Scalable Electrically Conductive Spray Coating Based on Block Copolymer Nanocomposites.

Currently available conductive inks present a challenge to achieving electrical performance without compromising mechanical properties, scalability, and processability. Here, we have developed blends of carbon black and the commercially available triblock copolymer, SEBS-g-MAH (FG1924G, Kraton), that can be readily applied as a conductive coating a spray coating process, for a wide range of insulating materials (fabric, wood, glass, and plastic). Simple but effective mechanical and chemical modifications of the ingredients can increase the electrical conductivity (~100 S/m) by an order of magnitude more than previously reported for carbon black composites; moreover, the coatings display excellent mechanical flexibility (tensile strain ~ 5.00 mm/mm). To correlate electrical conductivity and nanoscale structural changes with mechanical deformation, small-angle x-ray scattering during tensile testing was performed. We show that the nanocomposite can be produced using low cost ingredients (~$10/kg), ensuring scalability for fabrication of large-scale devices without specialized material synthesis. Equally important, the phase behavior of block copolymers can enable recovery from physical damage via thermal annealing, which is critical for product longevity.