Reactive crystallization in supercritical water.

超临界水中的反应结晶。

• 批准号: 07405036
• 负责人: ARAI Kunio
• 金额: $ 20.48万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07405036/
• 关键词: Supercritical water; Reaction Crystallization; Metal oxide fine particle; molecular dynamics simulation; Dielectric Spectra Analysis; Solvent structure; MD計算; MO計算; 溶媒和構造; noシミュレーション

The objective of our work was to examine supercritical water as a reaction solvent. We made both molecular simulations and experimental measurements in our studies. For the simulations, we used SPC model that was modified to have flexibility and to have cHarge located at the center of mass. We grafted a new intramolecular potential function to give the model applicability at high temperature. The new model could provide superior predictions of IR-spectra, pressure-volume-temperature, relations, saturation conditions, self diffusion coefficients, and other properties compared with current literature models for water. We also examined the dielectric behavior experimentally and theoretically. For the experiments, a new cell was constructed and used to study the behavior of hydrogen bonds as temperature and concentration of the system was varied up to about 373K.Alcohols were used as the solutes. We found that there were several regions of hydrogen bonding but that there was a continuous change in the time constants, in contrary to that reported in the literature. The three regions disappeared as the temperature was elevated indicating a weakening of the hydrogen bonding. However, simulation shows that hydrogen bonding still exists since bifurcated structure was found.

我们工作的目的是考察超临界水作为反应溶剂的作用。在我们的研究中，我们进行了分子模拟和实验测量。在模拟中，我们使用了SPC模型，该模型经过修改后具有灵活性，并使电荷位于质心。我们引入了一个新的分子内势函数来赋予模型在高温下的适用性。与现有的水的文献模型相比，新模型可以更好地预测红外光谱、压力-体积-温度关系、饱和条件、自扩散系数和其他性质。我们还从实验和理论上研究了其介电行为。在实验中，构建了一个新的反应池，用于研究当体系的温度和浓度变化到约373K时，氢键的行为。我们发现有几个氢键区域，但时间常数有一个连续的变化，与文献报道的相反。随着温度的升高，这三个区域消失，表明氢键减弱。然而，模拟表明，由于发现了分叉结构，氢键仍然存在。

项目成果

Tadafumi Adschiri, Yakima Hakuta, Kunio Arai: ""Reactive crystallization in supercritical water"" Symposium Series of Chemical Engineering. 49. 194 (1995)

Tadafumi Adschiri、Yakima Hakuta、Kunio Arai：““超临界水中的反应结晶””化学工程研讨会系列。

阿尻雅文: "超臨界水中での反応晶析" 化学工学シンポジウムシリーズ. 49. 194-199 (1995)

Masafumi Asiri：“超临界水中的反应结晶”化学工程研讨会系列。49. 194-199 (1995)