Modeling of Hierarchical Morphology of Carbon Nanotube Bundles in Polymer Composites

Abstract

The morphological features of carbon nanotube (CNT) polymer composites and their influence on the effective modulus are evaluated. The considered features include bundle formation from the helical sub‐bundles made of individual CNTs. The formation of bundles is considered as a result of agglomeration of individual nanotubes above and below onset of percolation and is related to electrical conductivity. The proposed geometrical model yields a bundle diameter that agrees closely with that of the experimentally measured by voltage‐contrast method and scanning electron microscopy analysis of polyimide nanocomposites. The proposed micromechanical analytical model includes the helical structure of a bundle and provides close agreement of the effective Young's modulus of nanocomposite over a wide range of CNT content. It is shown that considering the helical structure of CNT bundles and its effect on bundle modulus is vital for predicting the effective modulus of CNT‐polymer nanocomposite.

Thermo-electro–elastic behavior of a carbon nanotubes bundles–reinforced electro-active polymer hollow cylinder considering hierarchical structure of the bundles

“…Comparison of the composite moduli between self-consistent model in this paper and Halpin–Tsai model 53 : (a) axial modulus trueE33 and (b) transversal modulus trueE11.…”

“…The CNTBs are considered as a short fiber, which consists of many CNTs. Based on the self-consistent micromechanical model, 53,54 the equivalent axial elastic modulus trueE33 can be expressed as follows where trueξw=1 (for the straight CNTBs) is the weight factor incorporating waviness of a bundle. 55 trueξ1 is the finite width factor defined by the shear-lag load transfer model of Cox.…”

Estimation of dynamic thermo viscoelastic moduli of short fiber‐reinforced polymers based on a micromechanical model considering interphases/interfaces conditions

“…To explain the experimentally observed behavior of FRPs, various elastoplastic micromechanics models were proposed, including continuum mechanics and elasticity. Various analytical models based on Halpin‐Tsai for randomly oriented fillers, modified Cox model for short fibers, Mori‐Tanaka for medium inclusions, semi‐empirical Chamis model and self‐consistent field model for polycrystalline materials, and so on were applied to FRPs. Theoretically, in the last decade, much progress also has been made on the dynamic viscoelastic characterization for FRPs with either continuous or discontinuous fibers.…”