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2013 Volume 30 Issue 12
2013, 30(12): 1375-1385
doi: 10.3724/SP.J.1095.2013.20617
Abstract:
Micro Reactor Technique (MRT),which shows great advantages in heat transfer,mass transfer and mixing,can enhance the mixing process and control the reaction temperature precisely. In addition,it can dramatically shorten the screening period and scale-up process. This review emphasized the application of the microreactor technology in liquid phase reaction,gas phase reaction and gas-liquid phase reaction in detail. Meanwhile,photochemistry and electrochemistry were introduced briefly. We also presented the existing problems in such technique.
Micro Reactor Technique (MRT),which shows great advantages in heat transfer,mass transfer and mixing,can enhance the mixing process and control the reaction temperature precisely. In addition,it can dramatically shorten the screening period and scale-up process. This review emphasized the application of the microreactor technology in liquid phase reaction,gas phase reaction and gas-liquid phase reaction in detail. Meanwhile,photochemistry and electrochemistry were introduced briefly. We also presented the existing problems in such technique.
2013, 30(12): 1386-1392
doi: 10.3724/SP.J.1095.2013.30375
Abstract:
Photodynamic therapy (PDT) has emerged as a selective and non-invasive modality for the treatment of malignant tumors. Photosensitizers are the key component of PDT,which generates cytotoxic reactive oxygen species (ROS) in the presence of oxygen and light with appropriate wavelength. In clinical practice,three families of photosensitizer (PS) are used,including porphyrins,chlorophylls and bacteriochloyin/phthalocyanines. This review focused on the oncologic photosensilizers that were in clinical uses or trials and from the points of view of successful photosensitizers explored the future trends of PS and PDT.
Photodynamic therapy (PDT) has emerged as a selective and non-invasive modality for the treatment of malignant tumors. Photosensitizers are the key component of PDT,which generates cytotoxic reactive oxygen species (ROS) in the presence of oxygen and light with appropriate wavelength. In clinical practice,three families of photosensitizer (PS) are used,including porphyrins,chlorophylls and bacteriochloyin/phthalocyanines. This review focused on the oncologic photosensilizers that were in clinical uses or trials and from the points of view of successful photosensitizers explored the future trends of PS and PDT.
2013, 30(12): 1393-1398
doi: 10.3724/SP.J.1095.2013.30062
Abstract:
Ferrocene (Fc),a metallorganic sandwich-structured compound,can improve the electron transfer efficiency of sensor electrode effectively,due to its excellent redox property. In this review,we summarized the recent development of ferrocene and its derivatives in enzyme biosensors,immunosensors and chemical ion sensors,and then prospected a further development outlook.
Ferrocene (Fc),a metallorganic sandwich-structured compound,can improve the electron transfer efficiency of sensor electrode effectively,due to its excellent redox property. In this review,we summarized the recent development of ferrocene and its derivatives in enzyme biosensors,immunosensors and chemical ion sensors,and then prospected a further development outlook.
2013, 30(12): 1399-1403
doi: 10.3724/SP.J.1095.2013.30169
Abstract:
The viscosity of prepared polymer solution was increased by the precipitation of Fe2+ with NaOH from the sewage of the T28 district,Shengtuo oilfiled. The mechanism of reduced viscosity introduced by Fe2+ was studied by IR,fluorescence spectroscopy and SEM. The viscosity of polymer solution was elevated from 19.17 mPa·s to 92.50 mPa·s when treating the sewage containing 5.9 mg/L of Fe2+ with NaOH at pH 9. Fe2+ was found to split the polymer chain,weaken the association,destroy the spatial network structure of macromolecules,and lead to decreasing viscosity of the polymer solution. The precipitation of ferrous hydroxides from the polymer solution promotes the formation of compact spatial network structure of the polymer chains.
