- 作者: Shan Shan Jua, Tzong-Daw Wua, Yuh-Lin Yeha, Tai-Huei Weib, Jung-Yaw Huangcand Sheng Hsien Lina
- 中文摘要:
aInstitute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 10764, Taiwan, R.O.C.
bDepartment of Physics, National Chung-Cheng University, Ming-Hsiung, Chia Yi, Taiwan, R.O.C.
cInstitute of Electro-Optical Engineering, National Chiao-Tung University, Hsin-Chu, Taiwan 30050, R.O.C.
The surface vibrational spectroscopy of ethanol (C2H5OH, ethyl alcohol): water binary mixture, or the aqueous solution of ethanol, is investigated via sum frequency generation (SFG) in the OH region (3000 to 3900 cm-1). The bulk molar ratio of the ethanol is varied from x = 0.0024 to 0.20. Our concentration dependence results support the statement that the surface density of water molecules with a free dangling OH bond is about 25% in the air/water interface. It also indicates that the ethyl group of the surface ethanol molecules sticks out above the nominal surface, while the hydroxyl group alone is immersed in the mixture solution. And the surface layer is a mixed monolayer. We have demonstrated here that a LiNbO3 crystal containing -OH can be sufficient for the SFG spectroscopy measurement in the -OH region regardless of its absorption dip.
aInstitute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 10764, Taiwan, R.O.C.
bDepartment of Physics, National Chung-Cheng University, Ming-Hsiung, Chia Yi, Taiwan, R.O.C.
cInstitute of Electro-Optical Engineering, National Chiao-Tung University, Hsin-Chu, Taiwan 30050, R.O.C.
The surface vibrational spectroscopy of ethanol (C2H5OH, ethyl alcohol): water binary mixture, or the aqueous solution of ethanol, is investigated via sum frequency generation (SFG) in the OH region (3000 to 3900 cm-1). The bulk molar ratio of the ethanol is varied from x = 0.0024 to 0.20. Our concentration dependence results support the statement that the surface density of water molecules with a free dangling OH bond is about 25% in the air/water interface. It also indicates that the ethyl group of the surface ethanol molecules sticks out above the nominal surface, while the hydroxyl group alone is immersed in the mixture solution. And the surface layer is a mixed monolayer. We have demonstrated here that a LiNbO3 crystal containing -OH can be sufficient for the SFG spectroscopy measurement in the -OH region regardless of its absorption dip.
bDepartment of Physics, National Chung-Cheng University, Ming-Hsiung, Chia Yi, Taiwan, R.O.C.
cInstitute of Electro-Optical Engineering, National Chiao-Tung University, Hsin-Chu, Taiwan 30050, R.O.C.
The surface vibrational spectroscopy of ethanol (C2H5OH, ethyl alcohol): water binary mixture, or the aqueous solution of ethanol, is investigated via sum frequency generation (SFG) in the OH region (3000 to 3900 cm-1). The bulk molar ratio of the ethanol is varied from x = 0.0024 to 0.20. Our concentration dependence results support the statement that the surface density of water molecules with a free dangling OH bond is about 25% in the air/water interface. It also indicates that the ethyl group of the surface ethanol molecules sticks out above the nominal surface, while the hydroxyl group alone is immersed in the mixture solution. And the surface layer is a mixed monolayer. We have demonstrated here that a LiNbO3 crystal containing -OH can be sufficient for the SFG spectroscopy measurement in the -OH region regardless of its absorption dip. - 英文摘要: --
- 中文關鍵字: --
- 英文關鍵字: --