文献类型：期刊文献

英文题名：Experimental and density functional theory investigations on the antioxidant mechanism of carbon nanotubes

作者：Xu, Xiang[1];You, Yang[1];Liu, Xingyu[1];Wei, Dafu[1];Guan, Yong[1];Zheng, Anna[1]

机构：[1]East China Univ Sci & Technol, Sch Mat Sci & Engn, Minist Educ, Key Lab Ultrafine Mat, Shanghai 200237, Peoples R China

年份：2021

卷号：177

起止页码：189

外文期刊名：CARBON

收录：;EI(收录号：20211010021446);WOS:【SCI-EXPANDED(收录号:WOS:000639557600021)】；

基金：The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China (No. 21805086) and the Fundamental Research Funds for the Central Universities (No. 222201814004). The computational resources utilized in this research were provided by Shanghai Supercomputer Center. We would like to thank Editage (www.editage.cn) for English language editing.

语种：英文

外文关键词：Carbon nanotubes; Antioxidant mechanism; Density functional theory

摘要：Carbon nanotubes (CNTs) could improve the antioxidant properties of polymers because of their radical scavenging activities, but the interaction between CNTs and radicals is ambiguous. We investigated the thermal-oxidative aging resistance of fluorosilicone rubber (FSR) with and without multi-wall carbon nanotubes (MWCNTs), and tracked the concentration of peroxy radicals using chemiluminescence measurements. The results showed that 0.1-0.5 wt% of MWCNTs could block the auto-oxidation degradation of FSR by scavenging the alkyl radicals, thereby showing an antioxidant effect. Based on the structural characterizations of nanocarbons, a set of polycyclic aromatic phenols and polycyclic aryloxy radicals (PArO center dot) were constructed and optimized to mimic CNTs. The spin density distribution, spin population, and the formation and reaction of PArO center dot were calculated using density functional theory (DFT). The results indicated that the CNTs were an open-shell system with a spin density distribution focused on the aryloxy groups and nearby sp(2)-hybridized carbon atoms. Those atoms with spin populations ranging from 0 to 0.6 a.u. were inert but could react with high-reactivity radicals, including alkyl radicals. This mechanism was confirmed by electron spin resonance measurements of the nanocarbons and heat-treated pyrenols. This study contributed to the development of nanocarbons in antioxidants, catalysts, and reactive oxygen species scavengers. (c) 2021 Elsevier Ltd. All rights reserved.