文献类型：期刊文献

英文题名：Mechanochemical functionality of graphene additives in ultralow wear polytetrafluoroethylene composites

作者：Sun, Wei[1];Liu, Xiaojun[1];Liu, Kun[1];Xu, Jimin[1];Lu, Yunxiang[2,3];Ye, Jiaxin[1]

机构：[1]Hefei Univ Technol, Inst Tribol, Sch Mech Engn, Hefei, Anhui, Peoples R China;[2]East China Univ Sci & Technol, Key Lab Adv Mat, Shanghai, Peoples R China;[3]East China Univ Sci & Technol, Dept Chem, Shanghai, Peoples R China

年份：2021

卷号：184

起止页码：312

外文期刊名：CARBON

收录：;EI(收录号：20213410809735);WOS:【SCI-EXPANDED(收录号:WOS:000703614300007)】；

基金：The authors acknowledge support from the financial support from the National Natural Science Foundation of China (grant numbers 51875153 and 51875152, 51975174) and the Fundamental Research Funds for the Central Universities (JZ2021HGPA0062, JZ2020HGTB0054). We also gratefully thank Yu Ning, Gang Qian (Hefei University of Technology) for their help in spectroscopy analysis and Dr. Zhu (East China University of Science and Technology), Enze Xu (Hefei University of Technology) for their support in simulation work.

语种：英文

外文关键词：Graphene; PTFE; Ultralow wear; Mechanochemistry

摘要：Poly-tetrafluoroethylene (PTFE) is a well-known solid lubricant, but its poor wear resistance limits its tribological applications. Certain carbonaceous fillers reduce PTFE wear rate by up to 4000-fold with no sacrifice of the friction coefficient; whereas the responsible mechanisms remain unclear. We systematically studied the effects of three graphene fillers with different aggregate strengths (graphene nanoplates, few-layer graphene and single-layer graphene) on the wear resistance of graphene-PTFE composites. The results found (1) graphene of weak aggregate strength outperform that of strong aggregate strength by 100 times in wear reduction, (2) strong correlations between wear rate, tribofilm carboxylate signal intensity and filler-matrix area per unit composite mass. The carboxylate signals likely correspond to chemical bonding between mechanochemically degraded PTFE, graphene and the steel counterface within highly crosslinked and adherent transfer films and worn polymer surfaces. Results in this study support two independent (primary versus secondary) wear reduction hypotheses in literature which were further backed by DFT simulations of filler-matrix interactions, TEM/EDS analysis of wear debris, SEM/EDS images of the polymer surfaces, and environmental test results in a dry argon (Ar) atmosphere. The results of this paper are also of instructive value for the development of solid lubricants with highly controllable wear characteristics. (c) 2021 Elsevier Ltd. All rights reserved.