Lubrication performance and mechanisms of ZIF-8@PDA as water-based lubricant additives

As environmental awareness, waste minimization and conscious living gain widespread attention, endeavors have been dedicated to acquiring new water-based (WB) lubricants for green manufacturing. Zeolitic Imidazolate Framework-8 (ZIF-8), an important branch of metal organic frameworks (MOFs), can perform exceptional lubricity add-on water conditions. Nevertheless, surface functionalization of ZIF-8 nanoparticles is a key issue for promoting interfacial consistency and mixing stability in aqueous solutions. In this research work, the functionalization approach of ZIF-8 via polydopamine polymerization process (PDA) was adopted to enhance its dispersion durability in water. A ball-on-flat linear reciprocating tribometer was used to test the lubrication achievement of the functionalized ZIF-8@PDA as an additive nanoparticle in water under room temperature. The experimental findings revealed a significant lubrication improvement, with the coefficient of friction (COF) being decreased by 33.9% with a 4.0 wt% content of ZIF-8@PDA. The wear track width distance saw a reduction of 34.4% when utilizing a 2.0 wt% inclusion of ZIF-8@PDA. This lubrication enhancement accounts for microbearing and mending effects provided by ZIF-8@PDA.