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Título
Specific ion effects on the properties of cationic Gemini surfactant monolayers
Autor(es)
Materia
Cationic Gemini surfactant
Langmuir monolayers
Langmuir–Blodgett films
Hofmeister effect
Atomic force microscopy
Brewster angle microscopy
Fecha de publicación
2011
Editor
Elsevier
Citación
T. Alejo, M.D. Merchán, M.M. Velázquez, Specific ion effects on the properties of cationic Gemini surfactant monolayers, Thin Solid Films, Volume 519, Issue 16, 2011, Pages 5689-5695, ISSN 0040-6090, https://doi.org/10.1016/j.tsf.2011.03.018. (https://www.sciencedirect.com/science/article/pii/S0040609011006572)
Resumen
[EN]The effects of some anions of the Hofmeister series and different divalent cations of alkaline earth metals on the
properties of Langmuir monolayers of the cationic Gemini surfactant ethyl-bis (dimethyl octadecylammonium
bromide) have been investigated. Surface pressure and potential isotherms at the air–water interface were
obtained on aqueous subphases containing sodium salts with several anions of the Hofmeister series (Cl−,
NO3
−,Br−, I−,ClO4
−,and SCN−). The influence of the investigated anions on the monolayer properties can be
ordered according to the Hofmeister series with a change in the order between bromide and nitrate anions. On
the other hand, for a given anion, the cation of the salt also influences the surface properties of the Langmuir
films. The monolayers can be transferred onto mica by the Langmuir–Blodgett technique and then the
Langmuir–Blodgett films were characterized by atomic force microscopy (AFM). The AFM images show that
the molecules become more closely packed and nearly vertical to the surface when anions screen the electric
charge of the surfactant molecules.
URI
ISSN
0040-6090
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