A novel reactive P-containing composite with an ordered porous structure for suppressing nano-Al dust explosions

Abstract

A novel chemical suppressant ([email protected]2-MCM41) was synthesized via self-assembly. NH2-MCM-41 was prepared using diatomaceous earth (DE) as the silica source. FTIR spectra showed that phytic acid (PA) was successfully grafted onto synthesized NH2-MCM-41 via hydrogen bonding. The highly ordered mesoporous structure of [email protected]2-MCM41 was observed from TEM and small angle X-ray diffraction (SAXRD). The effectiveness of [email protected]2-MCM41 in the suppression of nano-Al dust explosions was investigated. Experimental results suggested that the addition of [email protected]2-MCM41 could effectively reduce the average flame propagation velocity (Vavg) and maximum explosion pressure (Pmax). After the addition of 16.7 wt% [email protected]2-MCM41, the Vavg of the gas-phase flame was reduced by 75%. With addition of 28.6 wt% [email protected]2-MCM41, the Pmax of nano-Al dust decreased by 65.7%. As the mass fraction of [email protected]2-MCM41was increased to 33.3%, nano-Al dust explosion was completely suppressed. The SEM, FTIR and EDS results showed that a complex sealing film was formed on the surface of the explosion products, which occupied the open sites on the Al surface and thereby interrupted the Al evaporation and surface reaction. Subsequently, the suppression mechanism by which phosphorus containing suppressants consume free radicals and the interaction of PA molecules with the aluminum particle surface were revealed in depth.