Browsing by Author "Shan, Xiaofei"

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    Analysis of Deformation Fixation of Thermally Compressed Scots Pine (Pinus sylvestris L.)
    Li, Lili; Shan, Xiaofei; Luo, Zhiying; Liu, Wenwen; Liu, Jianxia; Yu, Jianfang; Chen, Zhangjing; Wang, Ximing (MDPI, 2024-05-11)
    Heat treatment effectively inhibits the water absorption recovery of compressed wood. To elucidate this phenomenon, we prepared compressed pine and thermally compressed pine (heartwood and sapwood) using the hot pressing method at 160 °C, 180 °C, 200 °C, and 220 °C. The effects of chemical components, swelling stresses, and monosaccharides on modified wood recovery were investigated using regression analyses. Notably, the recovery of both compressed heartwood and sapwood during water absorption declined from 18.89% to 2.66% and from 58.40% to 1.60%, respectively, after heat treatment. Similarly, the swelling stresses of the compressed heartwood and sapwood at 220 °C, respectively, ranged from 0.693 MPa to 0.275 MPa and from 0.783 MPa to 0.330 MPa. These were close to the values of untreated heartwood (0.175 MPa) and sapwood (0.225 MPa). Regression functions indicated that the recovery of compressed wood is chemically dependent on hemicellulose and mechanically related to swelling stress. For monosaccharides, regression functions indicated that modified heartwood recovery primarily relied on mannose, whereas modified sapwood recovery was remarkably affected by mannose and xylose. This confirmed that the pyrolytic monosaccharides in hemicellulose promoted stress relaxation, which induced the deformation fixation of thermally compressed wood.
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    Wood for Application in Electrochemical Energy Storage Devices
    Shan, Xiaofei; Wu, Jing; Zhang, Xiaotao; Wang, Li; Yang, Junli; Chen, Zhangjing; Yu, Jianfang; Wang, Ximing (Elsevier, 2021-12-22)
    Nowadays, achieving powerful electrochemical energy conversion and storage devices is a major challenge of our society. Wood is a biodegradable and renewable material that naturally has a hierarchical porous structure, excellent mechanical performance, and versatile physicochemical properties. Wood-based materials and its derivatives are endowed with great potential as resources to fabricate advanced materials for energy storage, flexible electronics, and clean energy. Herein, we comprehensively overview the methodologies applied for the synthesis of various electrochemical energy storage systems and devices (e.g., supercapacitor, battery, catalytic hydrogen evolution, etc.), the strategies for tailoring the structures and conductivity, as well as their impact on electrochemical performance (energy and power density and long-term durability). Finally, an outlook of future opportunities and prospects in the synthesis and application of electrochemical energy storage is also presented.