以合成包裹体为腔体进行高温下流体的拉曼光谱原位分析

In situ Raman Spectroscopic Study of Fluid at High Temperature in Synthetic Inclusions

在冷封口的水热高压容器中 ,合成了组成分别为H2 O +4 2 0wt%CO2 和H2 O +8 4 2wt%CO2 的两种流体包裹体。以此合成的包裹体作为腔体 ,用显微激光拉曼探针测量了其中液态流体在 2 90 0～ 380 0cm-1范围的高温拉曼光谱 ,对其中液态水的氢键随温度的变化进行了讨论。研究结果表明 ,随着温度升高 ,流体中水分子的氢键作用不断减弱。组成为H2 O +4 2 0wt%CO2 的包裹体 ,在 372℃均一为液体 ,均一时 ,水分子的氢键发生了突变 ,均一后 ,氢键受温度的影响比较小 ,到 5 5 0℃它还存在着比较强的氢键作用。组成为H2 O+8 4 2wt%CO2 的流体在 6 0 6℃时由气液两相变为纯气相 ,一直到拉曼光谱测量的最高温度 5 80℃ ,液态水还保持着比较强的氢键作用。

Owing to the importance of the hydrogen bonding of water in liquid fluid at high temperatures, this paper used the mature synthetic inclusions technique to study the problem. Two fluid inclusions composed of H2O + 4.20 wt% CO2 and H2O + 8.40 wt% CO2, were synthesized in a hydrothermal high-pressure vessel, and the synthetic conditions were 600degreesC, and 120 MPa, and 650degreesC, and 90 MPa, respectively. The Raman spectra in the range of 2900-3800 cm(-1) of the liquid fluid in the inclusions were analyzed using laser Raman micro-probe. According to the spectra the hydrogen bonding of liquid water was studied at high temperatures. The hydrogen bonding of liquid water became weaker and weaker with increasing temperature. The hydrogen bonding of water in inclusions containing H2O + 4.20 wt% CO2, which became a mixed homogeneous liquid at 372degreesC, suddenly decreased at 372degreesC; while with increasing temperature after it became homogenous liquid fluid, the hydrogen bonding of water in mixed homogeneous liquid was less effected by the temperature, and remained relatively strong at 550degreesC. For the fluid of H2O + 8.40 wt% CO2, which became a mixed homogeneous gas at 606degreesC, the hydrogen bonding of water in liquid fluid still existed at the maximum temperature 580degreesC for Raman spectra analysis. The result also indicates that the study of fluid at high temperatures using synthetic inclusions technique is viable.