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2015 Volume 32 Issue 9
2015, 32(9): 977-986
doi: 10.11944/j.issn.1000-0518.2015.09.150112
Abstract:
p-Aminophenol (PAP) is an important chemical and pharmaceutical intermediate.Its synthesis from nitrobenzene (NB) has obvious advantages from the view of raw material,and the short reaction process as well as the low energy consumption.However,conventional liquid acid is usually used as catalyst in this reaction,which brings serious corrosion of equipment.Alkali is used to neutralize acid after the reaction to produce a great deal of solid waste of salt.Therefore,green technology for preparation of PAP from NB is of great significance,and becomes one of the hot research topics in these years.Most interests have been focused on searching for benign alternative to conventional liquid acid,and some progresses have been achieved,such as solid acid,acidic ionic liquid,Lewis acid,CO2-H2O system,and bi-functional catalysts with solid acid supported metal nanoparticles.Herein,we review the latest progresses on the hydrogenation of NB to PAP with these environmental benign acid catalysts and give the future development prospects.
p-Aminophenol (PAP) is an important chemical and pharmaceutical intermediate.Its synthesis from nitrobenzene (NB) has obvious advantages from the view of raw material,and the short reaction process as well as the low energy consumption.However,conventional liquid acid is usually used as catalyst in this reaction,which brings serious corrosion of equipment.Alkali is used to neutralize acid after the reaction to produce a great deal of solid waste of salt.Therefore,green technology for preparation of PAP from NB is of great significance,and becomes one of the hot research topics in these years.Most interests have been focused on searching for benign alternative to conventional liquid acid,and some progresses have been achieved,such as solid acid,acidic ionic liquid,Lewis acid,CO2-H2O system,and bi-functional catalysts with solid acid supported metal nanoparticles.Herein,we review the latest progresses on the hydrogenation of NB to PAP with these environmental benign acid catalysts and give the future development prospects.
2015, 32(9): 987-993
doi: 10.11944/j.issn.1000-0518.2015.09.150019
Abstract:
Four novel 1,2-O-isopropylidene-5-arylamino-α-glucofuranose derivatives were prepared using2-methyl-5-nitrobenzoicacid and 2-chloro-5-nitrobenzoic acid,respectively,as the starting materials by a synthetic route including chlorination of carboxylic acid,Friedel-Crafts acylation,reduction of carbonyl,reduction of nitro and reductive amination.The structures of intermediates and target compounds were characterized by IR,NMR and HRMS.The anti-tumor activities of target compounds on three kinds of cells were tested preliminarily by MTT method.The results indicate that the anti-tumor activitives of compound 1a1 is better than other three kinds of target compounds on three kinds of tumor cells,especially on A431(IC50:(6.54±1.34)μmol/L).
Four novel 1,2-O-isopropylidene-5-arylamino-α-glucofuranose derivatives were prepared using2-methyl-5-nitrobenzoicacid and 2-chloro-5-nitrobenzoic acid,respectively,as the starting materials by a synthetic route including chlorination of carboxylic acid,Friedel-Crafts acylation,reduction of carbonyl,reduction of nitro and reductive amination.The structures of intermediates and target compounds were characterized by IR,NMR and HRMS.The anti-tumor activities of target compounds on three kinds of cells were tested preliminarily by MTT method.The results indicate that the anti-tumor activitives of compound 1a1 is better than other three kinds of target compounds on three kinds of tumor cells,especially on A431(IC50:(6.54±1.34)μmol/L).
2015, 32(9): 994-998
doi: 10.11944/j.issn.1000-0518.2015.09.150020
Abstract:
A new nonlinear optical (NLO) organic material,1-ferrocenyl-3-((9-ethyl) carbazole-3-yl) acrylic ketone (FCAK),was synthesized and characterized by IR,MS,NMR and element analysis.The title compound exhibits third-order nonlinear optical properties.The related parameters were obtained by powder technique using the Nd:YAG laser.When the laser pulse is four nanoseconds,the nonlinear refractive index n2 is-3.5×10-18 m2/W,the nonlinear absorption coefficient β is -2.7×10-11 m/W,the third-order nonlinear polarizability χ(3) is 2.04×10-12 esu,the third-order nonlinear molecular hyperpolarizability γ is 1.1×10-30 esu.When the laser pulse is twenty one picoseconds,n2 is 0.55×10-18 m2/W,β is -0.6×10-11 m/W,χ(3) is 3.4×10-13 esu,γ is 0.13×10-30 esu.
