College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037, China; Fast-growing Tree & Agro-fibre Materials Engineering Center, Nanjing, 210037, China; Center for Renewable Carbon, University of Tennessee, Knoxville, TN 37996, USA.
College of Science, Nanjing Forestry University, Nanjing, 210037, China.
Carbohydr Polym. 2020 Apr 1;233:115632. doi: 10.1016/j.carbpol.2019.115632. Epub 2019 Nov 21.
Atmospheric low-temperature plasma has been widely applied in surface modification of lignocellulose for manufacturing lightweight, strong composites. This study is aimed at elaborating the structural changes of cellulose after plasma treatment and further understanding the mechanism underlying plasma-induced oxidation of cellulose. Experiments suggested that atmospheric low-temperature plasma exhibits strong capacity to cleave covalent bonds, leading to oxidation and degradation of cellulose. Theoretical analysis revealed that cleavage of CO covalent bond is the first-step reaction during plasma-induced oxidation due to its low bond dissociation energy (229.2 kJ mol). Subsequent pyranose ring-breaking reaction dominates dynamically and thermodynamically. Obtained outcomes are vital for fundamentally understanding the plasma-lignocellulose interaction. On that basis, plasma treatment for activation and oxidation of lignocellulose can be optimized and designed for improved efficiency. Wettability of lignocellulose can be thus improved in a short time, providing an opportunity to manufacture lignocellulose-based composites with enhanced efficiency and mechanical properties in future.
大气低温等离子体已广泛应用于木质纤维素的表面改性，以制造轻质、高强复合材料。本研究旨在阐述等离子体处理后纤维素的结构变化，并进一步了解等离子体诱导纤维素氧化的机制。实验表明，大气低温等离子体具有很强的切断共价键的能力，导致纤维素的氧化和降解。理论分析表明，由于 CO 共价键的键解离能（229.2 kJ/mol）较低，因此在等离子体诱导氧化过程中，CO 共价键的断裂是第一步反应。随后，吡喃糖环断裂反应在动力学和热力学上占主导地位。获得的结果对于从根本上理解等离子体-木质纤维素相互作用至关重要。在此基础上，可以对木质纤维素的等离子体处理进行优化和设计，以提高效率。这样可以在短时间内提高木质纤维素的润湿性，为未来制造具有增强效率和机械性能的木质纤维素基复合材料提供机会。
