Thiosemicarbazone-functionalized covalent organic frameworks for high-performance oil gel lubricant additives with enhanced stability and anti-wear properties

Herein, thiosemicarbazone (TC₁₈) modified DT-COF with long-chain was successfully achieved through a ball-milling method driven by a mechanochemical reaction. The resulting TC₁₈@DT-COF was stably dispersed in PAO40 oil gel for over 100 days. TC₁₈@DT-COF based oil gel demonstrated optimal tribological performance at 0.5 wt%, reducing the average friction coefficient of PAO40 base oils to 0.093 and decreasing the wear volume by 81.7 %. A detailed analysis of the worn surface composition suggested that the grafted thiosemicarbazone moieties on the DT-COF surface interact with the urea-based gelator, potentially forming hydrogen bonds. This interaction is thought to facilitate the adsorption of gelators, base oils, and TC₁₈@DT-COF nanosheets onto the friction interface, leading to form a robust protective friction film. Such a film contributes significantly to reducing friction and enhancing anti-wear performance.