The viscosity of prepared polymer solution was increased by the precipitation of Fe2+ with NaOH from the sewage of the T28 district,Shengtuo oilfiled. The mechanism of reduced viscosity introduced by Fe2+ was studied by IR,fluorescence spectroscopy and SEM. The viscosity of polymer solution was elevated from 19.17 mPa·s to 92.50 mPa·s when treating the sewage containing 5.9 mg/L of Fe2+ with NaOH at pH 9. Fe2+ was found to split the polymer chain,weaken the association,destroy the spatial network structure of macromolecules,and lead to decreasing viscosity of the polymer solution. The precipitation of ferrous hydroxides from the polymer solution promotes the formation of compact spatial network structure of the polymer chains.
2013, 30(12): 1404-1410
doi: 10.3724/SP.J.1095.2013.30040
Abstract:
The polyurethane-styrene-acrylate (PUSA) hybrid latexes were prepared by emulsion polymerization of a mixture of polyurethane (PU) prepolymer,butyl acrylate and styrene monomers. The obtained PU prepolymer was end capped by vinyl groups based on 1H NMR results. The particles' diameter was about 150 nm from the TEM. The thermostability of the hybrid latexes was improved when the content of PU was decreased,and the single Tg was located between those of PU and polystyrene-acrylate (PSA). When the resultant hybrid latexes were applied in paper-plastic and plastic-plastic laminating adhesives,the peel strengths were 14.1 N/2.5 cm and 12.2 N/2.5 cm, respectively.
The polyurethane-styrene-acrylate (PUSA) hybrid latexes were prepared by emulsion polymerization of a mixture of polyurethane (PU) prepolymer,butyl acrylate and styrene monomers. The obtained PU prepolymer was end capped by vinyl groups based on 1H NMR results. The particles' diameter was about 150 nm from the TEM. The thermostability of the hybrid latexes was improved when the content of PU was decreased,and the single Tg was located between those of PU and polystyrene-acrylate (PSA). When the resultant hybrid latexes were applied in paper-plastic and plastic-plastic laminating adhesives,the peel strengths were 14.1 N/2.5 cm and 12.2 N/2.5 cm, respectively.
2013, 30(12): 1411-1416
doi: 10.3724/SP.J.1095.2013.30137
Abstract:
The surface of calcium carbonate (CaCO3) was firstly pretreated with maleic anhydride (MAH) to introduce active double bond groups,then grafted chemically by polypropylene wax (PPW) via in-situ solid phase grafting to increase its compatibility with polypropylene. Three kinds of modified CaCO3 with different chemical grafting ratio of PPW were prepared by changing experimental conditions,and their PP-based composites were produced. The effects of interfacial interaction between CaCO3-MAH-PPW and PP matrix on the strength of PP-based composite filled with modified CaCO3 were studied. The results show that the dispersibility of CaCO3-MAH-PPW in PP is improved,suggesting an improved compatibility between them. With the improvement of grafting ratio of PPW on the surface of CaCO3,the interfacial interaction between CaCO3 and PP increases gradually. When the grafting ratio of PPW is 4.48 mg PPW/g CaCO3,the interfacial interaction between CaCO3 and PP is strongest and the decrease of tensile strength of composites is the least,the young's modulus increases most at the same time. When m(PP):m(CaCO3)=100:50,the young's modulus reaches 0.86 GPa,which is the 1.63 times of PP's. When the grafting ratio of PPW is 2.49 mg PPW/g CaCO3,the interfacial interaction between CaCO3 and PP is suitable and the notch impact strength of composites improves the most. And when m(PP):m(CaCO3)=100:10,its notch impact strength is 3.91 kJ/m2,which is the 1.35 times of PP's
