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2011 Volume 28 Issue 8
2011, 28(8): 855-863
doi: 10.3724/SP.J.1095.2011.00544
Abstract:
As one of the new anionic surfactants,sulfonated Gemini surfactants are formed by combining two or more sulfonated surfactants monomer via space groups through covalent bonds.They show potential applications in industry due to their improved properties such as higher surface activity,less critical micelle concentration(cmc),better washing ability,excellent blending performance with conventional anionic surfactants,unique rheologic behavior,good anti-salinity and so on.In this paper,the synthetic methods of a series of sulfonated Gemini surfactants are briefly reviewed according to the origin of the raw materials and the research direction on the synthesis of sulfonated Gemini surfactants is speculated.
As one of the new anionic surfactants,sulfonated Gemini surfactants are formed by combining two or more sulfonated surfactants monomer via space groups through covalent bonds.They show potential applications in industry due to their improved properties such as higher surface activity,less critical micelle concentration(cmc),better washing ability,excellent blending performance with conventional anionic surfactants,unique rheologic behavior,good anti-salinity and so on.In this paper,the synthetic methods of a series of sulfonated Gemini surfactants are briefly reviewed according to the origin of the raw materials and the research direction on the synthesis of sulfonated Gemini surfactants is speculated.
2011, 28(8): 864-868
doi: 10.3724/SP.J.1095.2011.00600
Abstract:
Polyphosphazene(PPZ) sub-micrometer spheres were prepared rapidly under room temperature via precipitation polymerization of hexachlorocyclotriphosphazene(HCCP) with 4,4'-sulfonyldiphenol(BPS),using acetonitrile as the solvent and triethylamine(TEA) as the acid-acceptor.The PPZ sub-micrometer spheres were characterized by FT-IR,elemental analysis and EDX,and their highly cross-linked structures were identified.SEM and TEM results indicated that the PPZ sub-micrometer spheres had diameter of about 410 nm,solid structure and smooth surface.TGA result showed that the thermal decomposition temperature of the PPZ sub-micrometer spheres was about 531℃.In addition,the formation mechanism of the PPZ submicrometer spheres was proposed.
Polyphosphazene(PPZ) sub-micrometer spheres were prepared rapidly under room temperature via precipitation polymerization of hexachlorocyclotriphosphazene(HCCP) with 4,4'-sulfonyldiphenol(BPS),using acetonitrile as the solvent and triethylamine(TEA) as the acid-acceptor.The PPZ sub-micrometer spheres were characterized by FT-IR,elemental analysis and EDX,and their highly cross-linked structures were identified.SEM and TEM results indicated that the PPZ sub-micrometer spheres had diameter of about 410 nm,solid structure and smooth surface.TGA result showed that the thermal decomposition temperature of the PPZ sub-micrometer spheres was about 531℃.In addition,the formation mechanism of the PPZ submicrometer spheres was proposed.
2011, 28(8): 869-873
doi: 10.3724/SP.J.1095.2011.00515
Abstract:
A room temperature ionic liquid,1-allyl-3-methylimidazolium tetrafluoroborate([AMIM]BF4) was prepared by a two-step synthesis.Then gel polymer electrolytes(GPE) prepared by incorporating the ionic liquid [AMIM]BF4 and poly(methyl methacrylate)(PMMA) were modified with aprotic solvents propylene carbonate(PC) and dimethyl carbonate(DMC) and SiO2 nano particles.The structure and properties of the GPE were studied by means of fourier transform infrared spectroscopy(FT-IR),A.C.impedance(AC),thermogravimetry(TG),and scanning electron microscope(SEM).The results showed that the introduction of aprotic solvents PC-DMC and nano-SiO2 particles increased the ionic conductivity of the GPE,which showed a highly ionic conductivity of up to 5.25×10-3 S/cm at room temperature.In addition,the conductive behavior of the GPE follows an Arrhenius equation.The gel polymer electrolytes shows high thermal stability and tends to decompose at temperature higher than 300℃.
A room temperature ionic liquid,1-allyl-3-methylimidazolium tetrafluoroborate([AMIM]BF4) was prepared by a two-step synthesis.Then gel polymer electrolytes(GPE) prepared by incorporating the ionic liquid [AMIM]BF4 and poly(methyl methacrylate)(PMMA) were modified with aprotic solvents propylene carbonate(PC) and dimethyl carbonate(DMC) and SiO2 nano particles.The structure and properties of the GPE were studied by means of fourier transform infrared spectroscopy(FT-IR),A.C.impedance(AC),thermogravimetry(TG),and scanning electron microscope(SEM).The results showed that the introduction of aprotic solvents PC-DMC and nano-SiO2 particles increased the ionic conductivity of the GPE,which showed a highly ionic conductivity of up to 5.25×10-3 S/cm at room temperature.In addition,the conductive behavior of the GPE follows an Arrhenius equation.The gel polymer electrolytes shows high thermal stability and tends to decompose at temperature higher than 300℃.
