A new type of BTP/Zeolites nanocomposites as mixed-phase fire suppressant: Preparation, characterization and extinguishing mechanism discussion

Abstract

A new type of nanocomposites consisting of solid 4A zeolites and gaseous fire extinguishing agent of 2- bromo-3, 3, 3-trifluoropropene (BTP) was fabricated in large scale, in which BTP anchored in the porous zeolite nanoparticles. A series of techniques were used to characterize the composites, including X-ray diffraction (XRD), nuclear magnetic resonance (NMR), field-emission scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), Fourier transforms infrared (FTIR) spectra and thermogravimetric analysis (TGA). Laboratory-scale fire extinguishment tests showed that thus-prepared nanocomposites as additives can greatly improve the performance of conventional sodium bicarbonate (NaHCO3) dry powder for relatively shorter extinguishing time and smaller amount of agents required. Such an improvement could be reasonably ascribed to the synergetic effect of solid NaHCO3 powder and the gaseous BTP desorbed from the zeolite host when presented to higher temperature, together with the porous zeolite as heterogeneous inhibition of flame free radicals. The possible fire extinguishing mechanism of the mixed phase powder-based suppressant was discussed in detail, which involved the simultaneous functions of three components of NaHCO 3, BTP and zeolite. Copyright © 2008 International Association For Fire Safety Science.