Modeling of density of state for polyethylene-nanotubes nanocomposites

摘要

At the nanoscale system, the efficiency of carbon nanotube (CNT) reinforcement between the CNTs and polymer matrices in terms of interfacial load transferring is assessed for both nonfunctionalized and functionalized interfaces. The simulations of the mechanical properties (stress-strain) of polyethylene (PE)/CNT nanocomposites by the molecular dynamics are currently an area of discussion in the literature. In this work, PE considered as a thermoplastic material is studied, in which the characterization of its nanoscale load transfer has been carried out through the classification of representative nanoscale interface elements for nonfunctionalized CNTs for the diverse values of lengths and diameters. First, the main evaluations based on the density functional theory and the molecular dynamics method were used with the aim to examine the effect of PE monomers. Then, the effect of the diameter of CNTs with nonfunctionalization content on the electronic and mechanical properties of single-walled carbon nanotubes was examined. The findings reveal that the density of states highlights the absence of orbital hybridization between the PE monomers and nanotubes, whereas the Mulliken charge analysis depicts that the PE polymer produces a positive charge that is directly proportional to the number of monomers with many chains of PE and different diameters of CNTs. The decrease in diameters implies an increase in nanocomposites stress. In addition, the results show that the reinforcements in the longitudinal direction are more promising than those in the transverse direction.