Gas in scattering media absorption spectroscopy for time-resolved characterization of gas diffusion processes in porous materials

0584856 - ÚFCH JH 2025 RIV NL eng J - Journal Article
Dostál, Michal - Suchánek, Jan - Bitala, P. - Klečka, V. - Nevrlý, Václav - Klímková, L. - Konečný, P. - Vořechovská, D. - Kubát, Pavel - Zelinger, Zdeněk
Gas in scattering media absorption spectroscopy for time-resolved characterization of gas diffusion processes in porous materials.
Measurement. Roč. 230, MAY 2024 (2024), č. článku 114494. ISSN 0263-2241. E-ISSN 1873-412X
R&D Projects: GA ČR GA22-19812S; GA TA ČR(CZ) SS03010139
Institutional support: RVO:61388955
Keywords : Absorption spectroscopy * Diode laser * Gas diffusion * Light scattering * Porous material
OECD category: Physical chemistry
Impact factor: 5.6, year: 2022
Method of publishing: Limited access
https://www.sciencedirect.com/science/article/pii/S0263224124003798?via%3Dihub

Signal denoising is a serious problem for in-situ laser diagnostics of gases dispersed in porous materials. An optical sensor system based on absorption spectroscopy of gases in a scattering environment was built using a 3D printed cell with reference samples of polystyrene foam. Selected A-band spectral lines of molecular oxygen were investigated using wavelength modulated spectroscopy with second harmonic detection. Quantitative information on the concentration of analyte dispersed in the porous medium was obtained at extremely low signal-to-noise ratio (SNR < 10). A spectral line shape fitting procedure based on the Gabor transform followed by a filtered inverse fast Fourier transform allowed to achieve a relatively high SNR with good linearity over a range of reduced oxygen concentrations in air. Finally, the applicability of the optical sensor system to monitor the diffusion of carbon dioxide into air dispersed in a Styrofoam sample and vice versa was successfully demonstrated.
Permanent Link: https://hdl.handle.net/11104/0352644