Login In
2017 Volume 34 Issue 1
2017, 34(1): 1-24
doi: 10.11944/j.issn.1000-0518.2017.01.160131
Abstract:
The detection of explosives is one of the urgent problems of the current international security concerns. In the past few decades, a large number of fluorescent sensing materials were developed for the detection of explosives in the gaseous state, liquid state or solid state through the fluorescence sensing method. In recent years, researchers have vigorously developed a variety of novel fluorescent materials to achieve fast, ultra-sensitive and ultra-selective detection of explosives. This review systematically summarizes recent advances in advanced fluorescent materials for the detection of explosives. Particalarly, conjugated polymers, small fluorophores, supramolecular systems, aggregation-induced emissive materials, and electrospun nanofibers from fluorescent nano-materials, are discussed. Fluorescence sensing methods are proved to be very promising in the field of explosive detection.
The detection of explosives is one of the urgent problems of the current international security concerns. In the past few decades, a large number of fluorescent sensing materials were developed for the detection of explosives in the gaseous state, liquid state or solid state through the fluorescence sensing method. In recent years, researchers have vigorously developed a variety of novel fluorescent materials to achieve fast, ultra-sensitive and ultra-selective detection of explosives. This review systematically summarizes recent advances in advanced fluorescent materials for the detection of explosives. Particalarly, conjugated polymers, small fluorophores, supramolecular systems, aggregation-induced emissive materials, and electrospun nanofibers from fluorescent nano-materials, are discussed. Fluorescence sensing methods are proved to be very promising in the field of explosive detection.
2017, 34(1): 25-39
doi: 10.11944/j.issn.1000-0518.2017.01.160258
Abstract:
Transition-metal-catalyzed olefin isomerization has played a crucial role in the synthesis of organic compounds, commodity chemicals, natural products, and petroleum feedstocks. Although noble metals such as Ru, Rh and Ir as catalysts for the conversions have made dramatic achievements, the disadvantages of the rare resource, high cost, and poisoning products have limited its wide application in the synthesis. Due to the abundant supply, low cost and easy removal from the final products, the first-row transition metals have attracted much attention from the chemists and have proven to be very promising with respect to the development of more sustainable catalytic system in olefin isomerizaton. This review summaried the advances in olefin isomerization catalyzed by iron, cobalt, nickel in the past years and illustrates the differences among different catalytic systems in catalytic activity, regio- and stereo-selectivity, and substrate scope. Recent developments in the olefin isomerization catalyzed by the first-row metals have proven to be very promising and effective. The reaction mechanism was discussed to have deep insight into the isomerization. The mechanism of olefin isomerization was illustrated clearly in the reported articles through intermolecular or intramolecular hydrogen shift, and the stereoselectivity and regioselectivity in different catalytic system was still worthy of further investigations. Further studies in the field to solve the challenges in high catalytic activity, stereoselectivity, and wide substrate scopes would bring the isomerization into better prospect.
Transition-metal-catalyzed olefin isomerization has played a crucial role in the synthesis of organic compounds, commodity chemicals, natural products, and petroleum feedstocks. Although noble metals such as Ru, Rh and Ir as catalysts for the conversions have made dramatic achievements, the disadvantages of the rare resource, high cost, and poisoning products have limited its wide application in the synthesis. Due to the abundant supply, low cost and easy removal from the final products, the first-row transition metals have attracted much attention from the chemists and have proven to be very promising with respect to the development of more sustainable catalytic system in olefin isomerizaton. This review summaried the advances in olefin isomerization catalyzed by iron, cobalt, nickel in the past years and illustrates the differences among different catalytic systems in catalytic activity, regio- and stereo-selectivity, and substrate scope. Recent developments in the olefin isomerization catalyzed by the first-row metals have proven to be very promising and effective. The reaction mechanism was discussed to have deep insight into the isomerization. The mechanism of olefin isomerization was illustrated clearly in the reported articles through intermolecular or intramolecular hydrogen shift, and the stereoselectivity and regioselectivity in different catalytic system was still worthy of further investigations. Further studies in the field to solve the challenges in high catalytic activity, stereoselectivity, and wide substrate scopes would bring the isomerization into better prospect.
