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2013 Volume 30 Issue 5
2013, 30(5): 489-499
doi: 10.3724/SP.J.1095.2013.20261
Abstract:
Over the past decade,energetic ionic salts of triazoles and tetrazoles have been studied widely. Insensitive,stable and environment friendly energetic ionic salts of high-formation enthalpy and high-density have been synthesized to meet the requirement of multi-functional materials in the fields of explosives and others. The research background,synthesis and performance of some energetic ionic salts based on triazole and tetrazole are reviewed,which can provide a reference for the research of energetic ionic salts.
Over the past decade,energetic ionic salts of triazoles and tetrazoles have been studied widely. Insensitive,stable and environment friendly energetic ionic salts of high-formation enthalpy and high-density have been synthesized to meet the requirement of multi-functional materials in the fields of explosives and others. The research background,synthesis and performance of some energetic ionic salts based on triazole and tetrazole are reviewed,which can provide a reference for the research of energetic ionic salts.
2013, 30(5): 500-505
doi: 10.3724/SP.J.1095.2013.20308
Abstract:
A new process was developed to oxidize 1-naphthylamine by H2O2 in acetic acid for preparing 1,4-naphthoquinone. The effects of the reaction temperature,the oxidation time,molar ratio of 1-naphthylamine to H2O2,the concentration of sulfuric acid and the concentration of H2O2 on the product yield were investigated. The optimal reaction conditions for preparing 1,4-naphthoquinone with yield higher than 52.2% are as followings:the molar ratio of 1-naphthylamine to H2O2 is 1:10,the mass concentration of H2O2 is 5%,the mass concentration of sulfuric acid is 45%,reaction temperature is 80℃,and reaction time is 3 h. This method has the advantages such as simplicity,easy separation of the product and short reaction time.
A new process was developed to oxidize 1-naphthylamine by H2O2 in acetic acid for preparing 1,4-naphthoquinone. The effects of the reaction temperature,the oxidation time,molar ratio of 1-naphthylamine to H2O2,the concentration of sulfuric acid and the concentration of H2O2 on the product yield were investigated. The optimal reaction conditions for preparing 1,4-naphthoquinone with yield higher than 52.2% are as followings:the molar ratio of 1-naphthylamine to H2O2 is 1:10,the mass concentration of H2O2 is 5%,the mass concentration of sulfuric acid is 45%,reaction temperature is 80℃,and reaction time is 3 h. This method has the advantages such as simplicity,easy separation of the product and short reaction time.
2013, 30(5): 506-510
doi: 10.3724/SP.J.1095.2013.20288
Abstract:
2-{2-Methyl-6-[2-(4-morpholin-4-yl-phenyl)-vinyl]-pyran-4-ylidene}-malononitrile(MDCM) and 2-{2,6-bis-[2-(4-morpholin-4-yl-phenyl)-vinyl]-pyran-4-ylidene}-malononitrile(BDCM) were synthesized from 2,6-dimethyl-4H-pyran-4-one,malononitrile,4-(4-formylphenyl) morpholine and piperidine. 1H NMR and elemental analysis were used to characterize two compounds. The fluorescence spectra of the two compounds in solutions with different concentration were investigated. The solvent effects which impact on the fluorescence properties and the characteristics of the fluorescence in acidic solution were also systematically studied. The result show that fluorescence center wavelengthes of both compounds are in the red region,and the spectra exhibit red-shifts with increasing the polarity and acidity of the solvents. It is also found that the derivatives of MDCM and BDCM at concentrations of 1 × 10-4 mol/L and 1 × 10-5 mol/L,respectively,exhibit the highest fluorescent intensities. The solid fluorescent maximum wavelength of the BDCM has a 37 nm red-shift longer than that of MDCM,because the conjugate system of BDCM is longer than that of MDCM.
2-{2-Methyl-6-[2-(4-morpholin-4-yl-phenyl)-vinyl]-pyran-4-ylidene}-malononitrile(MDCM) and 2-{2,6-bis-[2-(4-morpholin-4-yl-phenyl)-vinyl]-pyran-4-ylidene}-malononitrile(BDCM) were synthesized from 2,6-dimethyl-4H-pyran-4-one,malononitrile,4-(4-formylphenyl) morpholine and piperidine. 1H NMR and elemental analysis were used to characterize two compounds. The fluorescence spectra of the two compounds in solutions with different concentration were investigated. The solvent effects which impact on the fluorescence properties and the characteristics of the fluorescence in acidic solution were also systematically studied. The result show that fluorescence center wavelengthes of both compounds are in the red region,and the spectra exhibit red-shifts with increasing the polarity and acidity of the solvents. It is also found that the derivatives of MDCM and BDCM at concentrations of 1 × 10-4 mol/L and 1 × 10-5 mol/L,respectively,exhibit the highest fluorescent intensities. The solid fluorescent maximum wavelength of the BDCM has a 37 nm red-shift longer than that of MDCM,because the conjugate system of BDCM is longer than that of MDCM.
