Login In
2012 Volume 29 Issue 1
2012, 29(1): 1-8
doi: 10.3724/SP.J.1095.2012.00151
Abstract:
As one of the most effective methods for personal identification,the discovery and visualization of blood fingerprints play a key role in criminal investigation.According to the different reaction mechanism,the methods can be classified as chemical reaction;physical adsorption;biological labeling and optical photography.In this paper,we review the detection techniques and materials of the blood fingerprints and their advantages and disadvantages.In addition,we analyze the new trend and perspective in the blood fingerprints' examination.
As one of the most effective methods for personal identification,the discovery and visualization of blood fingerprints play a key role in criminal investigation.According to the different reaction mechanism,the methods can be classified as chemical reaction;physical adsorption;biological labeling and optical photography.In this paper,we review the detection techniques and materials of the blood fingerprints and their advantages and disadvantages.In addition,we analyze the new trend and perspective in the blood fingerprints' examination.
2012, 29(1): 9-13
doi: 10.3724/SP.J.1095.2012.00079
Abstract:
Phase change microcapsules were synthesized using chitosan as the shell material and paraffin as the core material via multi-emulsionization and cross-linking method.During the phase change of the paraffin,the microcapsules can store and release energy.The enthalpy value of the phase change of the microcapsules is higher than 110 J/g.The suitable phase change temperature can be obtained by changing the core material.The resultant microcapsules show excellent thermal stability,and remain stable below 150℃ as demonstrated by TGA measurement.The microcapsules also exhibit good solvent-resistance because of the cross-linking between chitosan and glutaraldehyde.
Phase change microcapsules were synthesized using chitosan as the shell material and paraffin as the core material via multi-emulsionization and cross-linking method.During the phase change of the paraffin,the microcapsules can store and release energy.The enthalpy value of the phase change of the microcapsules is higher than 110 J/g.The suitable phase change temperature can be obtained by changing the core material.The resultant microcapsules show excellent thermal stability,and remain stable below 150℃ as demonstrated by TGA measurement.The microcapsules also exhibit good solvent-resistance because of the cross-linking between chitosan and glutaraldehyde.
2012, 29(1): 14-17
doi: 10.3724/SP.J.1095.2012.00167
Abstract:
Organic-inorganic hybrid polyurethane composites with excellent heat-resistance were synthesized via reaction of toluene-2,4-diisocyanate(TDI) prepolymer,3,3-dichloro-4,4-diamino diphenylmethane(MOCA),aminopropyl triethoxysilane(APTEOS) and tetraethoxysilane(TEOS).Molecular structures and properties of the material were characterized by IR,TGA,friction tester and hardness analyzer.Thermal stabilities of the composites were greatly improved due to the introduction of the Si-O networks into the molecules.These materials show rather low friction coefficient(about 0.001 as speed higher than 200 r/min) and appropriate hardness(shore 92 A) for water-lubricated bearings application.The results confirmed that the organic-inorganic hybrid polyurethane composites prepared in this work were reliable for water-lubricated bearings production due to the excellent performances of wearability,high loadability and easy processibility.
Organic-inorganic hybrid polyurethane composites with excellent heat-resistance were synthesized via reaction of toluene-2,4-diisocyanate(TDI) prepolymer,3,3-dichloro-4,4-diamino diphenylmethane(MOCA),aminopropyl triethoxysilane(APTEOS) and tetraethoxysilane(TEOS).Molecular structures and properties of the material were characterized by IR,TGA,friction tester and hardness analyzer.Thermal stabilities of the composites were greatly improved due to the introduction of the Si-O networks into the molecules.These materials show rather low friction coefficient(about 0.001 as speed higher than 200 r/min) and appropriate hardness(shore 92 A) for water-lubricated bearings application.The results confirmed that the organic-inorganic hybrid polyurethane composites prepared in this work were reliable for water-lubricated bearings production due to the excellent performances of wearability,high loadability and easy processibility.
2012, 29(1): 18-22
doi: 10.3724/SP.J.1095.2012.00029
Abstract:
A series of high melt flow index(MFI) polypropylene(PP) in-reactor alloys with different contents of hexane soluble fraction was prepared by bulk-gas phase polymerization process using spherical Ziegler-Natta catalyst(phosphate as internal electron donor).The mechanical properties and microcosmic morphology of the obtained PP in-reactor alloys were investigated.It was found that the impact strength increased with the increase of hexane soluble fraction.Impact strength increased from 4.4 kJ/m2 to 52.7 kJ/m2.While the flexure strength and tensile strength slightly decreased,tensile strength decreased from 28.6 MPa to 19.5 MPa,the flexure strength decreased from 37.2 MPa to 21.5 MPa.According to the micrographs of FESEM,the ethylene-propylene rubber(EPR) phase was evenly dispersed in PP matrix and formed "core-shell" structure.