Synthesis and Flocculating Properties of Cationic Polyacrylamide by Aqueous Two-phase Polymerization
2011, 28(8): 874-878
doi: 10.3724/SP.J.1095.2011.00551
Abstract:
An aqueous two-phase polymerization of acrylamide(AM) with 2-(acryloyloxy) ethyl trimethylammonium chloride(DAC) was carried out using polyethylene glycol(PEG) as dispersant and ammonium persulfate as the initiator.A series of cationic polyacrylamide(CPAM) flocculants was prepared.Effects of the ratio of monomers on the relative molecular mass,monomer conversion and cationic degree were studied.The CPAM was used as flocculating agent for the Yellow River water.The influence of the dosage of CPAM,the pH value of water sample,the stirring speed,the mixing and standing time on the flocculating performance were studied.The results shows that the cationic degree of CPAM increases with the decrease ofm(AM)/m(CAD),while the relative molecular mass and conversion slightly decrease.The flocculating efficiency depends on the dosage of CPAM,the pH,stirring speed,and the stirring and standing time.The removal rate of the impurities in the water samples is 92% under the optimum conditions:pH=6,stirring speed 100 r/min,stirring time 15 min,standing time 10 min,CPAM 0.3 mg/L.
An aqueous two-phase polymerization of acrylamide(AM) with 2-(acryloyloxy) ethyl trimethylammonium chloride(DAC) was carried out using polyethylene glycol(PEG) as dispersant and ammonium persulfate as the initiator.A series of cationic polyacrylamide(CPAM) flocculants was prepared.Effects of the ratio of monomers on the relative molecular mass,monomer conversion and cationic degree were studied.The CPAM was used as flocculating agent for the Yellow River water.The influence of the dosage of CPAM,the pH value of water sample,the stirring speed,the mixing and standing time on the flocculating performance were studied.The results shows that the cationic degree of CPAM increases with the decrease of
Synthesis and Photo-Luminescence Properties of 3,5-Dinitro Salicylic Acid Europium/Polymer Materials
2011, 28(8): 879-886
doi: 10.3724/SP.J.1095.2011.00594
Abstract:
3,5-Dinitro salicylic acid Eu(Ⅲ) complex(EuDNS) and its polymer composites were synthesized.The complex and polymers were characterized by elemental analysis,IR,UV-Vis methods.Effects of the complex content and polymer materials on the fluorescence property were studied.The complex may form a chelate heterocyclic structure and result in a wide UV-Vis absorption band that is well matched to excited wavelength,so that the complex can emit strong characteristic red luminescence of Eu(Ⅲ) ion.Even if the mass fraction of complex is 0.25%,EuDNS/PMMA(PMMA:polymethyl-methacrylate) polymer has still very strong fluorescence property.The order of the emission from strong to weak for the copolymers is:P(MMA-co-St)> PMMA> P(MMA-co-AA)(AA:acrylic acid).The acrylic acid comonomer can quench luminescence.The results show the inhibition and retardation effects of the complex on free radical copolymerization of styrene/methyl methacrylate initiated with azobisisbutyronitrile at 60℃,and the inhibition effect increases with the increasing styrene(St) comonomer content,whereas P(MMA-co-St) transparence decreases.The EuDNS/PMMA polymer has a longer apparent fluorescent lifetime than the corresponding complex.
3,5-Dinitro salicylic acid Eu(Ⅲ) complex(EuDNS) and its polymer composites were synthesized.The complex and polymers were characterized by elemental analysis,IR,UV-Vis methods.Effects of the complex content and polymer materials on the fluorescence property were studied.The complex may form a chelate heterocyclic structure and result in a wide UV-Vis absorption band that is well matched to excited wavelength,so that the complex can emit strong characteristic red luminescence of Eu(Ⅲ) ion.Even if the mass fraction of complex is 0.25%,EuDNS/PMMA(PMMA:polymethyl-methacrylate) polymer has still very strong fluorescence property.The order of the emission from strong to weak for the copolymers is:P(MMA-co-St)> PMMA> P(MMA-co-AA)(AA:acrylic acid).The acrylic acid comonomer can quench luminescence.The results show the inhibition and retardation effects of the complex on free radical copolymerization of styrene/methyl methacrylate initiated with azobisisbutyronitrile at 60℃,and the inhibition effect increases with the increasing styrene(St) comonomer content,whereas P(MMA-co-St) transparence decreases.The EuDNS/PMMA polymer has a longer apparent fluorescent lifetime than the corresponding complex.
2011, 28(8): 887-891
doi: 10.3724/SP.J.1095.2011.00541
Abstract:
A new etherlized ferrocenylphosphine ligand,2-diphenylphosphino-ferrocenyl-ethyl-5-hydroxyl-3-oxo-pentyl ether,was prepared by the reaction of acetyl 1-(diphenylphosphinoferrocenyl) ethyl ester with diethylene glycol in 77% yield.Its structure was characterized by 1H NMR,13C NMR,31P NMR and MS.The synthesized ferrocenylphosphine has been applied as supporting ligand in the palladium-catalyzed Suzuki reaction;its ligated palladium catalyst is effective for coupling a range of aryl bromides as well as aryl chlorides having electron-withdrawing groups with phenylboronic acid to prepare the corresponding biaryls.The possible coordination of ether-oxygen to the Pd center may enhance the catalytic performance of the ligand for cross-coupling reaction.