2013, 30(5): 511-515
doi: 10.3724/SP.J.1095.2013.20280
Abstract:
Four aromatic tetrasulfonate calixarenes have been prepared in one pot and their extraction performances toward Ca2+, Pb2+ and some transition metal ions in chloroform were evaluated. The primary results revealed that the sulfonate-bridged calixarenes showed improved extraction capabilities toward several toxic cations such as Cr3+, Cd2+ and CO2+. The extracted percentages of Cr3+ by compound 2a and Cd2+ by compound 2b are 50.15% and 46.48%,respectively.
Four aromatic tetrasulfonate calixarenes have been prepared in one pot and their extraction performances toward Ca2+, Pb2+ and some transition metal ions in chloroform were evaluated. The primary results revealed that the sulfonate-bridged calixarenes showed improved extraction capabilities toward several toxic cations such as Cr3+, Cd2+ and CO2+. The extracted percentages of Cr3+ by compound 2a and Cd2+ by compound 2b are 50.15% and 46.48%,respectively.
2013, 30(5): 516-522
doi: 10.3724/SP.J.1095.2013.20536
Abstract:
The catalytic performances of the potassium-modified silica-supported catalysts with highly dispersed and isolated active sites containing a tiny amount of transition metal oxide(i.e.,K-M/SiO2(n(K):n(M):n(Si)=10:1:1000);M=V,Cr,Mn,Fe,Co,Ni,Cu,Zn) for the selective oxidation of propane were evaluated. The structures and physico-chemical properties of these catalysts were characterized by means of UV-Raman,CO2-TPD. The relationships among the catalytic performances of this series of catalysts for the selective oxidation of propane and their configuration structures of the transition metal cations were studied. The results indicate that the configuration structures of transition metal cations have large effect on the catalytic performances of the catalysts for the selective oxidation of propane. The stable cation structures with d-orbitals,which are fully occupied or empty,are good for the selective oxygenation of propane. But the cations,which have the relatively unstable d-electron structures with mixed valences,are good for the deep oxidation of propane.This relation between the cation structures of highly dispersed and isolated active sites of the catalysts and their catalytic performances is very similar to that found in the selective oxidation of ethane,which further demonstrates that the configuration structures of transition metal cations in the catalysts with highly dispersed and isolated active sites is the most important controlling factor to affect the catalytic performances of this kind of catalysts for the selective oxidation of low alkanes.
The catalytic performances of the potassium-modified silica-supported catalysts with highly dispersed and isolated active sites containing a tiny amount of transition metal oxide(i.e.,K-M/SiO2(n(K):n(M):n(Si)=10:1:1000);M=V,Cr,Mn,Fe,Co,Ni,Cu,Zn) for the selective oxidation of propane were evaluated. The structures and physico-chemical properties of these catalysts were characterized by means of UV-Raman,CO2-TPD. The relationships among the catalytic performances of this series of catalysts for the selective oxidation of propane and their configuration structures of the transition metal cations were studied. The results indicate that the configuration structures of transition metal cations have large effect on the catalytic performances of the catalysts for the selective oxidation of propane. The stable cation structures with d-orbitals,which are fully occupied or empty,are good for the selective oxygenation of propane. But the cations,which have the relatively unstable d-electron structures with mixed valences,are good for the deep oxidation of propane.This relation between the cation structures of highly dispersed and isolated active sites of the catalysts and their catalytic performances is very similar to that found in the selective oxidation of ethane,which further demonstrates that the configuration structures of transition metal cations in the catalysts with highly dispersed and isolated active sites is the most important controlling factor to affect the catalytic performances of this kind of catalysts for the selective oxidation of low alkanes.
2013, 30(5): 523-527
doi: 10.3724/SP.J.1095.2013.20282
Abstract:
Three aromatic diamines containing fluorine were synthesized. In addition,three kinds of diphenyl ether trifluoride polyimide films were prepared by polycondensation,and the polyimide film was prepared by using 4,4'-diaminodiphenylether(BADE) with 3,3',4,4'-biphenyltetracarboxylic dianhydride(BPDA) by the same method.The water vapor permeability,water absorption and thermal properties of these four kinds of polyimide film were studied. The results show that water vapor permeability of polymer PI-1(2,2'-BTF-4,4'-BADE+BPDA,BTF:bis(trifluoromethyl)) is 7.70 g/(h·m2),the water absorption is 0.67%,the glass transition temperature is 259.74℃,and the temperature of mass loss of 5% is 521.40℃,the polymer has good water vapor permeability and low water absorption.
