Effect of functional groups on the reinforcement of graphene oxide/resin nanocomposites

Functional group is of great significance for interface mechanical properties of nano composites, while functional groups screening is a great challenge due to the complex molecular behaviors. Herein, molecular dynamics and experiments probe the dynamics, molecular structure, and interfacial bonding at the GO/epoxy resin interface and the functional groups screening of GO to reinforce composites. The interface energy of the composites for the case of -OH, COOH, and -NH 2 is more than three times that of C=O and COC. The dynamics characteristics of the former ones show typic solid feature, while that of the latter ones exhibits liquid feature. The interface energy of -NH 2 case is the highest. The groups of -NH 2 and -COOH on the graphite sheet undergo condensation reactions to form amide bonds, transforming the two-dimensional sheet into three-dimensional wrinkled texture. The aminated GO reinforced composites exhibit the behavior of increasing cracks distribution to release stress.