Aluminum hypophosphite microspheres(AHP) were synthesized by hydrothermal method using NaH2PO2·H2O and AlCl3·6H2O as raw materials, and then the AHP microspheres were polymerized by surface polymerization of...Aluminum hypophosphite microspheres(AHP) were synthesized by hydrothermal method using NaH2PO2·H2O and AlCl3·6H2O as raw materials, and then the AHP microspheres were polymerized by surface polymerization of micro-nanospheres with cyclic cross-linked poly(cyclotriphosphazene-co-4,4'-sulfonyldiphenol)(PZS). A new organic-inorganic poly(phosphonitrile)-modified aluminum hypophosphite microspheres(PZS-AHP) were synthesized by encapsulation and applied to flame retardant thermoplastic polyurethane(TPU). The microstructure and chemical composition of the PZS-AHP microsphere were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray spectroscopy. The thermal stability of PZS-AHP microsphere was explored with thermogravimetric analysis. Thermogravimetric data indicate that the PZS-AHP microspheres have excellent thermal stability. The thermal and flame-retarding properties of the TPU composites were evaluated by thermogravimetric(TG), limited oxygen index tests(LOI), and cone calorimeter test(CCT). The TPU composite achieved vertical burning(UL-94) V-0 grade and LOI value reached 29.2% when 10 wt% PZS-AHP was incorporated. Compared with those of pure TPU, the peak heat release rate(pHRR) and total heat release(THR) of TPU/10%PZS-AHP decreased by 82.2% and 42.5%, respectively. The results of CCT indicated that PZS-AHP microsphere could improve the flame retardancy of TPU composites.展开更多
建立了液相色谱-串联质谱法快速测定小麦粉中5种非法添加物的分析方法。样品使用一级水直接提取,采用Agilent Eclipse Plus C18色谱柱,以0.1%甲酸+10 mmol·L^(-1)甲酸胺溶液和甲醇为流动相,梯度洗脱,采用电喷雾离子源的正负离子扫...建立了液相色谱-串联质谱法快速测定小麦粉中5种非法添加物的分析方法。样品使用一级水直接提取,采用Agilent Eclipse Plus C18色谱柱,以0.1%甲酸+10 mmol·L^(-1)甲酸胺溶液和甲醇为流动相,梯度洗脱,采用电喷雾离子源的正负离子扫描模式对小麦粉中5种非法添加物进行定性定量检测。结果表明,5种化合物在各自线性范围内具有良好的线性(r均大于0.9990),硫脲、曲酸、次磷酸盐的检出限为25μg·kg^(-1),定量限为50μg·kg^(-1),三聚硫氰酸三钠盐、苯甲羟肟酸的检出限为5μg·kg^(-1),定量限为10μg·kg^(-1),在低、中、高3个加标水平下,其回收率为82.1%~101.0%,RSD为0.8%~5.8%(n=6)。该方法专属性好,灵敏度高,前处理简单快速,可用于小麦粉中硫脲、曲酸、次磷酸盐、苯甲羟肟酸、三聚硫氰酸三钠盐的快速筛查和定量测定。展开更多
Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes （Fe^2＋/H2O2, UV/Fe^2＋/H2O2, and electrolysis/Fe^2＋/H2O2） in this study. Comparison of these techniques in oxidation...Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes （Fe^2＋/H2O2, UV/Fe^2＋/H2O2, and electrolysis/Fe^2＋/H2O2） in this study. Comparison of these techniques in oxidation efficiency was undertaken. It was found that Fenton process could not completely degrade citrate in the presence of hypophosphite since it caused a series inhibition. Therefore, UV light （photo-Fenton） or electron current （electro-Fenton） was applied to improve the degradation efficiency of the Fenton process. Results showed that both photo-Fenton and electro-Fenton processes could overcome the inhibition of hypophosphite, especially the electro-Fenton.展开更多
The electrocatalytic oxidation of hypophosphite on a nickel electrode has been studiedby means of in site UV-Vis subtractive reflectance spectroscopy. An absorbency band around 245um . which was ascribed to the format...The electrocatalytic oxidation of hypophosphite on a nickel electrode has been studiedby means of in site UV-Vis subtractive reflectance spectroscopy. An absorbency band around 245um . which was ascribed to the formation of an intermediate, PHO2-, was observed in theelectrocatalytic oxidation process. Accordingly, the electrocatalytic oxidation of hypophosphitemight undergo a H abstraction of hypophosphite from the P-H bond to form the phosphoruscentred radical PHO2-, which is subsequently electrooxidized to the final product, phosphite.展开更多
Electrochemical behavior of hypophosphite was studied with cyclic voltammogram in acidic solution(pH = 4.6) at 80℃. Two anodic peaks were observed on gold electrode at - 0.44V and - 0.59 V (SCE),respectively, and no ...Electrochemical behavior of hypophosphite was studied with cyclic voltammogram in acidic solution(pH = 4.6) at 80℃. Two anodic peaks were observed on gold electrode at - 0.44V and - 0.59 V (SCE),respectively, and no corresponding cathodic peaks were obtained. The one at - 0.44 V wits ascribed to the oxidation oftautomeric form of hypophosphite, the other at - 0.59 V was due to the oxidation of absorbed form of hypophosphite. The two oxidation reactions were believed to be the electron source of nickel ion reduction in electrolessnickel processes.展开更多
