title: Influence of ultrasound pretreatment on wood physiochemical structure.
abstract: As an initial step to increase the use of renewable biomass resources, this study was aimed at investigating the effects of ultrasound pretreatment on structural changes of wood. Samples were pretreated by ultrasound with the power of 300W and frequency of 28kHz in aqueous soda solution, aqueous acetic acid, or distilled water, then pretreated and control samples were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The results shown that ultrasound pretreatment is indeed effective in modifying the physiochemical structure of eucalyptus wood; the pretreatment decreased the quantity of alkali metals (e.g., potassium, calcium and magnesium) in the resulting material. Compared to the control group, the residual char content of samples pretreated in aqueous soda solution increased by 10.08%-20.12% and the reaction temperature decreased from 361°C to 341°C, however, in samples pretreated by ultrasound in acetic solution or distilled water, the residual char content decreased by 12.40%-21.45% and there were no significant differences in reactivity apart from a slightly higher maximum reaction rate. Ultrasound pretreatment increased the samples' crystallinity up to 35.5% and successfully removed cellulose, hemicellulose, and lignin from the samples; the pretreatment also increased the exposure of the sample to the treatment solutions, broke down sample pits, and generated collapses and microchannels on sample pits, and removed attachments in the samples.
authors: Beijing Key Laboratory of Wood Science and Engineering, College of Material Science and Technology, Beijing Forestry University, Beijing, PR China. Electronic address: hzbbjfu@126.com.
authors: Zhengbin
authors: Z
authors: He
authors: Beijing Key Laboratory of Wood Science and Engineering, College of Material Science and Technology, Beijing Forestry University, Beijing, PR China.
authors: Zhenyu
authors: Z
authors: Wang
authors: Beijing Key Laboratory of Wood Science and Engineering, College of Material Science and Technology, Beijing Forestry University, Beijing, PR China.
authors: Zijian
authors: Z
authors: Zhao
authors: Beijing Key Laboratory of Wood Science and Engineering, College of Material Science and Technology, Beijing Forestry University, Beijing, PR China. Electronic address: ysonglin@126.com.
authors: Songlin
authors: S
authors: Yi
authors: Beijing Key Laboratory of Wood Science and Engineering, College of Material Science and Technology, Beijing Forestry University, Beijing, PR China.
authors: Jun
authors: J
authors: Mu
authors: Beijing Key Laboratory of Wood Science and Engineering, College of Material Science and Technology, Beijing Forestry University, Beijing, PR China.
authors: Xiaoxu
authors: X
authors: Wang
mesh_terms: D055598:Chemical Phenomena; D005052:Eucalyptus / Q000737:chemistry; D013696:Temperature; D000069453:Ultrasonic Waves; D014934:Wood / Q000737:chemistry*
keywords: Crystallinity; Eucalyptus; FTIR; Thermostability; Ultrasound pretreatment