深海热液区主要成分的高温高压拉曼光谱分析

Study on Raman Spectra of Major Ingredient in Deep-sea Hydrothermal at High Temperature and High Pressure

模拟深海热液口环境(最高压力40 MPa,最高温度350℃),对深海热液区的主要成分CO2、CH4及其混合物的水溶液在不同压力和温度条件下的拉曼光谱进行探测和分析,结果显示:常温低压下CO2水溶液的Fermi双峰分别位于1 384.9 cm-1和1 278.3 cm-1处,CH4的水溶液拉曼峰υ1位于2 912.1 cm-1处,均比其气相的拉曼频移小;常温下CO2和CH4水溶液的拉曼特征峰随压力(≤40 MPa)的变化均不明显;在40 MPa的压力下随着温度的升高(≤350℃),CO2水溶液的Fermi双峰分别向高波数区移动了约3.4 cm-1和7.0 cm-1,而CH4水溶液的拉曼峰υ1向低波数区移动了约3.1cm-1;混合后升温过程中CO2的双峰分别向高波数区移动了约4.3 cm-1和3.8 cm-1,CH4的特征峰υ1向低波数区移动了4.5 cm-1。说明在室温到350℃范围内温度的变化对CO2和CH4水溶液拉曼频移有影响,频移量与温度线性相关,而压力在≤40 MPa范围内的改变对拉曼频移影响不明显。

The paper studied the Raman spectra of CO2, CH4 solution and their mixtures at different temperature and pressure, which were of most existence in deep-sea hydrotherm, in the simulative environment of deep-sea hydrotherm（40 MPa, 350℃ ）. The results of the study showed that the spectrum of the peak position of CH4 and CO2 bands at 2 912.1 cm^- 1, 1 384.9 cm^- 1 and 1 278.3 cm^-1 respectively in the condition of room temperature and low pressure. In room temperature their Raman shifts were not obvious as the pressure increased. The peak position of the CO2 bands increased 3.4 cm^-1 and 7.0 cm^-1 as fluid temperature（maximum 350 ℃ ） increased at the pressure of 40 MPa, whereas the peak position of CH4 decreased 3.1 cm-1. In the mixture, the peak position of the CO2 bands increased 4.3 cm^- 1 and 3.8 cm^- 1, while the v1 band of CH4 decreased 4.5 cm^-1 because of their interacting.