Dong Gaolong, Ding Shuyang, Peng Yitian
College of Mechanical Engineering, Donghua University, Shanghai 201620, China.
Nanomaterials (Basel). 2022 Dec 15;12(24):4462. doi: 10.3390/nano12244462.
The friction characteristics of two-dimensional materials in the ultraviolet (UV) radiation environment are important to the reliability of two-dimensional material nano-structures of space equipment. A novel mechanism of UV light-sensitive nano-friction on graphene was proposed by ultraviolet vacuum irradiation modification using an atomic force microscope (AFM). The surface roughness, adhesion force, and friction of graphene were gradually reduced over a time of irradiation below 3 min. UV185 passes through graphene and causes photochemical reactions between its bottom layer and Si/SiO substrate, resulting in hydroxyl, carboxyl, and silanol suspension bonds and sp3-like bonds, which enhances the binding energy of graphene on the substrate and inhibits the out-of-plane deformation resulting in roughness and friction reduction. However, as the irradiation time increased to 5 min, the friction force increased rapidly with the aging effect and the breakdown of sp3-like bonds between the graphene-substrate interface. This study presents a new method of controlling nanofriction on graphene based on UV irradiation-sensitive posterities in vacuum conditions, which is essential to the application of two-dimensional materials in aerospace equipment, to improve anti-aging properties and wear reduction.
二维材料在紫外（UV）辐射环境中的摩擦特性对于空间设备二维材料纳米结构的可靠性至关重要。利用原子力显微镜（AFM）通过紫外真空辐照改性，提出了一种关于石墨烯上紫外光敏感纳米摩擦的新机制。在低于3分钟的辐照时间内，石墨烯的表面粗糙度、粘附力和摩擦力逐渐降低。UV185穿透石墨烯并在其底层与Si/SiO衬底之间引发光化学反应，产生羟基、羧基和硅烷醇悬浮键以及类sp3键，这增强了石墨烯在衬底上的结合能并抑制了面外变形，从而导致粗糙度和摩擦力降低。然而，随着辐照时间增加到5分钟，摩擦力随着老化效应以及石墨烯 - 衬底界面间类sp3键的断裂而迅速增加。本研究提出了一种基于真空条件下紫外辐照敏感性后代来控制石墨烯纳米摩擦的新方法，这对于二维材料在航空航天设备中的应用、提高抗老化性能和减少磨损至关重要。