Three aromatic diamines containing fluorine were synthesized. In addition,three kinds of diphenyl ether trifluoride polyimide films were prepared by polycondensation,and the polyimide film was prepared by using 4,4'-diaminodiphenylether(BADE) with 3,3',4,4'-biphenyltetracarboxylic dianhydride(BPDA) by the same method.The water vapor permeability,water absorption and thermal properties of these four kinds of polyimide film were studied. The results show that water vapor permeability of polymer PI-1(2,2'-BTF-4,4'-BADE+BPDA,BTF:bis(trifluoromethyl)) is 7.70 g/(h·m2),the water absorption is 0.67%,the glass transition temperature is 259.74℃,and the temperature of mass loss of 5% is 521.40℃,the polymer has good water vapor permeability and low water absorption.
2013, 30(5): 528-533
doi: 10.3724/SP.J.1095.2013.20347
Abstract:
A new type of polyether copolymer-allyloxy polyether carboxylic acid sodium/acrylic acid(APEX/AA) was synthesized using water as solvent and APEX and AA as monomers. Polymer APEX/AA was characterized by infrared spectroscopy,thermogravimetric analysis and gel permeation chromatography. The dosage of APEX/AA,calcium ion concentration in solution,pH and temperature were evaluated on phosphate calcium scale inhibition efficiency through static method. The results show that the polymer APEX/AA has good thermal stability at temperature above 350℃,and its relative molecular mass distribution is controllable(PDI=1.41~1.88). The phosphate calcium scale inhibition efficiency of APEX/AA reached 100% when a concentration of 6 mg/L aqueous system was used. The results show that APEX/AA is suitable for water with a high calcium ion concentration (200~2000 mg/L),high pH(7.5~11.0) and high temperature(75~95℃). The scale inhibition effect of APEX/AA is superior to that of commercial calcium phosphate scale inhibitors such as 1-hydroxyethylidine-1,1-diphosphonic acid(HEDP),hydroxypropyl acrylate/acrylic acid(T-225) and 2-phosphonobutane-1,2,4-tricarboxylic acid(PBTCA),indicating that APEX/AA is an excellent non-phosphorus phosphate calcium scale inhibitor in the industrial circulating water systems.
A new type of polyether copolymer-allyloxy polyether carboxylic acid sodium/acrylic acid(APEX/AA) was synthesized using water as solvent and APEX and AA as monomers. Polymer APEX/AA was characterized by infrared spectroscopy,thermogravimetric analysis and gel permeation chromatography. The dosage of APEX/AA,calcium ion concentration in solution,pH and temperature were evaluated on phosphate calcium scale inhibition efficiency through static method. The results show that the polymer APEX/AA has good thermal stability at temperature above 350℃,and its relative molecular mass distribution is controllable(PDI=1.41~1.88). The phosphate calcium scale inhibition efficiency of APEX/AA reached 100% when a concentration of 6 mg/L aqueous system was used. The results show that APEX/AA is suitable for water with a high calcium ion concentration (200~2000 mg/L),high pH(7.5~11.0) and high temperature(75~95℃). The scale inhibition effect of APEX/AA is superior to that of commercial calcium phosphate scale inhibitors such as 1-hydroxyethylidine-1,1-diphosphonic acid(HEDP),hydroxypropyl acrylate/acrylic acid(T-225) and 2-phosphonobutane-1,2,4-tricarboxylic acid(PBTCA),indicating that APEX/AA is an excellent non-phosphorus phosphate calcium scale inhibitor in the industrial circulating water systems.
2013, 30(5): 534-541
doi: 10.3724/SP.J.1095.2013.20305
Abstract:
A series of acrylic ester resins with different pore structures was synthesized by varying the type and the amount of monomers,crosslinkers and pore-forming agents.Among of them,resin 1# polymerized by trimethylolpropanetrimethacrylate(TRIM) with suitable pore distribution structure,resin 5# by TRIM and triallylisocyanurate(TAIC) with amide groups,and the commercial macroporous acrylic resin XAD-7 were used to study the adsorption behavior of tylosin and the mechanism on acrylic ester resins. The resin 1# exhibited a better adsorption property toward adsorbate. Similar patterns of pH-dependent adsorption showed that the adsorption amounts of tylosin increased with the increase pH values. The amounts of tylosin adsorbed increased in the presence of NaCl while decreased with CuCl2 because of the dominant contribution of hydrophobic effect and size-exclusion effect. The adsorption kinetics of the three adsorbents followed the pseudo-second order model,while the adsorption isotherm data fit well to the Langmuir models,indicating the coverage of the surface by a mono-molecular layer. The apparent temperature influence on the adsorption process demonstrated that the "solvent replacement" was the dominant mechanism.