A series of high melt flow index(MFI) polypropylene(PP) in-reactor alloys with different contents of hexane soluble fraction was prepared by bulk-gas phase polymerization process using spherical Ziegler-Natta catalyst(phosphate as internal electron donor).The mechanical properties and microcosmic morphology of the obtained PP in-reactor alloys were investigated.It was found that the impact strength increased with the increase of hexane soluble fraction.Impact strength increased from 4.4 kJ/m2 to 52.7 kJ/m2.While the flexure strength and tensile strength slightly decreased,tensile strength decreased from 28.6 MPa to 19.5 MPa,the flexure strength decreased from 37.2 MPa to 21.5 MPa.According to the micrographs of FESEM,the ethylene-propylene rubber(EPR) phase was evenly dispersed in PP matrix and formed "core-shell" structure.
2012, 29(1): 23-28
doi: 10.3724/SP.J.1095.2012.00045
Abstract:
In this work,a new type of three dimensional(3D) nanochannel system was constructed using the electrospinning technology.A series mass fractions of polystyrene(PS:Mw=1.3×105 g/mol) solution with different concentration in the presences of certain amounts of sodium dodecyl sulfonate were spun via electrostatic spinning technology at different voltage.The fiber was crosslinked by heat treatment under 90℃ to obtain the 3D PS network template.Then the silicone oligomer(polydimethylsiloxane,PDMS) in hexane solution(containing 10% crosslinking agent) was infused into this fiber template,and crosslinked.After that,the PS fiber was dissolved in carbon disulfide via ultrasonication.The results from scanning electron microscopy and transmission electron microscopy showed that the PS fiber with diameter about 150 nm was fabricated at a voltage of 20 kV with the mass fraction of 10% in the presence of 0.5%SDS.The presence of SDS helped to improve the lubrication effect and make the elimination of PS easier.The obtained 3D channel had a diameter of 160 nm which was consistent with the fiber diameter of the template.This type of nanochannel system could be a good candidate for medical drug delivery and nanofluidic chips,etc.
In this work,a new type of three dimensional(3D) nanochannel system was constructed using the electrospinning technology.A series mass fractions of polystyrene(PS:Mw=1.3×105 g/mol) solution with different concentration in the presences of certain amounts of sodium dodecyl sulfonate were spun via electrostatic spinning technology at different voltage.The fiber was crosslinked by heat treatment under 90℃ to obtain the 3D PS network template.Then the silicone oligomer(polydimethylsiloxane,PDMS) in hexane solution(containing 10% crosslinking agent) was infused into this fiber template,and crosslinked.After that,the PS fiber was dissolved in carbon disulfide via ultrasonication.The results from scanning electron microscopy and transmission electron microscopy showed that the PS fiber with diameter about 150 nm was fabricated at a voltage of 20 kV with the mass fraction of 10% in the presence of 0.5%SDS.The presence of SDS helped to improve the lubrication effect and make the elimination of PS easier.The obtained 3D channel had a diameter of 160 nm which was consistent with the fiber diameter of the template.This type of nanochannel system could be a good candidate for medical drug delivery and nanofluidic chips,etc.
2012, 29(1): 29-36
doi: 10.3724/SP.J.1095.2012.00077
Abstract:
Narrowly distributed and size controllable cationic polystyrene(PS) nanoemulsions were prepared through modified microemulsion polymerization with a cationic gemini surfactant as emulsifier without using any cosurfactants.The main feature of the modified microemulsion polymerization is that most of the styrene in the form of preemulsion is post-added gradually into the initiated microemulsion,and the cationic gemini surfactant with high emulsifying property is employed to decrease particle size.The results show that a small amount of trimethylallylammonium chloride used as comonomer can reduce Z-average particle size and size distribution.Emulsifier content,initiator content and reaction temperature can affect particle size and size distribution of obtained colloid particles.The best experimental conditions for preparing the cationic polystyrene nanoparticles with small particle size as well as narrow size distribution are emulsifier content(the mass ratio versus styrene(St) at 5%~10%,initiator content at 1.0%~1.5%,reaction temperature at 70~75℃.The linear relationship between the Z-average particle size and St feeding amount demonstrates that Z-average particle size can be controlled by varying the St feeding amount.The result of effects of the polymerization process on the particle size and size distribution of nanoparticles shows that the modified microemulsion polymerization process(semi-continuous and pre-emulsification) possesses great superiority in preparing narrowly distributed polymer nanoparticles.