2017, 34(1): 40-45
doi: 10.11944/j.issn.1000-0518.2017.01.160095
Abstract:
Single-electron transfer living radical polymerization(SET-LRP) as an effective method is adopted to synthesize polymers with defined relative molecular mass, composition and specified molecular structure, which is powerful to adjust the molecular mass distribution of the obtained polymers in a wide range. To study the effects of the externally added anhydrous ferric chloride on the general SET-LRP polymerization kinetics of methyl acrylate, we carry out the research by using methyl 2-bromopropionate as the initiator and Cu(0)/tris(2-(dimethylamino)ethy)amine(Me6-TREN) as the composite catalytic system in dimethyl sulfoxide with different ratios of anhydrous ferric chloride. The experimental results indicate that the externally added anhydrous ferric chloride has an important influence on the polymerization kinetics of methyl acrylate. With increasing the concentration of iron ions in the solvent, the polymerization rates decrease and the induction period appears to be prolonged indicating that iron ions are involved in SET-LRP polymerization kinetics. This may be due to the decreased concentration of Cu(Ⅰ) relative to that of the reaction without the addition of any anhydrous ferric chloride. The current work will stimulate us to further clarify the origin of induction period in the copper(0) catalyzed SET-LRP of typical monomers.
Single-electron transfer living radical polymerization(SET-LRP) as an effective method is adopted to synthesize polymers with defined relative molecular mass, composition and specified molecular structure, which is powerful to adjust the molecular mass distribution of the obtained polymers in a wide range. To study the effects of the externally added anhydrous ferric chloride on the general SET-LRP polymerization kinetics of methyl acrylate, we carry out the research by using methyl 2-bromopropionate as the initiator and Cu(0)/tris(2-(dimethylamino)ethy)amine(Me6-TREN) as the composite catalytic system in dimethyl sulfoxide with different ratios of anhydrous ferric chloride. The experimental results indicate that the externally added anhydrous ferric chloride has an important influence on the polymerization kinetics of methyl acrylate. With increasing the concentration of iron ions in the solvent, the polymerization rates decrease and the induction period appears to be prolonged indicating that iron ions are involved in SET-LRP polymerization kinetics. This may be due to the decreased concentration of Cu(Ⅰ) relative to that of the reaction without the addition of any anhydrous ferric chloride. The current work will stimulate us to further clarify the origin of induction period in the copper(0) catalyzed SET-LRP of typical monomers.
2017, 34(1): 46-53
doi: 10.11944/j.issn.1000-0518.2017.01.160178
Abstract:
Epoxy resin(EP) nanocomposites have been regarded as high performance materials with the advantages of organic polymers, inorganic materials and nanoparticles. Herein, DGEBA/MWCNTs nanocomposites were prepared based on diglycidyl ether of bisphenol-A(DGEBA), methylhexahydrophthalic anhydride(MHHPA) as curing agent, and multi-walled carbon nanotubes(MWCNTs) as additive.The effect of MWCNTs(mass fraction less than 1.5%) on thermal and flame retardancy of DGEBA epoxy resin was explored by DGEBA/MWCNTs nanocomposites structure, thermal properties, thermal conductivity and cone calorimeter analysis. MWCNTs formed cluster when their mass fraction is 1.5%. With increasing the content of MWCNTs, the glass transition temperature(Tg) and the temperature at which 5% mass loss of the composites increase initially and then decrease, at the same time the residual carbon content increases. Thermal conductivity of the composite exhibits a trend of rising initially and then decreasing afterwards. The maximal thermal conductivity appears when the mass fraction of MWCNTs reaches 1%. The total heat release volume of these composites decreases and the total volume of smoke release increases compared to those of epoxy resin. Cone calorimeter tests show that the incorporation of MWCNTs into epoxy thermosets can improve its flame retardancy to some extent.
Epoxy resin(EP) nanocomposites have been regarded as high performance materials with the advantages of organic polymers, inorganic materials and nanoparticles. Herein, DGEBA/MWCNTs nanocomposites were prepared based on diglycidyl ether of bisphenol-A(DGEBA), methylhexahydrophthalic anhydride(MHHPA) as curing agent, and multi-walled carbon nanotubes(MWCNTs) as additive.The effect of MWCNTs(mass fraction less than 1.5%) on thermal and flame retardancy of DGEBA epoxy resin was explored by DGEBA/MWCNTs nanocomposites structure, thermal properties, thermal conductivity and cone calorimeter analysis. MWCNTs formed cluster when their mass fraction is 1.5%. With increasing the content of MWCNTs, the glass transition temperature(Tg) and the temperature at which 5% mass loss of the composites increase initially and then decrease, at the same time the residual carbon content increases. Thermal conductivity of the composite exhibits a trend of rising initially and then decreasing afterwards. The maximal thermal conductivity appears when the mass fraction of MWCNTs reaches 1%. The total heat release volume of these composites decreases and the total volume of smoke release increases compared to those of epoxy resin. Cone calorimeter tests show that the incorporation of MWCNTs into epoxy thermosets can improve its flame retardancy to some extent.
