Carbon spheres wrapped with 2D covalent organic polymer as lubricant additives for enhancing tribological properties

Abstract A facile and efficient hydrothermal strategy for producing carbon spheres (CS) wrapped with two-dimensional (2D) covalent organic polymer (CS/TriC) was accomplished. The CS/TriC particles shaped with a core-shell nanostructure were spherical, in which TriC nanosheets were connected to CS by C-N bonds. Wettability tests showed that the lipophilicity and polar forces of CS/TriC were greatly enhanced compared with functionalized-CS. Tribological tests showed that the coefficient of friction and wear rate were reduced by 21.1% and 38.1%, which were in line with the results of SEM and XPS analyses performed after tribotesting. These results showed that excellent lubrication performance of CS/TriC were due to synergistic effects of which CS loading effects and excellent adsorption performance of 2D covalent organic polymer nanosheets.