固液复合润滑体系中Cu纳米添加剂在碳膜表面的吸附特性对其边界润滑性能的影响机制

The environment friendly nano additives without sulfur and phosphorus can provide an efficient and precise solution to overcome the shortcomings of the existing small molecule additives, such as mismatching with carbon based films and polluting the environment. However, the adsorption mechanism of nano additives on the surface of carbon films is not clear. It is unable to design efficient nano additives for solid-liquid composite lubrication systems composed of different carbon films and base oils. Therefore, the research on the adsorption characteristics of nanoparticles on the carbon membrane surface and the establishment of structure-activity relationship between adsorption characteristics and tribological properties are urgent problems to design and develop suitable nano additives. In this project, oil soluble monodisperse Cu nanoparticles with different particle size will be synthetised by controlling conditions. Cu nanoparticles can be modified by different content, different chemical groups. The effect of Cu nanoparticle size, surface chemical properties on their adsorption characteristics on different carbon films such as adsorption desorption rate, surface coverage and stacking structure of adsorption layers will be studied. Combined with the tribological performance of the system in the boundary lubrication interval, the structure-activity relationship of adsorption characteristics of nano additives and their tribological properties would be established. It is a bel to provide operational theoretical guidance for the design and synthesis of high efficient nano additives for carbon film solid-liquid lubrication system.

以铜纳米颗粒为代表的无硫磷环境友好型纳米添加剂克服了现有小分子添加剂与碳基薄膜不匹配、污染环境等缺点，但其在碳膜表面的吸附机制尚不明确，无法针对不同碳膜与基础油组成的固液复合润滑系统设计出高效纳米添加剂，为此本项目拟开展铜纳米颗粒在碳膜表面吸附特性与边界润滑性能之间的关系研究。通过合成不同粒径单分散的油溶性Cu纳米微粒，利用不同结构、不同含量的化学基团对其进行二次修饰，考察在不同碳膜与基础油组成的系统中，纳米微粒的粒径、表面化学特性对其在碳膜表面的吸脱附速率、表面覆盖率、平衡吸附常数和吸附层堆叠结构等吸附特性的影响规律，结合系统在边界润滑区间的摩擦学性能，揭示纳米添加剂的吸附特性对系统摩擦学性能的影响机制，建立纳米添加剂的吸附特性与其在碳膜固液复合润滑系统中边界摩擦性能的构效关系。通过本项目的研究，为碳膜固液复合润滑系统设计合成高效纳米添加剂提供可操作的理论指导。

本项目利用极性溶剂诱导法，实现铜纳米微粒表面Zeta电位的有效调控。建立起Zeta电位、团聚粒径、流速等因素与纳米微粒吸附力之间的量化关系。并对铜纳米微粒在金属和DLC摩擦副上的吸附特性和摩擦学性能之间建立起可量化的构效关系。实现了高Zeta电位铜纳米微粒在DLC摩擦副表面的高效吸附和优异润滑。研究了铜纳米微粒对金属掺杂（a-C(Al)）、非金属掺杂（a-C(Si)）、氢掺杂（a-C(H)）和未掺杂（a-C）四类DLC碳膜的润滑机制。发现铜纳米微粒的沉积摩擦膜形成机制克服了ZDDP化学反应摩擦膜形成机制对DLC成分和硬度的选择性，表现出对不同掺杂元素和强度DLC的普遍适应性和高效减摩抗磨性。利用连续流原位热分解法制备了平均粒径4纳米的油溶性油胺修饰氧化铈纳米微粒。氧化铈的采用避免了铜纳米微粒对润滑油的催化氧化问题，通过与商用有机减摩剂的优化复配，促使氧化铈纳米微粒和GMO在GCr15/DLC摩擦配副系统中形成具有低摩擦高承载的粘弹性协同吸附摩擦膜，同时克服氧化物摩擦膜高摩擦和有机减摩剂抗磨能力差的问题，实现了DLC固液复合润滑系统的高效润滑。针对柴油发动机中的DLC、渗氮、铸铁等多种摩擦副材料，利用纳米复合添加剂对DLC等多种新型摩擦副的广谱适用性，研究了纳米微粒复合添加剂对柴油发动机低粘度润滑油/新型摩擦副复合润滑系统的摩擦学性能影响。纳米复合添加剂实现了发动机多种摩擦副的全区间减摩润滑，同时也实现了润滑油低温粘度的降低和黏度指数的提升，进一步提高低粘度柴机油的节能功效。. 本项目发表SCI和EI收录学术论文18篇；授权国家发明专利12件，美国发明专利1件；获河南省科学技术进步奖一等奖1项。培养硕士研究生5名。