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

Yizhong Cao; Haiming Hua; Pei Yang; Minzhi Chen; Weimin Chen; Siqun Wang; Xiaoyan Zhou

doi:10.1016/j.carbpol.2019.115632

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

Carbohydr Polym. 2020 Apr 1:233:115632. doi: 10.1016/j.carbpol.2019.115632. Epub 2019 Nov 21.

Authors

Yizhong Cao¹, Haiming Hua², Pei Yang³, Minzhi Chen³, Weimin Chen³, Siqun Wang⁴, Xiaoyan Zhou⁵

Affiliations

¹ 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.
² College of Science, Nanjing Forestry University, Nanjing, 210037, China.
³ College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037, China; Fast-growing Tree & Agro-fibre Materials Engineering Center, Nanjing, 210037, China.
⁴ Center for Renewable Carbon, University of Tennessee, Knoxville, TN 37996, USA.
⁵ College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037, China; Fast-growing Tree & Agro-fibre Materials Engineering Center, Nanjing, 210037, China; Dehua TB New Decoration Material Co., Ltd., Deqing, 313200, China. Electronic address: zhouxiaoyan@njfu.edu.cn.

PMID: 32059874
DOI: 10.1016/j.carbpol.2019.115632

Abstract

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.

Keywords: Atmospheric low-temperature plasma; Cellulose; Density functional theory (DFT); Oxidation; Reaction pathway.