Fire extinguishing properties of novel ferrocene/surfynol 465 dispersions

This paper reports a novel fire-extinguishing agent: an aqueous dispersion of fine ferrocene particles. In this study, the ferrocene–water–surfactant dispersions were prepared to optimize the gas-phase concentration of ferrocene, and their ability to extinguish heptane fires was examined. The fire-extinguishing efficiency was characterized by three parameters: the ferrocene concentration in the dispersion (0–175ppm), the surfactant used, and the ferrocene particle size (d50=10.4, 11.4, 21.5, and 68.8μm). The results indicated that (1) the ferrocene (d50=10.4mm)–water–surfynol 465 dispersion is the most stable among the dispersions tested, (2) the ferrocene–water–surfynol 465 dispersions have an optimal value of ferrocene concentration regarding the extinguishing time, and (3) in the ferrocene particle size range of 10.4–21.5μm, the minimum extinguishing time of the ferrocene–water–surfynol 465 dispersions is remarkably shorter (1.2s) than those observed when using a conventional wet chemical agent (45wt% aqueous solution of potassium carbonate, 12.9s). •Aqueous dispersions of ferrocene are most stable with surfynol 465.•The dispersions offer a shorter extinguishing time than 45wt% K2CO3 aq.•The dispersions have an optimum ferrocene concentration for fire extinguishing.•The extinguishing time depends on the particle size of ferrocene powders.