Study On The Construction Of Friction-induced CuAAC Reaction System And Its Tribological Performance

The mechanical energy-induced physicochemical reactions at the surface interface of lubricated materials during friction are considered to have a great influence on the properties and performance of the materials.Such surface interface mechanical stressinduced reactions are known as tribochemical reactions.The research of friction chemistry is important to improve the performance and service life of lubricating materials.The complexity and uncertainty of the friction chemical reaction process lead to the difficulty of in situ characterization of its reaction process,the initial research only based on the phenomenon of speculative reaction process,induction mechanism of action and failure mechanism,to guide the selection of lubricating materials and design development.Through certain design means to intervene in the friction chemical reaction process,so as to achieve the effect of using friction to induce the generation of lubricating substances.It is of great significance for the development,change and innovation of lubricating materials.In this paper,we start from the orderly design and dynamic regulation of tribochemical reactions to induce click chemistry reactions in the friction process to generate triazole products with good lubricating effect,in order to achieve adaptive interfacial friction control by converting the energy loss caused by friction into beneficial work.The main research of this paper is as follows:The classical click chemistry reaction,the copper(I)-catalyzed azide-alkyne cycloaddition reaction(Cu AAC reaction),was designed to be induced during the friction of Fe/Cu,and the friction-induced click chemistry in situ lubrication system was constructed using azide and alkyne substituted with different functional groups.The friction-induced occurrence of the reaction was demonstrated by means of organic spectroscopy and fluorescence monitoring of the reaction system.The system exhibited excellent adaptive interfacial friction modulation at the copper interface-the reaction products relied on friction to be generated and adsorbed at the interface,which in turn modulated the interfacial friction process and produced good friction reduction and anti-wear effects.The tribofilms established by the reaction were characterized and simulated by molecular dynamics to explore the interfacial behavior and friction modulation mechanism of the system,which demonstrated the excellent applicability of the click chemistry system to copper friction interfaces and built a friction-induced click chemistry friction modulation model for copper interfaces.To further extend the applicability of the system,copper nanoparticles were introduced into the system to induce Cu AAC reaction in the most widely used steel/steel friction process in industry.This system relies on the good metal interface affinity of tribochemical reactions and the dynamic nature of adsorption while generating,overcoming the problem of poor solubility of lubricating base oils and providing excellent performance in a variety of lubricating base oils.The interfacial assembly behavior of the system was further confirmed by the characterization of the interface after friction.The highly polar anion in the system drives the system to establish a first strong adsorption with the iron substrate,after which the repair effect of copper nanoparticles constructs a nascent surface,catalyzes the reaction to occur,and immediately establishes a second strong adsorption with the product.The system constructed a tribochemical reactive film with multiple adsorptions and demonstrated excellent friction reduction and anti-wear ability under high load,high frequency friction conditions.