IR spectroscopy of water vapor confined in nanoporous silica aerogel.

The absorption spectrum of the water vapor, confined in the nanoporous silica aerogel, was measured within 5000-5600 cm(-1) with the IFS 125 HR Fourier spectrometer. It has been shown, that tight confinement of the molecules by the nanoporous size leads to the strong lines broadening and shift. For water vapor lines, the HWHM of confined molecules are on the average 23 times larger than those for free molecules. The shift values are in the range from -0.03 cm(-1) to 0.09 cm(-1). Some spectral lines have negative shift. The data on the half-widths and center shifts for some strongest H(2)O lines have been presented.

[1]  Satoru Tsuchikawa,et al.  Near-Infrared Spectroscopic Monitoring of the Water Adsorption/Desorption Process in Modern and Archaeological Wood , 2008, Applied spectroscopy.

[2]  P. Norris,et al.  Neutron Radioscopic Measurement of Water Adsorption Coefficients in Aerogels , 2002 .

[3]  Y. Kharzheev,et al.  Use of silica aerogels in Cherenkov counters , 2008 .

[4]  S. Luijendijk.  The effect of wall collisions on the shape of microwave absorption lines , 1975 .

[5]  T. Poehler,et al.  Microwave time domain Fabry–Perot emission spectrometer , 1975 .

[6]  F. Kamke,et al.  Cluster theory for water sorption in wood , 2004, Wood Science and Technology.

[7]  A. Solodov,et al.  Measurements of N2-broadening and -shifting parameters of the water vapor spectral lines in the second hexad region , 2010 .

[8]  Gang Li,et al.  The HITRAN 2008 molecular spectroscopic database , 2005 .

[9]  P. Wagner,et al.  Line broadening and relaxation of three microwave transitions in ammonia by wall and intermolecular collisions , 1981 .

[10]  K. Smith,et al.  Self-broadened line parameters for water vapour in the spectral region 5000-5600 cm 1 , 2005 .

[11]  D. Grischkowsky,et al.  Terahertz time-domain spectroscopy of submonolayer water adsorption in hydrophilic silica aerogel. , 2004, Optics letters.

[12]  Gerhard Hummer,et al.  Water in nonpolar confinement: from nanotubes to proteins and beyond. , 2008, Annual review of physical chemistry.

[13]  S. Coy.  Speed dependence of microwave rotational relaxation rates , 1980 .

[14]  Sune Svanberg,et al.  Laser absorption spectroscopy of water vapor confined in nanoporous alumina: wall collision line broadening and gas diffusion dynamics. , 2010, Optics express.

[15]  François-Xavier Coudert,et al.  Dipole moment, hydrogen bonding and IR spectrum of confined water. , 2006, Chemphyschem : a European journal of chemical physics and physical chemistry.