The deactivation of nickel hydroxide to the electrooxidation of hypophosphite on anickel electrode was studied by means of in situ UV-Vis subtractive reflectance spectroscopy. Theexperimental results show that when th...The deactivation of nickel hydroxide to the electrooxidation of hypophosphite on anickel electrode was studied by means of in situ UV-Vis subtractive reflectance spectroscopy. Theexperimental results show that when the potential is lower than-1.0 V (SCE), the surfacc on nickelelectrode is free of nickel hydroxide, on which hypophosphite is active. When the potential movespositively to about-0.75V, two absorbency bands around 300 nm and 550 nm, which were ascribedto the formation of α-nickel hydroxide, were observed, nickel is oxidized to α-nickel hydroxide.Severe deactivation of the surface occurs when the nickel surface is covered with nickel hydroxide,which separates the hypophosphite ion from nickel substrate.展开更多
Kinetic model of hypophosphite oxidation on a nickel electrode was studied in D2O solution in order to reach a better understanding of the oxidation mechanism. In the model;he electrooxidation of hypophosphite undergo...Kinetic model of hypophosphite oxidation on a nickel electrode was studied in D2O solution in order to reach a better understanding of the oxidation mechanism. In the model;he electrooxidation of hypophosphite undergo a H abstraction of hypophosphite from the P-H bond to form the phosphorus-centered radical (PWO2-)-P-., which subsequently is electrochemically reacted with water to form the final product, phosphite. The kinetic equations were derived, and the kinetic parameters were obtained from a comparison of experimental results and the kinetic equations. The process of hypophosphite electrooxidation could be well simulated by this model.展开更多
Cobalt-Boron oxides containing catalyst CoO·B2O3 (CoB2O4) are synthesized for hydrogen generation by catalytic reforming of basic solution of sodium hypophosphite (NaH2PO2) and identified by chemical and X-ray an...Cobalt-Boron oxides containing catalyst CoO·B2O3 (CoB2O4) are synthesized for hydrogen generation by catalytic reforming of basic solution of sodium hypophosphite (NaH2PO2) and identified by chemical and X-ray analysis. Reforming is performed in temperature range of 30°C - 80°C. Reaction rate constants at each value of temperature (k30°C = 8.53 × 10?4 s?1;k40°C = 1.62 × 10?4 s??;k50°C = 3.06 × 10?3 s?1;k60°C = 5.06 × 10?3 s?1;k80°C = 1.39 × 10?2 s?1), temperature coefficient of rate of chemical reaction (γ = 0.917) and activation energy (EA = 49.59 kJ·mol?1) are calculated.展开更多
基金Supported by the Opening Project of Hubei Three Gorges Laboratory (No.SK213008)the Innovation Fund of Key Laboratory of Green Chemical Process of Ministry of Education (No.GCXP202109)。
文摘Aluminum hypophosphite microspheres(AHP) were synthesized by hydrothermal method using NaH2PO2·H2O and AlCl3·6H2O as raw materials, and then the AHP microspheres were polymerized by surface polymerization of micro-nanospheres with cyclic cross-linked poly(cyclotriphosphazene-co-4,4'-sulfonyldiphenol)(PZS). A new organic-inorganic poly(phosphonitrile)-modified aluminum hypophosphite microspheres(PZS-AHP) were synthesized by encapsulation and applied to flame retardant thermoplastic polyurethane(TPU). The microstructure and chemical composition of the PZS-AHP microsphere were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray spectroscopy. The thermal stability of PZS-AHP microsphere was explored with thermogravimetric analysis. Thermogravimetric data indicate that the PZS-AHP microspheres have excellent thermal stability. The thermal and flame-retarding properties of the TPU composites were evaluated by thermogravimetric(TG), limited oxygen index tests(LOI), and cone calorimeter test(CCT). The TPU composite achieved vertical burning(UL-94) V-0 grade and LOI value reached 29.2% when 10 wt% PZS-AHP was incorporated. Compared with those of pure TPU, the peak heat release rate(pHRR) and total heat release(THR) of TPU/10%PZS-AHP decreased by 82.2% and 42.5%, respectively. The results of CCT indicated that PZS-AHP microsphere could improve the flame retardancy of TPU composites.
