(491f) Pyrophoric Films Based on Nano-Sized Iron

Pyrophoric α-iron nanostructured porous coatings were prepared by a sol-gel technique. Iron oxide coating deposited on a non-porous metallic substrate was formed from FeCl₂ dissolved in ethanol in the presence of Brij-76 surfactant. The gelling process was conducted by the addition of propylene oxide. The surfactant was removed by washing in ethanol and the resulting coating was heat treated to form Fe₂O₃. The Fe₂O₃ coatings were reduced in H₂/N₂ atmosphere at temperatures above 500^oC and after cooling tested for their pyrophoricity in flowing air. These coatings have shown a strong affinity to oxygen. The effect of processing condition as well as thickness of the coating and it morphology on maximum combustion temperature and the duration of a pyrophoric reaction will be discussed. Experimental data will be compared to results obtained from one-dimensional mathematical model.