Bao Tianjiao, Wang Zhiyong, Zhao Yan, Wang Yan, Yi Xiaosu
Department of Materials Science and Engineering, Beihang University Beijing 100191 China
Beijing Institute of Aeronautical Materials Beijing 100095 China
RSC Adv. 2019 Nov 29;9(67):39230-39241. doi: 10.1039/c9ra07685a. eCollection 2019 Nov 27.
In oil lubrication systems, it is essential to continuously supply lubricant to the contact surface during practical applications. Herein, to realize its long-term stable dispersion in oil, graphene oxide was modified with polyisobutylene succinimide (PIBS, trade name T154), which is an effective dispersant for lubricating oils. Characterization of the T154-modified graphene oxide (GO-T154) by FTIR, XPS, and XRD revealed that the surface of the graphene platelets was covered by the T154 chains, and the dimensions of the graphene platelets had obviously decreased. The dispersion study demonstrated the long-term stability of a GO-T154/oil suspension, which could stand for more than a year without any significant precipitation. The lubricating property was greatly improved by the addition of GO-T154; more specifically, for the optimal performance, the friction coefficient decreased by 54%, and the wear rate decreased by 60%. Micro observation of the worn surfaces indicated that well-dispersed GO-T154 could enter the gap between the friction surfaces, forming a transfer film to separate the rubbing surface. With the long-term stability, high thermal stability and outstanding tribological properties of the suspension, GO-T154 promises to realize practical applications of graphene in lubricating oil.
在油润滑系统中，在实际应用过程中持续向接触表面供应润滑剂至关重要。在此，为了实现其在油中的长期稳定分散，用聚异丁烯琥珀酰亚胺（PIBS，商品名T154，一种有效的润滑油分散剂）对氧化石墨烯进行了改性。通过傅里叶变换红外光谱（FTIR）、X射线光电子能谱（XPS）和X射线衍射（XRD）对T154改性氧化石墨烯（GO-T154）进行表征，结果表明石墨烯片层表面被T154链覆盖，且石墨烯片层的尺寸明显减小。分散性研究表明GO-T154/油悬浮液具有长期稳定性，可在一年多的时间内不出现任何明显沉淀。添加GO-T154后润滑性能得到显著改善；更具体地说，在最佳性能下，摩擦系数降低了54%，磨损率降低了60%。对磨损表面的微观观察表明，分散良好的GO-T154能够进入摩擦表面之间的间隙，形成转移膜以分隔摩擦表面。鉴于该悬浮液具有长期稳定性、高热稳定性和出色的摩擦学性能，GO-T154有望实现石墨烯在润滑油中的实际应用。
