Processing and property investigation of high-density carbon nanostructured papers with superior conductive and mechanical properties

• The paper sheets are made of CNS that are highly aligned, cross-linked CNTs and bundled in flack-shaped architectures
• Simple and scalable method is developed for making very electrically conductive and mechanically strong paper sheets
• Compression process has been used to increase the density of the paper sheets from 0.6 to 1.6 g/cm3
• The electrical conductivity improved significantly by 113% with increasing the density of the CNS papers.
• The tensile strength and the Young’s modulus improved by 67% and 86% respectively as the density increases

Recently, Lockheed Martin Corporation has synthesized special types of carbon nanostructures (CNSs) that are made of highly aligned, but highly cross-linked, and relatively long carbon nanotubes that are bundled in flack-shaped architectures. In this paper, a simple and scalable method is developed for making very electrically conductive and mechanically strong paper sheets using these novel pre-aligned CNS materials to be used in various engineering applications. The electrical conductivity and mechanical properties of the as fabricated paper sheets have been improved significantly by increasing their density from 0.6 to 1.6 g/cm3 through pressing. The scanning electron microscope images of the surface and cross-section of the as fabricated and pressed papers show a very high degree of carbon nanotubes alignment, which indicated that the pre-alignment of CNSs remained unaltered even after the sonication and the pressing process. The electrical conductivity of the papers has been improved by 113% with increasing the density of the CNS papers. In addition, the mechanical properties improved with increasing the density. The tensile strength and the Young's modulus improved by 67% and 86% respectively as the density increases.

Fig. 1 SEM images of the carbon nanostructures (CNS): (a) SEM images shows CNS flacks (b) SEM zoom showing closely packed and aligned carbon nanotubes (CNTs) within one flack, and (c) a closer SEM zoom showing the forest networks of CNTs. CNS are provided by Lockheed Martin Company.Figure optionsDownload as PowerPoint slide