The Study on Physicochemical Characteristics of Wood Treated by Ultrasound-assisted Extraction

Zhenyu Wang


To evaluate the influence of ultrasound-assisted extraction (UAE) on the physicochemical characteristics of wood, UAE and Soxhlet extraction (SE) were used to treat Eucalyptus. In UAE, ultrasound with a frequency of 40 kHz and an intensity of 360 W was performed at 60 °C for 30 min. Comparison of UAE samples with Soxhlet-extracted and untreated samples indicated that both the extraction and cavitation effects of ultrasound played a significant role in the efficient alteration of wood characteristics. Identification of extractives by gas chromatography-mass spectrometry (GC/MS) suggested the presence of more low- and high-volatility components in UAE, whereas SE mainly consisted of moderate-volatility components. In thermogravimetry (TG) analysis, UAE samples obtained the highest maximum mass-loss rate (-52.1%/min) at the lowest temperature (378.4 °C). Volatile profiles obtained by thermogravimetry-infrared spectroscopy (TG-FTIR) indicated that CO and CH4 increased, whereas CO2 and formic acid decreased during pyrolysis after UAE. The release of CO and methanol components was mainly influenced by extraction; however, the emission of CO2, CH4, and formic acid responded more strongly to the effects of ultrasound. Scanning electron microscopy (SEM) images revealed that the fracture of pit membranes and small protuberances on the surface of the residues reflected the effects of ultrasound.


Wood; Ultrasound; Extraction; Physicochemical Characteristics; Pyrolysis

Full Text:


Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022,; Lucian A. Lucia, (919) 515-7707, URLs:; ISSN: 1930-2126