New Materials Technology a Coat of a Different Color

  • Published
  • By Max Alexander
  • Materials and Manufacturing
WRIGHT-PATTERSON AIR FORCE BASE, Ohio --  Working under an Air Force Research Laboratory Small Business Innovation Research Phase II contract, Conductive Composites Company, LLC, produced new polymer coatings novel in their capacity to provide--via single-material solution--both the conductivity needed for effective electromagnetic hardening and shielding and the range of colors needed for camouflage and similar optical spectrum management applications. In supplying distinct performance advantages, these high-performance coatings, which are easily applied by conventional spray or brush method, have significant potential for a wide variety of defense platforms.

The heretofore unavailable means for coating Air Force systems with conductive, colored material will enable systems designers to use just one material to achieve two vital functions: EM and optical spectrum management. In turn, the resultant hardening, shielding, and camouflage options made possible by this technology will support the availability of fully integrated, multifunctional solutions needed for successful warfighting operations.

Conductive Composites used nickel nanostrands to create the new class of advanced polymers. Nanostrands are self-assembled, three-dimensionally branched and interconnected, high-aspect-ratio submicron chains of pure nickel. They form a volumetrically continuous network of nano- and micro-level Faraday cages. Their complex, 3-D branching structure facilitates excellent conductivity with minimal volume displacement, which accordingly permits other functional materials (e.g., lubricants, hard particles, heat transfer particles) to be added to the coating without sacrificing the system's mechanical integrity.

Among the multifunctional additives that can be incorporated are those for achieving specific colors. For instance, the addition of titanium dioxide will lighten naturally dark nanostrand paints to assorted shades of gray. These gray-scale blends can undergo further tinting by way of colored pigments, producing a veritable palette of conductive coatings. To date, numerous matte tones and camouflages have undergone testing in a broad range of polymers applied to an equally diverse collection of surfaces. In terms of EM shielding, the coatings have achieved performance levels of 20 dB/mil thickness. The polymer coatings have proven themselves viable candidates for use in a number of commercial polymer systems as well, with many such systems reaching surface resistivity levels below 0.10 Ω/cm2 and volume conductance as high as 2000 cm2. Such results demonstrate the feasibility of using these lightweight, conductive paints as replacements for current aluminum and copper meshes, which are heavier and more susceptible to corrosion.