Cyclotriphosphazene derivatives can effectively improve the flame retardancy and fire safety of epoxy resins(EPs)via their influence on the pyrolysis process.In this work,the effects of hexa(5-methyl-2-pyridinoxyl)cyc...Cyclotriphosphazene derivatives can effectively improve the flame retardancy and fire safety of epoxy resins(EPs)via their influence on the pyrolysis process.In this work,the effects of hexa(5-methyl-2-pyridinoxyl)cyclotriphosphazene(HMPOP)incorporation on the initial pyrolysis of an EP at 500–3500 K were studied using the ReaxFF method.The pyrolysis fragments,initial reaction pathways,and main products were identified for the EP and EP/HMPOP composites.The activation energies were derived by fitting the weight percentage curves for solid species during the pyrolysis reactions and the obtained values were in good agreement with experimental data.The initial EP pyrolysis reactions included four major decomposition modes,which primarily involved the cleavage of C–O and C–N bonds.The main pyrolysis products were H_(2)O,CO,C_(2)H_(4),and CH_(2)O.HMPOP bonded with the oxygen-containing fragments to form larger molecular fragments and reduced the amounts of C_(0)–C_(4) products,especially that of the harmful gas CH_(2)O.Thus,HMPOP promoted the formation of carbon clusters and reduced the generation of combustible gases,ultimately decreasing the capacity for fire propagation.展开更多
Composites of 2D/0D Fe_(2)O_(3)-Bi_(3)TaO_(7)(FO-BTO)prepared by a hydrothermal method in which superfine Bi_(3)TaO_(7) particles were mounted onto lamellae of Fe_(2)O_(3) sheets could efficiently remove aqueous tetra...Composites of 2D/0D Fe_(2)O_(3)-Bi_(3)TaO_(7)(FO-BTO)prepared by a hydrothermal method in which superfine Bi_(3)TaO_(7) particles were mounted onto lamellae of Fe_(2)O_(3) sheets could efficiently remove aqueous tetracycline(TC)residues.The optimal composite FO-3BTO had a TC removal rate of 95%in 120 min under solar light,and its overall properties were better than those of reported photocatalysts.According to XRD,HRTEM,XPS,SEM,PL,EIS,and photocurrent tests,Fe_(2)O_(3) and Bi_(3)TaO_(7) composites formed on effective S-scheme heterojunctions,and the tight contact structure contributed to the increase in efficiency of aqueous TC residue removal.展开更多
基金the National Natural Science Foundation of China(51901209).
文摘Cyclotriphosphazene derivatives can effectively improve the flame retardancy and fire safety of epoxy resins(EPs)via their influence on the pyrolysis process.In this work,the effects of hexa(5-methyl-2-pyridinoxyl)cyclotriphosphazene(HMPOP)incorporation on the initial pyrolysis of an EP at 500–3500 K were studied using the ReaxFF method.The pyrolysis fragments,initial reaction pathways,and main products were identified for the EP and EP/HMPOP composites.The activation energies were derived by fitting the weight percentage curves for solid species during the pyrolysis reactions and the obtained values were in good agreement with experimental data.The initial EP pyrolysis reactions included four major decomposition modes,which primarily involved the cleavage of C–O and C–N bonds.The main pyrolysis products were H_(2)O,CO,C_(2)H_(4),and CH_(2)O.HMPOP bonded with the oxygen-containing fragments to form larger molecular fragments and reduced the amounts of C_(0)–C_(4) products,especially that of the harmful gas CH_(2)O.Thus,HMPOP promoted the formation of carbon clusters and reduced the generation of combustible gases,ultimately decreasing the capacity for fire propagation.
基金Financial support was provided by the National Natural Science Foundation of China(Grants Nos.51901209,21777078,and 22062016)the Major Project of Inner Mongolia Natural Science Foundation(Grant 2020ZD02)the Project of Research and Development of the Applied Technology for Inner Mongolia(Grant 2020SGG0065).
文摘Composites of 2D/0D Fe_(2)O_(3)-Bi_(3)TaO_(7)(FO-BTO)prepared by a hydrothermal method in which superfine Bi_(3)TaO_(7) particles were mounted onto lamellae of Fe_(2)O_(3) sheets could efficiently remove aqueous tetracycline(TC)residues.The optimal composite FO-3BTO had a TC removal rate of 95%in 120 min under solar light,and its overall properties were better than those of reported photocatalysts.According to XRD,HRTEM,XPS,SEM,PL,EIS,and photocurrent tests,Fe_(2)O_(3) and Bi_(3)TaO_(7) composites formed on effective S-scheme heterojunctions,and the tight contact structure contributed to the increase in efficiency of aqueous TC residue removal.
