Influence of polyethylene cross-linked functionalization on the interfacial properties of carbon nanotube-reinforced polymer nanocomposites: a molecular dynamics study.

The average pull-out force and interaction energy of polyethylene (PE) cross-linked functionalized carbon nanotubes (cfCNTs) embedded in polymer matrices (PE-cfCNTs@polymers) was studied using molecular dynamics (MD) simulations. Accordingly, the pull-out process of PE-cfCNTs from inside polymer matrices, i.e., Aramid and PE, was performed under displacement control. The results obtained were compared with those of pure carbon nanotube (CNT) incorporated into polymer matrices (pure CNT@polymers). The influence on the pull-out force and interaction energy between the CNT and polymer of the structure of polymer matrices, the weight percentage and two types of distribution patterns of cross-linked PE chains, namely mapped and wrapped, was investigated. The results indicate that the structure of the polymers and distribution patterns of cross-linked PE chains strongly affect important parameters related to interfacial properties. The average pull-out force of mapped and wrapped PE-cfCNTs@polymers increases as the weight of attached PE chains on the CNT surface increases. The effect of wrapped structures on increasing the pull-out force is greater than that of the mapped configurations. Also, the PE-cfCNTs@polymers show higher average pull-out forces than those of their pure counterparts. As the CNT pulls out from the polymer matrix, an approximately linear reduction in the absolute value of interaction energy with the pull-out displacement is observed. However, this trend is changed to some extent by imposing instability through the wrapped PE-cfCNTs.