Narrowly distributed and size controllable cationic polystyrene(PS) nanoemulsions were prepared through modified microemulsion polymerization with a cationic gemini surfactant as emulsifier without using any cosurfactants.The main feature of the modified microemulsion polymerization is that most of the styrene in the form of preemulsion is post-added gradually into the initiated microemulsion,and the cationic gemini surfactant with high emulsifying property is employed to decrease particle size.The results show that a small amount of trimethylallylammonium chloride used as comonomer can reduce Z-average particle size and size distribution.Emulsifier content,initiator content and reaction temperature can affect particle size and size distribution of obtained colloid particles.The best experimental conditions for preparing the cationic polystyrene nanoparticles with small particle size as well as narrow size distribution are emulsifier content(the mass ratio versus styrene(St) at 5%~10%,initiator content at 1.0%~1.5%,reaction temperature at 70~75℃.The linear relationship between the Z-average particle size and St feeding amount demonstrates that Z-average particle size can be controlled by varying the St feeding amount.The result of effects of the polymerization process on the particle size and size distribution of nanoparticles shows that the modified microemulsion polymerization process(semi-continuous and pre-emulsification) possesses great superiority in preparing narrowly distributed polymer nanoparticles.
2012, 29(1): 37-40
doi: 10.3724/SP.J.1095.2012.00036
Abstract:
Narrow dispersed CaCO3/poly(styrene-co-n-butylacrylate)(CaCO3/P(St-co-nBA)) composite particles with average diameter of 1.76 μm were obtained via a dispersion copolymerization of St and nBA in the presence of stearic acid modified nano-CaCO3 particles.The products were characterized by transmission electron microscopy(TEM),optical microscope(OM),fourier transfer infrared spectroscopy(FT-IR),thermogravimetric analysis(TGA),and X-ray diffraction(XRD).The TEM images indicated the composite particles had nano-CaCO3 core and P(St-co-nBA) shell structure.The TGA analysis results of composite particles before and after being extracted with dimethylbenzene showed the thermal decomposition temperature of the cladding polymer was higher than that of pure copolymer P(St-co-nBA),and some copolymer couldn't be extracted.The FT-IR spectra also confirmed the existence of copolymer on the composite particles after extracting.It suggested that the copolymer had chemical bonding with nano-CaCO3.The mass proportion of P(St-co-nBA) which couldn't be extracted with accounted for 6.6% based on the mass of nano-CaCO3.
Narrow dispersed CaCO3/poly(styrene-co-n-butylacrylate)(CaCO3/P(St-co-nBA)) composite particles with average diameter of 1.76 μm were obtained via a dispersion copolymerization of St and nBA in the presence of stearic acid modified nano-CaCO3 particles.The products were characterized by transmission electron microscopy(TEM),optical microscope(OM),fourier transfer infrared spectroscopy(FT-IR),thermogravimetric analysis(TGA),and X-ray diffraction(XRD).The TEM images indicated the composite particles had nano-CaCO3 core and P(St-co-nBA) shell structure.The TGA analysis results of composite particles before and after being extracted with dimethylbenzene showed the thermal decomposition temperature of the cladding polymer was higher than that of pure copolymer P(St-co-nBA),and some copolymer couldn't be extracted.The FT-IR spectra also confirmed the existence of copolymer on the composite particles after extracting.It suggested that the copolymer had chemical bonding with nano-CaCO3.The mass proportion of P(St-co-nBA) which couldn't be extracted with accounted for 6.6% based on the mass of nano-CaCO3.
2012, 29(1): 41-45
doi: 10.3724/SP.J.1095.2012.00041
Abstract:
The long afterglow luminescent material of SrAl2O4:Eu2+,Dy3+ was encapsulated with polystyrene foamed plastic via a simple physical technology,and charaeterized by means of X-ray diffraction patterns,fourier transform infrared spectroscopy,excitation and emission spectra,thermogravimetric analysis,and transmission electron microscopy observation.Its water durability was investigated.The results show that the encapsulated layer has a thickness of about 5~10 nm and the mass fraction of encapsulation amount is about 4.9%.The encapsulation does not change the inner structure of the phosphor and has barely influence on their photoluminescence.The encapsulation can effectively improve the water durability of the phosphors with initial intensity of 5.02 cd/m2.The decay time can reach up to over 10 h after immersed in water for 15 h.
The long afterglow luminescent material of SrAl2O4:Eu2+,Dy3+ was encapsulated with polystyrene foamed plastic via a simple physical technology,and charaeterized by means of X-ray diffraction patterns,fourier transform infrared spectroscopy,excitation and emission spectra,thermogravimetric analysis,and transmission electron microscopy observation.Its water durability was investigated.The results show that the encapsulated layer has a thickness of about 5~10 nm and the mass fraction of encapsulation amount is about 4.9%.The encapsulation does not change the inner structure of the phosphor and has barely influence on their photoluminescence.The encapsulation can effectively improve the water durability of the phosphors with initial intensity of 5.02 cd/m2.The decay time can reach up to over 10 h after immersed in water for 15 h.
