Glass fiber-reinforced polymer nanocomposite adhesive joints reinforced with aligned carbon nanofillers

In this paper, the effect of aligning multi-walled carbon nanotubes (MWCNTs) and graphene oxide nanoplatelets (GONPs) on the fracture behavior of glass-epoxy nanocomposite adhesive joints was studied experimentally. The nanofillers were aligned using an AC electric field along the adhesive thickness in double cantilever beam (DCB) specimens. A unidirectional carbon fiber layer was embedded as the second ply of each laminated substrate as an electrode inside the glass-epoxy composite laminates. Reinforcing the composite adhesive joints with randomly dispersed MWCNTs and GONPs resulted in the maximum improvements of 82% and 155% in the initiation fracture energy and the improvements of 19% and 69% in the maximum load, respectively. Furthermore, aligning MWCNTs and GONPs resulted in considerably higher improvements of 179% and 349% in the initiation fracture energy and 66% and 127% improvements in the maximum load, respectively and yet changed the failure pattern. The toughening mechanisms due to the addition of the nanofillers were investigated using scanning electron microscope (SEM).