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Vibrational spectra of molecular fluids in nanoporesтезисы доклада
Информация о цитировании статьи получена из
Web of Science
Дата последнего поиска статьи во внешних источниках: 20 апреля 2016 г.
- Авторы: Arakcheev V.G., Morozov V.B.
- Сборник: 21st International Conference on Spectral Line Shapes
- Тезисы
- Год издания: 2012
- Место издания: St.-Petersburg University St.-Petersburg, Russia
- Первая страница: 40
- Последняя страница: 40
- Аннотация: Coherent anti-Stokes Raman spectroscopy (CARS) is applied for quantitative analysis of carbon dioxide phase composition in pores of nanoporous glass samples at nearcritical temperatures. Measurements of the 1388 cm-1 Q-branch were made in a wide range of pressures corresponding to the coexistence of gas (gas-like), adsorbed and condensed liquid (liquid-like) phases in the pores. Modeling based on the concept of surface adsorption and capillary condensation is limited to subcritical temperatures. However, consideration of surface adsorption at nearcritical temperature is quite reasonable; it allows estimating condensed liquid (liquid-like) phase amount and mass fractions of different phase components. Measurements at 30.5 and 33oC obviously displayed inhomogeneous shapes of obtained spectra. An increase in the intensity of the low-frequency spectral wing can not be explained only by adsorption on the pore walls and, apparently, indicates the presence of the condensed liquid (liquid-like) phase in the pore volume. Fitting the experimental spectra and analysis of spectral contributions allows us to calculate amount and volume fractions of different phases inside nanopores. It was shown that relation between liquid (liquid-like) and gas (gas-like) phases strongly depends on temperature. The effects obviously reflect the critical fluid behavior in nanopores. At fixed temperature, pores in the sample with smaller pore radius are more filled with a condensed phase than in the sample with greater pore radius. In this way, the analysis of the CARS spectra is quite informative for quantitative evaluation of phase composition of near critical carbon dioxide in glass nanopores.
- Добавил в систему: Аракчеев Владимир Генрихович