Phase diagram of mixed monolayers of stearic acid and dimyristoylphosphatidylcholine. Effect of the acid ionization

Autores
Vega Mercado, Franco; Maggio, Bruno; Wilke, Natalia
Año de publicación
2011
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The aim of this work is to study the phase diagram of mixed monolayers composed of dimyristoylphosphatidylcholine (DMPC) and stearic acid (SA) at different ionic strength and bulk pH of the aqueous subphase. In this way, the effect of ionization of SA on the interaction and thus on phase separation with the DMPC matrix can be analyzed. To this purpose, we first determined the ionization state of pure SA monolayers as a function of the bulk subphase pH. The SA monolayers are nearly fully ionized at pH 10 and essentially neutral at pH 4 and the mixture of DMPC and SA was studied at those two pHs. We found that the DMPC-enriched phase admits more SA if the SA monolayer is in a liquid-expanded state, which is highly related to the acid ionization state, and thus to the bulk pH and ionic strength. At pH 4 the molecules hardly mix while at pH 10 the mixed monolayer with DMPC can admit between 30 and 100% of SA (depending on the lateral pressure) before phase separation is established. The addition of calcium ions to the subphase has a condensing effect on SA monolayers at all pHs and the solubility of SA in the DMPC matrix does not depend on the bulk pH in these conditions. The observed phase diagrams are independent on the manner in which the state of the mixed film is reached and may thus be considered states of apparent equilibrium. © 2011 Elsevier Ireland Ltd. All rights reserved.
Fil: Vega Mercado, Franco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentina
Fil: Maggio, Bruno. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentina
Fil: Wilke, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentina
Materia
Charged Surfactants Phase Diagram Monolayers
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/61596
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/61596
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Phase diagram of mixed monolayers of stearic acid and dimyristoylphosphatidylcholine. Effect of the acid ionizationVega Mercado, FrancoMaggio, BrunoWilke, NataliaCharged Surfactants Phase Diagram Monolayershttps://purl.org/becyt/ford/1.6https://purl.org/becyt/ford/1The aim of this work is to study the phase diagram of mixed monolayers composed of dimyristoylphosphatidylcholine (DMPC) and stearic acid (SA) at different ionic strength and bulk pH of the aqueous subphase. In this way, the effect of ionization of SA on the interaction and thus on phase separation with the DMPC matrix can be analyzed. To this purpose, we first determined the ionization state of pure SA monolayers as a function of the bulk subphase pH. The SA monolayers are nearly fully ionized at pH 10 and essentially neutral at pH 4 and the mixture of DMPC and SA was studied at those two pHs. We found that the DMPC-enriched phase admits more SA if the SA monolayer is in a liquid-expanded state, which is highly related to the acid ionization state, and thus to the bulk pH and ionic strength. At pH 4 the molecules hardly mix while at pH 10 the mixed monolayer with DMPC can admit between 30 and 100% of SA (depending on the lateral pressure) before phase separation is established. The addition of calcium ions to the subphase has a condensing effect on SA monolayers at all pHs and the solubility of SA in the DMPC matrix does not depend on the bulk pH in these conditions. The observed phase diagrams are independent on the manner in which the state of the mixed film is reached and may thus be considered states of apparent equilibrium. © 2011 Elsevier Ireland Ltd. All rights reserved.Fil: Vega Mercado, Franco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Maggio, Bruno. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Wilke, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaElsevier Ireland2011-07info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/61596Vega Mercado, Franco; Maggio, Bruno; Wilke, Natalia; Phase diagram of mixed monolayers of stearic acid and dimyristoylphosphatidylcholine. Effect of the acid ionization; Elsevier Ireland; Chemistry And Physics Of Lipids; 164; 5; 7-2011; 386-3920009-3084CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1016/j.chemphyslip.2011.05.004info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0009308411000673info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-15T14:52:10Zoai:ri.conicet.gov.ar:11336/61596instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-10-15 14:52:10.313CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Phase diagram of mixed monolayers of stearic acid and dimyristoylphosphatidylcholine. Effect of the acid ionization
title Phase diagram of mixed monolayers of stearic acid and dimyristoylphosphatidylcholine. Effect of the acid ionization
spellingShingle Phase diagram of mixed monolayers of stearic acid and dimyristoylphosphatidylcholine. Effect of the acid ionization
Vega Mercado, Franco
Charged Surfactants Phase Diagram Monolayers