The surface of calcium carbonate (CaCO3) was firstly pretreated with maleic anhydride (MAH) to introduce active double bond groups,then grafted chemically by polypropylene wax (PPW) via in-situ solid phase grafting to increase its compatibility with polypropylene. Three kinds of modified CaCO3 with different chemical grafting ratio of PPW were prepared by changing experimental conditions,and their PP-based composites were produced. The effects of interfacial interaction between CaCO3-MAH-PPW and PP matrix on the strength of PP-based composite filled with modified CaCO3 were studied. The results show that the dispersibility of CaCO3-MAH-PPW in PP is improved,suggesting an improved compatibility between them. With the improvement of grafting ratio of PPW on the surface of CaCO3,the interfacial interaction between CaCO3 and PP increases gradually. When the grafting ratio of PPW is 4.48 mg PPW/g CaCO3,the interfacial interaction between CaCO3 and PP is strongest and the decrease of tensile strength of composites is the least,the young's modulus increases most at the same time. When m(PP):m(CaCO3)=100:50,the young's modulus reaches 0.86 GPa,which is the 1.63 times of PP's. When the grafting ratio of PPW is 2.49 mg PPW/g CaCO3,the interfacial interaction between CaCO3 and PP is suitable and the notch impact strength of composites improves the most. And when m(PP):m(CaCO3)=100:10,its notch impact strength is 3.91 kJ/m2,which is the 1.35 times of PP's
2013, 30(12): 1417-1422
doi: 10.3724/SP.J.1095.2013.30259
Abstract:
Thermal conductivity,thermal expansion coefficient and dielectric constant of liquid epoxy resin filled with Al2O3 flakes or particles in single,binary or multiple hybrid particle sizes were investigated. The relationship between enhanced thermal performance and dense packing was studied by the fractal theory. The results show that the modified epoxy resin filled with single Al2O3 flakes or particles (~48 μm) exhibit superior comprehensive performance. The best thermal conductivity,dielectric constant and thermal expansion coefficient are obtained when the epoxy resin filled with the binary hybrid particles,where the volume fraction of the smaller particles in the mixed particles is 20%~40%. The particles in various sizes in a close packing pattern form the relatively minimum gap and the highest relative thermal conductivity is obtained when the fractal dimension D value of hybrid particle size is in a suitable range.
Thermal conductivity,thermal expansion coefficient and dielectric constant of liquid epoxy resin filled with Al2O3 flakes or particles in single,binary or multiple hybrid particle sizes were investigated. The relationship between enhanced thermal performance and dense packing was studied by the fractal theory. The results show that the modified epoxy resin filled with single Al2O3 flakes or particles (~48 μm) exhibit superior comprehensive performance. The best thermal conductivity,dielectric constant and thermal expansion coefficient are obtained when the epoxy resin filled with the binary hybrid particles,where the volume fraction of the smaller particles in the mixed particles is 20%~40%. The particles in various sizes in a close packing pattern form the relatively minimum gap and the highest relative thermal conductivity is obtained when the fractal dimension D value of hybrid particle size is in a suitable range.
2013, 30(12): 1423-1428
doi: 10.3724/SP.J.1095.2013.30017
Abstract:
Twenty four lateral difluorine substituted biphenyl liquid crystals were synthesized from 4-alkylcyclohexanecarboxylic acid and 4-bromo-2,3-difluoro-phenol by Grignard reaction,Huang Ming-long reduction,iodination,acid reaction,Suzuki cross-coupling reaction,Williamson reaction and esterification. The total yield is 4.2%~8.7%. The molecular structures of the compounds were confirmed with nuclear magnetic(1H NMR,13C NMR),infrared spectrometry,and mass spectrometry. Differential scanning calorimetry and polarising optical microscopy were used to measure the liquid crystal display properties of the target compounds. The results showed that the length of alkyl chain not only affects the melting and clearing point of compounds,but also the liquid crystal phase transition. Terminal olefins can reduce the melting point (about 3.7℃),improve the clearing point (about by 24.8℃),and broaden the nematic phase interval (from 54.1℃ to 82.6℃). Ester group can increase the clearing points and eliminate smectic phase. This series of compounds has potentials for use in the vertical alignment (VA) and in-plane switching (IPS) display modes.