A new nonlinear optical (NLO) organic material,1-ferrocenyl-3-((9-ethyl) carbazole-3-yl) acrylic ketone (FCAK),was synthesized and characterized by IR,MS,NMR and element analysis.The title compound exhibits third-order nonlinear optical properties.The related parameters were obtained by powder technique using the Nd:YAG laser.When the laser pulse is four nanoseconds,the nonlinear refractive index n2 is-3.5×10-18 m2/W,the nonlinear absorption coefficient β is -2.7×10-11 m/W,the third-order nonlinear polarizability χ(3) is 2.04×10-12 esu,the third-order nonlinear molecular hyperpolarizability γ is 1.1×10-30 esu.When the laser pulse is twenty one picoseconds,n2 is 0.55×10-18 m2/W,β is -0.6×10-11 m/W,χ(3) is 3.4×10-13 esu,γ is 0.13×10-30 esu.
2015, 32(9): 999-1004
doi: 10.11944/j.issn.1000-0518.2015.09.150038
Abstract:
Eight spiro heterobicyclic compounds were synthesized by the three component condensation reaction of aromatic aldehydes with urea and 2,2-dimethyl-1,3-dioxane-4,6-dione using boric acid as catalyst under solvent-free conditions.The results indicate that the yields range from 84% to 94% at 80℃ for 2.0~4.0 h using 10% molar fraction of boric acid (relative to the substrate of 2,2-dimethyl-1,3-dioxane-4,6-dione).Furthermore,a mechanism for the reaction catalyzed by boric acid was proposed.The main advantages of the present procedure are mild conditions,short reaction time and high yields.
Eight spiro heterobicyclic compounds were synthesized by the three component condensation reaction of aromatic aldehydes with urea and 2,2-dimethyl-1,3-dioxane-4,6-dione using boric acid as catalyst under solvent-free conditions.The results indicate that the yields range from 84% to 94% at 80℃ for 2.0~4.0 h using 10% molar fraction of boric acid (relative to the substrate of 2,2-dimethyl-1,3-dioxane-4,6-dione).Furthermore,a mechanism for the reaction catalyzed by boric acid was proposed.The main advantages of the present procedure are mild conditions,short reaction time and high yields.
2015, 32(9): 1005-1013
doi: 10.11944/j.issn.1000-0518.2015.09.150032
Abstract:
The 7-o-formylphenoxy ethoxy flavone was obtained from salicylaldehyde and 7-bromoethoxy flavones by solid phase synthetic method.Then fourteen flavone derivatives containing salicylidene Schiff bases were synthesized by the solid phase condensation reaction of 7-salicylidene ethoxy flavone with substituted N4-substituted semicarbazides,N4-substituted thiosemicarbazides and N-phenylglycine hydrazides.These new compounds were characterized by IR,1H NMR,ESI-MS and EA or HR-MS.Their scavenging effects on the superoxide radical (O2-·),hydroxyl radical (·OH) and DPPH·radical and their total reduction activities as well as the antimicrobial activities in vitro were evaluated.At 0.5 g/L concentration,most of the title compounds exhibit antioxidation effects and relatively antibacterial activity.Among them,the antibacterial activity of compound 3b is comparable to that of the control drug chloramphenicol.
