氮化碳纳米片对聚合物材料边界润滑状态摩擦学行为的影响机制

With the rapid development of modern engines, more and more motion components are being subjected to mixed and even severe boundary lubrication conditions. It is thus urgent to develop high-performance tribo-materials enduring the harsh service conditions. Owing to the excellent self-lubricating characteristics and chemical stability, polymer composites present high potential in developing tribo-pairs with long lifespan and high reliability. Graphitic carbon nitride exhibits high elastic modulus and possesses a unique layered structure; it can be an ideal candidate of reinforcing material for developing high-performance tribo-materials exposed to harsh rubbing conditions. In this work, carbon nitride nanosheets will be one-step synthesized and functionalized with ionic liquids and dopamine. The nanosheets will be dispersed uniformly in a polyimide matrix following an in-situ polymerization route. Effect of nanosheets’ structures and surface functionalization on the tribological performance of polyimide will be systematically investigated under oil lubrication conditions. The nanostructures and micro/nanomechanical properties of the friction interface will be explored. It is the objective of this project to reveal the influential mechanisms of functionalized carbon nitride nanosheets on the interface interactions. It is expected that the output of this work will gain an insight into the fundamental issues with respect to tribology of polymer nanocomposites. In particular, the results of this project will guide the design of high-performance polymer composites for applications under harsh boundary lubrication conditions.

随着现代发动机技术的迅猛发展，相关运动机构频繁处于混合甚至边界润滑区间运转，对摩擦副材料的可靠性和使用寿命提出了严峻挑战。聚合物复合材料具有良好的自润滑特性和化学稳定性等特点，在高可靠、长寿命摩擦副的设计和应用方面具有巨大潜力。石墨相氮化碳具有很高的弹性模量和独特的层状结构，其作为聚合物增强相具有优异的摩擦学性能。本项目拟设计制备二维氮化碳纳米片并进行表面功能化改性，采用原位聚合方式在聚酰亚胺基体中均匀分散功能化改性的氮化碳纳米片。系统研究氮化碳纳米片片层结构及表面功能化改性对聚酰亚胺油润滑条件下摩擦学性能的影响规律，深入表征摩擦界面的纳米结构与微/纳尺度性能，阐明氮化碳纳米片影响边界润滑摩擦副界面作用的本质。研究结果有望加深对油润滑条件下聚合物纳米复合材料摩擦学一般性科学问题的理解，为研制适用于苛刻边界润滑工况的聚合物复合材料提供理论指导。

我国国产机械装备技术的快速发展，使相关运动机构的运行工况愈加苛刻，频繁运转于边界润滑状态，这对摩擦副材料的运行可靠性及使用寿命提出了严峻挑战。本研究基于聚合物材料介质润滑体系的研究与发展，立足聚合物材料-金属摩擦副的润滑设计理念，采用简单的一步水热法制备了原位分散的水溶性氮化碳材料，将其作为绿色水润滑剂引入到聚合物-金属对摩体系中，深入研究了边界润滑条件下配副的摩擦学机理，系统阐述了边界润滑条件下水溶性氮化碳的片层结构及表面功能化改性对其摩擦学性能的影响规律，重点分析了摩擦副表面的摩擦化学反应，定量表征了摩擦界面转移膜的微纳米结构，揭示了水溶性氮化碳影响聚合物-金属边界润滑界面的作用本质。本项目工作拓展了氮化碳微纳米材料在摩擦学领域的新应用，研究结果可为苛刻边界润滑工况下新型水润滑剂的研制提供设计思路和技术方案。基于以上研究工作，相关成果已在Chemical Engineering Journal、Tribology International和《摩擦学学报》等本领域国内外知名期刊发表SCI论文3篇、EI论文1篇，申请发明专利6项，其中3项已获授权。