Factors that Affect Network Formation in Carbon Nanotube Composites and their Resultant Electrical Properties

Abstract

This review paper explores the formation of carbon nanotube (CNT) polymer composites as a function of material and processing parameters. The effect of different polymer systems, increasing multiwall CNT content, modification of CNTs, processing conditions, and aspect ratio are discussed in detail for multi-walled carbon nanotubes (MWCNT) composites along with some examples for SWCNT composites. All of these factors influence the microstructure and how the network of CNTs forms within it. Often, researchers choose to modify the CNTs to aid in their distribution; however, this may result in a reduction or increase in conductivity depending on many factors. The electrical properties are directly affected by changes in the CNT network and how the material has been processed. As soon as the network forms, percolation occurs and the conductivity increases. In order to understand how to control the properties of CNT composites, all material characteristics and processing conditions must be taken into account.