Enhancement of pullout energy in a single-walled carbon nanotube-polyethylene composite system via auxetic effect

Inter-tube bridging of carbon nanotubes (CNTs) is a reliable way to improve the inter-tube stress transfer abilities. The work describes the interfacial interactions provided by a wall-to-wall inter-tube bridging between two single-walled carbon nanotubes (SWCNTs) embedded in a polyethylene (PE) matrix. Molecular dynamics (MD) models of tube pullout phenomena represent by the embedding (10, 10)–(10, 10) SWCNT with interconnections into an amorphous PE matrix. The simulations show that the inter-tube bridging enhances the pullout energies significantly due to the three energy dissipative micro-mechanisms: stress-induced tube deformation with localized auxetic effect, “cutting through” (penetration) between linker and matrix, and the accompanying tube pullout. Moreover, the results also predict that linkers with longer aliphatic chains or aromatic rings provide further increase to the levels of the nanotube pullout energies. These are of potential importance in guiding the design of CNT/polymer composites through inter-tube linkage.