The 7-o-formylphenoxy ethoxy flavone was obtained from salicylaldehyde and 7-bromoethoxy flavones by solid phase synthetic method.Then fourteen flavone derivatives containing salicylidene Schiff bases were synthesized by the solid phase condensation reaction of 7-salicylidene ethoxy flavone with substituted N4-substituted semicarbazides,N4-substituted thiosemicarbazides and N-phenylglycine hydrazides.These new compounds were characterized by IR,1H NMR,ESI-MS and EA or HR-MS.Their scavenging effects on the superoxide radical (O2-·),hydroxyl radical (·OH) and DPPH·radical and their total reduction activities as well as the antimicrobial activities in vitro were evaluated.At 0.5 g/L concentration,most of the title compounds exhibit antioxidation effects and relatively antibacterial activity.Among them,the antibacterial activity of compound 3b is comparable to that of the control drug chloramphenicol.
2015, 32(9): 1014-1021
doi: 10.11944/j.issn.1000-0518.2015.09.150014
Abstract:
A hydrazone-type Schiff base pyridine-4-carboxylic acid (2,4-dihydroxy-phenylethylidene)-hydrazide (H2L) was synthesized and characterized by elemental analysis,IR,UV,FL spectra,TGA and X-ray diffraction single crystal analysis which result showed that the crystal of HL·1.5 H2O belongs to the monoclinic system,space group C2/c with cell parameters a=2.0102(2) nm,b=0.75891(8) nm,c=1.9530(2) nm,β=111.481(12)°,V=2.7725(5) nm3,Z=4,Dc=1.4292 g/cm3,R1=0.0422,wR2=0.1113,F (000)=1256.The compound formed 3-D supermolecule via intermolecular hydrogen bondings.The quantum chemical calculation was performed by means of Gaussian 09 program at B3 LYP/6-31G (d) basis set.After optimization of molecular geometry,some important thermodynamic parameters and structural parameters were obtained.The molecular dipole moment,C=N Wiberg bond order,Mulliken charge population and frontier molecular orbital energy have been analyzed and discussed.TD-DFT method is used to calculate the absorption and fluorescence spectra of the compound.CCDC 994067.
A hydrazone-type Schiff base pyridine-4-carboxylic acid (2,4-dihydroxy-phenylethylidene)-hydrazide (H2L) was synthesized and characterized by elemental analysis,IR,UV,FL spectra,TGA and X-ray diffraction single crystal analysis which result showed that the crystal of HL·1.5 H2O belongs to the monoclinic system,space group C2/c with cell parameters a=2.0102(2) nm,b=0.75891(8) nm,c=1.9530(2) nm,β=111.481(12)°,V=2.7725(5) nm3,Z=4,Dc=1.4292 g/cm3,R1=0.0422,wR2=0.1113,F (000)=1256.The compound formed 3-D supermolecule via intermolecular hydrogen bondings.The quantum chemical calculation was performed by means of Gaussian 09 program at B3 LYP/6-31G (d) basis set.After optimization of molecular geometry,some important thermodynamic parameters and structural parameters were obtained.The molecular dipole moment,C=N Wiberg bond order,Mulliken charge population and frontier molecular orbital energy have been analyzed and discussed.TD-DFT method is used to calculate the absorption and fluorescence spectra of the compound.CCDC 994067.
2015, 32(9): 1022-1027
doi: 10.11944/j.issn.1000-0518.2015.09.150064
Abstract:
Poly (ethylene 2,5-furandicarboxylate)(PEF)/poly (butylene succinate)(PBS) blends were obtained via melt blending,and the factors,such as the blending temperature,blending time,the screw speed and blending ratio on mechanical properties of PEF/PBS blends were studied in details.Their compatibility,thermal property,and mechanical property were investigated by scanning electron microscopy,differential scanning calorimetry,thermogravimetric analysis,and tensile testing and impact testing.When the content of PBS is 15%,the optimal blending processing conditions are mixing the blends at 230℃ for 90 s under the screw rotation speed of 150 r/min.Under the optimal conditions,the compatibility and thermal performance are good,the impact strength and tensile strength are the largest.Compared to PEF,the impact strength and the tensile strength of the blend increase 6 times and approximate 20%,respectively.The results in this work provide a new possibility for the application of biobased polymers.
