Suppression of different functional group modified powders on 9.5% CH4 air explosion and molecular simulation mechanism
Abstract Thiol and urea functionalized montmorillonite powders were successfully prepared by silane coupling agent treatments in this work. The pyrolysis characteristics, surface functional groups, and distribution of particle size of untreated montmorillonite powders (Mt) the hydroxyl functionalized montmorillonite (O Mt) the urea functionalized montmorillonite (N Mt) and the thiol functionalized montmorillonite (S Mt) which was derived from the previous research, were respectively characterized by utilizing the thermogravimetric differential scanning calorimetry, Fourier transform infrared spectroscopy, as well as the laser particle analyzer. The suppression effect of the S Mt, O Mt, Mt, and N Mt on a 9.5% CH4 explosion was tested in the duct system (5 L) The obtained results indicated that N Mt and O Mt exhibited a better explosion suppression effect than Mt and S Mt at the same mass concentration. Additionally, the methane/air explosion suppression mechanism of these powders could be explained by molecular simulation results that indicated the negatively electrophilic potential regions exist on the surface of O Mt and N Mt. Moreover, NH4, NCO and OH radicals, which can interrupt explosive chain reactions, were easily generated by N Mt and O Mt.