Artículo
Adsorption Kinetics of a Cationic Surfactant Bearing a Two-Charged Head at the Air-Water Interface
Fernández Leyes, Marcos Daniel
; Gimenez Reyes, Santiago Alberto; Cuenca, Victor Ezequiel
; Sánchez Morales, Jhon Freddy
; Ritacco, Hernán Alejandro
Fecha de publicación:
22/01/2020
Editorial:
MDPI AG
Revista:
Coatings
ISSN:
2079-6412
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
We studied the dynamics of adsorption at the air-water interface of a cationic surfactant bearing two charges, Gemini 12-2-12, at concentrations below and above the critical micelle concentration (cmc). We used maximum bubble pressure and Wilhelmy plate techniques in order to access all time scales in the adsorption process. We found that the adsorption dynamics are controlled by diffusion at the initial stage of the adsorption process (milliseconds) and it is kinetically controlled by an electrostatic barrier (minute) approaching the equilibrium surfactant surface concentration. Between these two extremes, we found several relaxation phenomena, all following exponential decays with characteristic times spanning from one to hundreds of seconds. By means of time-resolved surface potential measurements, we show that these processes involve charge redistribution within the interfacial region. The surface tension data are analyzed and interpreted in the framework of the free energy approach.
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Articulos(IFISUR)
Articulos de INSTITUTO DE FISICA DEL SUR
Articulos de INSTITUTO DE FISICA DEL SUR
Citación
Fernández Leyes, Marcos Daniel; Gimenez Reyes, Santiago Alberto; Cuenca, Victor Ezequiel; Sánchez Morales, Jhon Freddy; Ritacco, Hernán Alejandro; Adsorption Kinetics of a Cationic Surfactant Bearing a Two-Charged Head at the Air-Water Interface; MDPI AG; Coatings; 10; 2; 22-1-2020; 1-17
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