2012, 29(1): 46-51
doi: 10.3724/SP.J.1095.2012.00070
Abstract:
To improve the bioactivity and adhesion strength of hydroxyapatite(HA) coatings on titanium substrate,porous nano-HA coatings were deposited on titanium substrate using porogens such as glucose,starch and chitosan by electrophoretic deposition and sintering processes.The changes of surface morphology,chemical composition and phase composition of the porous HA coatings before and after immersion in simulated body fluid(SBF) were also investigated.The results showed that the porous HA coating was obtained by sintering at 700℃.These porous HA coating surfaces were covered by carbonate-apatite particles after immersion in 1.5 times ion concentration of SBF for 5 days,with diameter about 5~25 μm,indicating that these coatings possessed an excellent bioactivity on its surface.The adhesion strength between coating and substrate was up to 19.5 MPa using CS as porogens.The developed method is promising to develop new implant bioceramic materials of human bone.
To improve the bioactivity and adhesion strength of hydroxyapatite(HA) coatings on titanium substrate,porous nano-HA coatings were deposited on titanium substrate using porogens such as glucose,starch and chitosan by electrophoretic deposition and sintering processes.The changes of surface morphology,chemical composition and phase composition of the porous HA coatings before and after immersion in simulated body fluid(SBF) were also investigated.The results showed that the porous HA coating was obtained by sintering at 700℃.These porous HA coating surfaces were covered by carbonate-apatite particles after immersion in 1.5 times ion concentration of SBF for 5 days,with diameter about 5~25 μm,indicating that these coatings possessed an excellent bioactivity on its surface.The adhesion strength between coating and substrate was up to 19.5 MPa using CS as porogens.The developed method is promising to develop new implant bioceramic materials of human bone.
2012, 29(1): 52-56
doi: 10.3724/SP.J.1095.2012.00042
Abstract:
One-dimensional CuC2O4/ZnO heterostructures were successfully prepared via hydrothermal reaction for 10 h at 120℃ using CuC2O4 microspheres as templates.Thermal gravimetric analysis(TGA),field-emission scanning electron microscope(FESEM),energy dispersive X-ray spectrometry(EDX),transmission scanning electron microscope(TEM) and powder X-ray diffraction(XRD) were used to characterize the structure and morphology of the products.Results show that the obtained products are CuC2O4/ZnO nanorod bundles with 500 nm in diameter and 1 μm in length.Each rod bundle consists of many nanorods which grow along the same orientation.TEM image and EDX spectra show that the product is a uniformly heterostructured material formed from CuC2O4 and ZnO.
One-dimensional CuC2O4/ZnO heterostructures were successfully prepared via hydrothermal reaction for 10 h at 120℃ using CuC2O4 microspheres as templates.Thermal gravimetric analysis(TGA),field-emission scanning electron microscope(FESEM),energy dispersive X-ray spectrometry(EDX),transmission scanning electron microscope(TEM) and powder X-ray diffraction(XRD) were used to characterize the structure and morphology of the products.Results show that the obtained products are CuC2O4/ZnO nanorod bundles with 500 nm in diameter and 1 μm in length.Each rod bundle consists of many nanorods which grow along the same orientation.TEM image and EDX spectra show that the product is a uniformly heterostructured material formed from CuC2O4 and ZnO.
2012, 29(1): 57-62
doi: 10.3724/SP.J.1095.2012.00076
Abstract:
Vanadium containing hexagonal mesoporous silica(V-HMS) catalysts with different vanadium contents were prepared by sol-gel method with ammonium metavanadate used as the starting material of vanadium,and the obtained catalysts were characterized by powder X-ray diffraction(XRD),N2-adsorption techniques and H2-temperature programmed reduction(H2-TPR).The catalytic performance for hydroxylation of benzene with H2O2 to phenol was investigated.The results indicated that vanadium species was successfully incorporated into the framework of HMS,and a uniform mesoporous structure and good dispersion were found.Meanwhile,V-HMS exhibited superior catalytic performance in the hydroxylation of benzene to phenol.The good dispersion and isolated vanadium species were beneficial to the high catalytic activity of hydroxylation of benzene to phenol.When the mass fraction of V(5.8% mass fraction)-HMS was 2%,the reaction temperature was 60℃,and the reaction time was 5 h,the yield and selectivity of phenol achieved 18.55% and 100%,respectively.
Vanadium containing hexagonal mesoporous silica(V-HMS) catalysts with different vanadium contents were prepared by sol-gel method with ammonium metavanadate used as the starting material of vanadium,and the obtained catalysts were characterized by powder X-ray diffraction(XRD),N2-adsorption techniques and H2-temperature programmed reduction(H2-TPR).The catalytic performance for hydroxylation of benzene with H2O2 to phenol was investigated.The results indicated that vanadium species was successfully incorporated into the framework of HMS,and a uniform mesoporous structure and good dispersion were found.Meanwhile,V-HMS exhibited superior catalytic performance in the hydroxylation of benzene to phenol.The good dispersion and isolated vanadium species were beneficial to the high catalytic activity of hydroxylation of benzene to phenol.When the mass fraction of V(5.8% mass fraction)-HMS was 2%,the reaction temperature was 60℃,and the reaction time was 5 h,the yield and selectivity of phenol achieved 18.55% and 100%,respectively.
