Raman Spectra of Water to 400°C and 3000 bar
Raman Spectra of Water to 400°C and 3000 bar
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400°C 和 3000 bar 下水的拉曼光谱
DOI：
10.1002/bbpc.19910951202
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发表时间：
1991
影响因子：
3.5
通讯作者：
E. U. Franck
中科院分区：
文献类型：
--
作者：
W. Kohl;H. A. Lindner;E. U. Franck
描述了具有四个蓝宝石窗口的约1.6 cm 3内部体积的小尺寸高温、高压拉曼池。它可以用于400°C和3000 bar。在25°C至400°C的温度范围内，在0.04 g·cm−3至1.0 g·cm−3的密度范围内，测量了稀释在H2O中的HDO在2600 cm−1附近的OD伸缩谱带。水的临界温度Tc为374°C，临界密度Tc = 0.32 g°cm−3。在400°C的超临界温度下，OD带的密度为0.04至0.8 g·cm−3。在1.0 ~ 0.8 g·cm−3之间的密度几乎恒定的情况下，在25 ~ 400°C的温度范围内记录到谱带。因此，依赖于氢键的OD带可以在很宽的温度和压力范围内进行研究，避免直接的临界区域。在400°C和低密度下，尖锐的窄OD带的最大频率为2727 cm−1。它变得更宽，在0.8 g·cm−3时移动到2668 cm−1。一个非常宽的谱带出现在25°C和1 g·cm−3在2530 cm−1。测量了退偏比，应用了局部场校正，并允许确定各向同性和各向异性光谱。在较宽的温度和密度范围内，谱带形状的转变总是平滑的，没有明显的特征。与双组分氢键和非氢键“混合物”模型相比，Efimov等人提出的“连续”模型的描述似乎更可取。从这一描述中导出了特定的相互作用能。
A small-size high-temperature, high-pressure Raman cell of about 1.6 cm3 internal volume with four sapphire windows is described. It can be used to 400°C and 3000 bar. The OD-stretching bands around 2600 cm−1 of HDO diluted in H2O have been measured from 25°C to 400°C and in a density range between 0.04 g·cm−3 to 1.0 g·Cm−3. The critical temperature of water Tc is 374°C, the critical density ϱC = 0.32 g°cm−3. At the supercritical temperature of 400°C the OD-band was determined at densities from 0.04 to 0.8 g·cm−3. At nearly constant densities between 1.0 and 0.8 g·cm−3 the band was recorded from 25 to 400°C. Thus the OD-band, which depends on hydrogen bonding, could be studied in a wide range of temperatures and pressures, avoiding the immediate critical region.—At 400°C and low density the sharp narrow OD-band has a maximum frequency of 2727 cm−1. It becomes broader and shifts to 2668 cm−1 at 0.8 g·cm−3. A very broad band occurs at 25°C and 1 g·cm−3 at 2530 cm−1. Depolarization ratios were measured, local field corrections were applied and permitted the determination of isotropic and anisotropic spectra. The transition of band shape in the wide range of temperature and density is always smooth with no prominent features. As compared with a two-component hydrogen-bonded and non-bonded “mixture” model a description with a “continuum”-model as proposed by Efimov et al. appears to be preferable. Specific interaction energies have been derived from this description.