Poly (ethylene 2,5-furandicarboxylate)(PEF)/poly (butylene succinate)(PBS) blends were obtained via melt blending,and the factors,such as the blending temperature,blending time,the screw speed and blending ratio on mechanical properties of PEF/PBS blends were studied in details.Their compatibility,thermal property,and mechanical property were investigated by scanning electron microscopy,differential scanning calorimetry,thermogravimetric analysis,and tensile testing and impact testing.When the content of PBS is 15%,the optimal blending processing conditions are mixing the blends at 230℃ for 90 s under the screw rotation speed of 150 r/min.Under the optimal conditions,the compatibility and thermal performance are good,the impact strength and tensile strength are the largest.Compared to PEF,the impact strength and the tensile strength of the blend increase 6 times and approximate 20%,respectively.The results in this work provide a new possibility for the application of biobased polymers.
2015, 32(9): 1028-1032
doi: 10.11944/j.issn.1000-0518.2015.09.140452
Abstract:
(1-Adamantyl) NSiMe2(C5Me4)]TiMe2(c) was synthesized and characterized by elemental analysis,1H NMR,and single-crystal X-ray analysis.Propylene polymerization was conducted with complex c using modified methyaluminoxane (MMAO)/butylated hydroxytoluene (BHT) as a cocatalyst to compare the polymerization activity of complex c with that of tert-butylamido complex (tBuNSiMe2(C5Me4)]TiMe2)(a).The c-heptane system shows an activity of 562 kg (PP)/(mol(Ti)·h) which is two times higher than that of a-heptane system indicating that the activity is improved by the introduction of 1-adamantyl substituent to the amido ligand.
(1-Adamantyl) NSiMe2(C5Me4)]TiMe2(c) was synthesized and characterized by elemental analysis,1H NMR,and single-crystal X-ray analysis.Propylene polymerization was conducted with complex c using modified methyaluminoxane (MMAO)/butylated hydroxytoluene (BHT) as a cocatalyst to compare the polymerization activity of complex c with that of tert-butylamido complex (tBuNSiMe2(C5Me4)]TiMe2)(a).The c-heptane system shows an activity of 562 kg (PP)/(mol(Ti)·h) which is two times higher than that of a-heptane system indicating that the activity is improved by the introduction of 1-adamantyl substituent to the amido ligand.
2015, 32(9): 1033-1039
doi: 10.11944/j.issn.1000-0518.2015.09.150028
Abstract:
Co2/Al/Mgx layered double hydroxides (LDHs) with different Co2/Al/Mgx ratios (x=0.5,1,1.5and 2) were prepared and characterized by XRD,SEM,FT-IR,BET and ICP techniques.These catalysts were studied for selective oxidation of benzyl alcohol to benzaldehyde.The results indicate that the selectivity of benzaldehyde increases with increasing of Mg content.Under the optimized condition:0.02 mol of benzyl alcohol,100 mg of Co2AlMg1-LDH,0.04 mol of tert-butyl hydroperoxide,8 m L of acetonitrile,reaction temperature 60℃ and reaction time 9 h,the conversion of benzyl alcohol is 39.5% and the selectivity of benzaldehyde reaches 89.2%.The catalysts are reused 5 times without obvious loss of the catalytic activity and selectivity.
Co2/Al/Mgx layered double hydroxides (LDHs) with different Co2/Al/Mgx ratios (x=0.5,1,1.5and 2) were prepared and characterized by XRD,SEM,FT-IR,BET and ICP techniques.These catalysts were studied for selective oxidation of benzyl alcohol to benzaldehyde.The results indicate that the selectivity of benzaldehyde increases with increasing of Mg content.Under the optimized condition:0.02 mol of benzyl alcohol,100 mg of Co2AlMg1-LDH,0.04 mol of tert-butyl hydroperoxide,8 m L of acetonitrile,reaction temperature 60℃ and reaction time 9 h,the conversion of benzyl alcohol is 39.5% and the selectivity of benzaldehyde reaches 89.2%.The catalysts are reused 5 times without obvious loss of the catalytic activity and selectivity.
