte HAL
Article Dans Une Revue Journal of Physical Chemistry B Année : 2013

Structure and Kinetics of Fatty Acid Langmuir Mono layers on Zinc Salt Solutions

Sophie Cantin
Marie-Claude Fauré
  • Fonction : Auteur
  • PersonId : 864359
Françoise Perrot
  • Fonction : Auteur
  • PersonId : 832467
Michel Goldmann

Résumé

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.
Fichier non déposé

Dates et versions

hal-01238964 , version 1 (07-12-2015)

Identifiants

Citer

Sophie Cantin, Marie-Claude Fauré, Françoise Perrot, Michel Goldmann. Structure and Kinetics of Fatty Acid Langmuir Mono layers on Zinc Salt Solutions. Journal of Physical Chemistry B, 2013, 117 (50), pp.16275-16282. ⟨10.1021/jp407047a⟩. ⟨hal-01238964⟩
54 Consultations
0 Téléchargements

Altmetric

Partager

More