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2012 Volume 29 Issue 8
2012, 29(8): 855-862
doi: 10.3724/SP.J.1095.2012.20020
Abstract:
The importance of quantum dots(QDs) in fingerprints development,the preparation and optical properties of quantum dots are summarized in the paper.Especially recent progress of chemical synthesis,modification and application in fingerprint development of Ⅱ~Ⅵ quantum dots such as CdS series,CdTe series,CdSe series,ZnSe series,Ⅲ~Ⅴ quantum dots such as InP are discussed.Finally,the recent research of Ⅳ quantum dots(C and Si QDs) and the prospect for potential application in crime scence are also discussed.
The importance of quantum dots(QDs) in fingerprints development,the preparation and optical properties of quantum dots are summarized in the paper.Especially recent progress of chemical synthesis,modification and application in fingerprint development of Ⅱ~Ⅵ quantum dots such as CdS series,CdTe series,CdSe series,ZnSe series,Ⅲ~Ⅴ quantum dots such as InP are discussed.Finally,the recent research of Ⅳ quantum dots(C and Si QDs) and the prospect for potential application in crime scence are also discussed.
2012, 29(8): 863-867
doi: 10.3724/SP.J.1095.2012.00386
Abstract:
After incorporating o-tolidine(OTOL) into 3,3',4,4'-biphenyltetracarboxylic dianhydride(BPDA) and p-phenylenediamine(PPD) backbone,the mechanical properties of fibers were dramatically improved.The strength and modulus of BPDA/PPD/OTOL polyimide(PI) fiber(diamine molar ratio of n(PPD):n(OTOL)=70: 30) attained 1.50 and 80 GPa,respectively,which were two times of the tenacity of BPDA/PPD PI fibers.SEM pictures showed that the cross-sections of the fibers at each stage were circular and voids free,and also no obvious "skin-core" and microfibrillar structure and wide/small angle X-ray scattering(WAXD/SAXS) experiments indicated that the longitudinal stacks and the molecular orientation of PI fiber were improved in the heat-drawn process.
After incorporating o-tolidine(OTOL) into 3,3',4,4'-biphenyltetracarboxylic dianhydride(BPDA) and p-phenylenediamine(PPD) backbone,the mechanical properties of fibers were dramatically improved.The strength and modulus of BPDA/PPD/OTOL polyimide(PI) fiber(diamine molar ratio of n(PPD):n(OTOL)=70: 30) attained 1.50 and 80 GPa,respectively,which were two times of the tenacity of BPDA/PPD PI fibers.SEM pictures showed that the cross-sections of the fibers at each stage were circular and voids free,and also no obvious "skin-core" and microfibrillar structure and wide/small angle X-ray scattering(WAXD/SAXS) experiments indicated that the longitudinal stacks and the molecular orientation of PI fiber were improved in the heat-drawn process.
2012, 29(8): 868-872
doi: 10.3724/SP.J.1095.2012.00380
Abstract:
Phenylethynyl end-capped polyisoimide oligomers were synthesized in different solvents.The effects of different treatment temperature on melting viscosity and solubility of polyisoimide(PⅡ) and its corresponding polyimide(PⅠ) resins were discussed.The results showed that the effect of treatment temperature on melting viscosity of PⅡ was marginal but conceivable on solubility.The PⅡ exhibited excellent solubility in N-methylpyrrolidone(NMP) and tetrahydrofuran(THF).The PⅡ had less melt viscosity than PⅠ at same treatment temperature.The T5% of PⅡ oligomer increased with the elevation of treatment temperature.The T5% is 208℃,323℃ and 382℃ when the temperature of PⅡ treatment is 110℃,150℃ and 180℃,respectively.While the T5% of cured PⅡ is 550℃ suggesting that had excellent heat resistance.
Phenylethynyl end-capped polyisoimide oligomers were synthesized in different solvents.The effects of different treatment temperature on melting viscosity and solubility of polyisoimide(PⅡ) and its corresponding polyimide(PⅠ) resins were discussed.The results showed that the effect of treatment temperature on melting viscosity of PⅡ was marginal but conceivable on solubility.The PⅡ exhibited excellent solubility in N-methylpyrrolidone(NMP) and tetrahydrofuran(THF).The PⅡ had less melt viscosity than PⅠ at same treatment temperature.The T5% of PⅡ oligomer increased with the elevation of treatment temperature.The T5% is 208℃,323℃ and 382℃ when the temperature of PⅡ treatment is 110℃,150℃ and 180℃,respectively.While the T5% of cured PⅡ is 550℃ suggesting that had excellent heat resistance.