A series of acrylic ester resins with different pore structures was synthesized by varying the type and the amount of monomers,crosslinkers and pore-forming agents.Among of them,resin 1# polymerized by trimethylolpropanetrimethacrylate(TRIM) with suitable pore distribution structure,resin 5# by TRIM and triallylisocyanurate(TAIC) with amide groups,and the commercial macroporous acrylic resin XAD-7 were used to study the adsorption behavior of tylosin and the mechanism on acrylic ester resins. The resin 1# exhibited a better adsorption property toward adsorbate. Similar patterns of pH-dependent adsorption showed that the adsorption amounts of tylosin increased with the increase pH values. The amounts of tylosin adsorbed increased in the presence of NaCl while decreased with CuCl2 because of the dominant contribution of hydrophobic effect and size-exclusion effect. The adsorption kinetics of the three adsorbents followed the pseudo-second order model,while the adsorption isotherm data fit well to the Langmuir models,indicating the coverage of the surface by a mono-molecular layer. The apparent temperature influence on the adsorption process demonstrated that the "solvent replacement" was the dominant mechanism.
2013, 30(5): 542-548
doi: 10.3724/SP.J.1095.2013.20300
Abstract:
A zoledronic acid derivative,1-hydroxy-5-(2-ethyl-1H-imidazol-1-yl)pentane-1,1-diphosphonic acid(EIPeDP),was synthesized using 2-ethylimidazole,5-bromo valeric acid ethyl ester and PCl3 as the starting material and further labeled with 99mTc. The influence of the amount of EIPeDP and the pH value of the reaction system on the labeling yield of 99mTc-EIPeDP has been studied. Satisfactory radiolabelling yield(RLY) and the radiochemical purity(RCP) (over 97%) were obtained when the pH was 5~6 and the amount of EIPeDP,SnCl2·2H2O and Na 99mTcO4 were 5 mg,100 μg and 92.5 MBq,respectively. The radiolabeled complex was very stable in vitro. In vivo SPECT bone imaging of rabbit showed that a clearer image can be obtained from 99mTc-EIPeDP at 1 h post injection,which is superior to 99mTc-ZL and 99mTc-MDP. These results showed that 99mTc-EIPeDP is a potential bone imaging agent with advantages of simple preparation,good stability and superior bone imaging characteristics.
A zoledronic acid derivative,1-hydroxy-5-(2-ethyl-1H-imidazol-1-yl)pentane-1,1-diphosphonic acid(EIPeDP),was synthesized using 2-ethylimidazole,5-bromo valeric acid ethyl ester and PCl3 as the starting material and further labeled with 99mTc. The influence of the amount of EIPeDP and the pH value of the reaction system on the labeling yield of 99mTc-EIPeDP has been studied. Satisfactory radiolabelling yield(RLY) and the radiochemical purity(RCP) (over 97%) were obtained when the pH was 5~6 and the amount of EIPeDP,SnCl2·2H2O and Na 99mTcO4 were 5 mg,100 μg and 92.5 MBq,respectively. The radiolabeled complex was very stable in vitro. In vivo SPECT bone imaging of rabbit showed that a clearer image can be obtained from 99mTc-EIPeDP at 1 h post injection,which is superior to 99mTc-ZL and 99mTc-MDP. These results showed that 99mTc-EIPeDP is a potential bone imaging agent with advantages of simple preparation,good stability and superior bone imaging characteristics.
2013, 30(5): 549-554
doi: 10.3724/SP.J.1095.2013.20299
Abstract:
A novel label-free electrochemical aptamer biosensor was developed by using cysteine blocker as the electrochemical redox probe,and was used for the determination of thrombin. Electrochemical impedance spectroscopy was used to monitor the self-assembly process of aptamer biosensor. The electrochemical behaviors of the biosensor were characterized by the cyclic voltammetry and differential pulse voltammetry. The effects of the incubation time and test pH were investigated on the response of aptamer biosensor. The biosensor shows a good linear range of 10.0~10000 μg/L for thrombin with a detection limit of 2.47 μg/L.
A novel label-free electrochemical aptamer biosensor was developed by using cysteine blocker as the electrochemical redox probe,and was used for the determination of thrombin. Electrochemical impedance spectroscopy was used to monitor the self-assembly process of aptamer biosensor. The electrochemical behaviors of the biosensor were characterized by the cyclic voltammetry and differential pulse voltammetry. The effects of the incubation time and test pH were investigated on the response of aptamer biosensor. The biosensor shows a good linear range of 10.0~10000 μg/L for thrombin with a detection limit of 2.47 μg/L.