2015, 32(9): 1040-1047
doi: 10.11944/j.issn.1000-0518.2015.09.150075
Abstract:
Copper oxide/zinc oxide/3A molecular sieve (CuO/ZnO/3A) photocatalyst was prepared by impregnation method and calcined in 450℃,and the structure of Cu O/Zn O/3A was characterized by X-ray diffraction (XRD),UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS),and X-ray photoelectron spectroscopy (XPS).Its photocatalytic denitrification behavior was studied by pyridine-n-octane system for simulated oil source of nitrogen under visible light irradiation.The influences of the preparation conditions of the photocatalyst,the amount of photocatalyst and the time of light irradiation on the photocatalytic denitrification performance were investigated.With the increase of the amount of metal oxide,photocatalytic activity of the complex increased at first and then decreased.The CuO/ZnO/3A composite photocatalyst calcined at 400℃ for 5 h with 9.8% mass fraction of zinc and 28.6% of copper enabled 74.78% denitrification of the simulated oil system,after a reaction under visible light of 50 m L solution containing100 μg/g of pyridine for 150 min.
Copper oxide/zinc oxide/3A molecular sieve (CuO/ZnO/3A) photocatalyst was prepared by impregnation method and calcined in 450℃,and the structure of Cu O/Zn O/3A was characterized by X-ray diffraction (XRD),UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS),and X-ray photoelectron spectroscopy (XPS).Its photocatalytic denitrification behavior was studied by pyridine-n-octane system for simulated oil source of nitrogen under visible light irradiation.The influences of the preparation conditions of the photocatalyst,the amount of photocatalyst and the time of light irradiation on the photocatalytic denitrification performance were investigated.With the increase of the amount of metal oxide,photocatalytic activity of the complex increased at first and then decreased.The CuO/ZnO/3A composite photocatalyst calcined at 400℃ for 5 h with 9.8% mass fraction of zinc and 28.6% of copper enabled 74.78% denitrification of the simulated oil system,after a reaction under visible light of 50 m L solution containing100 μg/g of pyridine for 150 min.
2015, 32(9): 1048-1054
doi: 10.11944/j.issn.1000-0518.2015.09.150071
Abstract:
Three kinds of BiOBr crystal micropowders with different morphological structure have been synthesized via an ethylene glycol solvothermal route using the methylimidazolium bromide type ionic liquids[C4mim]Br,[C8mim]Br and[C12mim]Br as bromo source and soft template.The results from X-ray diffraction (XRD),scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis show that the as-prepared BiOBr products all belong to tetragonal phase in high purity.The BiOBr crystals along (110) lattice plane preferentially grow with the increase of carbon atom number (Cn) of substituent group in ionic liquid cation.The micro sized BiOBr particles clusters are all consisted of nanosize petal-like flakes via self-assembly,which show radial pattern from spherical center.As the Cn number increases,the particle size and surface pores all decrease,but the specific surface area increases.The three BiOBr powders possess different catalytic activity for visible photocatalytic degradation of aniline.The degradation ratios of the aniline solution are 54.13%,78.67% and 95.06% in 280 minutes,respectively.The photogenerated holes should be the main active species in the photodegradation process,but the hydroxyl radical just plays a minor role.
Three kinds of BiOBr crystal micropowders with different morphological structure have been synthesized via an ethylene glycol solvothermal route using the methylimidazolium bromide type ionic liquids[C4mim]Br,[C8mim]Br and[C12mim]Br as bromo source and soft template.The results from X-ray diffraction (XRD),scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis show that the as-prepared BiOBr products all belong to tetragonal phase in high purity.The BiOBr crystals along (110) lattice plane preferentially grow with the increase of carbon atom number (Cn) of substituent group in ionic liquid cation.The micro sized BiOBr particles clusters are all consisted of nanosize petal-like flakes via self-assembly,which show radial pattern from spherical center.As the Cn number increases,the particle size and surface pores all decrease,but the specific surface area increases.The three BiOBr powders possess different catalytic activity for visible photocatalytic degradation of aniline.The degradation ratios of the aniline solution are 54.13%,78.67% and 95.06% in 280 minutes,respectively.The photogenerated holes should be the main active species in the photodegradation process,but the hydroxyl radical just plays a minor role.
