The stability and dispersion of carbon nanotube-polymer solutions: A molecular dynamics study (original) (raw)

Carbon nanotubes (CNTs) have been explored to increase the mechanical properties and electrical conductivity of polymeric fibers through compounding with polymer to be extruded into fibers. However, this route creates major challenges because CNTs have strong cohesion and tend to aggregate and precipitate due to their poor interfacial interaction with polymers. CNTs can be individualized from agglomerations to enhance the mechanical and electrical properties of polymer fibers but even so the capillary forces during solvent drying creates CNTs bundling. In this study, classical molecular dynamics (MD) simulations are used to predict and characterize CNTs-polymer interface mechanism in two different polymer matrices: polyvinyl butyral (PVB) and polystyreneco-glycidyl methacrylate (P(St-co-GMA)). The dominated interface mechanisms are discovered to shed light on CNTs dispersion in solvent based systems and to explore the prerequisites for stabilized nanofluids. Our results showed that π-stacking interactions between aromatic groups and graphene surfaces of CNTs as in P(St-co-GMA) systems, play an important role in dispersion of CNTs, whereas slight repulsions between CNTs and PVB chains lead to large morphological differences and CNTs bundles in many chain systems. Altogether, the results indicated that polymers with structures having strong interactions with the surfaces of SWNTs through π-π interactions are more effective in dispersing CNTs and caused stabilized solutions in wet fiber processing.