Twenty four lateral difluorine substituted biphenyl liquid crystals were synthesized from 4-alkylcyclohexanecarboxylic acid and 4-bromo-2,3-difluoro-phenol by Grignard reaction,Huang Ming-long reduction,iodination,acid reaction,Suzuki cross-coupling reaction,Williamson reaction and esterification. The total yield is 4.2%~8.7%. The molecular structures of the compounds were confirmed with nuclear magnetic(1H NMR,13C NMR),infrared spectrometry,and mass spectrometry. Differential scanning calorimetry and polarising optical microscopy were used to measure the liquid crystal display properties of the target compounds. The results showed that the length of alkyl chain not only affects the melting and clearing point of compounds,but also the liquid crystal phase transition. Terminal olefins can reduce the melting point (about 3.7℃),improve the clearing point (about by 24.8℃),and broaden the nematic phase interval (from 54.1℃ to 82.6℃). Ester group can increase the clearing points and eliminate smectic phase. This series of compounds has potentials for use in the vertical alignment (VA) and in-plane switching (IPS) display modes.
2013, 30(12): 1429-1433
doi: 10.3724/SP.J.1095.2013.20578
Abstract:
Eleven new arylureido-acylthiourea derivatives have been synthesized by solid phase grinding under solvent-free conditions at room temperature. Their structures were confirmed by 1H NMR,IR and elementary analysis. The results of biological activity tests show that some target compounds have evident activity on plant growth when the concentration is 10 mg/L. Among these,N-phenylureido-N'-cinnamic acylthiourea and N-p-methylphenylureido-N'-cinnamic acylthiourea have good auxins activity,the effects are 54.13% and 46.79%,respectively, while N-p-methylphenylureido-N'-cinnamic acylthiourea and N-p-methylphenylureido-N'-phenoxyacetyl thiourea have excellent activity of cytokinin,the effects are 55.11% and 51.14%,respectively.
Eleven new arylureido-acylthiourea derivatives have been synthesized by solid phase grinding under solvent-free conditions at room temperature. Their structures were confirmed by 1H NMR,IR and elementary analysis. The results of biological activity tests show that some target compounds have evident activity on plant growth when the concentration is 10 mg/L. Among these,N-phenylureido-N'-cinnamic acylthiourea and N-p-methylphenylureido-N'-cinnamic acylthiourea have good auxins activity,the effects are 54.13% and 46.79%,respectively, while N-p-methylphenylureido-N'-cinnamic acylthiourea and N-p-methylphenylureido-N'-phenoxyacetyl thiourea have excellent activity of cytokinin,the effects are 55.11% and 51.14%,respectively.
2013, 30(12): 1434-1437
doi: 10.3724/SP.J.1095.2013.30015
Abstract:
In aqueous solution,the synthesis of aryl sulfides derivatives from the reaction between thiourea and aryl iodides using copper as catalyst under microwave irradiation was investigated. A variety of aryl sulfides can be synthesized with yields up to 90%.
In aqueous solution,the synthesis of aryl sulfides derivatives from the reaction between thiourea and aryl iodides using copper as catalyst under microwave irradiation was investigated. A variety of aryl sulfides can be synthesized with yields up to 90%.
2013, 30(12): 1438-1442
doi: 10.3724/SP.J.1095.2013.20590
Abstract:
With the assistance of microwave,a mixture of 2-(4-hydroxy-phenyl)-1,1,1,3,3,3-hexafluoropropan-2-ol isomers were obtained via the condensation between hexafluoroacetone trihydrate (HFA·3H2O) and phenol using potassium hydroxide as catalyst. The product was characterized by 1H NMR,IR and MS spectra. The results show that the microwave-assisted process can reduce the reaction time remarkably compared with conventional processes. Under optimal conditions with the microwave power 300 W at n(phenol):n (HFA·3H2O):n (KOH)=3.0:1.0:0.3,the reaction time are shortened from 35 h in conventional heating to 6 h,the total yield is increased from 87% to 90% with 94% selectivity.
With the assistance of microwave,a mixture of 2-(4-hydroxy-phenyl)-1,1,1,3,3,3-hexafluoropropan-2-ol isomers were obtained via the condensation between hexafluoroacetone trihydrate (HFA·3H2O) and phenol using potassium hydroxide as catalyst. The product was characterized by 1H NMR,IR and MS spectra. The results show that the microwave-assisted process can reduce the reaction time remarkably compared with conventional processes. Under optimal conditions with the microwave power 300 W at n(phenol):n (HFA·3H2O):n (KOH)=3.0:1.0:0.3,the reaction time are shortened from 35 h in conventional heating to 6 h,the total yield is increased from 87% to 90% with 94% selectivity.
