Tribological properties of differently shaped zinc-based metal-organic framework particles reinforced epoxy resin composites

In this work, two zinc-based metal-organic frameworks (Zn-MOFs) with different morphologies were successfully produced by the surfactant-mediated synthesis method. They were grown on the Polytetrafluoroethylene (PTFE)/polydopamine (PDA) to prepare PTFE/PDA/Zn-MOFs fiber fabrics. Then the epoxy resin (EP) matrix was poured onto fabrics to prepare EP/PTFE/PDA/Zn-MOF. PTFE was modified by introducing a PDA adhesion layer, which can provide absorption sites for Zn-MOFs growth and improve the bonding strength with EP. The microscopic morphologies and structures of the PTFE and modified PTFE were studied. Compared with pure EP, the friction coefficient and specific wear rate of the EP/PTFE/PDA/ZnMOF2 composite were reduced by 67% and 91%, and the EP/PTFE/PDA/ZnMOF1 composite were reduced by 55% and 88%, respectively, which were due to the loading of ZnMOF2 onto the PTFE surface, improving the interfacial bonding between the PTFE and EP matrix and can prevent the PTFE fabric from coming out of the EP matrix. ZnMOF2 also presents its structural advantage: the unique thin layer structure plays a vital role in friction and wear reduction. Two types of fiber-reinforced polymer materials were designed and the tribological properties of the EP/PTFE/PDA/Zn-MOFs composites were investigated. Compared with the cubic structure of ZnMOF1, the anti-friction and wear resistance of composites can be greatly improved by the ZnMOF2 nanosheets. It can be attributed to ZnMOF2 being easier to slide between layers when subjected to tangential forces.image

Automated summary

Two zinc-based metal-organic frameworks (Zn-MOFs) with different morphologies were successfully synthesized using a surfactant-mediated method. The addition of a polydopamine (PDA) adhesion layer on the Polytetrafluoroethylene (PTFE) improved bonding strength and allowed for the growth of Zn-MOFs on the PTFE surface. The incorporation of Zn-MOFs reduced the friction coefficient and wear rate of the composites, with ZnMOF2 showing superior performance due to its thin layer structure.