In order to clarify the chemical suppression mechanisms of CF3H, experimental and theoretical studies were conducted respectively in this paper. Firstly, the combustion species in low pressure laminar premixed flat me...In order to clarify the chemical suppression mechanisms of CF3H, experimental and theoretical studies were conducted respectively in this paper. Firstly, the combustion species in low pressure laminar premixed flat methane flames with CF3H addition is measured by synchrotron radiation molecular beam mass spectrometry （SR-MBMS） experimentally. Fire suppression chemistry of CF3H is investigated by selective detection of combustion radicals and intermediates in experimental process. Secondly, quantum chemistry calculations are performed to calculate the potential energy surfaces （PES） for the CF3H unimolecular dissociation reaction and reactions of CF3H with free radical OH and H at the B3LYP/6-311-F ＋G＊＊ and QCISD（T）/6-311＋＋G＊＊ levels. Finally, the chemical suppression mechanism of CF3H was discussed by comparing the theoretical calculation with experimental measurement.展开更多
The CO_2 laser induced room temperature reactions of CH_3CF_2H or another protium-donor CH_3CHClCH_3 with chlorine-atom donors (Z--Cl) CFCl_2CF_2Cl, CF_3CCl_3, CFCl_3 or CF_2Cl_2, have been investigated. Some of these...The CO_2 laser induced room temperature reactions of CH_3CF_2H or another protium-donor CH_3CHClCH_3 with chlorine-atom donors (Z--Cl) CFCl_2CF_2Cl, CF_3CCl_3, CFCl_3 or CF_2Cl_2, have been investigated. Some of these reactions can yield two important monomers (CF_2=CH_2 and CF_2=CFCl) for fluoropolymers simultaneously. The yield dependence of these two alkenes on experi- mental conditions has been studied. A laser-initiated chain process is supported by identifica- tion of Z--H intermediates in these reactions.展开更多
基金Project supported by the National Natural Science Foundation of China （No. 50706018） and Tianjin Research Program of Application Foundation and Advanced Technology （No. 08JCYBJC10700）.
文摘In order to clarify the chemical suppression mechanisms of CF3H, experimental and theoretical studies were conducted respectively in this paper. Firstly, the combustion species in low pressure laminar premixed flat methane flames with CF3H addition is measured by synchrotron radiation molecular beam mass spectrometry （SR-MBMS） experimentally. Fire suppression chemistry of CF3H is investigated by selective detection of combustion radicals and intermediates in experimental process. Secondly, quantum chemistry calculations are performed to calculate the potential energy surfaces （PES） for the CF3H unimolecular dissociation reaction and reactions of CF3H with free radical OH and H at the B3LYP/6-311-F ＋G＊＊ and QCISD（T）/6-311＋＋G＊＊ levels. Finally, the chemical suppression mechanism of CF3H was discussed by comparing the theoretical calculation with experimental measurement.
基金Project supported by the National Natural Science Foundation of China.
文摘The CO_2 laser induced room temperature reactions of CH_3CF_2H or another protium-donor CH_3CHClCH_3 with chlorine-atom donors (Z--Cl) CFCl_2CF_2Cl, CF_3CCl_3, CFCl_3 or CF_2Cl_2, have been investigated. Some of these reactions can yield two important monomers (CF_2=CH_2 and CF_2=CFCl) for fluoropolymers simultaneously. The yield dependence of these two alkenes on experi- mental conditions has been studied. A laser-initiated chain process is supported by identifica- tion of Z--H intermediates in these reactions.
