The 12CH4 absorption spectra in the range between 6600 and 12000 cm<sup>-1</sup> have been recorded at 296 K and 200 K by the Fourier spectrometer IFS – 125M at pressures from 11 to 300 mbar, and spectral resolution 0.03 cm<sup>-1</sup>. Low temperature cell with a length of 220 cm was used, which provided the threshold sensitivity to absorption of the order of 10<sup>-7</sup> cm<sup>-1</sup>. Empirical values of the lower state energy level were derived from the intensity ratios of the lines measured at 200 K and 296 K. Line assignment of the the 3ν<sub>3</sub> band of the <sup>12</sup>CH<sub>4</sub> molecule was performed. The parameters of Voigt contour (the line center, intensity) were determined using multi-fitting procedure at 296K.
The results of preliminary studies narrowband scattering of laser radiation with a wavelength of 532 nm of the complex system of "airgel - water", depending on the water content in airgel nanopores are presented. In order to study the scattering in nanoporous media broadband radiation two versions of photoacoustic calorimeter are tested.
The dynamic of the D<sub>2</sub>О in silica airgel absorption spectra in 4000…6000 cm<sup>-1</sup> were recorded using Fourier Transform spectrometer FS-125M at room temperature and pressure of 23.4 mbar with spectral resolution of 0.03 cm<sup>-1</sup>. It is shown that the D<sub>2</sub>O dimers to make a significant contribution into absorption when nanopores filled with gas molecules is small. Is present a detailed description of techniques for processing the primary experimental data.
The absorption spectra of the D<sub>2</sub>О monomer in 3600…4200 cm-1 were recorded using Fourier Transform spectrometer FS-125M at room temperature and pressure of 15 and 33 mbar with spectral resolution of 0.03 cm<sup>-1</sup> using 2.5 cm long absorption cell. Strong unblended D<sub>2</sub>O lines lying on the wing of the H<sub>2</sub>O stretching band were used to determine the line broadening parameters. They were determined from the line profile by Program VxpProfile. The differences between fitted line profiles and experimental ones do not exceed 2%. Registered D2O lines belong to (011) - (000) and (110) - (000) bands of the second triad. Self-broadening coefficients vary from 0.27 cm<sup>-1</sup>/atm to 0.445 cm<sup>-1</sup>/atm and they exceed 3 times the D<sub>2</sub>O-N2 line broadening coefficients in the v3. Calculations of self-broadening coefficients of the D2O lines were performed using semiempirical method based on the impact theory of broadening and included the correction factors. The calculated results well agree with experimental data.
The D<sub>2</sub>O absorption spectra adsorbed on the nanoporous airgel SiO<sub>2</sub> walls in the spectral range 4200 ... 5400 cm-1 are recorded. Two types of sample with pores of 60 nm wide - the nitrogen gas-treated and untreated airgels were examined. The untreated sample was prolonged evacuation and filling by the D<sub>2</sub>O saturated vapor. The nitrogen gas-treated sample was short-time pumping, accompanied by treatment with dry nitrogen, and re- lapping by the saturated vapor. As a result, the recorded absorption spectra were shown the changes the hydrophilic properties of the nanopores walls by modernity surface in the presence of nitrogen.