Dynamic registration of D2 16O absorption spectrum in silica aerogel |
| |
Authors: | L Sinitsa N Lavrentieva A Lugovskoi |
| |
Institution: | 1. Laboratory of molecular spectroscopy, V.E. Zuev Institute of Atmospheric Optics
, Tomsk, Russia;2. National Research Tomsk State University
, Tomsk, Russia sln@asd.iao.ru;4. National Research Tomsk State University
, Tomsk, Russia |
| |
Abstract: | Absorption spectra of the gas phase and adsorbed D2О in the silica aerogel with nanoscale pores were investigated in 3700–5400 cm?1 range using dynamic registration with Fourier Transform spectrometer IFS-125M. Two types of sample with pores of 60 nm wide – the nitrogen gas-treated and untreated aerogels – were examined. The surface treatment of the sample changes noticeably the broadband absorption of adsorbed water. Spectrum of D2O in the pores differs from the spectrum of bulk water as for bandwidth so for band maximum. It was found that treatment of the pores by dry nitrogen leads to increasing hydrophilic properties of the material and to change water band contour. The D2О line widths in both the aerogels exceed those of free monomer in 1.1–3 times at the same pressure. Calculations of self-broadening coefficients of the D2O lines were performed using semi-empirical method based on the impact theory of broadening and includes the correction factors. The calculated results well agree with experimental data. Greater differences were found for the shift of the line centre. The D2O line shifts in the treated pores significantly exceed line shifts in the untreated pores. For some lines, these shifts have the opposite sign indicating complex nature of the molecule–wall interaction. |
| |
Keywords: | confined water Fourier spectrometer absorption spectrum spectral line profiles line width and shift coefficients |
|
|