2017, 34(1): 54-59
doi: 10.11944/j.issn.1000-0518.2017.01.160093
Abstract:
Poly(ethylene 2,5-furandicarboxylate)(PEF) was synthesized based on 2,5-furanicarboxylica acid and ethylene glycol. Polyethylene terephthalate-b-poly(ethylene 2,5-furandicarboxylate)(PET-b-PEF) block copolymers were prepared by melt transesterification method. PET was partly replaced by PEF polyester. The properties of PET-b-PEF block copolymers were characterized by nuclear magnetic resonance spectormeter(NMR), differential scanning calorimeter(DSC), thermo gravimetric analysis(TGA) and X-ray diffraction(XRD). The results show that the glass transition temperature(Tg) of copolyesters is about 75.8~80.3℃. The Tg of the PET-b-PEF block copolyesters first decreases and then increases; the crystallinity and the melting temperature decrease with the increasing contents of PEF segments, moreover, there is no crystalline diffraction peaks for the copolyesters when the chain segment content of PEF is higher than 15%. The initial decomposition temperature of this series of copolyesters is about 392.2~407.9℃. PEF has excellent thermal properties similar to that of PET(403.3℃). In addition, the thermal stability of the copolyesters is better than that of PET, when the chain segment contents of PEF in the coplyester is less than 15%, and the initial decomposition temperature of PET-b-PEF block copolymers is close to that of PET.
Poly(ethylene 2,5-furandicarboxylate)(PEF) was synthesized based on 2,5-furanicarboxylica acid and ethylene glycol. Polyethylene terephthalate-b-poly(ethylene 2,5-furandicarboxylate)(PET-b-PEF) block copolymers were prepared by melt transesterification method. PET was partly replaced by PEF polyester. The properties of PET-b-PEF block copolymers were characterized by nuclear magnetic resonance spectormeter(NMR), differential scanning calorimeter(DSC), thermo gravimetric analysis(TGA) and X-ray diffraction(XRD). The results show that the glass transition temperature(Tg) of copolyesters is about 75.8~80.3℃. The Tg of the PET-b-PEF block copolyesters first decreases and then increases; the crystallinity and the melting temperature decrease with the increasing contents of PEF segments, moreover, there is no crystalline diffraction peaks for the copolyesters when the chain segment content of PEF is higher than 15%. The initial decomposition temperature of this series of copolyesters is about 392.2~407.9℃. PEF has excellent thermal properties similar to that of PET(403.3℃). In addition, the thermal stability of the copolyesters is better than that of PET, when the chain segment contents of PEF in the coplyester is less than 15%, and the initial decomposition temperature of PET-b-PEF block copolymers is close to that of PET.
2017, 34(1): 71-75
doi: 10.11944/j.issn.1000-0518.2017.01.160455
Abstract:
NiCo layered double hydroxides(NiCo-LDHs) are important electrode materials in batteries and supercapacitors, due to its layered structure and controllable ratio and kind of metal ions. In this paper, we studied the effect of La3+ ions on the crystal structures and electrochemical performances of NiCo-LDHs. According to ionic electronegativity, the values of La3+(1.327) and Co2+(1.377) are similar, leading to the replace of Co2+ by La3+ in La3+-doped NiCo-LDHs. La3+-doped NiCo-LDHs show high specific capacitance and rate performance, 1115 F/g at 1 A/g and 517 F/g at 30 A/g, respectively. XRD, FTIR and SEM prove that La3+ doping does not change the structures of NiCo-LDHs. However, CV and electrochemical impendence spectrum confirms that the nature of electron or ion transfer is adjusted by La3+ doping. Owing to the size effect of La3+ ions, the optimized ratio of La doping is 0.26%. La3+ ions doping in electrode materials can be a promising method to change their nature of electron or ion transfer(electron or ion conductivity).
