The thermal decomposition of 2-(4-methoxycarbonylphenyl)-5-nitryl-6-hydroxybenzoxazole(MNB) in N2 atmosphere was studied by thermogravimetry(TG) and differential thermogravimetry(DTG).It is a sequential process.The mo...The thermal decomposition of 2-(4-methoxycarbonylphenyl)-5-nitryl-6-hydroxybenzoxazole(MNB) in N2 atmosphere was studied by thermogravimetry(TG) and differential thermogravimetry(DTG).It is a sequential process.The molecular bond orders were calculated by GAMESS method and the IR spectra of MNB and its intermediates in thermal decomposition at various temperatures were determined.The mechanism of the thermal decomposition has been discussed,the C-N bond breakdown and the nitro group elimination occurred in the initial step of the decomposition.The thermal decomposition kinetic parameters such as apparent activation energy E=115.5kJ·mol-1,pre-exponential factor A = 1.698×1010 min-1 and apparent reaction order n = 0 were obtained according to test data.展开更多
In the presence of Triton X100,the color reaction of Mercury(Ⅱ)with 2hydroxy5nitrophenyldiazoaminoazobenene(HNPDAAB)was studied.Mercury(Ⅱ)reacts with HNPDAAB and forms a 1∶1 red complex at pH=95-110 buffer solution...In the presence of Triton X100,the color reaction of Mercury(Ⅱ)with 2hydroxy5nitrophenyldiazoaminoazobenene(HNPDAAB)was studied.Mercury(Ⅱ)reacts with HNPDAAB and forms a 1∶1 red complex at pH=95-110 buffer solution of Na2B4O7NaOH.The molar absorptivity is 256×105L·mol-1·cm-1.Beer’s law is obeyed in the concentration range of 0～12μg/25mL for Mercury(Ⅱ).The results are in agreement with those determined by the conventional method.This new method was used to determine trace mercury in wastewater.展开更多
文摘The thermal decomposition of 2-(4-methoxycarbonylphenyl)-5-nitryl-6-hydroxybenzoxazole(MNB) in N2 atmosphere was studied by thermogravimetry(TG) and differential thermogravimetry(DTG).It is a sequential process.The molecular bond orders were calculated by GAMESS method and the IR spectra of MNB and its intermediates in thermal decomposition at various temperatures were determined.The mechanism of the thermal decomposition has been discussed,the C-N bond breakdown and the nitro group elimination occurred in the initial step of the decomposition.The thermal decomposition kinetic parameters such as apparent activation energy E=115.5kJ·mol-1,pre-exponential factor A = 1.698×1010 min-1 and apparent reaction order n = 0 were obtained according to test data.
文摘In the presence of Triton X100,the color reaction of Mercury(Ⅱ)with 2hydroxy5nitrophenyldiazoaminoazobenene(HNPDAAB)was studied.Mercury(Ⅱ)reacts with HNPDAAB and forms a 1∶1 red complex at pH=95-110 buffer solution of Na2B4O7NaOH.The molar absorptivity is 256×105L·mol-1·cm-1.Beer’s law is obeyed in the concentration range of 0～12μg/25mL for Mercury(Ⅱ).The results are in agreement with those determined by the conventional method.This new method was used to determine trace mercury in wastewater.