2013, 30(5): 555-559
doi: 10.3724/SP.J.1095.2013.20312
Abstract:
The interaction between(E)-2((1,4-dihydroxy-9,10-anthraquinone-2-yl) methylene)-N-(4-methoxyphenyl) hydrazinecarbothioamide (EN) and human serum albumin (HSA) is investigated by fluorescence in Tris-HCl buffer solution (pH=7.4). The results of fluorescence experiments and three-dimensional fluorescence spectra indicate that the presence of EN can change the polarity of the hydrophobic microenvironment and induce minor changes of the secondary structure of HSA. Under the optimum conditions,the linear range of the protein is 1.380~165.6 mg/L and the detection limit is 0.414 mg/L with the synchronous fluorescence method.The contents of the proteins in human serum,saliva and urine samples are detected and the recovery is ranged from 98.4% to 105%. The effects of coexistent material are also investigated. The results of synchronous fluorescence method are in good agreement with the Coomassie Brilliant Blue(CBB) method.
The interaction between(E)-2((1,4-dihydroxy-9,10-anthraquinone-2-yl) methylene)-N-(4-methoxyphenyl) hydrazinecarbothioamide (EN) and human serum albumin (HSA) is investigated by fluorescence in Tris-HCl buffer solution (pH=7.4). The results of fluorescence experiments and three-dimensional fluorescence spectra indicate that the presence of EN can change the polarity of the hydrophobic microenvironment and induce minor changes of the secondary structure of HSA. Under the optimum conditions,the linear range of the protein is 1.380~165.6 mg/L and the detection limit is 0.414 mg/L with the synchronous fluorescence method.The contents of the proteins in human serum,saliva and urine samples are detected and the recovery is ranged from 98.4% to 105%. The effects of coexistent material are also investigated. The results of synchronous fluorescence method are in good agreement with the Coomassie Brilliant Blue(CBB) method.
2013, 30(5): 560-566
doi: 10.3724/SP.J.1095.2013.20302
Abstract:
Un-doped,N-doped,Gd-doped and Gd-N-codoped TiO2 nano-photocatalysts were successfully prepared by a sol-hydrothermal method. Their photocatalytic activities were evaluated by photocatalytic decoloration of methyl orange dye in aqueous solution under UV and visible light irradiation,respectively. The physicochemical properties of as-prepared samples were characterized by XRD,XPS,BET,UV-Vis and PL analytic techniques.The effect of Gd-N-codoping on the photoactivity of TiO2 was also discussed. The results showed that Gd-doping could effectively inhibit the recombination of photogenerated electron-hole pairs,then enhancing photo quantum efficiency. Gd-doping could inhibit the growth of crystalline size and improve the surface textural properties.Therefore,the UV photoactivity was obviously enhanced by Gd-doping. N-doping could make the absorption edge red-shift to visible light range by narrowing the electronic band structure,which enhanced the visible light photoactivity. Gd-N-codoping could further increase the absorption to visible light by narrowing the electronic band structure,and further decrease the crystalline size and improve the surface textural properties,therefore increasing the thermal stability. Compared to the single-doped TiO2,Gd-N-TiO2 significantly improved the photoactivity for decoloring methyl orange in aqueous solution under visible light irradiation,which was ascribed to the synergetic effect of Gd-N-codoping.
Un-doped,N-doped,Gd-doped and Gd-N-codoped TiO2 nano-photocatalysts were successfully prepared by a sol-hydrothermal method. Their photocatalytic activities were evaluated by photocatalytic decoloration of methyl orange dye in aqueous solution under UV and visible light irradiation,respectively. The physicochemical properties of as-prepared samples were characterized by XRD,XPS,BET,UV-Vis and PL analytic techniques.The effect of Gd-N-codoping on the photoactivity of TiO2 was also discussed. The results showed that Gd-doping could effectively inhibit the recombination of photogenerated electron-hole pairs,then enhancing photo quantum efficiency. Gd-doping could inhibit the growth of crystalline size and improve the surface textural properties.Therefore,the UV photoactivity was obviously enhanced by Gd-doping. N-doping could make the absorption edge red-shift to visible light range by narrowing the electronic band structure,which enhanced the visible light photoactivity. Gd-N-codoping could further increase the absorption to visible light by narrowing the electronic band structure,and further decrease the crystalline size and improve the surface textural properties,therefore increasing the thermal stability. Compared to the single-doped TiO2,Gd-N-TiO2 significantly improved the photoactivity for decoloring methyl orange in aqueous solution under visible light irradiation,which was ascribed to the synergetic effect of Gd-N-codoping.