2012, 29(8): 873-877
doi: 10.3724/SP.J.1095.2012.00371
Abstract:
In order to obtain more effective glycyrrhetinic derivatives,3-amino acid derivatives were synthesized from glycyrrhetinic acid via deoxidation of the 11-carbonyl group,ethyl esterification of the 30-carboxylic group and esterification of 3-hydroxyl group using Fmoc-protected amino acids,which include methionine,threonine,valine and phenylalanine,by dicyclohexylcarbodiimide(DCC)/dimethylaminopyridine(DMAP) coupling method in tetrahydrofuran.The final products were obtained by removing Fmoc using V(CH2Cl2): V((C2H5)2NH)=1: 1 solvent mixture with 80%~87% yields and characterized by 1H NMR and MS.Preliminary pharmacological research showed that compounds 5a~5d could protect the growth of E col.,Bacillus Subtilis and Yeast against high level of N,N-dimethylformamide.
In order to obtain more effective glycyrrhetinic derivatives,3-amino acid derivatives were synthesized from glycyrrhetinic acid via deoxidation of the 11-carbonyl group,ethyl esterification of the 30-carboxylic group and esterification of 3-hydroxyl group using Fmoc-protected amino acids,which include methionine,threonine,valine and phenylalanine,by dicyclohexylcarbodiimide(DCC)/dimethylaminopyridine(DMAP) coupling method in tetrahydrofuran.The final products were obtained by removing Fmoc using V(CH2Cl2): V((C2H5)2NH)=1: 1 solvent mixture with 80%~87% yields and characterized by 1H NMR and MS.Preliminary pharmacological research showed that compounds 5a~5d could protect the growth of E col.,Bacillus Subtilis and Yeast against high level of N,N-dimethylformamide.
2012, 29(8): 878-884
doi: 10.3724/SP.J.1095.2012.00410
Abstract:
A series of 2-(1,3,4-thiadiazolylaminomethyl)phenols was synthesized by reducing the C=N double bond of the intermediate Schiff bases prepared from the reaction of 2-amino-5-alkyl(aryl)-1,3,4-thiadiazoles and salicylaldehyde via either fractional step method or one-pot process.The yields of the products obtained from one-pot synthesis were higher and in the range of 56%~80%.The structures of the products were characterized by means of IR,1H NMR,13C NMR and MS.The fungicidal activity of the title compounds was evaluated preliminarily,some of which exhibited moderate activity against Alternaria alternata.The inhibitory rate of compound 3i was 76% at the concentration of 25 mg/L,and 70% for compounds 3f,3h,3k and 3l.
A series of 2-(1,3,4-thiadiazolylaminomethyl)phenols was synthesized by reducing the C=N double bond of the intermediate Schiff bases prepared from the reaction of 2-amino-5-alkyl(aryl)-1,3,4-thiadiazoles and salicylaldehyde via either fractional step method or one-pot process.The yields of the products obtained from one-pot synthesis were higher and in the range of 56%~80%.The structures of the products were characterized by means of IR,1H NMR,13C NMR and MS.The fungicidal activity of the title compounds was evaluated preliminarily,some of which exhibited moderate activity against Alternaria alternata.The inhibitory rate of compound 3i was 76% at the concentration of 25 mg/L,and 70% for compounds 3f,3h,3k and 3l.
2012, 29(8): 885-891
doi: 10.3724/SP.J.1095.2012.00414
Abstract:
Eighteen carboxylate derivatives of tetronic acid compounds were designed and synthesized by modifying the spirodiclofen of tetronic acid acaricide with bioisosterism and union of active group on the base of the structure-activity relationship.Their structures were characterized by 1H NMR,IR spectra and elemental analysis,and the single crystal structure of compound 6d was determined by X-ray diffraction analysis.The relationship between structures and activities has been analyzed by bioassay,several of them show high potential as novel acaricides.
