| Language: | English |
|---|---|
| Type: | Article |
| Authors: | Koichiro Sadakane, Natsuki Iguchi, Michihiro Nagao, Hitoshi Endo, Yuri B. Melnichenko and Hideki Seto |
| Journal: | Soft Matter |
| Volume: | 7 |
| Number: | 4 |
| Month: | 2 |
| Year: | 2011 |
| Actual year: | 2010 |
| Pages: | 1334-1340 |
| doi: | 10.1039/C0SM00598C |
| Abstract: | The effect of an antagonistic salt on the phase behavior and nanoscale structure of a mixture of D2O and 3-methylpyridine was investigated by visual inspection 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. These results suggest that the concentration fluctuation of the mixture of solvents is limited to a quasi two-dimensional space by the periodic structure induced by the adding the salt. The same behaviors were also observed in mixtures composed of water, 3-methylpyridine, and ionic surfactant. |
Koichiro Sadakane, Natsuki Iguchi, Michihiro Nagao, Hitoshi Endo, Yuri B. Melnichenko and Hideki Seto, Soft Matter, 7, 1334-1340 (2011)