title_short Phase diagram of mixed monolayers of stearic acid and dimyristoylphosphatidylcholine. Effect of the acid ionization
title_full Phase diagram of mixed monolayers of stearic acid and dimyristoylphosphatidylcholine. Effect of the acid ionization
title_fullStr Phase diagram of mixed monolayers of stearic acid and dimyristoylphosphatidylcholine. Effect of the acid ionization
title_full_unstemmed Phase diagram of mixed monolayers of stearic acid and dimyristoylphosphatidylcholine. Effect of the acid ionization
title_sort Phase diagram of mixed monolayers of stearic acid and dimyristoylphosphatidylcholine. Effect of the acid ionization
dc.creator.none.fl_str_mv Vega Mercado, Franco
Maggio, Bruno
Wilke, Natalia
author Vega Mercado, Franco
author_facet Vega Mercado, Franco
Maggio, Bruno
Wilke, Natalia
author_role author
author2 Maggio, Bruno
Wilke, Natalia
author2_role author
author
dc.subject.none.fl_str_mv Charged Surfactants Phase Diagram Monolayers
topic Charged Surfactants Phase Diagram Monolayers
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv The aim of this work is to study the phase diagram of mixed monolayers composed of dimyristoylphosphatidylcholine (DMPC) and stearic acid (SA) at different ionic strength and bulk pH of the aqueous subphase. In this way, the effect of ionization of SA on the interaction and thus on phase separation with the DMPC matrix can be analyzed. To this purpose, we first determined the ionization state of pure SA monolayers as a function of the bulk subphase pH. The SA monolayers are nearly fully ionized at pH 10 and essentially neutral at pH 4 and the mixture of DMPC and SA was studied at those two pHs. We found that the DMPC-enriched phase admits more SA if the SA monolayer is in a liquid-expanded state, which is highly related to the acid ionization state, and thus to the bulk pH and ionic strength. At pH 4 the molecules hardly mix while at pH 10 the mixed monolayer with DMPC can admit between 30 and 100% of SA (depending on the lateral pressure) before phase separation is established. The addition of calcium ions to the subphase has a condensing effect on SA monolayers at all pHs and the solubility of SA in the DMPC matrix does not depend on the bulk pH in these conditions. The observed phase diagrams are independent on the manner in which the state of the mixed film is reached and may thus be considered states of apparent equilibrium. © 2011 Elsevier Ireland Ltd. All rights reserved.
Fil: Vega Mercado, Franco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentina
Fil: Maggio, Bruno. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentina
Fil: Wilke, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentina
description The aim of this work is to study the phase diagram of mixed monolayers composed of dimyristoylphosphatidylcholine (DMPC) and stearic acid (SA) at different ionic strength and bulk pH of the aqueous subphase. In this way, the effect of ionization of SA on the interaction and thus on phase separation with the DMPC matrix can be analyzed. To this purpose, we first determined the ionization state of pure SA monolayers as a function of the bulk subphase pH. The SA monolayers are nearly fully ionized at pH 10 and essentially neutral at pH 4 and the mixture of DMPC and SA was studied at those two pHs. We found that the DMPC-enriched phase admits more SA if the SA monolayer is in a liquid-expanded state, which is highly related to the acid ionization state, and thus to the bulk pH and ionic strength. At pH 4 the molecules hardly mix while at pH 10 the mixed monolayer with DMPC can admit between 30 and 100% of SA (depending on the lateral pressure) before phase separation is established. The addition of calcium ions to the subphase has a condensing effect on SA monolayers at all pHs and the solubility of SA in the DMPC matrix does not depend on the bulk pH in these conditions. The observed phase diagrams are independent on the manner in which the state of the mixed film is reached and may thus be considered states of apparent equilibrium. © 2011 Elsevier Ireland Ltd. All rights reserved.
publishDate 2011
dc.date.none.fl_str_mv 2011-07
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/61596
Vega Mercado, Franco; Maggio, Bruno; Wilke, Natalia; Phase diagram of mixed monolayers of stearic acid and dimyristoylphosphatidylcholine. Effect of the acid ionization; Elsevier Ireland; Chemistry And Physics Of Lipids; 164; 5; 7-2011; 386-392
0009-3084
CONICET Digital
CONICET
url http://hdl.handle.net/11336/61596
identifier_str_mv Vega Mercado, Franco; Maggio, Bruno; Wilke, Natalia; Phase diagram of mixed monolayers of stearic acid and dimyristoylphosphatidylcholine. Effect of the acid ionization; Elsevier Ireland; Chemistry And Physics Of Lipids; 164; 5; 7-2011; 386-392
0009-3084
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1016/j.chemphyslip.2011.05.004
info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0009308411000673
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv Elsevier Ireland
publisher.none.fl_str_mv Elsevier Ireland
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 13.22299

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