Low friction under ultrahigh contact pressure enabled by self-assembled fluorinated azobenzene layers  

作　　者：Dandan XUE Zhi XU Linyuan GUO Wendi LUO Liran MA Yu TIAN Ming MA Qingdao ZENG Ke DENG Wenjing ZHANG Yichun XIA Shizhu WEN Jianbin LUO 

机构地区：[1]State Key Laboratory of Tribology in Advanced Equipment,Tsinghua University,Beijing 100084,China [2]National Center for Nanoscience and Technology,Beijing 100190,China

出　　处：《Friction》2024年第7期1434-1448,共15页摩擦（英文版）

基　　金：the support of the National Natural Science Foundation of China(51922058).

摘　　要：Extensive efforts have been made to pursue a low-friction state with promising applications in many fields,such as mechanical and biomedical engineering.Among which,the load capacity of the low-friction state has been considered to be crucial for industrial applications.Here,we report a low friction under ultrahigh contact pressure by building a novel self-assembled fluorinated azobenzene layer on an atomically smooth highly-oriented pyrolytic graphite(HOPG)surface.Sliding friction coefficients could be as low as 0.0005 or even lower under a contact pressure of up to 4 GPa.It demonstrates that the low friction under ultrahigh contact pressure is attributed to molecular fluorination.The fluorination leads to effective and robust lubrication between the tip and the self-assembled layer and enhances tighter rigidity which can reduce the stress concentration in the substrate,which was verified by density functional theory(DFT)and molecular dynamics(MD)simulation.This work provides a new approach to avoid the failure of ultralow friction coefficient under relatively high contact pressure,which has promising potential application value in the future.

关 键 词：ultrahigh contact pressure self-assembled layer FLUORINATION robust lubrication 

分 类 号：TH117.1[机械工程—机械设计及理论]