Desensitizing nano powders to electrostatic discharge ignition

• Nanoscale Al/CuO requires 13 vol.% CNT additive to desensitize ESD ignition.
• Electrical conductivities of 0.07 S/cm correspond to ESD non-ignition.
• Al/CuO reaction quenches for CNT greater than 2 vol. %.
• CNT safely neutralizes Al/CuO to ESD for nano and micron particle powders.
• Four times more CNT is needed for nano compared with micron powder.

Electrostatic discharge (ESD) is a main cause for ignition in powder media ranging from grain silos to fireworks. Nanoscale particles are orders of magnitude more ESD ignition sensitive than their micron scale counterparts. This study shows that at least 13 vol. % carbon nanotubes (CNT) added to nano-aluminum and nano-copper oxide particles (nAl + CuO) eliminates ESD ignition sensitivity. The CNT act as a conduit for electric energy and directs electric charge through the powder to desensitize the reactive mixture to ignition. For nanoparticles, the required CNT concentration for desensitizing ESD ignition acts as a diluent to quench energy propagation.

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