NiCo layered double hydroxides(NiCo-LDHs) are important electrode materials in batteries and supercapacitors, due to its layered structure and controllable ratio and kind of metal ions. In this paper, we studied the effect of La3+ ions on the crystal structures and electrochemical performances of NiCo-LDHs. According to ionic electronegativity, the values of La3+(1.327) and Co2+(1.377) are similar, leading to the replace of Co2+ by La3+ in La3+-doped NiCo-LDHs. La3+-doped NiCo-LDHs show high specific capacitance and rate performance, 1115 F/g at 1 A/g and 517 F/g at 30 A/g, respectively. XRD, FTIR and SEM prove that La3+ doping does not change the structures of NiCo-LDHs. However, CV and electrochemical impendence spectrum confirms that the nature of electron or ion transfer is adjusted by La3+ doping. Owing to the size effect of La3+ ions, the optimized ratio of La doping is 0.26%. La3+ ions doping in electrode materials can be a promising method to change their nature of electron or ion transfer(electron or ion conductivity).
2017, 34(1): 76-82
doi: 10.11944/j.issn.1000-0518.2017.01.160101
Abstract:
Porous silicon oxide/silicon/carbon composite was derived from micro-silicon monoxide with simple calcination, chemical vapor deposition and HF etching. The obtained c-SiOx/Si/C (c-refers to calcination) composite after etching possesses a high specific surface area of 32.9 m2/g and an average/mean pore distribution of 3 nm. The atomic ratio of Si/O in c-SiOx/Si/C is increased comparing to that of c-SiO/C without etching. The Si nano-crystallites were embedded in porous Si-suboxide, and the particles are covered by a uniform carbon layer with a thickness of 6 nm on the surface. The c-SiOx/Si/C with this particular structure exhibits a stable reversible capacity of ca. 645.1 mA·h/g after 50 cycles with the current density at 0.3 mA/g. In contrast, c-SiO/C composite without pores presents a reversible capacity of only ca. 466 mA·h/g under the same carbon coating condition. The different cycling performances of c-SiOx/Si/C and c-SiO/C may be consequences of their structural differences. It is believed that the rich nanopores of the c-SiOx/Si/C can endure and buffer the severe volume change of silicon upon lithium insertion and extraction and improve the mechanical integrity of composite.
Porous silicon oxide/silicon/carbon composite was derived from micro-silicon monoxide with simple calcination, chemical vapor deposition and HF etching. The obtained c-SiOx/Si/C (c-refers to calcination) composite after etching possesses a high specific surface area of 32.9 m2/g and an average/mean pore distribution of 3 nm. The atomic ratio of Si/O in c-SiOx/Si/C is increased comparing to that of c-SiO/C without etching. The Si nano-crystallites were embedded in porous Si-suboxide, and the particles are covered by a uniform carbon layer with a thickness of 6 nm on the surface. The c-SiOx/Si/C with this particular structure exhibits a stable reversible capacity of ca. 645.1 mA·h/g after 50 cycles with the current density at 0.3 mA/g. In contrast, c-SiO/C composite without pores presents a reversible capacity of only ca. 466 mA·h/g under the same carbon coating condition. The different cycling performances of c-SiOx/Si/C and c-SiO/C may be consequences of their structural differences. It is believed that the rich nanopores of the c-SiOx/Si/C can endure and buffer the severe volume change of silicon upon lithium insertion and extraction and improve the mechanical integrity of composite.
2017, 34(1): 83-89
doi: 10.11944/j.issn.1000-0518.2017.01.160094
Abstract:
Tyrosinase is a complicated copper containing oxidoreductase that is common in microorganism, plants, animals and human body, which plays a crucial role in melanin biosynthesis. Currently researches about tyrosinase inhibitors are mostly focused on natural extracts and organism. However, inorganic Dawson type polyoxometalates as tyrosinase inhibitors have been less reported. Two kinds of Dawson type polyoxometalates were synthesized and characterized by ultraviolet spectroscopy and infrared spectral analysis. The inhibitory effects of H6[P2Mo18O62] and H8[P2Mo17Cr (OH2) O61](abbreviated to P2Mo18 and P2Mo17Cr, respectively) on mushroom tyrosinase were investigated by ultraviolet spectrophotometry and enzymatic kinetics methods. P2Mo18 and P2Mo17Cr have significant inhibitory effects on tyrosinase, and the IC50 values of P2Mo18 and P2Mo17Cr are (0.482±0.009) mmol/L and (0.503±0.011) mmol/L for diphenolase, respectively. Enzymatic kinetics analysis indicates that P2Mo18 and P2Mo17Cr are reversible and competitive inhibitor, and the inhibition constant of P2Mo18 and P2Mo17Cr are 0.212 mmol/L and 0.249 mmol/L, respectively. Considering of IC50 values and inhibition constants, the inhibitory effect of P2Mo18 is slightly better than that of P2Mo17Cr. In conclusion, P2Mo18 and P2Mo17Cr show effective antityrosinase activities. Compared with arbutin, P2Mo18 and P2Mo17Cr have much more inhibitory effects on the diphenolase activity of tyrosinase. This study may provide reference foundation for the further study of the tyrosinase inhibitors, and also offer useful information for the comprehensive utilization of polyoxometalates.
