Two-Dimensional Melting and Phase Change of Binary Mixtures of CCl4and CHCl3Confined in ACF Nanospace Studied Using Solid-State1H NMR
| Autor: | Takahiro Ueda, Keisuke Miyakubo, Taro Eguchi, Hiroaki Omichi, Osamu Kubota, Yu Chen, Hirokazu Kobayashi |
|---|---|
| Rok vydání: | 2010 |
| Předmět: | |
| Zdroj: | Bulletin of the Chemical Society of Japan. 83:1323-1332 |
| ISSN: | 1348-0634 0009-2673 |
| DOI: | 10.1246/bcsj.20100169 |
| Popis: | Two-dimensional melting and phase changes of binary mixtures of CCl 4 and CHCl 3 confined in activated carbon fiber were examined using differential thermal analysis and 1 H wide-line NMR. Molecular assembly of CCl 4 confined in ACF nanospace with a slit width of 1.1 nm showed succeeding thermal anomalies corresponding to crystal-hexatic and hexatic-liquid transitions. Results showed that these thermal anomalies did not occur in a mixture of CHCl 3 and CC1 4 . This behavior differed greatly from the phase diagram for the bulk mixture between CHCl 3 and CCl 4 . Furthermore, the dynamic features of CHCl 3 molecule were examined using the 1 H wide-line NMR spectrum. The activation energy of the hopping motion changed from 7 kJ mol -1 for pure CHCl 3 to 13 kJ mol -1 for CHCl 3 with a 0.016 molar ratio in CCl 4 . In particular, a drastic increase in the activation energy was observed for doping with a trace amount of CHCl 3 , suggesting that molecular self-assembly of CC1 4 takes place in the ACF nanoslit because of the effective intermolecular interaction between CC1 4 molecules. The existence of CHCl 3 in CC1 4 brings about the remarkable impurity effect on two-dimensional melting and phase transition of CCl 4 confined in ACF nanospace. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|