2013, 30(12): 1443-1448
doi: 10.3724/SP.J.1095.2013.30073
Abstract:
The liquid phase cyclohexyamine oxidation reaction to prepare cyclohexanone oxime on NaY zeolite catalyst was studied. The effects of oxidant and solvent on the reaction were investigated. The results show that NaY zeolite has the best catalytic performance when acetonitrile and hydrogen peroxide were used as solvent and oxidant respectively. An orthogonal experimental method to study the response of the optimum conditions was carried out. The results show that the effects of the amount of catalyst,the amount of solvent,reaction time,reaction temperature and amount of oxidant on the yield of cyclohexanone oxime decrease in turn. The optimal reaction conditions are as follows:0.3 g catalyst,V (cyclohexylamine):V (solvents):V (oxidants)=1:3:3,65℃ and 2 h.
The liquid phase cyclohexyamine oxidation reaction to prepare cyclohexanone oxime on NaY zeolite catalyst was studied. The effects of oxidant and solvent on the reaction were investigated. The results show that NaY zeolite has the best catalytic performance when acetonitrile and hydrogen peroxide were used as solvent and oxidant respectively. An orthogonal experimental method to study the response of the optimum conditions was carried out. The results show that the effects of the amount of catalyst,the amount of solvent,reaction time,reaction temperature and amount of oxidant on the yield of cyclohexanone oxime decrease in turn. The optimal reaction conditions are as follows:0.3 g catalyst,V (cyclohexylamine):V (solvents):V (oxidants)=1:3:3,65℃ and 2 h.
2013, 30(12): 1449-1452
doi: 10.3724/SP.J.1095.2013.30053
Abstract:
Organic montmorillonites (OMMT) were prepared through ion exchange method using cationic surfactant cetyl trimethyl ammonium bromide (CTAB),anionic surfactant sodium dodecyl sulfate (SDS) and their mixture (CTAB-SDS). The structures of OMMT were characterized by FT-IR and XRD. The results show that CTAB and CTAB-SDS are intercalated into the layers of montmorillonite while SDS is not. The distances between the montmorillonite layers are increased from 1.5601 nm to 2.1946 nm and 1.8935 nm when CTAB and CTAB-SDS are used respectively. The resulted OMMTs with increased layer distances have a good dispersibility in styrene and show improved adsorption toward phenol.
Organic montmorillonites (OMMT) were prepared through ion exchange method using cationic surfactant cetyl trimethyl ammonium bromide (CTAB),anionic surfactant sodium dodecyl sulfate (SDS) and their mixture (CTAB-SDS). The structures of OMMT were characterized by FT-IR and XRD. The results show that CTAB and CTAB-SDS are intercalated into the layers of montmorillonite while SDS is not. The distances between the montmorillonite layers are increased from 1.5601 nm to 2.1946 nm and 1.8935 nm when CTAB and CTAB-SDS are used respectively. The resulted OMMTs with increased layer distances have a good dispersibility in styrene and show improved adsorption toward phenol.
2013, 30(12): 1453-1462
doi: 10.3724/SP.J.1095.2013.20546
Abstract:
Based on mimicking the environment of the active center of vanadium haloperoxidase (V-HPOs),we designed and synthesized two kinds of peroxovanadium complexes:Na[VO(O2)2 (C10H8N2)]·8H2O(1) and K3H[(VO)2 (O2)4(μ2-O)]·H2O(2),which were structurally characterized by X-ray single crystal diffraction,elemental analysis,IR and UV-Vis spectroscopies. Structural analyses reveal that complex 1 crystallized in an triclinic system with space group P-1,a=0.7213 (2) nm,b=1.1269 (4) nm,c=1.3728 (4) nm,α=68.349 (4)°,β=89.178 (4)°,γ=88.050 (4)°,V=1.0365 (6) nm3 and the complex 2 crystallized in an monoclinic system with space group P21/c, a=0.67047 (12) nm,b=0.99503 (18) nm,c=1.5817 (3) nm,α=γ=90°,β=93.739 (2)°,V=1.0530 (3) nm3. Complex 1 has a distorted pentagonal bipyramidal geometry,while complex 2 has a distorted octahedron geometry. In addition,by studying the bromination reaction activity,it shows that the peroxovanadium complexes can be considered as a potential functional model of bromoperoxidase.
