Effect of Different Particle Size of Nano-Zinc Oxide on the Surface Binding Energy in Polyimide/Zinc Oxide Composites

The surface binding energy between the polyimide(PI) and zinc oxide (ZnO) have been simulated using the molecular dynamics theory. The PI / ZnO model has been established by using Forcite program package of Materials Studio software. The total atoms number about 300 million, the radius of the nano-ZnO cluster model have five groups are respectively 0.5 nm, 1 nm, 1.5 nm, 2 nm, 2.5 nm. The effect of different particle size of nano-ZnO on surface binding energy in PI / ZnO composites was investigated. The relationship between the surface binding energy of PI / ZnO composites and the nano-Zno radius, the maximum of surface binding energy were obtained. The computed results show that the intermolecular bonds between nano-ZnO and PI are mainly van der waals bonds. And the surface atomic number of nano-ZnO increases along with the increasing of nano-ZnO radius, indicating that the increasing of contact surface between the nano-ZnO and PI, which lead to the surface binding energy increases, the total energy lower and the system more stable.