2015, 32(9): 1055-1060
doi: 10.11944/j.issn.1000-0518.2015.09.150027
Abstract:
A new bicapped Keggin molybdenum-vanadium polyoxometalate[Cu (2,2'-bpy)3]{[Cu (2,2'-bpy)2]2HPⅤMo8ⅥV6ⅣO42}}·2H2O 1(bpy=bipyridien) was prepared under hydrothermal conditions,and characterized by elemental analysis,IR,X-ray photoelectron spectroscopy,powder and single crystal X-ray diffraction analysis.The compound 1 crystallized in a monoclinic system,with a C2/c space group:a=2.8734(3) nm,b=1.47333(12) nm,c=2.31023(16) nm,β=112.509(5)°,V=9.0351(12) nm3,Z=1,R1=0.0489,wR2=0.1286.The polyoxoanion of compound 1 is a bi-capped P/Mo/V Keggin cluster supporting two copper complexes fragment through the oxygen of capping V atoms of polyoxoanion.Compound 1 exhibits an extended three-dimensional supramolecular network via hydrogen-bonding and π-π stacking interactions between polyoxoanion,water molecules and 2,2'-bpy molecules.
A new bicapped Keggin molybdenum-vanadium polyoxometalate[Cu (2,2'-bpy)3]{[Cu (2,2'-bpy)2]2HPⅤMo8ⅥV6ⅣO42}}·2H2O 1(bpy=bipyridien) was prepared under hydrothermal conditions,and characterized by elemental analysis,IR,X-ray photoelectron spectroscopy,powder and single crystal X-ray diffraction analysis.The compound 1 crystallized in a monoclinic system,with a C2/c space group:a=2.8734(3) nm,b=1.47333(12) nm,c=2.31023(16) nm,β=112.509(5)°,V=9.0351(12) nm3,Z=1,R1=0.0489,wR2=0.1286.The polyoxoanion of compound 1 is a bi-capped P/Mo/V Keggin cluster supporting two copper complexes fragment through the oxygen of capping V atoms of polyoxoanion.Compound 1 exhibits an extended three-dimensional supramolecular network via hydrogen-bonding and π-π stacking interactions between polyoxoanion,water molecules and 2,2'-bpy molecules.
2015, 32(9): 1061-1069
doi: 10.11944/j.issn.1000-0518.2015.09.150111
Abstract:
A water-soluble weakly crosslinked xanthan gum (XG) was synthesized using sodium trimetaphosphate (STMP) as a crosslinker,and the synthesis conditions were optimized based on the viscosity of the STMP crosslinked XG (denoted as SP-c-XG) solutions.Effects of electrolyte (NaCl and Ca Cl2) mass fraction (0~5.0%),p H (2~11),and temperature (20~70℃) on the rheological properties of the SP-c-XG solutions were investigated and compared with those of XG solutions.The results show that,under the studied conditions,the rheological curves of both SP-c-XG and XG solutions are pseudoplastic and can be described by Herschel-Bulkley model.The yield stress,apparent viscosity and dynamic moduli of the SP-c-XG and XG solutions initially decrease and then increase with increasing electrolyte concentration,but they initially increase and then decrease with increasing p H.Increasing temperature results in a decrease in these rheological parameter values for both SP-c-XG and XG solutions.The rheological properties of the SP-c-XG solution are similar to those of the XG solution.However,compared with the XG solution,the SP-c-XG solution exhibits higher yield stress and apparent viscosity,especially stronger elasticity and temperature resistance,indicating its use potential in enhanced oil recovery.