Eighteen carboxylate derivatives of tetronic acid compounds were designed and synthesized by modifying the spirodiclofen of tetronic acid acaricide with bioisosterism and union of active group on the base of the structure-activity relationship.Their structures were characterized by 1H NMR,IR spectra and elemental analysis,and the single crystal structure of compound 6d was determined by X-ray diffraction analysis.The relationship between structures and activities has been analyzed by bioassay,several of them show high potential as novel acaricides.
2012, 29(8): 892-897
doi: 10.3724/SP.J.1095.2012.00441
Abstract:
Three novel asymmetric trimethine benzothiazole cyanine dyes with different N-substituents were designed and synthesized.The structures of the dyes were characterized,and the maximums of the spectral absorption and emission of the dyes in ethanol were found in the range of 629~635 nm and 656~672 nm.The Stokes shift values for dyes 8,9 and 10 were 23,37 and 27 nm,respectively.The dyes were almost non-fluorescent in solvents with a low fluorescent quantum yield of less than 0.021 in ethanol,which could reduce the background interference greatly.The photodegradation experiment showed that the introduction of benzyl group on the heteroaromatic rings improved the photostabilites of the dyes obviously.The oxidizing potentials for the dyes 8,9 and 10 were at 0.535,0.456 and 0.399 V vs SCE,which was consistent with the data of photodegradation experiment.
Three novel asymmetric trimethine benzothiazole cyanine dyes with different N-substituents were designed and synthesized.The structures of the dyes were characterized,and the maximums of the spectral absorption and emission of the dyes in ethanol were found in the range of 629~635 nm and 656~672 nm.The Stokes shift values for dyes 8,9 and 10 were 23,37 and 27 nm,respectively.The dyes were almost non-fluorescent in solvents with a low fluorescent quantum yield of less than 0.021 in ethanol,which could reduce the background interference greatly.The photodegradation experiment showed that the introduction of benzyl group on the heteroaromatic rings improved the photostabilites of the dyes obviously.The oxidizing potentials for the dyes 8,9 and 10 were at 0.535,0.456 and 0.399 V vs SCE,which was consistent with the data of photodegradation experiment.
2012, 29(8): 898-905
doi: 10.3724/SP.J.1095.2012.00362
Abstract:
A study on the inhibition type and mechanism was performed to screen the extract of G. inflata Bat.with the strongest inhibition effect on mushroom tyrosinase.The roots of G. inflata Bat.were extracted using different solvents sequentially.The inhibitory potencies and capacities of various extracts of G. inflata Bat.,which were obtained from solvents including glycyrrhizic acid,waste liquid from glycyrrhizic acid extraction,petroleum ether extract,chloroform extract,ethyl acetate extract,n-butyl alcohol extract and water extract,toward mushroom tyrosinase with L-DOPA as the substrate were investigated.Radicals scavenging activity were examined using 2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt(ABTS) radical cation(ABTS·﹢),hydroxyl radical(HO·) assay.The inhibition type on mushroom tyrosinase was obtained from Lineweaver-Burk plots.The inhibition mechanism on mushroom tyrosinase was explored combining its radicals scavenging ability.The results showed that the ethyl acetate extract had the strongest inhibitory capacity among seven extracts with IC50=3.4775 g/L,which also exhibited the strongest radical scavenging ability with IC50 of 0.0442 g/L for ABTS·﹢ and rate constant of 4.634×108 L/(g·s) for HO· scavenging reaction.There was a family of lines with a common intercept on the 1/v axis but with different slopes on Lineweaver-Burk plots with K1 value of 0.6667 g/L.In summary,the ethyl acetate extract is a reversible and competitive inhibitor,its inhibition mechanism on mushroom tyrosinase can be described as combining the capacity of scavenging oxygen free radicals with the ability of binding to the enzyme competitively.