2013, 30(5): 567-572
doi: 10.3724/SP.J.1095.2013.20398
Abstract:
The precursor Sn0.75Ti(OCH2CH2OH)(7-x) was synthesized by electrolysis of titanium and tin in glycol solution. Nano-crystalline SnO2/TiO2 powder was prepared by direct hydrolysis from the precursor and then calcined for 2 h at 400℃. The metal alkoxide was characterized by FT-IR and Raman spectra. The mono-dispersed structure and the diameter of nano-SnO2/TiO2 were observed by XRD and SEM.The results showed that SnO2/TiO2 of 100~200 nm was obtained in organic solution. The highly active nano-SnO2/TiO2 electrode was prepared using electro-synthesis and sol-gel method. The cyclic voltammetry was used to study the redox behavior and electro-catalytic activity of the nano-SnO2/TiO2 electrode in HCl/m-NO2C6H4OH solution. The current density of the electrode increased obviously and reached to 143 × 10-3 A/cm2. The electrode potential difference of the redox peaks decreased obviously. The COD removal rate of m-nitrophenol reached to 86.1% and the SnO2/TiO2 electrode had high electro-catalytic activities.
The precursor Sn0.75Ti(OCH2CH2OH)(7-x) was synthesized by electrolysis of titanium and tin in glycol solution. Nano-crystalline SnO2/TiO2 powder was prepared by direct hydrolysis from the precursor and then calcined for 2 h at 400℃. The metal alkoxide was characterized by FT-IR and Raman spectra. The mono-dispersed structure and the diameter of nano-SnO2/TiO2 were observed by XRD and SEM.The results showed that SnO2/TiO2 of 100~200 nm was obtained in organic solution. The highly active nano-SnO2/TiO2 electrode was prepared using electro-synthesis and sol-gel method. The cyclic voltammetry was used to study the redox behavior and electro-catalytic activity of the nano-SnO2/TiO2 electrode in HCl/m-NO2C6H4OH solution. The current density of the electrode increased obviously and reached to 143 × 10-3 A/cm2. The electrode potential difference of the redox peaks decreased obviously. The COD removal rate of m-nitrophenol reached to 86.1% and the SnO2/TiO2 electrode had high electro-catalytic activities.
2013, 30(5): 573-577
doi: 10.3724/SP.J.1095.2013.20285
Abstract:
Electrochemical behaviors of catechol(CAT),resorcinol(RE) and hydroquinone(HQ) in 0.5 mol/L sulfuric acid aqueous solution were studied using cyclic voltammetry.Voltammetric behaviors of CAT,Re and HQ in the coexisting system were studied using cyclic voltammetry and differential pulse voltammetry method. The results show that obvious separation effect is achieved under conditions of pH=0 (sulfuric acid),scan rate of 10 mV/s,and scan potential of 0~1.2 V(vs.Ag/Cl). Under optimal conditions,the detection limit was 3.9 × 10-6,3.9 × 10-6 and 7.8 × 10-6 mol/L for CAT,RE,and HQ,respectively,in mixture of three substances using differential pulse voltammetry. The method is applied in the analysis of synthesized samples,and the accuracy and precision well satisfy the requirements of the analysis.
Electrochemical behaviors of catechol(CAT),resorcinol(RE) and hydroquinone(HQ) in 0.5 mol/L sulfuric acid aqueous solution were studied using cyclic voltammetry.Voltammetric behaviors of CAT,Re and HQ in the coexisting system were studied using cyclic voltammetry and differential pulse voltammetry method. The results show that obvious separation effect is achieved under conditions of pH=0 (sulfuric acid),scan rate of 10 mV/s,and scan potential of 0~1.2 V(vs.Ag/Cl). Under optimal conditions,the detection limit was 3.9 × 10-6,3.9 × 10-6 and 7.8 × 10-6 mol/L for CAT,RE,and HQ,respectively,in mixture of three substances using differential pulse voltammetry. The method is applied in the analysis of synthesized samples,and the accuracy and precision well satisfy the requirements of the analysis.
2013, 30(5): 578-583
doi: 10.3724/SP.J.1095.2013.20293
Abstract:
A novel electrochemical sensor poly-2,2-bipyridyl(Pbpy)/1-phenyl-3-methyl-4-(2-furoyl)-5-pyrazolone(HPMαFP)/glassy carbon(GC) composite film modified electrode was prepared for the determination of xanthine(XN). Cyclic voltammetry and differential pulse voltammetry were used to characterize the electrochemical behavior and to study the reaction mechanism of XN on the electrode. Compared with the bare GCE and Pbpy/GCE,the Pbpy/HPMαFP/GCE showed an excellent electrocatalytical effect on the oxidation of XN with a significant increase of the peak current. The results indicated that a synergistic effect existed between Pbpy and HPMαFP on the electrode.Linear calibration curve was obtained within the concentration range 6 × 10-7 to 1 × 10-5 mol/L and 1 × 10-5 to 1 × 10-4 mol/L,respectively,in phosphate buffer solution(PBS) of pH=8.0 with a scan rate 100 mV/s. The detection limit was 1 × 10-8 mol/L. This electrode could be used for the direct detection of XN in the presence of uric acid(UA) and ascorbic acid(AA),and also the XN in urine samples with satisfactory results.