Tyrosinase is a complicated copper containing oxidoreductase that is common in microorganism, plants, animals and human body, which plays a crucial role in melanin biosynthesis. Currently researches about tyrosinase inhibitors are mostly focused on natural extracts and organism. However, inorganic Dawson type polyoxometalates as tyrosinase inhibitors have been less reported. Two kinds of Dawson type polyoxometalates were synthesized and characterized by ultraviolet spectroscopy and infrared spectral analysis. The inhibitory effects of H6[P2Mo18O62] and H8[P2Mo17Cr (OH2) O61](abbreviated to P2Mo18 and P2Mo17Cr, respectively) on mushroom tyrosinase were investigated by ultraviolet spectrophotometry and enzymatic kinetics methods. P2Mo18 and P2Mo17Cr have significant inhibitory effects on tyrosinase, and the IC50 values of P2Mo18 and P2Mo17Cr are (0.482±0.009) mmol/L and (0.503±0.011) mmol/L for diphenolase, respectively. Enzymatic kinetics analysis indicates that P2Mo18 and P2Mo17Cr are reversible and competitive inhibitor, and the inhibition constant of P2Mo18 and P2Mo17Cr are 0.212 mmol/L and 0.249 mmol/L, respectively. Considering of IC50 values and inhibition constants, the inhibitory effect of P2Mo18 is slightly better than that of P2Mo17Cr. In conclusion, P2Mo18 and P2Mo17Cr show effective antityrosinase activities. Compared with arbutin, P2Mo18 and P2Mo17Cr have much more inhibitory effects on the diphenolase activity of tyrosinase. This study may provide reference foundation for the further study of the tyrosinase inhibitors, and also offer useful information for the comprehensive utilization of polyoxometalates.
2017, 34(1): 90-97
doi: 10.11944/j.issn.1000-0518.2017.01.160447
Abstract:
A series of adsorbents based on waste paper cellulose was prepared by oxidative ring-opening, amination and sulfhydrylation reaction. The adsorption capacity of the cellulose modified by amino thiourea/glutaraldehyde on coordination anion AgCl43- is the best in both the single system and the mixed system containing high levels of Cu (Ⅱ) and Ni (Ⅱ) chlorides. The maximum adsorption capacity of Ag (Ⅰ) can reach 171.16 mg/g. Reasons for different adsorption effects and the electrostatic adsorption mechanism of coordination anion Ag (Ⅰ) on the adsorbent were discussed based on IR, XPS and thermodynamics and so on, which can be ascribed to the electrostatic interaction between AgCl43- and the protonated thiol group of thiolmide group.
A series of adsorbents based on waste paper cellulose was prepared by oxidative ring-opening, amination and sulfhydrylation reaction. The adsorption capacity of the cellulose modified by amino thiourea/glutaraldehyde on coordination anion AgCl43- is the best in both the single system and the mixed system containing high levels of Cu (Ⅱ) and Ni (Ⅱ) chlorides. The maximum adsorption capacity of Ag (Ⅰ) can reach 171.16 mg/g. Reasons for different adsorption effects and the electrostatic adsorption mechanism of coordination anion Ag (Ⅰ) on the adsorbent were discussed based on IR, XPS and thermodynamics and so on, which can be ascribed to the electrostatic interaction between AgCl43- and the protonated thiol group of thiolmide group.
