The flame-retardant properties of polyurethane(PU)containing ammonium polyphosphate(APP)and aluminum hydroxide(ATH)were investigated.Moreover,the flame retardant performance was investigated through thermogravimetric ...The flame-retardant properties of polyurethane(PU)containing ammonium polyphosphate(APP)and aluminum hydroxide(ATH)were investigated.Moreover,the flame retardant performance was investigated through thermogravimetric analysis,limiting oxygen index(LOI),vertical combustion(UL 94),and cone calorimeter.When 15 wt%APP and 5 wt%ATH were added together,the PU/15%APP/5%ATH sample shows better thermal stability and flame-retardant properties.When 15 wt%APP and 5 wt%ATH were added together,the LOI value of the PU/15%APP/5%ATH sample was 30.5%,and UL 94 V-0 rating was attained.Compared with PU,the peak heat release rate(PHRR),total heat release(THR),and average effective heat combustion(av-EHC)of the PU/15%APP/5%ATH sample decreased by 43.1%,21.0%,and 29.4%,respectively.In addition,the flame-retardant mechanism was investigated through cone calorimeter.The APP/ATH addition simultaneously exerted condensed phase and gas phase flame retardant effects.APP and ATH have synergistic flame retardant properties.展开更多
Yoon’s equation which predicted point of zero charge of complex oxide should predict the zero point of net charge (ZPNC) of mixture of variable and permanent charge rather than the point of zero charge (PZC) of the v...Yoon’s equation which predicted point of zero charge of complex oxide should predict the zero point of net charge (ZPNC) of mixture of variable and permanent charge rather than the point of zero charge (PZC) of the variable chare component. The calculated values with modified Yoon’s equation agreed with the experimental values.展开更多
Aluminum hydroxide sol (consisting of aluminum hydroxide nano-particles) prepared by a hydrothermal method was used as nano-aluminum adjuvant adsorbed the inactived Newcastle disease virus (NDV). The zeta potential of...Aluminum hydroxide sol (consisting of aluminum hydroxide nano-particles) prepared by a hydrothermal method was used as nano-aluminum adjuvant adsorbed the inactived Newcastle disease virus (NDV). The zeta potential of aluminum hydroxide colloidal particles,the inactivated NDV and the nano-aluminum adjuvant NDV are +48.16 mV,?13.8 mV and +39.97 mV,respec-tively. The nano-aluminum adjuvant vaccine was transparent and stable without precipitate,whereas the conventional aluminum ad-juvant vaccine was turbid and a white precipitate was visible soon. The hemagglutination inhibition (HI) titers of the nano-aluminum adjuvant group were generally higher than those of the conventional aluminum group except the titer on day 29. The results show that the nano-aluminum adjuvant has better stability and higher levels of antibodies for a longer time than the conventional aluminum adjuvant.展开更多
Alum has an excellent safety record and is the only licensed inorganic adjuvant for human vaccines.However,the exploration of alum nanosheets as chemotherapy drug delivery system,especially the clarification about the...Alum has an excellent safety record and is the only licensed inorganic adjuvant for human vaccines.However,the exploration of alum nanosheets as chemotherapy drug delivery system,especially the clarification about the relationship between structures and drug loading properties,is totally insufficient.Herein,aluminum hydroxides(AlOOH)nanosheets with tunable specific surface area and pore size were synthesized by adjusting the synthesis time in the presence of triblock copolymers.The obtained materials exhibited the highest surface area about 470 m2/g.The structure-dependent chemotherapy drug loading capability for AlOOH nanosheets was observed:the higher specific surface area and pore size are,the higher amount of chemotherapy drug is loaded.AlOOH nanosheets loaded with doxorubicin showed a pH-dependent sustained release behavior with quick release in low pH about 5 and slow release in pH around 7.4.Doxorubicin-loaded AlOOH nanosheets exhibited much higher cancer cellular uptake efficiency than that in free form by flow cytometry.Moreover,doxorubicin-loaded AlOOH nanosheets with high specific surface area showed an increased cellular uptake efficiency and enhanced ratios of apoptosis and necrosis,compared with those showing low specific surface area.Therefore,AlOOH nanosheets are promising materials as chemotherapy drug delivery system.展开更多
γ-Al2O3 was prepared by hydrothermal synthesis usingρ-Al2O3 and urea as raw materials.In this work,the eff ects of the molar ratio of CO(NH2)2/Al and reaction temperature were investigated,and a Pt–Sn–K/γ-Al2O3 c...γ-Al2O3 was prepared by hydrothermal synthesis usingρ-Al2O3 and urea as raw materials.In this work,the eff ects of the molar ratio of CO(NH2)2/Al and reaction temperature were investigated,and a Pt–Sn–K/γ-Al2O3 catalyst was prepared.The ammonium aluminum carbonate hydroxide(AACH),γ-Al2O3,and Pt–Sn–K/γ-Al2O3 were characterized by X-ray diff raction,scanning electron microscopy,transmission electron microscopy,N2 adsorption–desorption,thermogravimetry–differential thermal analysis,and NH3 temperature-programmed desorption techniques.The reactivity of Pt–Sn–K/γ-Al2O3 for propane dehydrogenation was tested in a micro-fixed-bed reactor.The results show thatγ-Al2O3 with a specific surface area of 358.1 m 2/g and pore volume of 0.96 cm 3/g was obtained when the molar ratio of CO(NH2)2/Al was 3:1 and the reaction temperature was 140℃.The alumina obtained by calcination of AACH has a higher specific surface area and larger pore volume than the industrial pseudo-boehmite does.The catalyst prepared from AACH as precursor showed high selectivity and conversion,which can reach 96.1%and 37.6%,respectively,for propane dehydrogenation.展开更多
基金Supported by the Natural Science Foundation of Guangdong(Nos.2014A030313241,2014B090901068,and 2016A010103003).