Based on mimicking the environment of the active center of vanadium haloperoxidase (V-HPOs),we designed and synthesized two kinds of peroxovanadium complexes:Na[VO(O2)2 (C10H8N2)]·8H2O(1) and K3H[(VO)2 (O2)4(μ2-O)]·H2O(2),which were structurally characterized by X-ray single crystal diffraction,elemental analysis,IR and UV-Vis spectroscopies. Structural analyses reveal that complex 1 crystallized in an triclinic system with space group P-1,a=0.7213 (2) nm,b=1.1269 (4) nm,c=1.3728 (4) nm,α=68.349 (4)°,β=89.178 (4)°,γ=88.050 (4)°,V=1.0365 (6) nm3 and the complex 2 crystallized in an monoclinic system with space group P21/c, a=0.67047 (12) nm,b=0.99503 (18) nm,c=1.5817 (3) nm,α=γ=90°,β=93.739 (2)°,V=1.0530 (3) nm3. Complex 1 has a distorted pentagonal bipyramidal geometry,while complex 2 has a distorted octahedron geometry. In addition,by studying the bromination reaction activity,it shows that the peroxovanadium complexes can be considered as a potential functional model of bromoperoxidase.
2013, 30(12): 1463-1469
doi: 10.3724/SP.J.1095.2013.30039
Abstract:
Thiol-stablized cadmium telluride quantum dots (CdTe QDs) were synthesized in aqueous solution.The effects of precursor concentrations and the types of thiol stabilizer were fully investigated and discussed.The variation in the growth rate of aqueous CdTe QDs was further studied to correlate the photophysical properties of the as-prepared CdTe QDs with the types of the added small molecule and macromolecule electrolytes. The experimental results reveal that the nature of the stabilizers and the additives of electrolyte influence significantly on the growth rate of CdTe QDs and hence the fluorescence intensity when compared with the precursor concentrations. The poly (sodium acrylic acid) has a more pronounced deactivating effect on the growth-up of CdTe QDs when compared with sodium acetate,and the growth rate of CdTe QDs is mainly determined by the relative diffusion rate of the monomer.
Thiol-stablized cadmium telluride quantum dots (CdTe QDs) were synthesized in aqueous solution.The effects of precursor concentrations and the types of thiol stabilizer were fully investigated and discussed.The variation in the growth rate of aqueous CdTe QDs was further studied to correlate the photophysical properties of the as-prepared CdTe QDs with the types of the added small molecule and macromolecule electrolytes. The experimental results reveal that the nature of the stabilizers and the additives of electrolyte influence significantly on the growth rate of CdTe QDs and hence the fluorescence intensity when compared with the precursor concentrations. The poly (sodium acrylic acid) has a more pronounced deactivating effect on the growth-up of CdTe QDs when compared with sodium acetate,and the growth rate of CdTe QDs is mainly determined by the relative diffusion rate of the monomer.
2013, 30(12): 1470-1475
doi: 10.3724/SP.J.1095.2013.30158
Abstract:
The silicotungstic acid (SiWA) modified carbon supported Pd (Pd/C-SiWA) catalyst was prepared with immersing method. The chronoamperometric experiment shows that the current density are 0.013 A/mg and 0.082 A/mg at 3000 s for the Pd/C and Pd/C-SiWA catalysts,which are the 2.5% and 14.1% of that at 10 s,respectively. The result suggests that the electrocatalytic activity and stability of the Pd/C-SiWA catalyst for formic acid oxidation are much better than that of the Pd/C catalyst. This is attributed to that the Pd/C-SiWA catalyst inhibits the decomposition of formic acid leading to the decrease in the poisoning effect of CO. Thus,the electrocatalytic stability of the Pd/C catalyst for formic acid oxidation is improved.