A study on the inhibition type and mechanism was performed to screen the extract of G. inflata Bat.with the strongest inhibition effect on mushroom tyrosinase.The roots of G. inflata Bat.were extracted using different solvents sequentially.The inhibitory potencies and capacities of various extracts of G. inflata Bat.,which were obtained from solvents including glycyrrhizic acid,waste liquid from glycyrrhizic acid extraction,petroleum ether extract,chloroform extract,ethyl acetate extract,n-butyl alcohol extract and water extract,toward mushroom tyrosinase with L-DOPA as the substrate were investigated.Radicals scavenging activity were examined using 2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt(ABTS) radical cation(ABTS·﹢),hydroxyl radical(HO·) assay.The inhibition type on mushroom tyrosinase was obtained from Lineweaver-Burk plots.The inhibition mechanism on mushroom tyrosinase was explored combining its radicals scavenging ability.The results showed that the ethyl acetate extract had the strongest inhibitory capacity among seven extracts with IC50=3.4775 g/L,which also exhibited the strongest radical scavenging ability with IC50 of 0.0442 g/L for ABTS·﹢ and rate constant of 4.634×108 L/(g·s) for HO· scavenging reaction.There was a family of lines with a common intercept on the 1/v axis but with different slopes on Lineweaver-Burk plots with K1 value of 0.6667 g/L.In summary,the ethyl acetate extract is a reversible and competitive inhibitor,its inhibition mechanism on mushroom tyrosinase can be described as combining the capacity of scavenging oxygen free radicals with the ability of binding to the enzyme competitively.
2012, 29(8): 906-909
doi: 10.3724/SP.J.1095.2012.00379
Abstract:
Polyethylene glycol p-perfluorous nonenyloxyphenyl sulflonates(PFNPS-PEG-n) were synthesized from p-perfluorous nonenyloxyphenylsulfonyl chloride(PFNPSC) and polyethylene glycol(PEG-n),and were characterized by IR and 19F NMR,respectively.The effects of average relative molecular mass of PEG-n and reaction time on alcoholysis were investigated.The performances of these surfactants such as surface tensions,foaming characterisitics and emulsifiabilities were studied.The surface activity of PFNPS-PEG-n synthesized from PEG-600 is the best,and the optimal reaction conditions are n(PFNPSC): n((PEG-600)=1: 1,reacts at 40℃ for 6~8 h in CCl4 in the present of NEt3.The critical micelle concentration(CMC) of PFNPS-PEG-600 is 0.56 g/L,and its γCMC is 19.1 mN/m;20 mL 1 g/L PFNPS-PEG-600 will produce 95 mL foam,and its half-life time is 75 s.Emulsifiability of PFNPS-PEG-1000 is the best among PFNPS-PEG-n.
Polyethylene glycol p-perfluorous nonenyloxyphenyl sulflonates(PFNPS-PEG-n) were synthesized from p-perfluorous nonenyloxyphenylsulfonyl chloride(PFNPSC) and polyethylene glycol(PEG-n),and were characterized by IR and 19F NMR,respectively.The effects of average relative molecular mass of PEG-n and reaction time on alcoholysis were investigated.The performances of these surfactants such as surface tensions,foaming characterisitics and emulsifiabilities were studied.The surface activity of PFNPS-PEG-n synthesized from PEG-600 is the best,and the optimal reaction conditions are n(PFNPSC): n((PEG-600)=1: 1,reacts at 40℃ for 6~8 h in CCl4 in the present of NEt3.The critical micelle concentration(CMC) of PFNPS-PEG-600 is 0.56 g/L,and its γCMC is 19.1 mN/m;20 mL 1 g/L PFNPS-PEG-600 will produce 95 mL foam,and its half-life time is 75 s.Emulsifiability of PFNPS-PEG-1000 is the best among PFNPS-PEG-n.
2012, 29(8): 910-914
doi: 10.3724/SP.J.1095.2012.00392
Abstract:
The inclusion properties of piroxicam(PX) by β-cyclodextrin(β-CD),hydroxypropyl-β-cyclodextrin(HP-β-CD),and sulfobutyl ether-β-cyclodextrin(SBE-β-CD) were studied by fluorescence spectroscopy,differential scanning calorimetry(DSC) and NMR at different pH.The results showed that the 1: 2.5 inclusion compounds were formed between piroxicam and CDs.Based on the formation constants,which were 2.0×106,1.8×106,1.2×106 in neutral media,the inclusion capacity showed the order of SBE-β-CD >HP-β-CD >β-CD.
The inclusion properties of piroxicam(PX) by β-cyclodextrin(β-CD),hydroxypropyl-β-cyclodextrin(HP-β-CD),and sulfobutyl ether-β-cyclodextrin(SBE-β-CD) were studied by fluorescence spectroscopy,differential scanning calorimetry(DSC) and NMR at different pH.The results showed that the 1: 2.5 inclusion compounds were formed between piroxicam and CDs.Based on the formation constants,which were 2.0×106,1.8×106,1.2×106 in neutral media,the inclusion capacity showed the order of SBE-β-CD >HP-β-CD >β-CD.
