Influence of Waviness on the Elastic Properties of Aligned Carbon Nanotube Polymer Matrix Nanocomposites

摘要

The promise of enhanced performance has motivated the study of onedimensional nanomaterials, especially aligned carbon nanotubes (A-CNTs), forthe reinforcement of polymeric materials. While early work has shown that CNTshave remarkable theoretical properties, more recent work on aligned CNT polymermatrix nanocomposites (A-PNCs) have reported mechanical properties that areorders of magnitude lower than those predicted by rule of mixtures. This largedifference primarily originates from the morphology of the CNTs that reinforcethe A-PNCs, which have significant local curvature commonly referred to aswaviness, but are commonly modeled using the oversimplified straight columngeometry. Here we used a simulation framework capable of analyzing 10$^{5}$wavy CNTs with realistic stochastic morphologies to study the influence ofwaviness on the compliance contribution of wavy A-CNTs to the effective elasticmodulus of A-PNCs, and show that waviness is responsible for the orders ofmagnitude \textit{over-prediction} of the A-PNC effective modulus by existingtheoretical frameworks that both neglect the shear deformation mechanism and donot properly account for the CNT morphpology. Additional work to quantify themorphology of A-PNCs in three dimensions and simulate their full elasticconstitutive relations is planned.