High Pressure Raman Spectra of Silicone Oil

The Raman spectra of silicone oil with different viscosities(Silicone oil AP 150 wacker, Baysilone oil M1000 and Baysilone oil M30000) as a function of pressure up to 20 GPa were investigated in a diamond anvil cell. The pressure dependence of Raman vibrations of these silicone oils were obtained and analyzed. The results indicated that the molecular structure or configuration of Baysilone oil M1000 changes at 0. 47 GPa and that of Baysilone oil M30000 changes at 0. 31 GPa, respectively. This is confirmed by the decrease of the intensity of the Si-O stretch vibration and the emerging of novel vibrations at the corresponding solidification point. In addition, it was found that the pressure dependence of the vibrational frequencies changes and some vibrational modes disappear at 10, 8 and 4. 5 GPa for Silicone oil AP 150 wacker, Baysilone oil M1000 and Baysilone oil M30000, respectively, indicating the inherent structural change of these silicone oils.