2012, 29(8): 915-920
doi: 10.3724/SP.J.1095.2012.00408
Abstract:
Tungstomolybdophosphate acid with Dawson structure was prepared by hydrothermal synthesis and characterized by means of FT-IR,UV-Vis and TG-DTA.The synthesis of adipic acid from the reaction of cyclohexanone with 30% hydrogen peroxide under microwave irradiation was used as a probe to study the catalytic activity of tungstomolybdophosphate acid.The main effects of the reaction were optimized with orthogonal experiments.The results show that under the optimal conditions,i.e.the molar ratio of C6H10O:H2O2: H2C2O4: H6P2W9Mo9O62·24H2O =100: 400: 1.25: 0.25,100℃ for the reaction temperature,400 W for the microwave power,and 3.5 h for the irradiation time,the isolated yield of adipic acid can reach 87.33% with a purity of 99.7%.The filtration containing the catalyst can be concentrated by the rotary evaporation and be reused five times by facile separation of the product after reaction,with an isolated yield of above 45.89% for adipic acid.
Tungstomolybdophosphate acid with Dawson structure was prepared by hydrothermal synthesis and characterized by means of FT-IR,UV-Vis and TG-DTA.The synthesis of adipic acid from the reaction of cyclohexanone with 30% hydrogen peroxide under microwave irradiation was used as a probe to study the catalytic activity of tungstomolybdophosphate acid.The main effects of the reaction were optimized with orthogonal experiments.The results show that under the optimal conditions,i.e.the molar ratio of C6H10O:H2O2: H2C2O4: H6P2W9Mo9O62·24H2O =100: 400: 1.25: 0.25,100℃ for the reaction temperature,400 W for the microwave power,and 3.5 h for the irradiation time,the isolated yield of adipic acid can reach 87.33% with a purity of 99.7%.The filtration containing the catalyst can be concentrated by the rotary evaporation and be reused five times by facile separation of the product after reaction,with an isolated yield of above 45.89% for adipic acid.
2012, 29(8): 921-925
doi: 10.3724/SP.J.1095.2012.00367
Abstract:
V-AlPO5 molecular sieves synthesized by the hydrothermal method was confirmed by XRD patterns.The catalytic activity of V-AlPO5 toward the benzene hydroxylation was influenced by the different synthetic conditions.The catalyst prepared from the optimized condition showed a relative high reaction activity toward the probed reaction.The optimistic reaction conditions:0.2 g catalysts,0.2 g ascorbic acid,10 mmol benzene and 15 mmol 35% H2O2 were added in 6 mL acetonitrile,the reaction was kept for 24 h under 55℃.Under these conditions,the phenol yield was 16.1% with a selectivity of 86.8%.
V-AlPO5 molecular sieves synthesized by the hydrothermal method was confirmed by XRD patterns.The catalytic activity of V-AlPO5 toward the benzene hydroxylation was influenced by the different synthetic conditions.The catalyst prepared from the optimized condition showed a relative high reaction activity toward the probed reaction.The optimistic reaction conditions:0.2 g catalysts,0.2 g ascorbic acid,10 mmol benzene and 15 mmol 35% H2O2 were added in 6 mL acetonitrile,the reaction was kept for 24 h under 55℃.Under these conditions,the phenol yield was 16.1% with a selectivity of 86.8%.
2012, 29(8): 926-932
doi: 10.3724/SP.J.1095.2012.000072
Abstract:
Acidification by HCl or H2SO4 was applied for modifying bentonite.The Au catalysts supported on acid-activated bentonite had been prepared by the methods of aqueous impregnation,deposition-precipitation and cationic absorption.CO oxidation was used as a probe reaction to characterize the catalytic performance.The samples were characterized by BET,XRD and TEM.The BET results showed that the surface area and pore volume had a substantial improvement.The results of CO oxidation showed that a higher catalyst activity was achieved by Au supported on H2SO4 acidified bentontie.The calculation result by XRD indicated that the Au particles supported on H2SO4 acidified bentontie had smaller size.Small Au particles could be obtained by the method of cationic absorption.Au catalysts with higher catalytic activity could be obtained by the conditions of adsorption for 48 h,calcination at 450℃ and H2 reduction at 150℃.
