Adsorption of 1-Decyl-3-methylimidazolium Bromide and Solvation Structure of Bromide at the Air/Water Interface

Autor: Makoto Aratono, Toru Ozeki, Asuka Onohara, Takanori Takiue, Kei Shimamoto, Daiki Murakami, Hiroki Matsubara, Iwao Watanabe, Hajime Tanida
Rok vydání: 2008
Předmět:
Zdroj: Analytical Sciences. 24:1279-1283
ISSN: 1348-2246
0910-6340
DOI: 10.2116/analsci.24.1279
Popis: The adsorbed film of 1-decyl-3-methylimidazolium bromide (DeMIMB) at the air/water interface was investigated employing the surface tension measurement and the x-ray absorption fine structure method under the total reflection condition (TRXAFS). From the surface tension measurement, the surface excess concentrations of ions were determined. From the XAFS measurement, two solvation states of bromide ion were found in the adsorbed film, which were assigned to be "free-Br" and "bound-Br". The hydration number of the former was estimated to be 6 while that of the latter was estimated to be 4. The results based on the XAFS analysis provided significant information on the formation of domains in the adsorbed film; the most conceivable situation is that the adsorbed molecules are definitely not homogeneously dispersed, but domains (islands or clusters) are dispersed in the adsorbed film. A regular and rather tight stacking of immidazolium rings may be formed in the domains.
Databáze: OpenAIRE
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