2012, 29(1): 63-68
doi: 10.3724/SP.J.1095.2012.00053
Abstract:
A novel photo-Fenton-like system consisting of PW11O39Fe(Ⅲ)(H2O)4-[PW11Fe(Ⅲ)(H2O)] was applied to degrade the aqueous bio-refractory organic pollutant aniline(ArNH2).The homogeneous photo-catalysis of PW11Fe(Ⅲ)(H2O) for ArNH2 degradation was studied in detail under an artificial UV irradiation in the presence of hydrogen peroxide(H2O2),in which the effects of initial ArNH2,H2O2 and PW11Fe(Ⅲ)(H2O) concentration on the photo-catalytic rate of ArNH2 degradation were examined.The experimental results show that a complete ArNH2 degradation was obtained in less than 60 min in a pH=6.86 mixed phosphate solution containing 0.1 mmol/L PW11Fe(Ⅲ)(H2O)+0.2 mmol/L H2O2+0.1 mmol/L ArNH2 under a 300 W Hg lamp irradiation,and a total organic carbon(TOC) removal of ca.52% was achieved.A mechanism of photocatalytic decomposition of H2O2 to hydroxyl radicals by PW11Fe(Ⅲ)(H2O) was proposed and a comparison of ArNH2 photo-catalytic degradation in acidic and neutral solutions was discussed.
A novel photo-Fenton-like system consisting of PW11O39Fe(Ⅲ)(H2O)4-[PW11Fe(Ⅲ)(H2O)] was applied to degrade the aqueous bio-refractory organic pollutant aniline(ArNH2).The homogeneous photo-catalysis of PW11Fe(Ⅲ)(H2O) for ArNH2 degradation was studied in detail under an artificial UV irradiation in the presence of hydrogen peroxide(H2O2),in which the effects of initial ArNH2,H2O2 and PW11Fe(Ⅲ)(H2O) concentration on the photo-catalytic rate of ArNH2 degradation were examined.The experimental results show that a complete ArNH2 degradation was obtained in less than 60 min in a pH=6.86 mixed phosphate solution containing 0.1 mmol/L PW11Fe(Ⅲ)(H2O)+0.2 mmol/L H2O2+0.1 mmol/L ArNH2 under a 300 W Hg lamp irradiation,and a total organic carbon(TOC) removal of ca.52% was achieved.A mechanism of photocatalytic decomposition of H2O2 to hydroxyl radicals by PW11Fe(Ⅲ)(H2O) was proposed and a comparison of ArNH2 photo-catalytic degradation in acidic and neutral solutions was discussed.
2012, 29(1): 69-74
doi: 10.3724/SP.J.1095.2012.00078
Abstract:
A simulating device for magnetic drug targeting and release in human body was fabricated by using peristaltic pump,NdFeB magnet,polyethylene pipe,water bath and glass tube.The device was used to test the magnetic drug targeting and release property of a model magnetic drug-carried particles Fe3O4@DFUR-LDH(DFUR:doxifluridine,LDH:layered double hydroxide).It is found that the retention of the Fe3O4@DFUR-LDH particles can be achieved to 85.3%,and it decreases as increasing the distance between the magnet and Fe3O4@DFUR-LDH particles in this device.Increasing the velocity of the release medium can also lead to the decrease of the retention of Fe3O4@DFUR-LDH particles.It also reveals that the drug release rate of Fe3O4@DFUR-LDH particles increases gradually as increasing the velocity of the releasing medium in this device.By modifying the pipe system,the situation when the drug was continuously consumed in the human body was also simulated.This device can not only simulate the magnetic targeting,but also analyze the drug release behavior of the magnetic drug-carried particles retained in a special site with the use of a magnetic field,thus providing an effective way to analyze the properties of magnetic drug-carried particles before submitting to the clinical study.
A simulating device for magnetic drug targeting and release in human body was fabricated by using peristaltic pump,NdFeB magnet,polyethylene pipe,water bath and glass tube.The device was used to test the magnetic drug targeting and release property of a model magnetic drug-carried particles Fe3O4@DFUR-LDH(DFUR:doxifluridine,LDH:layered double hydroxide).It is found that the retention of the Fe3O4@DFUR-LDH particles can be achieved to 85.3%,and it decreases as increasing the distance between the magnet and Fe3O4@DFUR-LDH particles in this device.Increasing the velocity of the release medium can also lead to the decrease of the retention of Fe3O4@DFUR-LDH particles.It also reveals that the drug release rate of Fe3O4@DFUR-LDH particles increases gradually as increasing the velocity of the releasing medium in this device.By modifying the pipe system,the situation when the drug was continuously consumed in the human body was also simulated.This device can not only simulate the magnetic targeting,but also analyze the drug release behavior of the magnetic drug-carried particles retained in a special site with the use of a magnetic field,thus providing an effective way to analyze the properties of magnetic drug-carried particles before submitting to the clinical study.
