Highly electrically conductive carbon nanostructured mats fabricated out of aligned CNTs-based flakes

Abstract

In this work, a novel material based on carbon nanostructures (CNS), developed by Applied NanoStructured Solutions, was used with the goal of fabricating scalable CNS-based mats as an alternative to commercially available CNT-based mats. Statistical and experimental methods have been used to determine how the amount of surfactant and the sonication time that is used during fabrication of the mats have affected their mechanical and electrical properties. A strong statistically-significant interaction between surfactant/CNS mass ratio and sonication time was observed. Factorial ANOVA suggested that the combination of a surfactant/CNS mass ratio of approximately 2 and a sonication time of 5 min are optimal for electrical conductivity; this combination used the minimum amount of surfactant and the minimum sonication time of all the values investigated in the study. Samples with combinations of a surfactant/CNS mass ratio of 2 and a sonication time of <5 min (which contained no dispersed CNS flakes) broke during the sampling process owing to their poor mechanical properties. This demonstrates that the mechanical properties depend strongly on both sonication time and surfactant/CNS mass ratio. Samples with a surfactant/CNS mass ratio of 4 and 2 × 10 min (with 5 min in between) sonication showed the best mechanical and electrical properties. The experiments improved the understanding of the CNS-flake dispersion process, which in turn allowed improving the manufacturing process of the CNS mats. The results indicated that CNS are likely to be superior to CNTs for some industrial applications such as: (1) flexible supercapacitors as the obtained specific capacitance is 100.2 F/g, and (2) the electromagnetic interference shielding (EMI SH) as the obtained overall shielding of CNS mats is 48 dB.