From a single carbon nanotube to an entangled network of bundles: Mesoscopic simulations of CNT films and nanocomposite materials
A.N. Volkov, W. Jacobs, L.V. Zhigilei
University of Virginia, US
Keywords: interactions among nanotubes, mesoscopic simulations, CNT bundles, nanocomposites
Abstract:A mesoscopic computational model that explicitly accounts for the shapes of individual CNTs, and, due to this feature, enables a direct representation of all CNT/CNT and CNT/matrix interfaces within the material is developed. The model uses a novel computationally-efficient “tubular potential” method for representation of van der Waals interactions among the CNTs Polymer chains are represented in the framework of the “bead-and-spring” model, parameterized to provide an adequate description of a generic polymer matrix. The model is implemented in a parallel computer code that enables simulations of micrometer-scale samples containing tens of thousands of CNTs. The simulations performed for a system composed of randomly distributed and oriented CNTs predict a spontaneous self-assembly of CNTs into a continuous network of bundles with partial hexagonal ordering of CNTs within the bundles. The mechanical behavior of CNT films and nanocomposites under conditions of quasi-static or impact loading is investigated. The mechanisms responsible for the plastic deformation, impact resistance and fracture of the CNT-reinforced nanocomposites are discussed based on the results of the simulations and related to available experimental observations. The current work is devoted to the development of a mesoscopic model for simulation of charring of CNT-based organic-matrix nanocomposites in a high-temperature environment.