title: Aggregation of 1-dodecyl-3-methylimidazolium nitrate in water and benzene studied by SANS and 1H NMR.
abstract: Aggregation of imidazolium-based ionic liquid, C(12)mim(+)NO(3)(-), in both polar solvent of water and nonpolar solvent of benzene was elucidated by electrical conductivity, small-angle neutron scattering (SANS), and (1)H NMR measurements. The electrical conductivities of C(12)mim(+)NO(3)(-)-water solutions at 298 K as a function of ionic liquid concentration showed a break point at 8.4 mmol dm(-3) as a cmc. However, those of C(12)mim(+)NO(3)(-)-benzene solutions drastically increase in accordance with a cubic function of concentration, but without a break point. The SANS profiles of both aqueous and benzene solutions obviously differ from each other. The profiles of the aqueous solutions indicated the formation of polydisperse spherical micelles. Those of the benzene solutions revealed Ornstein-Zernike behavior. Thus, C(12)mim(+)NO(3)(-) forms clusters in the benzene solutions, but the shape of clusters is indefinite. On the basis of the (1)H NMR chemical shifts of the aqueous solutions, the effect of nitrate on the formation of micelles was discussed on a microscopic scale. Furthermore, the interactions among C(12)mim(+), NO(3)(-), and benzene molecules in the benzene solutions were considered according to the (1)H NMR data.
authors: Department of Chemistry and Applied Chemistry, Graduate School of Science and Engineering, Saga University, Honjo-machi, Saga 840-8502, Japan. takamut@cc.saga-u.ac.jp
authors: Toshiyuki
authors: T
authors: Takamuku
authors: Takuya
authors: T
authors: Shimomura
authors: Koichiro
authors: K
authors: Sadakane
authors: Mikiko
authors: M
authors: Koga
authors: Hideki
authors: H
authors: Seto