24℃和0.1～900 MPa压力下乙醇的拉曼光谱研究

The Study of Raman Spectra for Ethanol under the Pressures of 0.1-900 MPa at 24 ℃

在24 ℃和0.1～900 MPa压力下测量了含50%水的乙醇溶液和纯乙醇的激光拉曼光谱. 研究结果表明, 纯乙醇和50%乙醇溶液中的C-H基团振动波数均随压力的增大而增大, 它们的各振动峰与压力的关系分别为: 纯乙醇: ν1=2 881.890+0.001 27 P+6.213×10-6 P2;ν2=2 928.707+0.004 38 P+4.772×10-6 P2;ν3=2 973.457+0.008 89 P+3.245×10-6 P2;50%乙醇溶液: ν1 =2 885.616+0.010 8 P-2.699×10-6 P2;ν2 =2 932.734+0.013 7 P-3.346×10-6 P2;ν3 =2 978.115+0.016 5 P-4.914×10-6 P2. 另外, 还观察到在低于550 MPa压力范围, 50%乙醇溶液中的氢键强度随压力的增大而明显增加, 550 MPa以上压力时不再随压力而发生变化.

Experimental measurement and study of Raman spectra for pure ethanol and 50% ethanol aqueous solution has been conducted at ambient temperature and the pressures of 0.1-900 MPa by using Cubic Zirconia anvil cell. The result shows that the frequency of C--H stretch vibration increases with increasing pressure and each of their relation between the frequency and pressure can be expressed as following： for pure ethanol： v1 = 2 881. 890 ＋ 0. 001 27 P ＋ 6. 213 × 10^-6 P2 ; v2 = 2 928.707 ＋ 0.004 38 P ＋ 4.772 × 10^-6 P2 ; v3 = 2973.457 ＋ 0. 008 89 P ＋ 3.245 × 10^-6 P2 ; for 50% ethanol aqueous solution： v1 = 2 885.616 ＋ 0. 010 8 P - 2.699× 10^-6 P2 ; v2 =2 932.734＋0.013 7 P-3.346× 10^-6 P2 ; v3 =2 978.115＋0.016 5 P-4.914× 10^-6 P2. Furthermore, the authors have observed that at the pressure lower than 550 MPa, the strength of hydrogen bonding becomes stronger with increasing pressure.