A new etherlized ferrocenylphosphine ligand,2-diphenylphosphino-ferrocenyl-ethyl-5-hydroxyl-3-oxo-pentyl ether,was prepared by the reaction of acetyl 1-(diphenylphosphinoferrocenyl) ethyl ester with diethylene glycol in 77% yield.Its structure was characterized by 1H NMR,13C NMR,31P NMR and MS.The synthesized ferrocenylphosphine has been applied as supporting ligand in the palladium-catalyzed Suzuki reaction;its ligated palladium catalyst is effective for coupling a range of aryl bromides as well as aryl chlorides having electron-withdrawing groups with phenylboronic acid to prepare the corresponding biaryls.The possible coordination of ether-oxygen to the Pd center may enhance the catalytic performance of the ligand for cross-coupling reaction.
2011, 28(8): 892-896
doi: 10.3724/SP.J.1095.2011.00686
Abstract:
Five precursors,N-(tert-butoxycarbonyl)-O-(2-mosyloxyethyl/nosyloxyethyl)-L-tyrosine methyl ester(9a,11a) and N-(tert-butoxycarbonyl)-O-(2-mosyloxyethyl/tosyloxyethyl/nosyloxyethyl)-L-tyrosine tert-butyl ester(9b,10b,11b),were designed and synthesized for O-(2-[18F]fluoroethyl)-L-tyrosine([18F]FET) used in positron emission tomography(PET) for tumor imaging.These compounds were prepared by the esterification of methanol or transesterification of tert-butyl acetate with L-tyrosine,protection of the amine group with di-tert-butyl dicarbonate,and then nucleophilic substitution with glycol sulfonate in three steps with overall yields varied from 30% to 67%.
Five precursors,N-(tert-butoxycarbonyl)-O-(2-mosyloxyethyl/nosyloxyethyl)-L-tyrosine methyl ester(9a,11a) and N-(tert-butoxycarbonyl)-O-(2-mosyloxyethyl/tosyloxyethyl/nosyloxyethyl)-L-tyrosine tert-butyl ester(9b,10b,11b),were designed and synthesized for O-(2-[18F]fluoroethyl)-L-tyrosine([18F]FET) used in positron emission tomography(PET) for tumor imaging.These compounds were prepared by the esterification of methanol or transesterification of tert-butyl acetate with L-tyrosine,protection of the amine group with di-tert-butyl dicarbonate,and then nucleophilic substitution with glycol sulfonate in three steps with overall yields varied from 30% to 67%.
2011, 28(8): 897-900
doi: 10.3724/SP.J.1095.2011.00485
Abstract:
Four new metal complexes were synthesized by the reaction of tetrandrine(Tet,extracted from Stephania tetrandra S.Moore) with M(NO3)2·3H2O(M=Cu,Zn,Co,Ni) in ethanol and characterized by FT-IR and UV.The power-time curves of bacteriostatic activities of Tet,its four metal complexes and metal nitrates with different concentrations(c) were determined by the titration microcalorimetry method.The growth rate constants(μ) of E.coli were calculated using logistic equation.The relationships of μ-c for the investigated systems were established and the inhibitory concentrations were optimized.By comparing their optimized inhibitory concentrations,it was found that the bacteriostatic activities of the four metal-Tet complexes on E.coli were superior to those of M(NO3)2·3H2O and Tet.
Four new metal complexes were synthesized by the reaction of tetrandrine(Tet,extracted from Stephania tetrandra S.Moore) with M(NO3)2·3H2O(M=Cu,Zn,Co,Ni) in ethanol and characterized by FT-IR and UV.The power-time curves of bacteriostatic activities of Tet,its four metal complexes and metal nitrates with different concentrations(c) were determined by the titration microcalorimetry method.The growth rate constants(μ) of E.coli were calculated using logistic equation.The relationships of μ-c for the investigated systems were established and the inhibitory concentrations were optimized.By comparing their optimized inhibitory concentrations,it was found that the bacteriostatic activities of the four metal-Tet complexes on E.coli were superior to those of M(NO3)2·3H2O and Tet.
2011, 28(8): 901-906
doi: 10.3724/SP.J.1095.2011.00606
Abstract:
Self-assembly of tobacco mosaic virus(TMV) particles by drying TMV buffered solution constrained in a capillary tube,between two parallel glass slides and in a cylinder-on-flat geometry were studied,respectively.Optical microscopy(OM) and atomic force microscopy(AFM) were employed to characterize the patterns produced.Effect of the concentration of TMV on patterns was also explored.The results show that highly ordered structures could be fabricated under these three confined conditions which were attributed to the periodical,repetitive "stick-slip" motion of the contact line.Stripes parallel to the contact line but perpendicular to the long axis of the capillary tube were formed in a glass capillary tube after evaporation.As the solution front moved inward,both l(span of a stripe) and w(width of a stripe) gradually increased.When drying TMV buffered solution trapped between two glass slides,patterns in a tetramerous radial symmetry were produced.From each side of the slide,both l and w increased as stripes approached the longitudinal axis to the center.Parallel gradient straight stripes were obtained when TMV buffered solution was allowed to evaporate from a cylinder-on-flat geometry.As the contact line propagated from the capillary edge toward the cylinder/Si contact center,both l and w decreased.The values of l for the outermost,middle and innermost regions are 28.4,20.9 and 8.4 μm,respectively.While the values of w are 17.5,9.2 and 0.8 μm,correspondingly.Moreover,the height of the stripe decreased from 33.9 nm to 30.4 nm,finally to 29.5 nm.In all patterns formed under these three kinds of confinement conditions,individual TMV particles aligned parallel to the contact line,which could not only relieve the strong dipole-dipole repulsion between TMV particles,but also effectively minimize the interfacial energy.Concentration of TMV had the same effect on patterns under these three confinements:both l and w increased with the increase of concentration until no stripe patterns were observed and continuous films of TMV were formed.