A novel electrochemical sensor poly-2,2-bipyridyl(Pbpy)/1-phenyl-3-methyl-4-(2-furoyl)-5-pyrazolone(HPMαFP)/glassy carbon(GC) composite film modified electrode was prepared for the determination of xanthine(XN). Cyclic voltammetry and differential pulse voltammetry were used to characterize the electrochemical behavior and to study the reaction mechanism of XN on the electrode. Compared with the bare GCE and Pbpy/GCE,the Pbpy/HPMαFP/GCE showed an excellent electrocatalytical effect on the oxidation of XN with a significant increase of the peak current. The results indicated that a synergistic effect existed between Pbpy and HPMαFP on the electrode.Linear calibration curve was obtained within the concentration range 6 × 10-7 to 1 × 10-5 mol/L and 1 × 10-5 to 1 × 10-4 mol/L,respectively,in phosphate buffer solution(PBS) of pH=8.0 with a scan rate 100 mV/s. The detection limit was 1 × 10-8 mol/L. This electrode could be used for the direct detection of XN in the presence of uric acid(UA) and ascorbic acid(AA),and also the XN in urine samples with satisfactory results.
2013, 30(5): 584-589
doi: 10.3724/SP.J.1095.2013.20311
Abstract:
The influence of the crystal structure of TiO2 on the electrocatalytic performance of Ir catalyst supported on TiO2(Ir/TiO2) for the ammonia oxidation was is investigated. It shows that the electrocatalytic performance of the Ir/TiO2 with rutile structure(Ir/TiO2-R) is much better than that of the Ir/TiO2 with the anatase structure(Ir/TiO2-A). The physicochemical and electrochemical characterizations reveal that the enhancement in the electrocatalytic performance of the Ir/TiO2-R catalyst may be attributed to the uniform dispersion of Ir nanoparticles and a large surface area of TiO2-R.
The influence of the crystal structure of TiO2 on the electrocatalytic performance of Ir catalyst supported on TiO2(Ir/TiO2) for the ammonia oxidation was is investigated. It shows that the electrocatalytic performance of the Ir/TiO2 with rutile structure(Ir/TiO2-R) is much better than that of the Ir/TiO2 with the anatase structure(Ir/TiO2-A). The physicochemical and electrochemical characterizations reveal that the enhancement in the electrocatalytic performance of the Ir/TiO2-R catalyst may be attributed to the uniform dispersion of Ir nanoparticles and a large surface area of TiO2-R.
2013, 30(5): 590-595
doi: 10.3724/SP.J.1095.2013.20321
Abstract:
Modified by silane coupling agents,polyacrylonitrile(PAN) fiber was deposited with silver by electroless plating with solution containing rare earth lanthanum. The grain size of the silver particle,the crystal structure and surface morphology of the silver-coated fiber film,and the electrochemical property of the plating solution were characterized by nano particle sizer(Nano-ZS),X-ray diffraction(XRD),scanning electron microscopy(SEM),cathodic polarization curves,and cyclic voltammetry(CV),respectively. The effects of lanthanum nitrate on the speed of plating,quality of the silver film and electrochemical property of the plating solution were analyzed. The results showed that the speed of metallic ion depositing and the quality of the silver-coated fiber film were improved with the addition of appropriate amount of lanthanum nitrate in the plating solution. With the concentration of lanthanum nitrate increase from 0 g/L to 0.01 g/L in the plating solution,the polarization degree was increased,and the redox current peak and the speed of metallic ion deposition were also increased.
Modified by silane coupling agents,polyacrylonitrile(PAN) fiber was deposited with silver by electroless plating with solution containing rare earth lanthanum. The grain size of the silver particle,the crystal structure and surface morphology of the silver-coated fiber film,and the electrochemical property of the plating solution were characterized by nano particle sizer(Nano-ZS),X-ray diffraction(XRD),scanning electron microscopy(SEM),cathodic polarization curves,and cyclic voltammetry(CV),respectively. The effects of lanthanum nitrate on the speed of plating,quality of the silver film and electrochemical property of the plating solution were analyzed. The results showed that the speed of metallic ion depositing and the quality of the silver-coated fiber film were improved with the addition of appropriate amount of lanthanum nitrate in the plating solution. With the concentration of lanthanum nitrate increase from 0 g/L to 0.01 g/L in the plating solution,the polarization degree was increased,and the redox current peak and the speed of metallic ion deposition were also increased.
