受賞記事
中性子散乱による水／有機溶媒／塩混合溶液系の新秩序構造の解明
キーワード:
soft matter physics,
chemical physics,
solution chemistry,
self-organization,
solvation effect,
critical phenomena,
SANS
2013 年 23 巻 3 号 p. 191-196
詳細
2013 年 23 巻 3 号 p. 191-196
The effect of an antagonistic salt on the phase behavior and nanoscale structure of a mixture of water / organic solvent was investigated by visual inspection, optical microscope, and small-angle neutron scattering (SANS). The addition of the antagonistic salt, namely sodium tetraphenylborate (NaBPh4), induces the shrinking of the two-phase region in contrast to the case in which a normal (hydrophilic) salt is added. Below the phase separation point, the SANS profiles cannot be described by the Ornstein-Zernike function owing to the existence of a long-range periodic structure. With increasing salt concentration, the critical exponents change from the values of 3D-Ising and approach those of 2D-Ising. Furthermore, an ordered phase with multilamellar (onion) structures was confirmed in an off-critical mixture of D2O and 3-methylpyridine containing 85 mM of a NaBPh4 although no surfactants or polymers are contained.
