Study on network structure of hydrogen bonding for supercritical and subcritical aqueous solutions.

超临界和亚临界水溶液氢键网络结构的研究。

• 批准号: 16350006
• 负责人: NISHIKAWA Keiko
• 金额: $ 9.86万
• 依托单位: Chiba University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16350006/
• 关键词: Supercritical fluids; Supercritical aqueous solution; Hydrogen bonding; Density fluctuation; Concentration fluctuation; Small-angle X-ray Scattering; Near infra-red spectrum; Raman scattering; 水和構造

Experimental data by small-angle X-ray scattering (SAXS) give us the most information on the structural fluctuation of sub-critical and supercritical aqueous solutions. Extended X-ray absorption fine structure (EXAFS) experiments are suitable to obtain the information of structure in microscopic scale. We developed a sample holder applicable to both SAXS and EXAFS experiments.We have started the experiments to elucidate the concentration fluctuations of supercritical solutions, which give us information on mixing scheme of the solutions. In this project, we studied the following three systems.1) Sub-critical CH_3OH-H_2OComparing the results with those of ambient conditions, it has been shown that the density fluctuation increases significantly with the rise in temperature and pressure, whereas concentration fluctuation remains unchanged. Namely, it is concluded that the hydrogen bonding networks are similar in ambient and sub-critical state of the mixture.2) Supercritical Xe-Kr3) Supercritical CO_2-CHF_3In studies 2) and 3), we developed the methodology to obtain partial molar volumes and isothermal compressibility of supercritical solutions. Using these data in addition to the SAXS data, we can obtain the concentration fluctuation of the solutions.We have also developed a spectrometer for near infra-red absorption, which is suitable to elucidate the forms of hydrogen bonding. We have applied this apparatuse to some ambient aqueous solutions and sub-critical water.

小角 X 射线散射 (SAXS) 的实验数据为我们提供了有关亚临界和超临界水溶液结构涨落的最多信息。扩展X射线吸收精细结构（EXAFS）实验适合获取微观尺度的结构信息。我们开发了适用于 SAXS 和 EXAFS 实验的样品架。我们已经开始实验来阐明超临界溶液的浓度波动，这为我们提供了有关溶液混合方案的信息。在本项目中，我们研究了以下三个系统。1）亚临界CH_3OH-H_2O与环境条件下的结果比较，发现随着温度和压力的升高，密度波动显着增大，而浓度波动保持不变。也就是说，得出的结论是，氢键网络在混合物的环境和亚临界状态下是相似的。2)超临界Xe-Kr3)超临界CO_2-CHF_3在研究2)和3)中，我们开发了获得部分摩尔体积的方法和超临界溶液的等温压缩性。除了SAXS数据之外，利用这些数据，我们可以获得溶液的浓度波动。我们还开发了近红外吸收光谱仪，适合阐明氢键的形式。我们已将该装置应用于一些环境水溶液和亚临界水。

项目成果

Time Evolution of Density Fluctuation in Supercritical Region : Part 2.Comparison of Hydrogen- and Non-hydrogen- Bonded Fluids

超临界区密度涨落的时间演化：第 2 部分：氢键流体和非氢键流体的比较

• 发表时间: 2005
• 期刊: The Journal of Physical Chemistry A109
• 作者: D.Kajiya;K.Nishikawa;K.Saitow
• 通讯作者: K.Saitow

Time Evolution of Density Fluctuation in Supercritical Region : Part 2. Comparison of Hydrogen- and Non-hydrogen- Bonded Fluids

超临界区密度涨落的时间演化：第 2 部分：氢键流体和非氢键流体的比较

• 发表时间: 2005
• 期刊: The Journal of Physical Chemistry A109
• 作者: D.Kajiya;K.Nishikawa;K.Saitow
• 通讯作者: K.Saitow

Time Evolution of Density Fluctuation in Supercritical Region : Part I. Nonhydrogen Bonded Fluids Studied by Dynamic Light Scattering.

超临界区密度涨落的时间演化：第一部分。通过动态光散射研究非氢键流体。

• 发表时间: 2005
• 期刊: The Journal of physical Chemistry A109
• 作者: K.Saitow;D.Kajiya;K.Nishikawa
• 通讯作者: K.Nishikawa

Time Evolution of Density Fluctuation in Supercritical Region : Part 2. Comparison of Hydrogen-and Non-hydrogen-Bonded Fluids

超临界区密度涨落的时间演化：第 2 部分：氢键流体和非氢键流体的比较

• 发表时间: 2005
• 期刊: The Journal of Physical Chemistry A109
• 作者: D.Kajiya;K.Nishikawa;K.Saiow
• 通讯作者: K.Saiow

Dynamics of Density Fluctuation of Supercritical Fluid Mapped on Phase Diagram.

相图上的超临界流体密度涨落动力学。

• 发表时间: 2004
• 期刊: Journal of the American Chemical Society 126
• 作者: K.Saitow;D.Kajiya;K.Nishikawa
• 通讯作者: K.Nishikawa