Self-assembly of tobacco mosaic virus(TMV) particles by drying TMV buffered solution constrained in a capillary tube,between two parallel glass slides and in a cylinder-on-flat geometry were studied,respectively.Optical microscopy(OM) and atomic force microscopy(AFM) were employed to characterize the patterns produced.Effect of the concentration of TMV on patterns was also explored.The results show that highly ordered structures could be fabricated under these three confined conditions which were attributed to the periodical,repetitive "stick-slip" motion of the contact line.Stripes parallel to the contact line but perpendicular to the long axis of the capillary tube were formed in a glass capillary tube after evaporation.As the solution front moved inward,both l(span of a stripe) and w(width of a stripe) gradually increased.When drying TMV buffered solution trapped between two glass slides,patterns in a tetramerous radial symmetry were produced.From each side of the slide,both l and w increased as stripes approached the longitudinal axis to the center.Parallel gradient straight stripes were obtained when TMV buffered solution was allowed to evaporate from a cylinder-on-flat geometry.As the contact line propagated from the capillary edge toward the cylinder/Si contact center,both l and w decreased.The values of l for the outermost,middle and innermost regions are 28.4,20.9 and 8.4 μm,respectively.While the values of w are 17.5,9.2 and 0.8 μm,correspondingly.Moreover,the height of the stripe decreased from 33.9 nm to 30.4 nm,finally to 29.5 nm.In all patterns formed under these three kinds of confinement conditions,individual TMV particles aligned parallel to the contact line,which could not only relieve the strong dipole-dipole repulsion between TMV particles,but also effectively minimize the interfacial energy.Concentration of TMV had the same effect on patterns under these three confinements:both l and w increased with the increase of concentration until no stripe patterns were observed and continuous films of TMV were formed.
2011, 28(8): 907-912
doi: 10.3724/SP.J.1095.2011.00563
Abstract:
Nanometer hybrid rare earth solid superacid was prepared by sol-gel method.Tetrabutyl titanate was hydrolyzed and condensation polymerized,then doped with rare earth elements of Ce and La,respectively,by immersion process,and activated under certain temperatures to give a nanometer hybrid rare earth solid superacid catalyst.The structure and morphology of samples were characterized by FT-IR,SEM,and XRD.The results show that the SO42- is bonded to the metal oxide by bridged bidentate coordination mode.XRD shows the crystal form is anatase,and SEM reveals the catalyst is globular shape.It also proves that the rare earth solid superacid catalysts exhibit high catalytic activity for the esterification of stearic acid.The precursor soaked in the solution c(Ce4+)=0.12 mol/L,c(H2SO4)=1.0 mol/L and the solution c(La3+)=0.07 mol/L,c(H2SO4)=1.25 mol/L for 10~14 h,then calcinated at 500~550℃ for 3 h to obtain the solid superacid catalysts.Under the optimum conditions,the yields of esterification can reach 97.8% and 96.7%,respectively,by using these catalysts.
Nanometer hybrid rare earth solid superacid was prepared by sol-gel method.Tetrabutyl titanate was hydrolyzed and condensation polymerized,then doped with rare earth elements of Ce and La,respectively,by immersion process,and activated under certain temperatures to give a nanometer hybrid rare earth solid superacid catalyst.The structure and morphology of samples were characterized by FT-IR,SEM,and XRD.The results show that the SO42- is bonded to the metal oxide by bridged bidentate coordination mode.XRD shows the crystal form is anatase,and SEM reveals the catalyst is globular shape.It also proves that the rare earth solid superacid catalysts exhibit high catalytic activity for the esterification of stearic acid.The precursor soaked in the solution c(Ce4+)=0.12 mol/L,c(H2SO4)=1.0 mol/L and the solution c(La3+)=0.07 mol/L,c(H2SO4)=1.25 mol/L for 10~14 h,then calcinated at 500~550℃ for 3 h to obtain the solid superacid catalysts.Under the optimum conditions,the yields of esterification can reach 97.8% and 96.7%,respectively,by using these catalysts.
2011, 28(8): 913-917
doi: 10.3724/SP.J.1095.2011.00586
Abstract:
Tb3+ -doped CePO4 core-shell microspheres with diameter of 2~3 μm were hydrothermally synthesized at pH=1.0 without using any template or surfactant.It was observed that the shells of these spheres were composed by nanorods with a diameter of about 20~30 nm and lengths up to 200~300 nm.The time-dependent experiments were also carried out to investigate their growing process.Initially,aggregated spherical products were formed.Then,some particles grew on its surface.As a result of Ostwald ripening,the size of the product increased.Finally,at the expense of the cores inside the spheres,the surface of the product experienced a change from nanoparticles to nanorods.The luminescent properties and luminescence decay lifetimes of CePO4:Tb core shell microspheres were performed,indicating that the strongest emission intensity was reached with 10% molar fraction of Tb3+ ions,which might be ascribed to the concentration quenching effect.