2012, 29(1): 75-79
doi: 10.3724/SP.J.1095.2012.00054
Abstract:
Using isovanillin as the starting material,the lactone ring-opened taspine derivative(compound 8) was obtained via bromination,benzylation,oxidation,Ulmman reaction and catalytic hydrogenation.Based on this,we designed and synthesized two novel lactone ring-opened taspine coumarin ester fluorescent derivatives with substituted coumarin(compounds 9a and 9b).The structures of the target compounds were characterized by means of IR,1H NMR and MS.The fluorescence and the anti-tumor activities of the target compounds were preliminarily examined.
Using isovanillin as the starting material,the lactone ring-opened taspine derivative(compound 8) was obtained via bromination,benzylation,oxidation,Ulmman reaction and catalytic hydrogenation.Based on this,we designed and synthesized two novel lactone ring-opened taspine coumarin ester fluorescent derivatives with substituted coumarin(compounds 9a and 9b).The structures of the target compounds were characterized by means of IR,1H NMR and MS.The fluorescence and the anti-tumor activities of the target compounds were preliminarily examined.
2012, 29(1): 80-83
doi: 10.3724/SP.J.1095.2012.00065
Abstract:
3,5-Diaminopyridine and 3,5-dimethoxycarbonylamino-pyridine were prepared from 3,5-dimethylpyridine in three steps including oxidation of methyl,amination and Hofmann degradation with the total yield of 64% and 68%,respectively.The reaction conditions of every step were studied and the intermediates and target compounds were characterized by 1H NMR,MS/MS,and IR.The reactions proceed under atmosphere pressure with mild reaction conditions,easy post treatment and high efficiency.
3,5-Diaminopyridine and 3,5-dimethoxycarbonylamino-pyridine were prepared from 3,5-dimethylpyridine in three steps including oxidation of methyl,amination and Hofmann degradation with the total yield of 64% and 68%,respectively.The reaction conditions of every step were studied and the intermediates and target compounds were characterized by 1H NMR,MS/MS,and IR.The reactions proceed under atmosphere pressure with mild reaction conditions,easy post treatment and high efficiency.
2012, 29(1): 84-89
doi: 10.3724/SP.J.1095.2012.00057
Abstract:
The conversion of aluminum citrate(AlCit) to dawsonite is the key step to the alumina process named "AlCit-dawsonite-alumina".The reaction conditions including the dosage of sodium bicarbonate,pH,reaction temperature and reaction time,were found to be related to the conversion of AlCit.Orthogonal experimental design was employed to optimize the reaction conditions.About 76% of AlCit was conversed to dawsonite under the optimized conditions:NaHCO3/Al molar ratio of 5,pH of 11,temperature of 80℃ and reaction time of 3 h,comparing to 65% obtained under preliminary experimental conditions.
The conversion of aluminum citrate(AlCit) to dawsonite is the key step to the alumina process named "AlCit-dawsonite-alumina".The reaction conditions including the dosage of sodium bicarbonate,pH,reaction temperature and reaction time,were found to be related to the conversion of AlCit.Orthogonal experimental design was employed to optimize the reaction conditions.About 76% of AlCit was conversed to dawsonite under the optimized conditions:NaHCO3/Al molar ratio of 5,pH of 11,temperature of 80℃ and reaction time of 3 h,comparing to 65% obtained under preliminary experimental conditions.
2012, 29(1): 90-94
doi: 10.3724/SP.J.1095.2012.00062
Abstract:
The solvent extraction of samarium and yttrium using 8-hydroxyquinoline(HQ)-n-heptane in nitric acid medium was systematically investigated including the effects of various parameters,such as HQ concentration,NO3- concentration and pH value in equilibrated aqueous solution on the distribution ratio of rare earth.The distribution ratio increased with the increase of HQ concentration and pH value and decreased with the increase of NO3- concentration.The formed complex was believed to be M(NO3)Q(HQ)(OH) based on the results from slop method and charge balance.The complex extraction mechanism of samarium and yttrium by HQ in nitric acid was confirmed.
The solvent extraction of samarium and yttrium using 8-hydroxyquinoline(HQ)-n-heptane in nitric acid medium was systematically investigated including the effects of various parameters,such as HQ concentration,NO3- concentration and pH value in equilibrated aqueous solution on the distribution ratio of rare earth.The distribution ratio increased with the increase of HQ concentration and pH value and decreased with the increase of NO3- concentration.The formed complex was believed to be M(NO3)Q(HQ)(OH) based on the results from slop method and charge balance.The complex extraction mechanism of samarium and yttrium by HQ in nitric acid was confirmed.
