Molecular Dynamics Simulation of Mechanical Properties and Interaction Energy of Polythiophene/ Polyethylene/Poly(p-phenylenevinylene) and CNTs Composites

摘要

Carbon nanotubes (CNTs) have very important applications in ultrastrong lightweight materials. CNTs can improve mechanical properties of polymer matrix such as breaking stress and Young's modulus. In this article, we studied the interaction between polythiophene (PT)/polyethylene (PE)/poly(p-phenylenevinylene) (PPV) and CNTs by molecular dynamics (MD) simulation based on a reactive force field (ReaxFF). We studied the influence of CNT diameter, polymer type, and temperature on interaction energy. We found that a large radius CNT at low temperature shows the strongest interaction energy with PT. In addition, we computed the mechanical properties of CNTs-polymer composites such as the breaking stress, breaking strain, and Young's modulus. Our results show that there is a direct relation between mechanical properties and interaction energy. We found that the mechanical properties of CNTs-PT composite are better than CNTs-PPV and CNTs-PE and it is a good candidate for ultrastrong lightweight materials. We studied the influence of temperature on the mechanical properties. Our results show that CNTs-polymer composites show stronger mechanical properties at low temperature. We found that ReaxFF can reproduce the other force fields results and it is a very powerful force field to study the various properties of CNTs-polymer composites.