Macroscopic superlubricity of potassium hydroxide solution achieved by incorporating in-situ released graphene from friction pairs  

作　　者：Hongyu LIANG Xinjie CHEN Yongfeng BU Meijuan XU Gang ZHENG Kaixiong GAO Xijun HUA Yonghong FU Junyan ZHANG 

机构地区：[1]Institute of Advanced Manufacturing and Modern Equipment Technology,School of Mechanical Engineering,Jiangsu University,Zhenjiang 212013,China [2]Institute for Energy Research,Jiangsu University,Zhenjiang 212013,China [3]ZhenJiang SiLian Mechatronic Technology Co.,Ltd.,Zhenjiang 212009,China [4]State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Lanzhou 730000,China

出　　处：《Friction》2023年第4期567-579,共13页摩擦（英文版）

基　　金：supported by the National Natural Science Foundation of China(52075224,21975109,51975252,and 52075225);Natural Science Foundation of Jiangsu Province(BK20201423);Foundation of State Key Laboratory of Solid Lubrication(LSL-1801);Tribology Science Fund of State Key Laboratory of Tribology(SKLTKF18B03).

摘　　要：Graphene(G),as a typical two-dimensional material,is often used as an additive for liquid lubricants.However,graphene is mostly added to liquid lubricants in a one-time manner in friction;it mainly exists in the form of multilayer agglomerated structures due to theπ–πstacking between graphene sheets,making it unable to fully exert the synergistic lubrication function.Herein,we propose a new macroscopic superlubric system of graphene/potassium hydroxide(G/KOH)solution;and the graphene additive involved is exfoliated in-situ from graphene/epoxy(G/EP)friction pair by friction,continuously providing freshly-peeled graphene into KOH solution and minimizing the adverse effects of graphene agglomeration.Moreover,the in-situ produced graphene additive has thinner thickness and better anti-aggregation ability,which provide more graphene to accommodate OH−,form more stacked sandwich structures of OH−/graphene/OH−between friction pairs(i.e.,equivalent to a moving pulley block with more wheels),and finally realize superlubricity.This study develops a new liquid superlubric system suitable for alkaline environments,and at the same time proposes a new way to gradually release graphene additives in situ,rather than adding them all at once,deepening the understanding to liquid superlubricity mechanism,and paving the experimental foundation for the practical application of macroscopic superlubricity.

关 键 词：liquid superlubricity concentrated potassium hydroxide(KOH)solution in-situ graphene(G)additives stacked sandwich structure electric double layer(EDL) hydrogen bonds(H-bonds) 

分 类 号：TH117[机械工程—机械设计及理论]