Theoretical Study of Elementary Steps in the Reactions between Aluminum and Teflon Fragments under Combustive Environments

Abstract

Gas-phase reactions between aluminum particles and Teflon fragments were studied to develop a fundamental understanding of the decomposition reactions and combustion processes of the Al-Teflon composites. The reactions were investigated theoretically using ab initio calculations at the MP2/aug-cc-pVDZ level, with the final thermokinetic data obtained with coupled cluster theory (CCSD(T)/aug-cc-pVTZ). Among reactions under oxygen-lean conditions, CF 3 + Al f CF 2 + AlF channel is the fastest, followed by the CF 2 + Al f CF + AlF and CF + Al f C + AlF channels. Under oxygen-rich conditions, reactions of COF with aluminum are probed to be faster than those involving COF 2 species. Reaction path multiplicity has been considered. Our results show that multiplicity plays a very important role in determining the reaction order, that is first order or addition-elimination reactions of Al with CF 3 are predicted to be faster than those proceeding through direct abstraction or second order. In addition, the present kinetic model suggests that CF 3 + Al f CF 2 + AlF with m ) 1 and COF + Al f CO + AlF channels are very competitive under the same thermal conditions. The computed enthalpies of reaction are systematically compared with the available literature. The predicted kinetic model and its time constants (τ) are in good qualitative agreement with experimental observations of the reactions between Al nanoparticles and Teflon for the 500-1200 K temperature range.

Hydrophobic coatings deposited with an atmospheric pressure microplasma jet

“…The presence of oxygen in the plasma, even under N 2 environment, caused by working under atmospheric pressure conditions and the layer of oxidized aluminium on the surface, enables reaction channels that lead to the creation of carbonic fluorides (COF x ), through many reactions originating from different fragments of C 4 F 8, which are reviewed in [15] , for example: …”

Multistage reaction pathways in detonating RDX

“…6 The reaction time in turn is essentially determined by what intermediated reaction products are produced, i.e., the reaction pathways. [6][7][8] It has been suggested that the slow formation time of certain products play an essential role in determining the reaction time of some HEs. 6,9,10 However, the molecular process that determine the reaction time are largely unknown.…”

Modeling kinetics for the reaction of aluminum and teflon and the simulation of its energetic flow motion

“…such a reaction system were studied by Losada et. al [3] and serve as the basis for this paper. Let { ji ν } (1≤j ≤S, 1≤i ≤N) be the stoichiometric matrix for the reaction system.…”

“…The system of ordinary differential equations (ODEs) (eqs. 1-3) is computed with the rate data set shown in [3] and the resulting λ profiles of the solution at various initial conditions in the range of temperature up to 4000 K, Figure 1. Note that the temperature of the mixture under reaction decreases significantly at initial reaction period as shown in Figure 1.…”