Molecular insights into the interfacial adhesion mechanism between carbon nanotubes and epoxy resin

In recent years, carbon nanotubes (CNTs) have garnered widespread attention and have been deemed the preferred option for the creation of epoxy composites, owing to their outstanding mechanical properties. Despite this, the interaction between pure CNTs and epoxy resin is primarily dependent on van der Waals forces and therefore, the interfacial forces are weak, making it challenging for effective load transfer. To enhance the mechanical properties of the composites, surface functionalization is often deemed a more favorable method for improving interfacial bond strength. This study employs molecular dynamics simulations to examine the interfacial bonding characteristics between functionalized CNTs and epoxy resin. The results demonstrate that functional group modification can significantly improve the interfacial adhesion between CNTs and epoxy resin, and the incorporation of functional groups can enhance the crosslinking degree of the epoxy resin at the interface. The hydrogen bond network established between the CNTs and epoxy resin after functional group modification, and the high stability of the bond cooperation, are factors contributing to the excellent interfacial performance. Functionalization enhances the interfacial interaction between epoxy resin and carbon nanotubes and improves the stability of interfacial bonding.