Conductive, Low-Cost Carbon Prepreg Mat

This Phase I effort will demonstrate the production of large area carbon nanopaper prepreg mats with very high electrical conductivity and EMI shielding capabilities. Currently, metal structures, metallic fillers, and metallic coating are used to provide ESD and EMI shielding, but issues such as weight and corrosion make these materials less than ideal. Carbon nanotubes and nano graphene platelets have shown great promise for EMI shielding and other composite property improvements, but have to date been unavailable as a continuous sheet good that would enable use in conventional composite processing. It is proposed to overcome these limits with blends of non-metallic, moderately-priced, commercially available nanomaterials having high electrical conductivity which are formulated into a continuous roll of non-woven nanopaper prepreg mat. Non-optimized compositions of hand sheets of non-woven mats with an areal weight of 20 g/m2 and comprised of PAN carbon fiber with carbon nanofiber have shown z-directional surface conductivities of 35 milli-ohm/sq. Other researchers have conductivities of 4600 S/cm when carbon nanofiber is combined with nickel coated carbon fiber with a baseline value of 2300 S/cm. The proposed mat will be much less than $10/gram and available in continuous form at the end of Phase I. BENEFIT: The current effort is focused on EMI shielding; however, the resulting nanopaper prepreg could broadly apply to signature control, thermal conduction, and lightning strike protection. This material would be valuable for unrelated but high volume applications as a continuous multi-functional ply for structural composites having improved interlaminar properties and high vibration damping as well as improved electrical and thermal transport properties.