油酸功能化金属有机框架纳米片的摩擦学性能研究  

Tribological properties of metal-organic framework nanosheets functionalized by oleic acid

作　　者：于鸿翔 刘小龙 郑治文 陈海杰 乔旦[1] 冯大鹏[1] 龚珍彬 董国俊 YU HongXiang;LIU XiaoLong;ZHENG ZhiWen;CHEN HaiJie;QIAO Dan;FENG DaPeng;GONG ZhenBin;DONG GuoJun(State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Lanzhou 730000,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院兰州化学物理研究所,固体润滑国家重点实验室,兰州730000 [2]中国科学院大学材料与光电研究中心,北京100049

出　　处：《中国科学：技术科学》2023年第3期445-456,共12页Scientia Sinica(Technologica)

基　　金：中国科学院青年创新促进会(编号:2021422);兰州化学物理研究所青年科技工作者协同创新联盟合作基金(编号:HZJJ20-06)资助项目。

摘　　要：利用对苯二甲酸与乙酸铜为原料,采用超声辅助自组装合成了铜基金属有机框架(Cu-MOF)纳米片,之后通过超声处理将油酸分子修饰于Cu-MOF表面,得到Cu-MOF@OA纳米片.相比于Cu-MOF纳米片,Cu-MOF@OA纳米片在保持片状结构的同时,其尺寸进一步减小,同时也使团聚问题得到了极大改善,在基础油500 N中表现出良好的分散稳定性.摩擦学试验表明,在1.0 wt.%的添加浓度下,Cu-MOF@OA展现出最佳的摩擦学性能,其摩擦系数降低至基础油的3/5,磨损体积降低至基础油的1/6.最后,利用扫描电子显微镜(SEM)与X射线光电子能谱(XPS)对Cu-MOF@OA纳米片润滑后的磨痕进行形貌和特征元素的表征,探究其润滑机制.结果表明,摩擦过程中在负载和剪切应力的共同作用下,Cu-MOF@OA纳米片、基础油以及铁基底三者之间发生了复杂的摩擦化学反应,形成了由含氮物质、含碳物质与铁氧化物组成的摩擦膜,降低了摩擦磨损.Terephthalic acid and copper acetate were used as raw materials,and copper-based metal-organic framework(Cu-MOF)nanosheets were synthesized by ultrasonic-assisted self-assembly.Afterward,oleic acid(OA)molecules were successfully modified on the surface of Cu-MOF by ultrasonic treatment to acquire Cu-MOF@OA nanosheets.The morphology of Cu-MOF@OA maintained its sheet structure;however,the size of the nanosheets was reduced,and the agglomeration problem was considerably alleviated compared with Cu-MOF nanosheets.The Cu-MOF@OA nanosheets exhibited good dispersion stability in 500 N base oil.The tribological tests indicated that Cu-MOF@OA showed the best tribological properties at the addition concentration of 1.0 wt.%.Moreover,the friction coefficient and wear volume were reduced to 3/5 and 1/6 of the base oil,respectively.Finally,scanning electron microscopy and X-ray photoelectron spectroscopy were applied to characterize the morphology and characteristic elements of wear scar lubricated by Cu-MOF@OA nanosheets and explore the lubrication mechanism.The results indicated that complex tribochemical reactions occur among Cu-MOF@OA,base oil,and iron substrate under the action of load and shear stress during the friction experiment,forming a tribofilm composed of nitrogenous substances,carbonaceous substances,and iron oxides,which reduce the friction and wear of metal surfaces.

关 键 词：金属有机框架 分子修饰 润滑添加剂 摩擦学性能 

分 类 号：TB383.1[一般工业技术—材料科学与工程] TH117.2[机械工程—机械设计及理论]