Tb3+ -doped CePO4 core-shell microspheres with diameter of 2~3 μm were hydrothermally synthesized at pH=1.0 without using any template or surfactant.It was observed that the shells of these spheres were composed by nanorods with a diameter of about 20~30 nm and lengths up to 200~300 nm.The time-dependent experiments were also carried out to investigate their growing process.Initially,aggregated spherical products were formed.Then,some particles grew on its surface.As a result of Ostwald ripening,the size of the product increased.Finally,at the expense of the cores inside the spheres,the surface of the product experienced a change from nanoparticles to nanorods.The luminescent properties and luminescence decay lifetimes of CePO4:Tb core shell microspheres were performed,indicating that the strongest emission intensity was reached with 10% molar fraction of Tb3+ ions,which might be ascribed to the concentration quenching effect.
2011, 28(8): 918-923
doi: 10.3724/SP.J.1095.2011.00595
Abstract:
Sn thin films on Cu foil substrate were prepared by vacuum evaporation and investigated as the anode materials of rechargeable lithium-ion batteries.The surface morphology and composition of the asprepared films were characterized by scanning electron microscopy(SEM) and X-ray diffraction(XRD).The electrochemical performance of the film electrodes was measured using CR2032 coin-type cells.The experimental results show that the deposited films are composed of nano/micro particles,which are enlarged with increasing both the evaporation power and the substrate temperature.This behavior is correlated with the electrochemical performance of the film electrode.It is found that at 200 W and 150℃,the thin film with small particle of Cu6Sn5 phase displays a discharge capacity of 527 mA·h/g after 20 cycles.
Sn thin films on Cu foil substrate were prepared by vacuum evaporation and investigated as the anode materials of rechargeable lithium-ion batteries.The surface morphology and composition of the asprepared films were characterized by scanning electron microscopy(SEM) and X-ray diffraction(XRD).The electrochemical performance of the film electrodes was measured using CR2032 coin-type cells.The experimental results show that the deposited films are composed of nano/micro particles,which are enlarged with increasing both the evaporation power and the substrate temperature.This behavior is correlated with the electrochemical performance of the film electrode.It is found that at 200 W and 150℃,the thin film with small particle of Cu6Sn5 phase displays a discharge capacity of 527 mA·h/g after 20 cycles.
2011, 28(8): 924-930
doi: 10.3724/SP.J.1095.2011.00570
Abstract:
In order to improve the performance of a gelled electrolyte and decrease its internal resistance,sodium ligninsulfonate was used as an additive to the gelled electrolyte.The properties and electrochemistry of the gelled electrolytes with and without additives were studied by viscosity test,aging test,cyclic voltammetry(CV),and electrochemical impedance spectroscopy(EIS).The data indicated that when the mass fraction of SiO2 was 3.0%,the viscosity of the gel electrolyte with 0.01% additives is increased by 6 times comparing with the gel electrolyte without additives.The volume of precipitated water and the internal resistance of gelled electrolyte decrease as the additive is added.The optimum conditions are obtained.The dosage(mass fraction) of additives is 0.005%~0.01%,and the fumed silica is 3.0%.UV-Vis,FT-IR,SEM and TEM were used to characterize the gelled electrolyte with and without additives.The results show that the microstructure of gelled electrolyte is more porous with improved ion conduction,and the sulphuric acid solution can therefore be stored more easily with addition of sodium liginsulfonate.
In order to improve the performance of a gelled electrolyte and decrease its internal resistance,sodium ligninsulfonate was used as an additive to the gelled electrolyte.The properties and electrochemistry of the gelled electrolytes with and without additives were studied by viscosity test,aging test,cyclic voltammetry(CV),and electrochemical impedance spectroscopy(EIS).The data indicated that when the mass fraction of SiO2 was 3.0%,the viscosity of the gel electrolyte with 0.01% additives is increased by 6 times comparing with the gel electrolyte without additives.The volume of precipitated water and the internal resistance of gelled electrolyte decrease as the additive is added.The optimum conditions are obtained.The dosage(mass fraction) of additives is 0.005%~0.01%,and the fumed silica is 3.0%.UV-Vis,FT-IR,SEM and TEM were used to characterize the gelled electrolyte with and without additives.The results show that the microstructure of gelled electrolyte is more porous with improved ion conduction,and the sulphuric acid solution can therefore be stored more easily with addition of sodium liginsulfonate.
2011, 28(8): 931-935
doi: 10.3724/SP.J.1095.2011.00553
Abstract:
The Ir-Co/C catalyst was prepared via a liquid phase reduction method.X-ray diffraction(XRD) and transmission electron microscope(TEM) results indicated that Co atoms enter the crystal lattice of Ir and form the Ir-Co alloy as evidenced by the lattice constriction of Ir and the aggregation of Ir particles could be suppressed.The electrochemical investigation illustrated that comparing with the Ir/C catalyst,the onset potential of the NH3 oxidation is negatively shifted about 100 mV,the peak current density is increased about 100% and the electrocatalytic stability is also increased at the Ir-Co/C catalyst.In addition,the sensitivity and the detection limit of NH3 are decreased at the Ir-Co/C catalyst.The results illustrate that the electrocatalytic performance of the Ir-Co/C catalyst for the NH3 oxidation is obviously better than that of the Ir/C catalyst.Thus,the Ir-Co/C catalyst has a potential application in the electrochemical NH3 sensor.
