Increased exothermic reactivity of polytetrafluoroethylene-coated aluminum powders: Impact of powder size reduction

Polytetrafluoroethylene (PTFE)-coated aluminum (PTFE/Al) powder was synthesized to evaluate its exothermic reactivity with the reduction in Al powder size. The exothermic enthalpy energies of uncoated Al powders clearly increase as the particle size decreases from 30 to 5 μm. Thus, the PTFE/Al (5 μm) powder exhibited the highest exothermic enthalpy energy of 4300 J/g, which is approximately two times higher than that of uncoated Al (5 μm) and PTFE/Al (30 μm) powders. The findings clarify that the combination of powder size reduction and PTFE coating results in both a considerable enhancement of exothermic reactivity and tailorable enthalpy energy values.