A water-soluble weakly crosslinked xanthan gum (XG) was synthesized using sodium trimetaphosphate (STMP) as a crosslinker,and the synthesis conditions were optimized based on the viscosity of the STMP crosslinked XG (denoted as SP-c-XG) solutions.Effects of electrolyte (NaCl and Ca Cl2) mass fraction (0~5.0%),p H (2~11),and temperature (20~70℃) on the rheological properties of the SP-c-XG solutions were investigated and compared with those of XG solutions.The results show that,under the studied conditions,the rheological curves of both SP-c-XG and XG solutions are pseudoplastic and can be described by Herschel-Bulkley model.The yield stress,apparent viscosity and dynamic moduli of the SP-c-XG and XG solutions initially decrease and then increase with increasing electrolyte concentration,but they initially increase and then decrease with increasing p H.Increasing temperature results in a decrease in these rheological parameter values for both SP-c-XG and XG solutions.The rheological properties of the SP-c-XG solution are similar to those of the XG solution.However,compared with the XG solution,the SP-c-XG solution exhibits higher yield stress and apparent viscosity,especially stronger elasticity and temperature resistance,indicating its use potential in enhanced oil recovery.
2015, 32(9): 1070-1074
doi: 10.11944/j.issn.1000-0518.2015.09.150052
Abstract:
High strength bulk aluminum has been prepared by mechanical milling and press-forming processes.The bulk aluminum exhibits a high tensile strength of 537 MPa and a yield strength of 495 MPa.Characterization of microstructures reveals that the grain size of the bulk aluminum is between 0.5~5 μm.The high strength of pure aluminum is benefit from the fine grain size.The low fabrication cost with mechanical milling and press-forming is suitable for industrialized production.
High strength bulk aluminum has been prepared by mechanical milling and press-forming processes.The bulk aluminum exhibits a high tensile strength of 537 MPa and a yield strength of 495 MPa.Characterization of microstructures reveals that the grain size of the bulk aluminum is between 0.5~5 μm.The high strength of pure aluminum is benefit from the fine grain size.The low fabrication cost with mechanical milling and press-forming is suitable for industrialized production.
2015, 32(9): 1075-1080
doi: 10.11944/j.issn.1000-0518.2015.09.150048
Abstract:
Nano-porous copper film was prepared by sol-gel electroplating.Using copper sheet as anode,the effects of the plating solution composition,plating time,cathode substrate and plating voltage on the morphology of the plating layer were investigated in the plating voltage at 5 V.Scanning electron microscopy and X-ray diffraction methods were utilized to analyze the morphology and crystal forms to obtain the optimum conditions for preparing the copper films.The particle size of the copper film is about 100 nm,grain size is about 25 nm,and an enhanced (111) texture exists in the cooper film.XRD analysis depicts that the attached chitosan gel protects the copper film from being oxidized.The plating current tends to be stable at a low value after a certain time of plating.Chitosan gel prevents further deposition of copper ions in the bath on the substrate.
Nano-porous copper film was prepared by sol-gel electroplating.Using copper sheet as anode,the effects of the plating solution composition,plating time,cathode substrate and plating voltage on the morphology of the plating layer were investigated in the plating voltage at 5 V.Scanning electron microscopy and X-ray diffraction methods were utilized to analyze the morphology and crystal forms to obtain the optimum conditions for preparing the copper films.The particle size of the copper film is about 100 nm,grain size is about 25 nm,and an enhanced (111) texture exists in the cooper film.XRD analysis depicts that the attached chitosan gel protects the copper film from being oxidized.The plating current tends to be stable at a low value after a certain time of plating.Chitosan gel prevents further deposition of copper ions in the bath on the substrate.
2015, 32(9): 1081-1087
doi: 10.11944/j.issn.1000-0518.2015.09.140446
Abstract:
An ITO supported nanostructure manganese dioxide thin film electrode,fabricated by chronoamperometry was evaluated as a potential electrode for electrochemical capacitors.The nucleation mechanism was examined by fitting the experimental data (chronoamperometry) into the Scharifker/Hills nucleation models.SEM images of the electrodeposits show that the microstructure of manganese dioxide is affected by the deposition period.The capacity of the three kinds of manganese dioxide electrode materials formed by different nucleation mechanisms was investigated by cycle voltammetry,constant current chargedischarge method and AC impedance.The results show that the nucleation follows an instantaneous nucleation mechanism in the solution of 0.1 mol/L Mn2+ under a 0.365 V step potential,and mixed instantaneous and progressive nucleation mechanism in the solution of 0.01 mol/L Mn2+ under a 0.418 V step potential.The nucleation follows a progressive nucleation mechanism in the solution of 0.5 mmol/L Mn2+ under a 0.515 V step potential.It is obvious that the instantaneous nucleation is beneficial to preparing deposit sediment which has high specific surface area.Compare with other electrolytic deposit materials,this kind of material displays a better capacitance performance,implying that the capacitance performance can be influenced via different deposit approaches.