2017, 34(1): 98-104
doi: 10.11944/j.issn.1000-0518.2017.01.160115
Abstract:
Mg/Al layered compounds were prepared by using Na2CO3/NaOH, NaOH and NH4OH as precipitants. Their Cr (Ⅵ) adsorption properties were studied using simulated wastewater containing Cr (Ⅵ). The structures of Mg/Al layered compounds were discussed in combination with X-ray diffraction XRD and Brunauer Emmett Teller (BET) methods surface area experiments. The results show that Mg/Al layered compounds have higher crystallinity, perfect layered structure, larger specific surface area and suitable pore distribution by using Na2CO3/NaOH as the precipitator. The optimal absorption efficiency of Cr (Ⅵ) can be reached when pH values are 7.0~9.0, and solid-liquid ratio at room temperature for 9 h is 1 g to 500 mL. The saturated adsorption capacity of Mg/Al layered compounds is 199.4 mg/g under the optimal conditions. The Cr (Ⅵ) in wastewater is removed by forming layered superamolecular compounds between anions containing Cr (Ⅵ) and Mg/Al layered compounds. The remaining Cr (Ⅵ) concentration of laboratory wastewater initially containing 226.1 mg/L is less than 0.5 mg/L after six absorption cycles with Mg/Al layered compounds. The treated wastewater is in line with national sewage comprehensive emission standard (GB8978-1996). Mg/Al layered compounds are excellent absorbents for disposing laboratory wastewater containing Cr (Ⅵ).
Mg/Al layered compounds were prepared by using Na2CO3/NaOH, NaOH and NH4OH as precipitants. Their Cr (Ⅵ) adsorption properties were studied using simulated wastewater containing Cr (Ⅵ). The structures of Mg/Al layered compounds were discussed in combination with X-ray diffraction XRD and Brunauer Emmett Teller (BET) methods surface area experiments. The results show that Mg/Al layered compounds have higher crystallinity, perfect layered structure, larger specific surface area and suitable pore distribution by using Na2CO3/NaOH as the precipitator. The optimal absorption efficiency of Cr (Ⅵ) can be reached when pH values are 7.0~9.0, and solid-liquid ratio at room temperature for 9 h is 1 g to 500 mL. The saturated adsorption capacity of Mg/Al layered compounds is 199.4 mg/g under the optimal conditions. The Cr (Ⅵ) in wastewater is removed by forming layered superamolecular compounds between anions containing Cr (Ⅵ) and Mg/Al layered compounds. The remaining Cr (Ⅵ) concentration of laboratory wastewater initially containing 226.1 mg/L is less than 0.5 mg/L after six absorption cycles with Mg/Al layered compounds. The treated wastewater is in line with national sewage comprehensive emission standard (GB8978-1996). Mg/Al layered compounds are excellent absorbents for disposing laboratory wastewater containing Cr (Ⅵ).
2017, 34(1): 105-110
doi: 10.11944/j.issn.1000-0518.2017.01.160104
Abstract:
Four compounds[M (en)(H2O)4]·1, 5-nds·(H2O)2(M=Ni (1), Co (2), Cd (3), Cu (4), based on ethylene diamine (en) and 1, 5-naphthalenedisulfonic acid (nds), were synthesized by hydrothermal synthesis method under room temperature. The structures of the crystals were confirmed by X-ray diffraction (XRD) method and SHELXTL-97 software. The four compounds have the same three dimensional (3D) framework in monoclinic C2/c space group, only different in metal atoms. The cell parameters of compound 1 are:a=1.69026(19) nm, b=1.01373(11) nm, c=1.3448(3) nm, α=90°, β=120.2650°, γ=90°, V=1.9901(5) nm3, Z=4, Dc=1.713 g/cm3, F(000)=1072, R1=0.0326, wR2=0.0867. One metal atom is coordinated to four oxygen atoms from water molecules and two nitrogen atoms of one ethylene diamine. There exit abundant hydrogen bonds interactions between free water molecules and oxygen atoms in 1, 5-naphthalenedisulfonic acid anion. One dimensional chains were formed through abundant hydrogen bonds and one[Ni (en)(H2O)4]2+ located between each two nds2-. The two adjacent[Ni (en)(H2O)4]2+ arranged by the opposite mode (head to head). The properties of the two compounds were characterized by XRD, thermal gravimetric analysis (TGA), fluorescence spectroscopy and multi-function spectrometer. The molecular recognition properties of compound 3 with M=Cd in methanol solution was studied. The compound 3 was solved in different solvents in which the highest strength of fluorescence spectroscopy occurs in methanol solution. The strength of fluorescence spectroscopy decreases, with increasing concentration of methanol which may have potential applications in fluorescence probe to recognize polarity.