The Ir-Co/C catalyst was prepared via a liquid phase reduction method.X-ray diffraction(XRD) and transmission electron microscope(TEM) results indicated that Co atoms enter the crystal lattice of Ir and form the Ir-Co alloy as evidenced by the lattice constriction of Ir and the aggregation of Ir particles could be suppressed.The electrochemical investigation illustrated that comparing with the Ir/C catalyst,the onset potential of the NH3 oxidation is negatively shifted about 100 mV,the peak current density is increased about 100% and the electrocatalytic stability is also increased at the Ir-Co/C catalyst.In addition,the sensitivity and the detection limit of NH3 are decreased at the Ir-Co/C catalyst.The results illustrate that the electrocatalytic performance of the Ir-Co/C catalyst for the NH3 oxidation is obviously better than that of the Ir/C catalyst.Thus,the Ir-Co/C catalyst has a potential application in the electrochemical NH3 sensor.
2011, 28(8): 936-941
doi: 10.3724/SP.J.1095.2011.00552
Abstract:
Activated carbon(AC) was modified by supercritical fluidic methanol in order to obtain materials with different surface properties.Several techniques were used to characterize the activated carbon and Ru/AC catalysts including N2 physisorption,Boehm titration,XPS and temperature-programmed reduction(TPR).The results show that supercritical fluid treatment does not remarkably change the surface structure of activated carbon,but significantly reduce the amount of the surface acidic groups.Thus Ru deposited on them will assemble.These led to a higher dispersion of Ru and enhanced the activity of the catalysts prepared by impregnation of AC supported with RuCl3 solution.The activities of Ru/AC catalysts for hydrogenation of glucose were tested under 4.0 MPa and 120℃.The results show that activities of Ru/AC catalysts prepared by supercritical fluid treatment are increased,and the highest reaction rate(in Ru mass unit) for hydrogenation of glucose reaches 118.65 mmol/(min·g),which was 1.96 times higher than that without treatment.
Activated carbon(AC) was modified by supercritical fluidic methanol in order to obtain materials with different surface properties.Several techniques were used to characterize the activated carbon and Ru/AC catalysts including N2 physisorption,Boehm titration,XPS and temperature-programmed reduction(TPR).The results show that supercritical fluid treatment does not remarkably change the surface structure of activated carbon,but significantly reduce the amount of the surface acidic groups.Thus Ru deposited on them will assemble.These led to a higher dispersion of Ru and enhanced the activity of the catalysts prepared by impregnation of AC supported with RuCl3 solution.The activities of Ru/AC catalysts for hydrogenation of glucose were tested under 4.0 MPa and 120℃.The results show that activities of Ru/AC catalysts prepared by supercritical fluid treatment are increased,and the highest reaction rate(in Ru mass unit) for hydrogenation of glucose reaches 118.65 mmol/(min·g),which was 1.96 times higher than that without treatment.
2011, 28(8): 942-948
doi: 10.3724/SP.J.1095.2011.00559
Abstract:
Fly ash,a kind of industrial solid waste material produced during the combustion of coal in the electricity generation,was utilized to prepare a novel carbon/fly ash composite adsorbent with core-shell structures by a partial carbonization and sulfonation process.The prepared composite adsorbent was characterized with XPS,FT-IR,SEM,XRD and gas adsorption experiments.The results showed that fly ash was coated by graphite-like carbon nanoparticles.The carbon,oxygen,silica and sulfur are the main elements on the surface of the prepared composite adsorbent.Among them,the carbon and oxygen elements are the dominant superficial elements.An abundant of mesopores existed on the surface of the composite adsorbent.The Brunauer Emmett Teller(BET) surface area SBET is 5.4 m2/g.Meanwhile,an abundant of oxygen functional groups,such as carboxyl,hydroxyl and sulfonic groups,which were very effective in capturing cationic organic dyes and heavy metal ions and acted as the main adsorption sites of the composite adsorbent,were successfully introduced on the composite adsorbent surface.The adsorption capacity of the prepared composite for typical cationic dye methylene blue and heavy metal ions was also investigated and compared with activated carbon and fly ash under the same experimental condition.The results show that the composite adsorbent exhibits excellent adsorption performance.The adsorption capacity for methylene blue can reach about 83.7% of activated carbon adsorption capacity,and the adsorption capacity for heavy metal ions Cd2+,Ni2+,Pb2+ and Cu2+ can reach about 104.3%,131.1%,170.5% and 127.3% of the capacity of activated carbon,respectively.The adsorption capacity for methylene blue and heavy metal ions is far more than that of fly ash.The prepared carbon/fly ash composite adsorbent can be used as a potential substitute of activated carbon for heavy metal ions or organic dyes adsorption in waste water.
