Molecular Dynamics Simulations of Interactions at the Interface Between Functionalized Carbon Nanofibers and Polymer Resins

The discovery of vapor grown carbon nanofibers has created a significant opportunity to develop high performance and cost-effective nanocomposite materials. However, significant challenges in the development of such composite materials lie in the poor dispersion of carbon nanofibers into polymer resins and the weak interfacial bonding between carbon nanofibers and polymer resins. These critical issues have to be addressed by chemical functionalization of carbon nanofibers. Understanding molecular interactions between functionalized carbon nanofibers and polymer resins is a crucial step towards their potential use in nanocomposites. In this work, the effects of surface functional groups on the molecular interactions between carbon nanofibers and polymer resins have been studied by using molecular dynamics simulations. It was found that chemical functionalization of vapor grown carbon nanofibers increased the amount of surface functional groups which disturbed the original smooth graphitic planes of carbon nanofibers. The functionalization of vapor grown carbon nanofibers decreased the amount of π-bonds on the nanofiber surface, which resulted in the weaker interaction with polymer resins. The simulation results provided fundamental information for the rational functionalization of vapor grown carbon nanofibers to manipulate their nanoscale properties in a predicative manner.