Four compounds[M (en)(H2O)4]·1, 5-nds·(H2O)2(M=Ni (1), Co (2), Cd (3), Cu (4), based on ethylene diamine (en) and 1, 5-naphthalenedisulfonic acid (nds), were synthesized by hydrothermal synthesis method under room temperature. The structures of the crystals were confirmed by X-ray diffraction (XRD) method and SHELXTL-97 software. The four compounds have the same three dimensional (3D) framework in monoclinic C2/c space group, only different in metal atoms. The cell parameters of compound 1 are:a=1.69026(19) nm, b=1.01373(11) nm, c=1.3448(3) nm, α=90°, β=120.2650°, γ=90°, V=1.9901(5) nm3, Z=4, Dc=1.713 g/cm3, F(000)=1072, R1=0.0326, wR2=0.0867. One metal atom is coordinated to four oxygen atoms from water molecules and two nitrogen atoms of one ethylene diamine. There exit abundant hydrogen bonds interactions between free water molecules and oxygen atoms in 1, 5-naphthalenedisulfonic acid anion. One dimensional chains were formed through abundant hydrogen bonds and one[Ni (en)(H2O)4]2+ located between each two nds2-. The two adjacent[Ni (en)(H2O)4]2+ arranged by the opposite mode (head to head). The properties of the two compounds were characterized by XRD, thermal gravimetric analysis (TGA), fluorescence spectroscopy and multi-function spectrometer. The molecular recognition properties of compound 3 with M=Cd in methanol solution was studied. The compound 3 was solved in different solvents in which the highest strength of fluorescence spectroscopy occurs in methanol solution. The strength of fluorescence spectroscopy decreases, with increasing concentration of methanol which may have potential applications in fluorescence probe to recognize polarity.
2017, 34(1): 111-117
doi: 10.11944/j.issn.1000-0518.2017.01.160385
Abstract:
The magnetic nanoparticles (NPs) coated with silica NPs (Fe3O4@SiO2) were prepared by chemical co-precipation method. A multifunctional magnetic nanocomposite (Fe3O4@SiO2-Pyh) was fabricated by grafting pyridoxal hydrazide (Pyh) to the surface of Fe3O4@SiO2 NPs via hexamethylene diisocyanate. The structure, morphology, and magnetic property of Fe3O4@SiO2-Pyh were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, and X-ray powder diffraction. The Fe3O4@SiO2-Pyh has a clear core shell architecture, in which an average particle diameter is 50~55 nm with about 15 nm SiO2 shell. Fe3O4@SiO2-Pyh contains -CO-NH-N=CH-active groups, which can coordinate with Cu2+ to form stable complex. Based on this principle we established an analytical method for the determination of Cu2+, which was characterized by UV-Vis spectroscopy. The linear range of detecting Cu2+ concentration is 3.4×10-7~4.5×10-6 mol/L with detection limit 1.03×10-7 mol/L. Moreover, the nanocomposites display superparamagnetic properties, which can be used for effective separation of excess Cu2+ from the liquid phase by applying an external magnetic field. As-synthesized Fe3O4@SiO2-Pyh can be a good candidate for selective detection and simple removal of Cu2+ in environmental fields.
The magnetic nanoparticles (NPs) coated with silica NPs (Fe3O4@SiO2) were prepared by chemical co-precipation method. A multifunctional magnetic nanocomposite (Fe3O4@SiO2-Pyh) was fabricated by grafting pyridoxal hydrazide (Pyh) to the surface of Fe3O4@SiO2 NPs via hexamethylene diisocyanate. The structure, morphology, and magnetic property of Fe3O4@SiO2-Pyh were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, and X-ray powder diffraction. The Fe3O4@SiO2-Pyh has a clear core shell architecture, in which an average particle diameter is 50~55 nm with about 15 nm SiO2 shell. Fe3O4@SiO2-Pyh contains -CO-NH-N=CH-active groups, which can coordinate with Cu2+ to form stable complex. Based on this principle we established an analytical method for the determination of Cu2+, which was characterized by UV-Vis spectroscopy. The linear range of detecting Cu2+ concentration is 3.4×10-7~4.5×10-6 mol/L with detection limit 1.03×10-7 mol/L. Moreover, the nanocomposites display superparamagnetic properties, which can be used for effective separation of excess Cu2+ from the liquid phase by applying an external magnetic field. As-synthesized Fe3O4@SiO2-Pyh can be a good candidate for selective detection and simple removal of Cu2+ in environmental fields.
