title: Thermal-lens study of photochemical reaction kinetics.
abstract: We consider the time dependence of the absorption coefficient due to the photoinduced chemical reaction (PCR) and species diffusion to calculate the temperature rise in the thermal-lens (TL) effect. The TL signal at the detector plane is also calculated. This theoretical approach removes the restriction that the PCR time constant is much greater than the characteristic TL time constant, which was assumed in a previously published model. Hydrocarbon fuel and aqueous Cr(VI) samples are investigated, and quantitative experimental results for the thermal, optical, and PCR properties are obtained. While similar results were obtained for the Cr(VI) solution using the previous and present models, the relative difference between the PCR time constants extracted from the same experimental data for a hydrocarbon fuel sample is found to be more than 220%. This demonstrates the significant difference of the two models.
authors.affiliation: National Research Council Canada, Institute for Fuel Cell Innovation, 4250 Wesbrook Mall, Vancouver, British Columbia V6T 1W5, Canada. AstrathNGC@pq.cnpq.br
authors.forename: Nelson G C
authors.initials: NG
authors.lastname: Astrath
authors.forename: Francine B G
authors.initials: FB
authors.lastname: Astrath
authors.forename: Jun
authors.initials: J
authors.lastname: Shen
authors.forename: Jianqin
authors.initials: J
authors.lastname: Zhou
authors.forename: Kirk H
authors.initials: KH
authors.lastname: Michaelian
authors.forename: Craig
authors.initials: C
authors.lastname: Fairbridge
authors.forename: Luis C
authors.initials: LC
authors.lastname: Malacarne
authors.forename: Paulo R B
authors.initials: PR
authors.lastname: Pedreira
authors.forename: A N
authors.initials: AN
authors.lastname: Medina
authors.forename: Mauro L
authors.initials: ML
authors.lastname: Baesso