Computer simulations of catanionic surfactants adsorbed at air/water interfaces. II. Full coverage

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We extend our previous molecular dynamics experiments [Rodriguez, J. Phys. Chem. B 109, 24427 (2005)] to the analysis of the adsorption of catanionic surfactants at water/air interfaces, at a surfactant coverage close to that of the saturated monolayer: 30.3 Å2 per headgroup. The mixture of surfacta...

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Autores principales: Clavero, E., Rodriguez, J., Laria, D.
Formato: Artículo publishedVersion
Lenguaje:Inglés
Publicado: 2007
Materias:
Adsorption
Density (specific gravity)
Molecular dynamics
Phase interfaces
Substrates
Dodecytrimethylammonium
Interfacial domains
Tessellation
Water/air interfaces
Cationic surfactants
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00219606_v127_n12_p_Clavero
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling paperaa:paper_00219606_v127_n12_p_Clavero2023-06-12T16:43:17Z Computer simulations of catanionic surfactants adsorbed at air/water interfaces. II. Full coverage J Chem Phys 2007;127(12) Clavero, E. Rodriguez, J. Laria, D. Adsorption Density (specific gravity) Molecular dynamics Phase interfaces Substrates Dodecytrimethylammonium Interfacial domains Tessellation Water/air interfaces Cationic surfactants We extend our previous molecular dynamics experiments [Rodriguez, J. Phys. Chem. B 109, 24427 (2005)] to the analysis of the adsorption of catanionic surfactants at water/air interfaces, at a surfactant coverage close to that of the saturated monolayer: 30.3 Å2 per headgroup. The mixture of surfactants investigated corresponds to equal amounts of dodecytrimethylammonium (DTA) and dodecylsulfate (DS). The structure of the interface is analyzed in terms of the local densities and orientational correlations of all relevant interfacial species. In accordance with experimental evidence, the DTA headgroups penetrate deeper into the aqueous substrate than the DS ones, although the average positions of all headgroups, with respect to the interface, lie in positions somewhat more external than the ones observed at lower coverages. Average tail tilts are close to 45°. The characteristics of the headgroup-water substrate correlations are also analyzed using a tessellation procedure of the interface. The density and polarization responses of the interfacial domains closest to the DS headgroups are enhanced, compared to those adjacent to the DTA detergents. Dynamical aspects related to the diffusion and to the orientational correlations of different water layers in close contact with the surfactant are also investigated. © 2007 American Institute of Physics. Fil:Clavero, E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Rodriguez, J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Laria, D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2007 info:eu-repo/semantics/article info:ar-repo/semantics/artículo info:eu-repo/semantics/publishedVersion application/pdf eng info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00219606_v127_n12_p_Clavero
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
language Inglés
orig_language_str_mv eng
topic Adsorption
Density (specific gravity)
Molecular dynamics
Phase interfaces
Substrates
Dodecytrimethylammonium
Interfacial domains
Tessellation
Water/air interfaces
Cationic surfactants
spellingShingle Adsorption
Density (specific gravity)
Molecular dynamics
Phase interfaces
Substrates
Dodecytrimethylammonium
Interfacial domains
Tessellation
Water/air interfaces
Cationic surfactants
Clavero, E.
Rodriguez, J.
Laria, D.
Computer simulations of catanionic surfactants adsorbed at air/water interfaces. II. Full coverage
topic_facet Adsorption
Density (specific gravity)
Molecular dynamics
Phase interfaces
Substrates
Dodecytrimethylammonium
Interfacial domains
Tessellation
Water/air interfaces
Cationic surfactants
description We extend our previous molecular dynamics experiments [Rodriguez, J. Phys. Chem. B 109, 24427 (2005)] to the analysis of the adsorption of catanionic surfactants at water/air interfaces, at a surfactant coverage close to that of the saturated monolayer: 30.3 Å2 per headgroup. The mixture of surfactants investigated corresponds to equal amounts of dodecytrimethylammonium (DTA) and dodecylsulfate (DS). The structure of the interface is analyzed in terms of the local densities and orientational correlations of all relevant interfacial species. In accordance with experimental evidence, the DTA headgroups penetrate deeper into the aqueous substrate than the DS ones, although the average positions of all headgroups, with respect to the interface, lie in positions somewhat more external than the ones observed at lower coverages. Average tail tilts are close to 45°. The characteristics of the headgroup-water substrate correlations are also analyzed using a tessellation procedure of the interface. The density and polarization responses of the interfacial domains closest to the DS headgroups are enhanced, compared to those adjacent to the DTA detergents. Dynamical aspects related to the diffusion and to the orientational correlations of different water layers in close contact with the surfactant are also investigated. © 2007 American Institute of Physics.
format Artículo
Artículo
publishedVersion
author Clavero, E.
Rodriguez, J.
Laria, D.
author_facet Clavero, E.
Rodriguez, J.
Laria, D.
author_sort Clavero, E.
title Computer simulations of catanionic surfactants adsorbed at air/water interfaces. II. Full coverage
title_short Computer simulations of catanionic surfactants adsorbed at air/water interfaces. II. Full coverage
title_full Computer simulations of catanionic surfactants adsorbed at air/water interfaces. II. Full coverage
title_fullStr Computer simulations of catanionic surfactants adsorbed at air/water interfaces. II. Full coverage
title_full_unstemmed Computer simulations of catanionic surfactants adsorbed at air/water interfaces. II. Full coverage
title_sort computer simulations of catanionic surfactants adsorbed at air/water interfaces. ii. full coverage
publishDate 2007
url http://hdl.handle.net/20.500.12110/paper_00219606_v127_n12_p_Clavero
work_keys_str_mv AT claveroe computersimulationsofcatanionicsurfactantsadsorbedatairwaterinterfacesiifullcoverage
AT rodriguezj computersimulationsofcatanionicsurfactantsadsorbedatairwaterinterfacesiifullcoverage
AT lariad computersimulationsofcatanionicsurfactantsadsorbedatairwaterinterfacesiifullcoverage
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