Miscibility and distribution of counterions of imidazolium ionic liquid mixtures at the air/water surface

The miscibility and distribution of Br(-) and BF(4)(-) ions of imidazolium ionic liquid mixtures, 1-hexyl-3-methylimidazolium bromide (HMIMBr) + 1-hexyl-3-methylimidazolium tetrafluoroborate (HMIMBF(4)), at the air/water surface were investigated by surface tensiometry and the total-reflection XAFS...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 25(2009), 17 vom: 01. Sept., Seite 9954-9
1. Verfasser: Shimamoto, Kei (VerfasserIn)
Weitere Verfasser: Onohara, Asuka, Takumi, Hiroki, Watanabe, Iwao, Tanida, Hajime, Matsubara, Hiroki, Takiue, Takanori, Aratono, Makoto
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2009
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article
Beschreibung
Zusammenfassung:The miscibility and distribution of Br(-) and BF(4)(-) ions of imidazolium ionic liquid mixtures, 1-hexyl-3-methylimidazolium bromide (HMIMBr) + 1-hexyl-3-methylimidazolium tetrafluoroborate (HMIMBF(4)), at the air/water surface were investigated by surface tensiometry and the total-reflection XAFS (TRXAFS) method. Tensiometry showed that the surface density of BF(4)(-) was much larger than that of Br(-), the adsorbed films of the HMIMBr-HMIMBF(4) mixture were greatly enriched in BF(4)(-) at all surface tensions, and the excess Gibbs energy of adsorption was positive. However, TRXAFS revealed that the Br ions were all in the free-Br state solvated by six water molecules in the mixed adsorbed film. Entropy-originated nonideal mixing, where a kind of segregation of the counterion distribution takes place in the interfacial region, was suggested in the mixture
Beschreibung:Date Completed 03.11.2009
Date Revised 26.08.2009
published: Print
Citation Status PubMed-not-MEDLINE
ISSN:1520-5827
DOI:10.1021/la901114e