Kinetics of the thermal decomposition of tetramethylsilane behind the reflected shock waves between 1058 and 1194 K

Abstract

Thermal decomposition of tetramethylsilane (TMS) diluted in argon was studied behind the reflected shock waves in a single pulse shock tube (SPST) in the temperature range of 1058-1194 K. The major products formed in the decomposition are methane (CH 4 ) and ethylene (C 2 H 4 ); whereas ethane and propylene were detected in lower concentrations. The decomposition of TMS seems to be initiated via Si-C bond scission by forming methyl radicals (CH 3 ) and trimethylsilyl radicals ((CH 3 ) 3 Si). The total rate coefficients obtained for the decomposition of TMS were fit to Arrhenius equation in two different temperature regions 1058-1130 K and 1130-1194 K. The temperature dependent rate coefficients obtained are k total (1058-1130 K) = (4.61 ± 0.70) ×10 18 exp (−(79.9 kcal mol −1 ± 3.5)/RT) s −1 , k total (1130-1194 K) = (1.33 ± 0.19) ×10 6 exp (−(15.3 kcal mol −1 ± 3.5)/RT) s −1 . The rate coefficient for the formation of CH 4 is obtained to be k methane (1058-1194 K) = (4.36 ± 1.23) ×10 14 exp (−(61.9 kcal mol −1 ± 4.9)/RT) s −1 . A kinetic scheme containing 21 species and 38 elementary reactions was proposed and simulations were carried out to explain the formation of all the products in the decomposition of tetramethylsilane.

Thermal Decomposition of 2-Methyltetrahydrofuran behind Reflected Shock Waves over the Temperature Range of 1179–1361 K

“…The driven section was separated from the driver section by an aluminum diaphragm. Since the description, working principle, and experimental procedure of a SPST are discussed in our previous publications, − only brief discussion is given here. The reaction mixture consists of the test molecule (2-MTHF) and the internal standard (1,1,1-trifluoroethane, TFE) diluted in argon to a desired pressure.…”

“…The decomposition of this has well been studied behind reflected shock waves. − The latest rate coefficient for the above reaction reported by Matsugi et al [ k (1,1,1-trifluoroethane → 1,1-difluoroethylene + HF) = 5.71 × 10 46 T –9.341 exp­(−47,073/ T ) s –1 ] was used in the temperature measurement calculations. The procedures for calculating the reaction temperature using the internal standard has been discussed in our previous articles. − , …”

“…The procedures for calculating the reaction temperature using the internal standard has been discussed in our previous articles. [20][21][22]26 3. MATERIALS AND CHEMICALS He (99.999%) used as a driver gas was from Praxiar, Inc. Argon (99.999%, Praxiar), methane (99.5%, Praxiar), ethane (99.5%, Praxiar), ethylene (99.5%, Praxiar), propylene (99.5%, Praxiar), 1,3-butadiene (99.5%, Praxiar), 1,1,1-trifluoroethane (99.5%, SynQuest Lab, USA), and 1,1-difluoroethylene (99.5%, SynQuest Lab) were used without further purification.…”

Theoretical Investigation on H-Abstraction Reactions of Silanes with H and CH3 Attacking: A Comparative Study with Alkane Counterparts

“…11,12 Britten et al 13 developed a kinetic model of silane (SiH 4 ) to describe the combustion characteristics under a wide range of conditions, while Miller et al 14 updated the Britten model using their calculated rate constants of SiH 3 + O 2 reactions. Parandaman et al 15 studied the kinetics of the thermal decomposition of tetramethylsilane (TeMS, Si(CH 3 ) 4 ) behind the reflected shock waves and developed a pyrolysis model of TeMS. Sela et al 16 investigated the TeMS decomposition in a shock tube using gas chromatography/ mass spectrometry (GC/MS) and high-repetition-rate time-offlight mass spectrometry (HRR-TOF-MS).…”