Tunable morphology and its influence on electrical, thermal and mechanical properties of carbon nanostructure-buckypaper

摘要

In this study, free-standing buckypapers (BPs) made up of a three-dimensional network of multi-walled carbon nanotubes (MWCNTs) that are branched, cross-linked, and share common walls, defined henceforth as multi-walled carbon nanostructures (MWCNSs) are characterized to obtain their electrical, thermal and mechanical properties. Two types of free-standing sheets are studied, namely uncompressed buckypapers (UBPs) and compressed buckypapers (CBPs). Both are processed via a vacuum filtration method, with subsequent compressive force applied between platen presses to obtain CBP. CBPs are found to exhibit improved thermal and electrical conductivities since higher density of CNT networks leads to more conductive pathways. However, mechanical properties of CBPs and UBPs are approximately the same. Local anisotropic behavior of both BPs allows them to have either positive or negative Poisson's ratio. While UBP is suitable for membrane applications due to its mechanical stability and well-defined pore characteristics, the CBP offers a compact structure that can reduce penetration of the polymer matrix in composite applications such as for integrated circuit packaging and EMI shielding. (C) 2016 Elsevier Ltd. All rights reserved.