文摘建立了液相色谱-串联质谱法快速测定小麦粉中5种非法添加物的分析方法。样品使用一级水直接提取,采用Agilent Eclipse Plus C18色谱柱,以0.1%甲酸+10 mmol·L^(-1)甲酸胺溶液和甲醇为流动相,梯度洗脱,采用电喷雾离子源的正负离子扫描模式对小麦粉中5种非法添加物进行定性定量检测。结果表明,5种化合物在各自线性范围内具有良好的线性(r均大于0.9990),硫脲、曲酸、次磷酸盐的检出限为25μg·kg^(-1),定量限为50μg·kg^(-1),三聚硫氰酸三钠盐、苯甲羟肟酸的检出限为5μg·kg^(-1),定量限为10μg·kg^(-1),在低、中、高3个加标水平下,其回收率为82.1%~101.0%,RSD为0.8%~5.8%(n=6)。该方法专属性好,灵敏度高,前处理简单快速,可用于小麦粉中硫脲、曲酸、次磷酸盐、苯甲羟肟酸、三聚硫氰酸三钠盐的快速筛查和定量测定。
基金The authors thank the "National" Science Council, Taiwan, China for financially supporting (No. NSC95- 2211-E-006-032).
文摘Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes （Fe^2＋/H2O2, UV/Fe^2＋/H2O2, and electrolysis/Fe^2＋/H2O2） in this study. Comparison of these techniques in oxidation efficiency was undertaken. It was found that Fenton process could not completely degrade citrate in the presence of hypophosphite since it caused a series inhibition. Therefore, UV light （photo-Fenton） or electron current （electro-Fenton） was applied to improve the degradation efficiency of the Fenton process. Results showed that both photo-Fenton and electro-Fenton processes could overcome the inhibition of hypophosphite, especially the electro-Fenton.
文摘The electrocatalytic oxidation of hypophosphite on a nickel electrode has been studiedby means of in site UV-Vis subtractive reflectance spectroscopy. An absorbency band around 245um . which was ascribed to the formation of an intermediate, PHO2-, was observed in theelectrocatalytic oxidation process. Accordingly, the electrocatalytic oxidation of hypophosphitemight undergo a H abstraction of hypophosphite from the P-H bond to form the phosphoruscentred radical PHO2-, which is subsequently electrooxidized to the final product, phosphite.
文摘Electrochemical behavior of hypophosphite was studied with cyclic voltammogram in acidic solution(pH = 4.6) at 80℃. Two anodic peaks were observed on gold electrode at - 0.44V and - 0.59 V (SCE),respectively, and no corresponding cathodic peaks were obtained. The one at - 0.44 V wits ascribed to the oxidation oftautomeric form of hypophosphite, the other at - 0.59 V was due to the oxidation of absorbed form of hypophosphite. The two oxidation reactions were believed to be the electron source of nickel ion reduction in electrolessnickel processes.
文摘The deactivation of nickel hydroxide to the electrooxidation of hypophosphite on anickel electrode was studied by means of in situ UV-Vis subtractive reflectance spectroscopy. Theexperimental results show that when the potential is lower than-1.0 V (SCE), the surfacc on nickelelectrode is free of nickel hydroxide, on which hypophosphite is active. When the potential movespositively to about-0.75V, two absorbency bands around 300 nm and 550 nm, which were ascribedto the formation of α-nickel hydroxide, were observed, nickel is oxidized to α-nickel hydroxide.Severe deactivation of the surface occurs when the nickel surface is covered with nickel hydroxide,which separates the hypophosphite ion from nickel substrate.
基金The work was supported by the Natural Science Foundation of the Education Commission of Hunan Province(No.99C57)
文摘Kinetic model of hypophosphite oxidation on a nickel electrode was studied in D2O solution in order to reach a better understanding of the oxidation mechanism. In the model;he electrooxidation of hypophosphite undergo a H abstraction of hypophosphite from the P-H bond to form the phosphorus-centered radical (PWO2-)-P-., which subsequently is electrochemically reacted with water to form the final product, phosphite. The kinetic equations were derived, and the kinetic parameters were obtained from a comparison of experimental results and the kinetic equations. The process of hypophosphite electrooxidation could be well simulated by this model.
文摘Cobalt-Boron oxides containing catalyst CoO·B2O3 (CoB2O4) are synthesized for hydrogen generation by catalytic reforming of basic solution of sodium hypophosphite (NaH2PO2) and identified by chemical and X-ray analysis. Reforming is performed in temperature range of 30°C - 80°C. Reaction rate constants at each value of temperature (k30°C = 8.53 × 10?4 s?1;k40°C = 1.62 × 10?4 s??;k50°C = 3.06 × 10?3 s?1;k60°C = 5.06 × 10?3 s?1;k80°C = 1.39 × 10?2 s?1), temperature coefficient of rate of chemical reaction (γ = 0.917) and activation energy (EA = 49.59 kJ·mol?1) are calculated.