文摘The flame-retardant properties of polyurethane(PU)containing ammonium polyphosphate(APP)and aluminum hydroxide(ATH)were investigated.Moreover,the flame retardant performance was investigated through thermogravimetric analysis,limiting oxygen index(LOI),vertical combustion(UL 94),and cone calorimeter.When 15 wt%APP and 5 wt%ATH were added together,the PU/15%APP/5%ATH sample shows better thermal stability and flame-retardant properties.When 15 wt%APP and 5 wt%ATH were added together,the LOI value of the PU/15%APP/5%ATH sample was 30.5%,and UL 94 V-0 rating was attained.Compared with PU,the peak heat release rate(PHRR),total heat release(THR),and average effective heat combustion(av-EHC)of the PU/15%APP/5%ATH sample decreased by 43.1%,21.0%,and 29.4%,respectively.In addition,the flame-retardant mechanism was investigated through cone calorimeter.The APP/ATH addition simultaneously exerted condensed phase and gas phase flame retardant effects.APP and ATH have synergistic flame retardant properties.
文摘Yoon’s equation which predicted point of zero charge of complex oxide should predict the zero point of net charge (ZPNC) of mixture of variable and permanent charge rather than the point of zero charge (PZC) of the variable chare component. The calculated values with modified Yoon’s equation agreed with the experimental values.
基金Supported by the National Science and Technology Supporting Program in the Eleventh Five-Year Plan of China (2006BAD06A08)
文摘Aluminum hydroxide sol (consisting of aluminum hydroxide nano-particles) prepared by a hydrothermal method was used as nano-aluminum adjuvant adsorbed the inactived Newcastle disease virus (NDV). The zeta potential of aluminum hydroxide colloidal particles,the inactivated NDV and the nano-aluminum adjuvant NDV are +48.16 mV,?13.8 mV and +39.97 mV,respec-tively. The nano-aluminum adjuvant vaccine was transparent and stable without precipitate,whereas the conventional aluminum ad-juvant vaccine was turbid and a white precipitate was visible soon. The hemagglutination inhibition (HI) titers of the nano-aluminum adjuvant group were generally higher than those of the conventional aluminum group except the titer on day 29. The results show that the nano-aluminum adjuvant has better stability and higher levels of antibodies for a longer time than the conventional aluminum adjuvant.
基金National Institute for Materials Science of Japan
文摘Alum has an excellent safety record and is the only licensed inorganic adjuvant for human vaccines.However,the exploration of alum nanosheets as chemotherapy drug delivery system,especially the clarification about the relationship between structures and drug loading properties,is totally insufficient.Herein,aluminum hydroxides(AlOOH)nanosheets with tunable specific surface area and pore size were synthesized by adjusting the synthesis time in the presence of triblock copolymers.The obtained materials exhibited the highest surface area about 470 m2/g.The structure-dependent chemotherapy drug loading capability for AlOOH nanosheets was observed:the higher specific surface area and pore size are,the higher amount of chemotherapy drug is loaded.AlOOH nanosheets loaded with doxorubicin showed a pH-dependent sustained release behavior with quick release in low pH about 5 and slow release in pH around 7.4.Doxorubicin-loaded AlOOH nanosheets exhibited much higher cancer cellular uptake efficiency than that in free form by flow cytometry.Moreover,doxorubicin-loaded AlOOH nanosheets with high specific surface area showed an increased cellular uptake efficiency and enhanced ratios of apoptosis and necrosis,compared with those showing low specific surface area.Therefore,AlOOH nanosheets are promising materials as chemotherapy drug delivery system.
基金Hebei University of Technology and CNOOC Tianjin Chemical Research and Design Institute Co.,Ltd.
文摘γ-Al2O3 was prepared by hydrothermal synthesis usingρ-Al2O3 and urea as raw materials.In this work,the eff ects of the molar ratio of CO(NH2)2/Al and reaction temperature were investigated,and a Pt–Sn–K/γ-Al2O3 catalyst was prepared.The ammonium aluminum carbonate hydroxide(AACH),γ-Al2O3,and Pt–Sn–K/γ-Al2O3 were characterized by X-ray diff raction,scanning electron microscopy,transmission electron microscopy,N2 adsorption–desorption,thermogravimetry–differential thermal analysis,and NH3 temperature-programmed desorption techniques.The reactivity of Pt–Sn–K/γ-Al2O3 for propane dehydrogenation was tested in a micro-fixed-bed reactor.The results show thatγ-Al2O3 with a specific surface area of 358.1 m 2/g and pore volume of 0.96 cm 3/g was obtained when the molar ratio of CO(NH2)2/Al was 3:1 and the reaction temperature was 140℃.The alumina obtained by calcination of AACH has a higher specific surface area and larger pore volume than the industrial pseudo-boehmite does.The catalyst prepared from AACH as precursor showed high selectivity and conversion,which can reach 96.1%and 37.6%,respectively,for propane dehydrogenation.