2017, 34(1): 118-122
doi: 10.11944/j.issn.1000-0518.2017.01.160132
Abstract:
Acanthopanax leaf flavonoids liposome, acanthopanax leaf drop pills, and acanthopanax leaf flavonoid extract were fed to rats by intragastric administration to study the bioavailability and pharmacokinetics of hyperoside, and appropriate dosage form of acanthopanax leaf flavonoid by liquid chromatography-tandem mass spectrometry(LC-MS/MS). Pharmacokinetic data were processed with PKsolver software. The main pharmacokinetic parameters maximum plasma concentrations(Cmax) are (210.24±10.3), (254.12±9.2), and (349.34±12.5) μg/L for acanthopanax leaf flavonoids liposome, acanthopanax leaf drop pills and acanthopanax leaf flavonoid extract, respectively; area under the curve from zero to t(AUC0-t) is (30.7±2.7), (35.01±1.98), and (45.2±2.8) μg/(mL·min), respectively; mean retention time(MRT) is (334.42±75.36), (394.56±90.26), and (640.35±84.26) min, respectively. The results show that compared with acanthopanax leaf flavonoids extracts and acanthopanax leaf drop pills, the Cmax and bioavailability of acanthopanax leaf flavonoids liposome are increased, the elimination rate of acanthopanax leaf flavonoids liposome is reduced. Liposome is expected to be the suitable dosage form of acanthopanax leaf flavonoids, and may become the new research direction in the field of chinese medicine chemistry.
Acanthopanax leaf flavonoids liposome, acanthopanax leaf drop pills, and acanthopanax leaf flavonoid extract were fed to rats by intragastric administration to study the bioavailability and pharmacokinetics of hyperoside, and appropriate dosage form of acanthopanax leaf flavonoid by liquid chromatography-tandem mass spectrometry(LC-MS/MS). Pharmacokinetic data were processed with PKsolver software. The main pharmacokinetic parameters maximum plasma concentrations(Cmax) are (210.24±10.3), (254.12±9.2), and (349.34±12.5) μg/L for acanthopanax leaf flavonoids liposome, acanthopanax leaf drop pills and acanthopanax leaf flavonoid extract, respectively; area under the curve from zero to t(AUC0-t) is (30.7±2.7), (35.01±1.98), and (45.2±2.8) μg/(mL·min), respectively; mean retention time(MRT) is (334.42±75.36), (394.56±90.26), and (640.35±84.26) min, respectively. The results show that compared with acanthopanax leaf flavonoids extracts and acanthopanax leaf drop pills, the Cmax and bioavailability of acanthopanax leaf flavonoids liposome are increased, the elimination rate of acanthopanax leaf flavonoids liposome is reduced. Liposome is expected to be the suitable dosage form of acanthopanax leaf flavonoids, and may become the new research direction in the field of chinese medicine chemistry.
2017, 34(1): 60-70
doi: 10.11944/j.issn.1000-0518.2017.01.160396
Abstract:
Three-dimensional WO3·0.33H2O hierarchical microstructures consisting of nanorods have been successfully constructed through a facile hydrothermal route, employing sodium tungstate and dodecylbenzenesulfonic acid(DBSA) as precursors without the assistance of any additives. Remarkably, DBSA not only acts as a reagent to provide H+ but also serves as a surfactant to tailor the morphology of the as-synthesized products. The hierarchically-structured WO3·0.33H2O displays a strong structure-enhanced photocatalytic activity for the degradation of rhodamine B(RhB) under visible light irradiation, and the degradation ratio of RhB is 100% and is still kept at a high degradation ratio after using 5 times.
Three-dimensional WO3·0.33H2O hierarchical microstructures consisting of nanorods have been successfully constructed through a facile hydrothermal route, employing sodium tungstate and dodecylbenzenesulfonic acid(DBSA) as precursors without the assistance of any additives. Remarkably, DBSA not only acts as a reagent to provide H+ but also serves as a surfactant to tailor the morphology of the as-synthesized products. The hierarchically-structured WO3·0.33H2O displays a strong structure-enhanced photocatalytic activity for the degradation of rhodamine B(RhB) under visible light irradiation, and the degradation ratio of RhB is 100% and is still kept at a high degradation ratio after using 5 times.
