In order to understand how pressure, temperature and CH₄ and CO₂ molecules effect Raman spectrum of liquid water better, some experimental investigations of Raman spectrum of water with gas (CH₄, CO₂ and mixture of CH₄ and CO₂) dissolved are carried out at different temperature (up to 350°C) under high pressure (40MPa) and under different pressure (up to 40MPa) at room temperature using high-temperature and high-pressure set-up (top temperature is 350°C and top pressure is 40MPa). The band of the stretching vibration of water between 3000 and 3800 cm^-1 has been studied. The results show pressure has little influence on Raman spectrum of water for all samples in our pressure variation range while temperature affects Raman spectrum of water significantly in the range room temperature to 350°C. Peak position, FWHM and the parameter R₂₁ all vary sharply along temperature. As temperature is raised, peak positions shift to high frequency, FWHM decrease significantly and the parameters R₂₁ increase with increasing temperature as EXP function in studied temperature range for all samples. All these variations have a relation with hydrogen bond. In addition, CO₂ or CH₄ dissolved in water makes all parameters vary along temperature more obviously and the CH₄ molecule modifies the Raman spectrum of H₂O much than the CO₂ molecule.

Date Published: 29 August 2009
PDF: 8 pages
Proc. SPIE 7382, International Symposium on Photoelectronic Detection and Imaging 2009: Laser Sensing and Imaging, 73823J (29 August 2009); doi: 10.1117/12.836601

Published in SPIE Proceedings Vol. 7382:
International Symposium on Photoelectronic Detection and Imaging 2009: Laser Sensing and Imaging
Farzin Amzajerdian; Chun-qing Gao; Tian-yu Xie, Editor(s)