2013, 30(5): 596-601
doi: 10.3724/SP.J.1095.2013.20310
Abstract:
Dithiocarbamate modified glucose(DTCG),an environment-friendly corrosion inhibitor,has been synthesized. Corrosion inhibition effect of DTCG self-assembled monolayers(SAMs) formed on copper surface was measured in 3% NaCl solution using electrochemical impedance and polarization curve methods. The results indicate that DTCG SAM has good corrosion inhibition effect for copper and its inhibition efficiency can be close to 97% after self-assembling in 120 mg/L DTCG for 4 h. Quantum chemical calculations also show that DTCG possesses excellent anticorrosion performance.
Dithiocarbamate modified glucose(DTCG),an environment-friendly corrosion inhibitor,has been synthesized. Corrosion inhibition effect of DTCG self-assembled monolayers(SAMs) formed on copper surface was measured in 3% NaCl solution using electrochemical impedance and polarization curve methods. The results indicate that DTCG SAM has good corrosion inhibition effect for copper and its inhibition efficiency can be close to 97% after self-assembling in 120 mg/L DTCG for 4 h. Quantum chemical calculations also show that DTCG possesses excellent anticorrosion performance.
2013, 30(5): 602-607
doi: 10.3724/SP.J.1095.2013.20295
Abstract:
Carbon coated monoclinic Li3V2(PO4)3 cathode material was prepared by the carbothermal reduction method. X-ray diffraction result showed that the material is phase pure monoclinic Li3V2(PO4)3 with space group of P21/n. HRTEM revealed a surfacial carbon layer with thickness about 5~10 nm. The material showed a reversible discharge capacity of 120 mA·h/g(C/4 rate),115 mA·h/g(1C rate) and 110 mA·h/g(2C rate) in the voltage window of 3.0~4.3 V,which maintained excellent cycle stability after 300 cycles. The material suffered from a capacity loss in the initial charge-discharge cycles. The irreversible capacity loss was mainly due to the progressive formation of a solid electrolyte interface(SEI) that could be observed under HRTEM. FTIR analysis showed that the chemical species of the SEI film mainly contained some organic compounds such as ROCO2Li,RCO2Li,and aliphatic,as well as some inorganic compounds such as Li2CO3,LixPFy or LixPOyFz.
Carbon coated monoclinic Li3V2(PO4)3 cathode material was prepared by the carbothermal reduction method. X-ray diffraction result showed that the material is phase pure monoclinic Li3V2(PO4)3 with space group of P21/n. HRTEM revealed a surfacial carbon layer with thickness about 5~10 nm. The material showed a reversible discharge capacity of 120 mA·h/g(C/4 rate),115 mA·h/g(1C rate) and 110 mA·h/g(2C rate) in the voltage window of 3.0~4.3 V,which maintained excellent cycle stability after 300 cycles. The material suffered from a capacity loss in the initial charge-discharge cycles. The irreversible capacity loss was mainly due to the progressive formation of a solid electrolyte interface(SEI) that could be observed under HRTEM. FTIR analysis showed that the chemical species of the SEI film mainly contained some organic compounds such as ROCO2Li,RCO2Li,and aliphatic,as well as some inorganic compounds such as Li2CO3,LixPFy or LixPOyFz.
2013, 30(5): 608-610
doi: 10.3724/SP.J.1095.2013.20351
Abstract:
The O-desmethylvenlafaxines were prepared from venlafaxine reacted with new demethylation reagents cysteine sodium and sodium penicillamine,respectively.The corresponding yields are 86% and 82%,respectively.Since the synthesis could be fulfilled in a one-pot approach by mixing cysteine sodium salt,sodium penicillamine preparation and venlafaxine demethylation together,the reaction was fairly simplified.The optimal reaction conditions are:N-methyl pyrrolidone as the solvent,reaction temperature of 175℃ and the pH value of 9.5 for product to crystallize.
The O-desmethylvenlafaxines were prepared from venlafaxine reacted with new demethylation reagents cysteine sodium and sodium penicillamine,respectively.The corresponding yields are 86% and 82%,respectively.Since the synthesis could be fulfilled in a one-pot approach by mixing cysteine sodium salt,sodium penicillamine preparation and venlafaxine demethylation together,the reaction was fairly simplified.The optimal reaction conditions are:N-methyl pyrrolidone as the solvent,reaction temperature of 175℃ and the pH value of 9.5 for product to crystallize.
