Application of Micro-FTIR Spectroscopy to Study Molecular Structure of Desorbed Water in Heat-Treated Wood During Moisture Desorption Process

Abstract

For getting a better understanding of molecular association between water and wood, molecular structure of desorbed water in a typical wood (i.e. heat-treated wood) during moisture desorption process was investigated using micro-FTIR spectroscopy. Spectra were collected in the relative humidity (RH) region from high level to low level. A qualitative analysis of these spectra and corresponding difference spectra confirmed moisture sorption sites and determined main spectral region affected by moisture sorption. In addition, from component peak analysis of the identified spectral region of difference spectra, three component peaks were attributed to three types of bound water. Based on change of bound water against RH, the entire moisture desorption process of heat-treated wood could be separated to three parts. Moreover, molecular structure of desorbed water in these three parts was demonstrated, separately.

Keywords:

• Molecular association
• moisture desorption process
• desorbed water
• micro-FTIR spectroscopy

Additional information

Funding

The work was financed by National Natural Science Foundation of China (Grant No. 31500475), Natural Science Foundation of Hunan Province, China (Grant No. 2019JJ50981), Research Foundation of Education Bureau of Hunan Province, China (Grant No. 18A166) and Scientific Innovation Fund for Post-graduates of Central South University of Forestry and Technology (Grant No. CX20192073).