(606e) Chemically Driven, Carbon Nanotube-Guided Thermopower Waves

Coupling an exothermic chemical reaction with a nanotube or nanowire possessing a high axial thermal conductivity creates a self-propagating reactive wave along its length. Such waves are realized using a 7-nm cyclotrimethylene-trinitramine annular shell around a multi-walled carbon nanotube and are amplified by more than 10⁴ times the bulk value, propagating more than 2 m/s, with an effective thermal conductivity of 1.28 ± 0.2 kW/m/K at 2860 K. This wave produces a concomitant electrical pulse of disproportionately high specific power, as large as 7 kW/kg, that we identify as a thermopower wave. Here, thermally excited carriers flow in the direction of the propagating reaction with specific power that scales inversely with size. The reaction also produces an anisotropic pressure wave of decomposition gases of exceedingly high total impulse per mass of 300 N-s/kg and specific impulse per total mass (5.5 s/µg) suggesting possible applications to micro-propulsion and actuators.