Investigation into the reaction mechanism underlying the atmospheric low-temperature plasma-induced oxidation of cellulose

• Published in: Carbohydrate polymers 2020-04, Vol.233, p.115632-115632, Article 115632
• Main Authors: Cao, Yizhong, Hua, Haiming, Yang, Pei, Chen, Minzhi, Chen, Weimin, Wang, Siqun, Zhou, Xiaoyan
• Format: Article
• Language: English
• Subjects: Atmospheric low-temperature plasma; Cellulose; Density functional theory (DFT); Oxidation; Reaction pathway
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2019.115632

[Display omitted] •Plasma possesses energetic particles and strong capacity to deconstruct cellulose.•Plasma-induced cleavage of β-glucosidic bond and hydrogen bond are pronounced.•Cleavage of C4O covalent bond is the first-step reaction.•Subsequent pyranose ring-breaking reaction is dominant generating carbonyl.•Carboxyl can be generated via an endothermic oxidation reaction. 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 C4O covalent bond is the first-step reaction during plasma-induced oxidation due to its low bond dissociation energy (229.2 kJ mol−1). 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.