Estimation of spectral absorption function range via LII measurements of flame-synthesized TiO2 nanoparticles

• Published in: Applied physics. B, Lasers and optics Lasers and optics, 2023-11, Vol.129 (11), Article 179
• Main Authors: Yi, Junghwa, Betrancourt, Christopher, Darabiha, Nasser, Franzelli, Benedetta
• Format: Article
• Language: English
• Subjects: Absorption spectra; Applied physics; Carbon black; Engineering; Fluence; Laser induced incandescence; Lasers; Metal oxides; Nanoparticles; Optical Devices; Optics; Photonics; Physical Chemistry; Physics; Physics and Astronomy; Quantum Optics; Spectral sensitivity; Synthesis; Titanium dioxide
• ISSN: 0946-2171; 1432-0649
• DOI: 10.1007/s00340-023-08115-7

The Laser-Induced Incandescence (LII) technique is widely used for the study of soot production in flames. More recently, it has also drawn attention also for the characterization of metal-oxide flame synthesis. To retrieve the particle volume fraction from the LII signal, information on the effective particle temperature and the absorption function E ( m λ ) depending on the wavelength are needed. In this study, a new approach is proposed to determine these parameters from LII measurements at a given laser fluence by accounting for the spectral shape of E ( m λ ) obtained from the estimated effective particle temperature. The feasibility of the method is first demonstrated on a carbon black nanoparticle aerosol in a non-reactive cold environment. A good agreement with the literature data for E ( m λ ) is found. The developed approach is then applied to TiO 2 nanoparticles produced by flame synthesis. The obtained spectral response of E ( m λ ) is in line with the literature results for TiO 2 . The proposed approach represents an essential step toward in-situ estimation of particle volume fraction from the LII signal, which can be a valuable tool for further characterization of metal-oxide flame synthesis.