2012, 29(1): 95-99
doi: 10.3724/SP.J.1095.2012.00052
Abstract:
Macroporous carbon supported Ir(Ir/MC) and Vulcan XC-72 carbon supported Ir(Ir/XC) catalysts were prepared respectively.Based on the characterization of the catalysts using the energy dispersive spectroscopy,X-ray diffraction spectroscopy and Raman spectroscopy,the electrocatalytic performances of the two catalysts for the ammonia oxidation were investigated.It was found that the peak current density of the ammonia oxidation at the Ir/MC catalyst electrode is 38.7% larger than that at the Ir/XC catalyst electrode and the electrocatalytic stability of the Ir/MC catalyst is better than that of the Ir/XC catalyst.Because the average size and the relative crystallinity of the Ir particles in the Ir/MC catalyst is similar to that in the Ir/XC catalyst,the above results can be attributed to the larger pore size and porosity as well as the higher conductivity due to the high graphitization extent of MC.
Macroporous carbon supported Ir(Ir/MC) and Vulcan XC-72 carbon supported Ir(Ir/XC) catalysts were prepared respectively.Based on the characterization of the catalysts using the energy dispersive spectroscopy,X-ray diffraction spectroscopy and Raman spectroscopy,the electrocatalytic performances of the two catalysts for the ammonia oxidation were investigated.It was found that the peak current density of the ammonia oxidation at the Ir/MC catalyst electrode is 38.7% larger than that at the Ir/XC catalyst electrode and the electrocatalytic stability of the Ir/MC catalyst is better than that of the Ir/XC catalyst.Because the average size and the relative crystallinity of the Ir particles in the Ir/MC catalyst is similar to that in the Ir/XC catalyst,the above results can be attributed to the larger pore size and porosity as well as the higher conductivity due to the high graphitization extent of MC.
2012, 29(1): 100-105
doi: 10.3724/SP.J.1095.2012.00037
Abstract:
The microstructure and composition of the stainless steel water tubes used for the condensers in power plants and the deposits near the corrosion holes were analyzed by SEM and EDS,respectively.The electrochemical reaction mechanism of MnS dissolution and microbial corrosion were explored,and a synergistic effect of both corrosions was found in the process of pitting corrosion.Based on the comprehensive analysis of various factors affecting the stainless-steel's corrosion,some preventive measures are put forward to help the stainless steel condensers function smoothly.
The microstructure and composition of the stainless steel water tubes used for the condensers in power plants and the deposits near the corrosion holes were analyzed by SEM and EDS,respectively.The electrochemical reaction mechanism of MnS dissolution and microbial corrosion were explored,and a synergistic effect of both corrosions was found in the process of pitting corrosion.Based on the comprehensive analysis of various factors affecting the stainless-steel's corrosion,some preventive measures are put forward to help the stainless steel condensers function smoothly.
2012, 29(1): 106-112
doi: 10.3724/SP.J.1095.2012.00031
Abstract:
In order to provide a reference for octenyl succinic anhydride(OSA)-modified starch and methyl oleate used in green pesticide preparations,the formulation of the lambda-cyhalothrin oil-in-water emulsion with OSA-modified starch and methyl oleate as emulsifier and solvent was studied.Furthermore,the effects of different processing parameters,including the concentration of pretreating fluid of OSA-modified starch,rotational speed and shearing time on the stability of emulsion were studied by measuring oil droplet diameter distribution.Results demonstrated that OSA-modified starch had excellent emulsification ability to methyl oleate.High stable emulsions(2.5%) could be prepared with OSA-modified starch.The mean droplet diameters of emulsion were about 1.2 μm,and increased by only 0.1~0.3 μm after storing at 25℃ for 6 months or at(54±2)℃ for 14 days,and approximately 100% of the oil remained stable in the emulsion.Higher stable emulsions could be prepared by emulsification at high viscosity with mass fraction of pretreating fluid of OSA-modified starch in the range of 15%~25%.Smaller oil droplet diameters were obtained when the rotational speed was increased,which had no significant effect on homogeneity of emulsions.On the other hand,an increase of the shearing time reduced the span of oil droplet diameter distribution,but had no significant impact on the mean oil droplet diameter.Lambda-cyhalothrin oil-in-water emulsion prepared with OSA-modified starch had a better stability than the conventional emulsions.The results of this study show that OSA-modified starch and methyl oleate can be used as an effective emulsifier and solvent for the environment-friendly lambda-cyhalothrin oil-in-water emulsion formulations.