Fly ash,a kind of industrial solid waste material produced during the combustion of coal in the electricity generation,was utilized to prepare a novel carbon/fly ash composite adsorbent with core-shell structures by a partial carbonization and sulfonation process.The prepared composite adsorbent was characterized with XPS,FT-IR,SEM,XRD and gas adsorption experiments.The results showed that fly ash was coated by graphite-like carbon nanoparticles.The carbon,oxygen,silica and sulfur are the main elements on the surface of the prepared composite adsorbent.Among them,the carbon and oxygen elements are the dominant superficial elements.An abundant of mesopores existed on the surface of the composite adsorbent.The Brunauer Emmett Teller(BET) surface area SBET is 5.4 m2/g.Meanwhile,an abundant of oxygen functional groups,such as carboxyl,hydroxyl and sulfonic groups,which were very effective in capturing cationic organic dyes and heavy metal ions and acted as the main adsorption sites of the composite adsorbent,were successfully introduced on the composite adsorbent surface.The adsorption capacity of the prepared composite for typical cationic dye methylene blue and heavy metal ions was also investigated and compared with activated carbon and fly ash under the same experimental condition.The results show that the composite adsorbent exhibits excellent adsorption performance.The adsorption capacity for methylene blue can reach about 83.7% of activated carbon adsorption capacity,and the adsorption capacity for heavy metal ions Cd2+,Ni2+,Pb2+ and Cu2+ can reach about 104.3%,131.1%,170.5% and 127.3% of the capacity of activated carbon,respectively.The adsorption capacity for methylene blue and heavy metal ions is far more than that of fly ash.The prepared carbon/fly ash composite adsorbent can be used as a potential substitute of activated carbon for heavy metal ions or organic dyes adsorption in waste water.
2011, 28(8): 949-955
doi: 10.3724/SP.J.1095.2011.00666
Abstract:
Two novel exocyclic ring-fused dipyrrometheneboron difluoride(BODIPY) dyes substituted with p-hydroxyphenyl or phenyl subunit at the meso-position have been prepared.Their absorption and steady-state fluorescence properties are investigated in polar and nonpolar solvents.The fluorometric titration measurements were carried out to examine their responsive abilities to pH change in the basic CH3CN-H2O solution.The results indicate that strong fluorescence of dye 1 is significantly quenched by adding OH- to the solution,and the addition of the CF3COOH into the basic solution restores the quenched fluorescence.In CH3CN-H2O(volume ratio 1:1) solution,dye 1 can be qualified as a very sensitive fluorescent probe for pH sensing in the alkaline region,with a pKa value as 10.23 when the excitation and emission wavelengths of dye 1 are 490 nm and 540 nm,respectively.
Two novel exocyclic ring-fused dipyrrometheneboron difluoride(BODIPY) dyes substituted with p-hydroxyphenyl or phenyl subunit at the meso-position have been prepared.Their absorption and steady-state fluorescence properties are investigated in polar and nonpolar solvents.The fluorometric titration measurements were carried out to examine their responsive abilities to pH change in the basic CH3CN-H2O solution.The results indicate that strong fluorescence of dye 1 is significantly quenched by adding OH- to the solution,and the addition of the CF3COOH into the basic solution restores the quenched fluorescence.In CH3CN-H2O(volume ratio 1:1) solution,dye 1 can be qualified as a very sensitive fluorescent probe for pH sensing in the alkaline region,with a pKa value as 10.23 when the excitation and emission wavelengths of dye 1 are 490 nm and 540 nm,respectively.
2011, 28(8): 956-962
doi: 10.3724/SP.J.1095.2011.00598
Abstract:
The chemical components of Ligusticum chuanxiong Hort.were extracted by steam distillation and supercritical CO2 extraction,and analyzed by combined capillary gas chromatography-mass spectrometry(GCMS).Thirty and thirty four compounds were identified,respectively,and their relative contents were determined.This study revealed that the major components of L.chuanxiong Hort.by steam distillation and supercritical CO2 extraction were(Z)-ligustilide.The chemical components from L.chuanxiong Hort.extracted by supercritical CO2 extraction possessed more bioactive substances such as butylphthalide,butylidene phthalide,senkyunolide A,(Z)-ligustilide,(E)-ligustilide and senkyunolide I.However,the components from L.chuanxiong Hort.extracted by steam distillation contained more terpenes except for the bioactive substances.Therefore,supercritical CO2 extraction has more productivity than steam distillation for the extraction of the bioactive substances from L.chuanxiong Hort.Through the interpretation and summarization of the regular patterns of the lactones with unsaturated and saturated side chains from L.chuanxiong Hort.,the structures of the lactones with unsaturated side chain such as(Z)-ligustilide,(E)-ligustilide,butylidene phthalide and senkyunolide I as well as the lactones with saturated side chain such as butylphthalide and senkyunolide A have been determined.
The chemical components of Ligusticum chuanxiong Hort.were extracted by steam distillation and supercritical CO2 extraction,and analyzed by combined capillary gas chromatography-mass spectrometry(GCMS).Thirty and thirty four compounds were identified,respectively,and their relative contents were determined.This study revealed that the major components of L.chuanxiong Hort.by steam distillation and supercritical CO2 extraction were(Z)-ligustilide.The chemical components from L.chuanxiong Hort.extracted by supercritical CO2 extraction possessed more bioactive substances such as butylphthalide,butylidene phthalide,senkyunolide A,(Z)-ligustilide,(E)-ligustilide and senkyunolide I.However,the components from L.chuanxiong Hort.extracted by steam distillation contained more terpenes except for the bioactive substances.Therefore,supercritical CO2 extraction has more productivity than steam distillation for the extraction of the bioactive substances from L.chuanxiong Hort.Through the interpretation and summarization of the regular patterns of the lactones with unsaturated and saturated side chains from L.chuanxiong Hort.,the structures of the lactones with unsaturated side chain such as(Z)-ligustilide,(E)-ligustilide,butylidene phthalide and senkyunolide I as well as the lactones with saturated side chain such as butylphthalide and senkyunolide A have been determined.
