Artículo
Intermediate structures for higher level arrangements: catching disk-like micelles in decane phosphonic acid aqueous solutions
Schulz, Erica Patricia
; Piñeiro, Angel; Rodríguez, José Luis Mariano; Minardi, Rosanna Marina; Frechero, Marisa Alejandra
; Schulz, Pablo Carlos
Fecha de publicación:
04/2013
Editorial:
American Chemical Society
Revista:
Journal of Physical Chemistry B
ISSN:
1520-6106
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
It has been proposed that disk-like micelles may be precursors to the formation of lamellar liquid crystals. The possibility of obtaining n-decane phosphonic acid (DPA) disklike micelles in aqueous solution without the addition of a second ionic surfactant led us to study in detail the low-concentration range of this system by both a battery of experimental techniques and molecular dynamics (MD) simulations. The experimental results indicate that premicelles with some capacity to solubilize dyes are formed at 0.05 mM. The critical micelle concentration (cmc) was found to be 0.260 ± 0.023 mM, much lower than that previously reported in the literature. Spherical micelles, which immediately grow, leading to disk-like micelles, are probably formed at this concentration. At 0.454 ± 0.066 mM, disk-like micelles become unstable, giving rise to the formation of an emulsion of lamellar mesophase that dominates the system beyond 0.670 ± 0.045 mM. These experimental results were corroborated by MD simulations which, additionally, allow describing the structure of the obtained micelles at atomic level. The analysis of the MD trajectories revealed the presence of strong intermolecular hydrogen bonds between the surfactant headgroups, producing a compact polar layer with low water content. The formation of such H-bond network could explain the ability of this surfactant to form disk-like micelles at concentrations close to the cmc.
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Articulos(CCT - BAHIA BLANCA)
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - BAHIA BLANCA
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - BAHIA BLANCA
Articulos(INQUISUR)
Articulos de INST.DE QUIMICA DEL SUR
Articulos de INST.DE QUIMICA DEL SUR
Citación
Schulz, Erica Patricia; Piñeiro, Angel; Rodríguez, José Luis Mariano; Minardi, Rosanna Marina; Frechero, Marisa Alejandra; et al.; Intermediate structures for higher level arrangements: catching disk-like micelles in decane phosphonic acid aqueous solutions; American Chemical Society; Journal of Physical Chemistry B; 117; 20; 4-2013; 6231–6240
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