In order to provide a reference for octenyl succinic anhydride(OSA)-modified starch and methyl oleate used in green pesticide preparations,the formulation of the lambda-cyhalothrin oil-in-water emulsion with OSA-modified starch and methyl oleate as emulsifier and solvent was studied.Furthermore,the effects of different processing parameters,including the concentration of pretreating fluid of OSA-modified starch,rotational speed and shearing time on the stability of emulsion were studied by measuring oil droplet diameter distribution.Results demonstrated that OSA-modified starch had excellent emulsification ability to methyl oleate.High stable emulsions(2.5%) could be prepared with OSA-modified starch.The mean droplet diameters of emulsion were about 1.2 μm,and increased by only 0.1~0.3 μm after storing at 25℃ for 6 months or at(54±2)℃ for 14 days,and approximately 100% of the oil remained stable in the emulsion.Higher stable emulsions could be prepared by emulsification at high viscosity with mass fraction of pretreating fluid of OSA-modified starch in the range of 15%~25%.Smaller oil droplet diameters were obtained when the rotational speed was increased,which had no significant effect on homogeneity of emulsions.On the other hand,an increase of the shearing time reduced the span of oil droplet diameter distribution,but had no significant impact on the mean oil droplet diameter.Lambda-cyhalothrin oil-in-water emulsion prepared with OSA-modified starch had a better stability than the conventional emulsions.The results of this study show that OSA-modified starch and methyl oleate can be used as an effective emulsifier and solvent for the environment-friendly lambda-cyhalothrin oil-in-water emulsion formulations.
2012, 29(1): 113-117
doi: 10.3724/SP.J.1095.2012.00060
Abstract:
Thermotropic layered phase transition compounds decylammonium tetrachlorozincate((n-C16H33NH3)2ZnCl4,C16Zn) and hexadecylammonium tetrachlorozincate((n-C18H37NH3)2ZnCl4,C18Zn) were synthesized,and a series of their mixtures were prepared from absolute ethanol.The compounds exhibit high enthalpy solid-solid phase transition in the temperature range of 340~370 K.Subsolidus binary phase diagram of C16Zn-C18Zn was established by differential thermal analysis and X-ray diffraction.In the phase diagram,new material(n-C16H33NH3)(n-C18H37NH3)ZnCl4 at w(C16Zn)=41.11% and two eutectoid invariants at w(C16Zn)=16.19% and w(C16Zn)=63.07% are observed.Two eutectic point temperatures are about 356 K and 353 K.In contrast to other similar system,there are three noticeable solid solution ranges(α,β,γ) at the left,right,and middle boundary of the phase diagram,respectively.
Thermotropic layered phase transition compounds decylammonium tetrachlorozincate((n-C16H33NH3)2ZnCl4,C16Zn) and hexadecylammonium tetrachlorozincate((n-C18H37NH3)2ZnCl4,C18Zn) were synthesized,and a series of their mixtures were prepared from absolute ethanol.The compounds exhibit high enthalpy solid-solid phase transition in the temperature range of 340~370 K.Subsolidus binary phase diagram of C16Zn-C18Zn was established by differential thermal analysis and X-ray diffraction.In the phase diagram,new material(n-C16H33NH3)(n-C18H37NH3)ZnCl4 at w(C16Zn)=41.11% and two eutectoid invariants at w(C16Zn)=16.19% and w(C16Zn)=63.07% are observed.Two eutectic point temperatures are about 356 K and 353 K.In contrast to other similar system,there are three noticeable solid solution ranges(α,β,γ) at the left,right,and middle boundary of the phase diagram,respectively.
2012, 29(1): 118-122
doi: 10.3724/SP.J.1095.2012.00058
Abstract:
The determination of triclosan in antimicrobial textiles was established by a gas chromatography(GC) method coupled with an electron capture detector(ECD).As for the positive samples,GC/MS was used for the confirmation of triclosan.Triclosan in antimicrobial textiles was microwave-assisted extracted using dichloromethane as the extraction solvent.This method was rapid,accurate and sensitive.The detection limit was 1 μg/kg at the signal to noise ratio of 3(S/N=3).The recovery ratio varied from 90% to 106%,while the RSD was all less than 6%.Triclosan in commercially available antimicrobial textiles was analyzed using the established method,and the results showed that a large amount of triclosan existed in some commercially available antimicrobial textiles.
The determination of triclosan in antimicrobial textiles was established by a gas chromatography(GC) method coupled with an electron capture detector(ECD).As for the positive samples,GC/MS was used for the confirmation of triclosan.Triclosan in antimicrobial textiles was microwave-assisted extracted using dichloromethane as the extraction solvent.This method was rapid,accurate and sensitive.The detection limit was 1 μg/kg at the signal to noise ratio of 3(S/N=3).The recovery ratio varied from 90% to 106%,while the RSD was all less than 6%.Triclosan in commercially available antimicrobial textiles was analyzed using the established method,and the results showed that a large amount of triclosan existed in some commercially available antimicrobial textiles.