2011, 28(8): 963-968
doi: 10.3724/SP.J.1095.2011.00526
Abstract:
The isotherms and the adsorption amount of alkyl aryl sulfonates with five types of relative molecular mass(Mr) distribution were measured on the solid-liquid interface.The impacts of Mr,Mr distribution,adsorption temperature,and the inorganic salt on the adsorption of alkyl aryl sulfonate compounds on the oil sand/quartz sand surface were discussed,respectively.The results showed that the adsorption amount of the five types of alkyl aryl sulfonate compounds were decreased in the following order:the incremental distribution,normal distribution,reverse normal distribution,descending distribution,uniform distribution;while the adsorption amount of alkyl aryl sulfonate compounds on the oil sands surface increased with the increase of their Mr and the NaCl concentration,and decreased with the increase of the adsorption temperature.The effect of NaCl on the adsorption of the alkyl aryl sulfonate compounds on the oil sands surface was slightly greater than that on the quartz sands surface.Moreover,it was found that CaCl2,MgCl2,Na2 SO4 etc.have a more significant effect on the adsorption amount than NaCl.
The isotherms and the adsorption amount of alkyl aryl sulfonates with five types of relative molecular mass(Mr) distribution were measured on the solid-liquid interface.The impacts of Mr,Mr distribution,adsorption temperature,and the inorganic salt on the adsorption of alkyl aryl sulfonate compounds on the oil sand/quartz sand surface were discussed,respectively.The results showed that the adsorption amount of the five types of alkyl aryl sulfonate compounds were decreased in the following order:the incremental distribution,normal distribution,reverse normal distribution,descending distribution,uniform distribution;while the adsorption amount of alkyl aryl sulfonate compounds on the oil sands surface increased with the increase of their Mr and the NaCl concentration,and decreased with the increase of the adsorption temperature.The effect of NaCl on the adsorption of the alkyl aryl sulfonate compounds on the oil sands surface was slightly greater than that on the quartz sands surface.Moreover,it was found that CaCl2,MgCl2,Na2 SO4 etc.have a more significant effect on the adsorption amount than NaCl.
2011, 28(8): 969-973
doi: 10.3724/SP.J.1095.2011.00003
Abstract:
A poly(p-aminobenzene sulfonic acid)/graphene composite modified glassy carbon electrode(GCE) was fabricated and the electrochemical behaviors of mercury on the modified electrode were investigated.The results show that the electrochemical response of Hg2+ at the modified electrode is significantly improved compared with the bare GCE.After 5 min accumulation at -1.2 V in a 0.1 mol/L pH=4.0 PBS,the peak currents vary linearly with the concentration of Hg2+ over the range from 1.0×10-6 to 5.0×10-4 mol/L with the detection limit of 5.0×10-7 mol/L.The correlation coefficiency is 0.995.Using this modified electrode,trace amounts of Hg2+ in water samples are determined with recoveries of 92.2%~105.2%.
A poly(p-aminobenzene sulfonic acid)/graphene composite modified glassy carbon electrode(GCE) was fabricated and the electrochemical behaviors of mercury on the modified electrode were investigated.The results show that the electrochemical response of Hg2+ at the modified electrode is significantly improved compared with the bare GCE.After 5 min accumulation at -1.2 V in a 0.1 mol/L pH=4.0 PBS,the peak currents vary linearly with the concentration of Hg2+ over the range from 1.0×10-6 to 5.0×10-4 mol/L with the detection limit of 5.0×10-7 mol/L.The correlation coefficiency is 0.995.Using this modified electrode,trace amounts of Hg2+ in water samples are determined with recoveries of 92.2%~105.2%.
2011, 28(8): 974-976
doi: 10.3724/SP.J.1095.2011.00549
Abstract:
Chlorination of xanthenone by thionyl chloride gave an intermediate 9,9-dichloroxanthene.The obtained chlorinated product is free of further isolation and purification and can react with o-cresol or 2,6-dimethylphenol for the preparation of two xthanenebiphenols including 9,9-bis(4-hydroxy-3-methylphenyl) xanthene and 9,9-bis(4-hydroxy-3,5-dimethylphenyl) xanthene with corresponding yields of 81% and 80.5%.Their structures were characterized by elemental analysis,FTIR,1H NMR and 13C NMR spectra.The present method has advantages such as mild reaction conditions,convenient manipulation and good yield.
Chlorination of xanthenone by thionyl chloride gave an intermediate 9,9-dichloroxanthene.The obtained chlorinated product is free of further isolation and purification and can react with o-cresol or 2,6-dimethylphenol for the preparation of two xthanenebiphenols including 9,9-bis(4-hydroxy-3-methylphenyl) xanthene and 9,9-bis(4-hydroxy-3,5-dimethylphenyl) xanthene with corresponding yields of 81% and 80.5%.Their structures were characterized by elemental analysis,FTIR,1H NMR and 13C NMR spectra.The present method has advantages such as mild reaction conditions,convenient manipulation and good yield.
