Influence of polymeric and cross-linked nano-hole interfaces on the tensile response of carbon nanotube bundles: A mesoscopic distinct element method approach

Abstract

While atomistic simulations can quantify the nano-mechanical properties of carbon nanotube (CNT) interfaces, they become impractical when it comes to predicting their functions within CNT assemblies. Using the mesoscopic distinct element method (MDEM) for CNTs, we perform coarse-grained multiscale simulation to compare the impact of polymeric and cross-linking interfaces in highly discontinuous CNT bundle and network assemblies subjected to simple tension. Viscous friction and contact shear bonds are used in MDEM to capture the polymeric and cross-linking nano-mechanics computed separately with atomistic methods. Cross-linking is found to be the most effective at increasing elastic moduli and tensile strengths of the CNT bundles. These properties can be diminished by the nano-holes in the CNT wall associated with irradiation-generated cross-linking and captured here into the contacts representing CNT stretching. Simulations indicate the need to balance the benefits and drawbacks of the radiation-induced morphological changes in order to manufacture CNT yarns with superior tensile characteristics.