The silicotungstic acid (SiWA) modified carbon supported Pd (Pd/C-SiWA) catalyst was prepared with immersing method. The chronoamperometric experiment shows that the current density are 0.013 A/mg and 0.082 A/mg at 3000 s for the Pd/C and Pd/C-SiWA catalysts,which are the 2.5% and 14.1% of that at 10 s,respectively. The result suggests that the electrocatalytic activity and stability of the Pd/C-SiWA catalyst for formic acid oxidation are much better than that of the Pd/C catalyst. This is attributed to that the Pd/C-SiWA catalyst inhibits the decomposition of formic acid leading to the decrease in the poisoning effect of CO. Thus,the electrocatalytic stability of the Pd/C catalyst for formic acid oxidation is improved.
2013, 30(12): 1476-1480
doi: 10.3724/SP.J.1095.2013.30147
Abstract:
The gold/active carbon (Au/XC) and gold/tungsten carbide XC(Au/WC-XC) catalysts were prepared with the polyvinyl alcohol (PVA) protection method and their electrocatalytic activity for the oxygen reduction and formic acid tolerance ability were investigated. It was found that the electrocatalytic activity of the Au/WC-XC catalyst for the oxygen reduction is much better than that of the Au/XC catalyst. In addition,the Au/WC-XC catalyst has a high formic acid tolerance ability. Thus,the Au/WC-XC catalyst is suitable to be used as the cathodic catalyst in direct formic acid fuel cell.
The gold/active carbon (Au/XC) and gold/tungsten carbide XC(Au/WC-XC) catalysts were prepared with the polyvinyl alcohol (PVA) protection method and their electrocatalytic activity for the oxygen reduction and formic acid tolerance ability were investigated. It was found that the electrocatalytic activity of the Au/WC-XC catalyst for the oxygen reduction is much better than that of the Au/XC catalyst. In addition,the Au/WC-XC catalyst has a high formic acid tolerance ability. Thus,the Au/WC-XC catalyst is suitable to be used as the cathodic catalyst in direct formic acid fuel cell.
2013, 30(12): 1481-1488
doi: 10.3724/SP.J.1095.2013.20594
Abstract:
We used a suspension polymerization method to prepare magnetic molecularly imprinted polymers by using Rhodamine B as the template molecule. The obtained materials were characterized,and their properties were compared with those obtained from bulk polymerization. The results reveal that,Fe3O4 magnetic nanoparticles of the two kinds of polymers show good crystal morhpologies. The shape of M-MIPs prepared by suspension polymerization are regular with the microspheres size about 50 μm. Saturation magnetization of the M-MIPs (suspension polymerization) is 5.406 emu/g, which is larger than that obtained from bulk polymerization (1.772 emu/g). In addition,the former is in favour of the fast magnetic separation than the latter. Compared with bulk polymerization,the adsorption of M-MIPs (suspension polymerization) is 1.8 times higher. In terms of adsorption's capacity,selectivity and reusability,the results of M-MIPs (suspension polymerization) are superior to those of bulk polymerization. Two kinds of adsorbents follow the Langmuir adsorption model. The processes of suspension polymerization and bulk polymerization can be fitted to the second-order and first-order kinetics adsorption,respectively. Through comparative studies,the M-MIPs of suspension polymerization possess high selective adsorption properties to Rhodamine B molecules,which can be used in enrichment and analysis application.
We used a suspension polymerization method to prepare magnetic molecularly imprinted polymers by using Rhodamine B as the template molecule. The obtained materials were characterized,and their properties were compared with those obtained from bulk polymerization. The results reveal that,Fe3O4 magnetic nanoparticles of the two kinds of polymers show good crystal morhpologies. The shape of M-MIPs prepared by suspension polymerization are regular with the microspheres size about 50 μm. Saturation magnetization of the M-MIPs (suspension polymerization) is 5.406 emu/g, which is larger than that obtained from bulk polymerization (1.772 emu/g). In addition,the former is in favour of the fast magnetic separation than the latter. Compared with bulk polymerization,the adsorption of M-MIPs (suspension polymerization) is 1.8 times higher. In terms of adsorption's capacity,selectivity and reusability,the results of M-MIPs (suspension polymerization) are superior to those of bulk polymerization. Two kinds of adsorbents follow the Langmuir adsorption model. The processes of suspension polymerization and bulk polymerization can be fitted to the second-order and first-order kinetics adsorption,respectively. Through comparative studies,the M-MIPs of suspension polymerization possess high selective adsorption properties to Rhodamine B molecules,which can be used in enrichment and analysis application.
