Investigation of Lightning and EMI Shielding Properties of SWNT Buckypaper Nanocomposites

摘要

In this exploratory research project, a unique technical approach was developed to incorporate SWNTs buckypaper materials into conventional fiber- reinforced and foam composite structures for improving EMI and lightning strike protection properties. The EMI shielding and lightning strike attenuation properties of the composites with the surface layer of SWNT buckypaper nanocomposite were preliminarily characterized. Four types of the designed EMI/lightning strike testing composite samples with buckypapers were produced. Each sample had two layers of random or magnetically aligned buckypapers covering at surface. The results show that the foam structures with the buckypaper surface can achieve as much as 26 dB of EMI shielding over the test range of 455 to 500 MHz, compared to the control panel of pure foam structure. This attenuation result was remarkable considering the fact that the amount of nanotubes was less than 700 mg per test panel. The results also show that the random buckypaper samples exhibited better EMI shielding properties. However, a slight reduction of EMI shielding occurred in the carbon fiber composites with the buckypaper surface, compared to the controlled panel. For the lightning strike resistance, no visible improvement was observed. Further improvements in electrical conductivity of the buckypaper composites are vital for utilizing SWNTs to realize EMI and lightning strike resistance properties for composite structures.