An ITO supported nanostructure manganese dioxide thin film electrode,fabricated by chronoamperometry was evaluated as a potential electrode for electrochemical capacitors.The nucleation mechanism was examined by fitting the experimental data (chronoamperometry) into the Scharifker/Hills nucleation models.SEM images of the electrodeposits show that the microstructure of manganese dioxide is affected by the deposition period.The capacity of the three kinds of manganese dioxide electrode materials formed by different nucleation mechanisms was investigated by cycle voltammetry,constant current chargedischarge method and AC impedance.The results show that the nucleation follows an instantaneous nucleation mechanism in the solution of 0.1 mol/L Mn2+ under a 0.365 V step potential,and mixed instantaneous and progressive nucleation mechanism in the solution of 0.01 mol/L Mn2+ under a 0.418 V step potential.The nucleation follows a progressive nucleation mechanism in the solution of 0.5 mmol/L Mn2+ under a 0.515 V step potential.It is obvious that the instantaneous nucleation is beneficial to preparing deposit sediment which has high specific surface area.Compare with other electrolytic deposit materials,this kind of material displays a better capacitance performance,implying that the capacitance performance can be influenced via different deposit approaches.
2015, 32(9): 1088-1092
doi: 10.11944/j.issn.1000-0518.2015.09.150004
Abstract:
According to the acidicity difference between the main impurity and benzafibrate,carbon dioxide was introduced into the alkaline product solution to remove the impurity from benzafibrate in the post-treatment process.The yield and content of the treated products were determined to compare the separation effect with different methods of precipitation and recrystallization.Compared with recrystallization,the yield of the product treated with CO2 was increased from 62.5% to 70.9%.The method not only reduced the relatively large solvent consumption and product loss caused by the repeated recrystallization,but also effectively improved the removal rate of impurities and decreased the separation cost.
According to the acidicity difference between the main impurity and benzafibrate,carbon dioxide was introduced into the alkaline product solution to remove the impurity from benzafibrate in the post-treatment process.The yield and content of the treated products were determined to compare the separation effect with different methods of precipitation and recrystallization.Compared with recrystallization,the yield of the product treated with CO2 was increased from 62.5% to 70.9%.The method not only reduced the relatively large solvent consumption and product loss caused by the repeated recrystallization,but also effectively improved the removal rate of impurities and decreased the separation cost.
2015, 32(9): 1093-1098
doi: 10.11944/j.issn.1000-0518.2015.09.150033
Abstract:
The detection of imprint left by zinc coatings on human skins was studied.The affecting factors such as contact time,time elapse from the contact to the reaction,concentration of 2-(5-bromo-2-pyridylazo)-5-(diethylamino) phenol (5-Br-PADAP) reagent and washing on the intensity and resolution of imprints were studied and the reliability of this method was verified.As shown in experimental results,good imprints can be obtained with a concentration of 1 g/L of 5-Br-PADAP,contact time of 10 s,time elapse of less than 4 h.This method can develop imprints left by zinc coatings sensitively as a good supplement for the detection of imprints left by nonferrous metal tools.
The detection of imprint left by zinc coatings on human skins was studied.The affecting factors such as contact time,time elapse from the contact to the reaction,concentration of 2-(5-bromo-2-pyridylazo)-5-(diethylamino) phenol (5-Br-PADAP) reagent and washing on the intensity and resolution of imprints were studied and the reliability of this method was verified.As shown in experimental results,good imprints can be obtained with a concentration of 1 g/L of 5-Br-PADAP,contact time of 10 s,time elapse of less than 4 h.This method can develop imprints left by zinc coatings sensitively as a good supplement for the detection of imprints left by nonferrous metal tools.
