Abstract

This study discusses the use of near infrared spectroscopy for monitoring of the process by which biomass is modified by light-irradiation and heat treatment. As a change in the colour of wood is closely related to the change in its physicochemical structure, we investigated the relationship between the tristimulus values and the diffusely-reflected near infrared spectra of wood samples during a constrained modification process. Such basic research is required to develop a new method of colouring wood without paint. The change in colour with heat treatment was much greater in light-irradiated wood than in non-irradiated wood. The change in the colour of wood by light-irradiation and heat treatment is related to the degradation of lignin and hemicellulose, which was evident from the variation of absorption bands at 1672 nm for CH in aromatic skeletal and 1724 nm for CH in furanose or pyranose. NIR spectroscopy will become a useful method for the detection of a change in chemical structure of wood caused by light-irradiated and heat treatment.

© 2003 NIR Publications

Laser heat treatments driven by integrated beams: role of irradiation nonuniformities

José-Luis Ocaña, Angel García-Beltrán, Ferran Laguarta, Jesús Armengol, Núria Lupón, and Fidel Vega
Appl. Opt. 38(21) 4570-4576 (1999)

Fiber-optic differential absorption sensor for accurately monitoring biomass in a photobioreactor

Nianbing Zhong, Qiang Liao, Xun Zhu, and Mingfu Zhao
Appl. Opt. 54(2) 228-235 (2015)

Study on the effect of heat-annealing and irradiation on spectroscopic properties of Bi:α-BaB₂O₄ single crystal

Jun Xu, Hengyu Zhao, Liangbi Su, Jun Yu, Peng Zhou, Huili Tang, Lihe Zheng, and Hongjun Li
Opt. Express 18(4) 3385-3391 (2010)

Effect of heat treatments on the performance of polymer optical fiber sensor

Nianbing Zhong, Mingfu Zhao, Qiang Liao, Xun Zhu, Yishan Li, and Zhonggang Xiong
Opt. Express 24(12) 13394-13409 (2016)

Spectroscopic properties of Er³⁺ doped germanate glasses before and after a heat treatment process

Arnaud Lemiere, Bartosz Bondzior, Luukas Kuusela, Alexander Veber, and Laeticia Petit
Opt. Mater. Express 13(1) 218-228 (2023)