Tribological gain enabled by the synergy of copper nanoparticles and friction induced in situ tribo-click reaction

The tribochemical reactions generated at the relative motion interface are considered to have a positive or negative effect on the performance when lubricating materials are in use. Obviously, these tribochemical reactions are complex and uncontrollable during sliding, resulting in an uncertainty in their performance. To enhance the lubricating properties through tribochemical reactions, herein, we designed an interfacial friction modulation system for the targeted induction of effective substance production. Noteworthily, this system achieves self-adaptive friction modulation through the targeted induction of click chemistry at the interface by copper nanoparticles and friction. In this modulation, active products are generated at the sliding interface and exert their immediate and robust lubricating improvement, avoiding exogenous synthesis and addition. By virtue of the dynamics of the tribochemical reactions, the system exhibits interesting interfacial behaviors and excellent self-adaptive properties. This system overcomes the solubility problem in various base oils and demonstrates superior performance. These important results demonstrate the possibility of regulating the friction state by the ordered design relying on tribochemical reactions. Also, the system provides a new avenue for interfacial friction modulation and the development of lubricating materials.