Through the work conducted on this program, Foster-Miller demonstrated that conductive sealants with single wall carbon nanotube (SWNT) additives achieve comparable conductivity to commercially available aerospace sealants, while being 40 percent lighter. We are working to optimize sealant electrical and mechanical properties, and improve the manufacturing robustness to a level that can support commercial manufacture and sale of a SWNT sealant product.

The Office of Naval Research set out to find alternative gap sealants for aircraft due to performance and cost issues. Typical conductive sealants consist of an elastomer matrix with dispersed metal particles. The major drawback of these materials is the high loading required to achieve conductivity, resulting in sealant limitations, including: high density, which adds weight; increased viscosity, making application difficult; increased stiffness, making cracking more likely, and lowered adhesion from high filler loading.  The result is decreased performance over a lifetime and increased costs due to additional maintenance requirements.

SWNTs are ideal conductive additives because of their combination of high electrical and thermal conductivity, good chemical and thermal resistance, high aspect ratio, and low density. The main detriment to their use had been agglomeration to form nanotube bundles. The methods for achieving good dispersion of SWNTs developed on this program were key to achieving highly conductive sealants with low loading.

Return to Embedded Software

Printable Version