自组装氧化石墨烯薄膜层间键合方式调控与润滑机理研究

苛刻真空服役环境对氧化石墨烯润滑薄膜力学性能和润滑性能提出了更高的要求。前期研究表明，以离子键配位实现层间结合的氧化石墨烯薄膜具有类似贝壳珍珠层的致密多层结构，表现出优异的力学性能和润滑性能，适应多环境工况。但薄膜层间键合方式的微观作用机制与润滑机理还尚未得以阐明。本项目拟采用自组装技术，通过调控金属离子种类和价态，制备仿贝壳层状结构的氧化石墨烯薄膜；研究薄膜层间金属离子与含氧官能团的键合方式对微观结构、层间作用力及力学性能和润滑性能的影响；探讨薄膜在摩擦过程中内部结构和外部服役环境耦合作用下的润滑机理；揭示薄膜微观结构和层间作用力—力学性能—润滑性能之间的关联机制，在此基础上，提出通过调控薄膜层间键合方式优化氧化石墨烯薄膜润滑性能的策略。研究结果可为发展高性能氧化石墨烯润滑薄膜提供理论依据和技术支撑。

Higher requirements are required for mechanical and lubricating properties of graphene oxide (GO) lubricating films in harsh vacuum service environment. Previous studies discovered that the GO film assembled by ionic bond coordination has a compact multilayer structure similar to shell nacreous, showing excellent mechanical and lubricating properties under multiple environmental conditions. However, the microscopic mechanism of the interlayer binding and the corresponding lubrication mechanism has not been studied. In this project, nacre-like lamellar GO film is designed to be prepared by self-assembly method and by regulating the types and valence states of metal ions. By studying the influence of binding mode between metal ions and oxygen-containing functional groups within layers on the microstructure, interlayer interaction, mechanical and lubricating properties of as-prepared GO films. The lubrication mechanism of GO films under the coupled effect between internal structure and external service environment in the friction process will be illustrated. The relationship between microstructure and interlayer interaction, mechanical properties and lubricating properties of GO films will be revealed. A strategy for optimizing the lubrication performance of GO films by regulating the interlayer binding mode will be proposed. The results will provide theoretical and technical support of the development of GO lubricating films with high performances.