2013, 30(12): 1489-1493
doi: 10.3724/SP.J.1095.2013.30296
Abstract:
NaPF6 (as an ion-pairing agent) was added to the extraction solution of Rhizoma coptidis and Cortex phellodend containing[C6MIM] [Br] (as hydrophilic ionic liquid (IL)). A cloudy solution formed as a result of the formation of fine droplets of[C6MIM] [PF6]. After centrifugation,the sedimented phase enriched with alkaloids was analyzed by HPLC with UV detection. In this method, several important parameters,such as the type and volume of ILs,the amount of NaPF6,solution pH,extraction time and centrifugation time,influencing the extraction efficiency of IL-ISFME (in situ solvent formation microextraction) were optimized. Under optimal conditions,berberine,palmatine and coptisine exhibit good linearity,with correlation coefficients of 0.9998,0.9996 and 0.9997,respectively,a linear range of 1~2000 μg/L and the detection limit of 0.5 μg/L. The spiked recovery for each analyte is in the range of 96.52%~104.34%. The experimental results indicate that the proposed method is successfully applied to the analysis of three alkaloids in Rhizoma coptidis and Cortex phellodend.
NaPF6 (as an ion-pairing agent) was added to the extraction solution of Rhizoma coptidis and Cortex phellodend containing[C6MIM] [Br] (as hydrophilic ionic liquid (IL)). A cloudy solution formed as a result of the formation of fine droplets of[C6MIM] [PF6]. After centrifugation,the sedimented phase enriched with alkaloids was analyzed by HPLC with UV detection. In this method, several important parameters,such as the type and volume of ILs,the amount of NaPF6,solution pH,extraction time and centrifugation time,influencing the extraction efficiency of IL-ISFME (in situ solvent formation microextraction) were optimized. Under optimal conditions,berberine,palmatine and coptisine exhibit good linearity,with correlation coefficients of 0.9998,0.9996 and 0.9997,respectively,a linear range of 1~2000 μg/L and the detection limit of 0.5 μg/L. The spiked recovery for each analyte is in the range of 96.52%~104.34%. The experimental results indicate that the proposed method is successfully applied to the analysis of three alkaloids in Rhizoma coptidis and Cortex phellodend.
2013, 30(12): 1494-1496
doi: 10.3724/SP.J.1095.2013.20574
Abstract:
Twelve new 7-substituted-3,6-diarylpyrazolo[1,5-a]pyrimidines were synthesized by the aminizations of the derivatives of 5,7-dichloro-3-(2,4-dichlorophenyl)-2-methyl-6-phenylpyrazolo[1,5-a]pyrimidine. These derivatives were prepared by the reaction of 3-(2,4-dichlorophenyl)-2-methyl-6-phenylpyrazolo[1,5-a]pyrimidine-5,7-diol and phosphorus oxychloride. The products were characterized by IR,1H NMR,elemental analysis and single crystal X-ray diffraction analysis.
Twelve new 7-substituted-3,6-diarylpyrazolo[1,5-a]pyrimidines were synthesized by the aminizations of the derivatives of 5,7-dichloro-3-(2,4-dichlorophenyl)-2-methyl-6-phenylpyrazolo[1,5-a]pyrimidine. These derivatives were prepared by the reaction of 3-(2,4-dichlorophenyl)-2-methyl-6-phenylpyrazolo[1,5-a]pyrimidine-5,7-diol and phosphorus oxychloride. The products were characterized by IR,1H NMR,elemental analysis and single crystal X-ray diffraction analysis.