Acidification by HCl or H2SO4 was applied for modifying bentonite.The Au catalysts supported on acid-activated bentonite had been prepared by the methods of aqueous impregnation,deposition-precipitation and cationic absorption.CO oxidation was used as a probe reaction to characterize the catalytic performance.The samples were characterized by BET,XRD and TEM.The BET results showed that the surface area and pore volume had a substantial improvement.The results of CO oxidation showed that a higher catalyst activity was achieved by Au supported on H2SO4 acidified bentontie.The calculation result by XRD indicated that the Au particles supported on H2SO4 acidified bentontie had smaller size.Small Au particles could be obtained by the method of cationic absorption.Au catalysts with higher catalytic activity could be obtained by the conditions of adsorption for 48 h,calcination at 450℃ and H2 reduction at 150℃.
2012, 29(8): 933-937
doi: 10.3724/SP.J.1095.2012.00375
Abstract:
According to combustion theory and chemical structure of chloroacetophenone,the principle for destroying chloroacetophenone by incineration was analyzed,and the reaction products and equation of the incineration were determined.By incineration experiments,the major influencing factors,such as feed-in waste quantity,feed-in time interval,temperatures of the first and second fireboxes,were discussed.Moreover,the optimized parameters for destroying chloroacetophenone by incineration equipment were determined.As a result,chloroacetophenone may be scientifically and thoroughly destroyed by the special incineration equipment under the following optimized parameters:the excess air coefficient is 2.5,the feed-in waste quantity is 400 g each time,the feed-in time interval is 3 min,the temperature of the first firebox is 800℃,while the second firebox is 1200℃.
According to combustion theory and chemical structure of chloroacetophenone,the principle for destroying chloroacetophenone by incineration was analyzed,and the reaction products and equation of the incineration were determined.By incineration experiments,the major influencing factors,such as feed-in waste quantity,feed-in time interval,temperatures of the first and second fireboxes,were discussed.Moreover,the optimized parameters for destroying chloroacetophenone by incineration equipment were determined.As a result,chloroacetophenone may be scientifically and thoroughly destroyed by the special incineration equipment under the following optimized parameters:the excess air coefficient is 2.5,the feed-in waste quantity is 400 g each time,the feed-in time interval is 3 min,the temperature of the first firebox is 800℃,while the second firebox is 1200℃.
2012, 29(8): 938-941
doi: 10.3724/SP.J.1095.2012.00211
Abstract:
Using phenanthroline(phen) as an auxiliary azide-bridging ligand,a Co2+ coordination polymer [Co2(μ1,1-N3)2(phen)2(N3)2],was prepared hydrothermally.The complex was characterized by IR,elemental analysis,X-ray single crystal diffraction.The bridging manner of azide in this complex was discussed and the magnetic properties were measured.The complex belongs to the triclinic system(space group of P1) with a=0.69272(14) nm,b=1.0318(2) nm,c=1.0381(2) nm,α=64.47(3)°,β=71.02(3)°,γ=85.79(3)°,Z=1,V=0.6312(2) nm3,D=1.701 mg/m3,F(000)=326.
Using phenanthroline(phen) as an auxiliary azide-bridging ligand,a Co2+ coordination polymer [Co2(μ1,1-N3)2(phen)2(N3)2],was prepared hydrothermally.The complex was characterized by IR,elemental analysis,X-ray single crystal diffraction.The bridging manner of azide in this complex was discussed and the magnetic properties were measured.The complex belongs to the triclinic system(space group of P1) with a=0.69272(14) nm,b=1.0318(2) nm,c=1.0381(2) nm,α=64.47(3)°,β=71.02(3)°,γ=85.79(3)°,Z=1,V=0.6312(2) nm3,D=1.701 mg/m3,F(000)=326.
2012, 29(8): 942-947
doi: 10.3724/SP.J.1095.2012.00394
Abstract:
TiO2 graphene composite was obtained by a one step hydrothermal method,using graphite oxide and commercial TiO2 as precursors.The morphology and structure of the composite were examined by scanning electron microscopy,transition electron microscopy,X-ray diffraction,N2 adsorption-desorption and Raman spectrum.The as-prepared TiO2-graphene photocatalyst possessed great adsorptivity of dyes,extended light absorption range,and efficient charge separation properties.Hence,in the photodegradation of methylene blue,a significant enhancement in efficiency was observed with TiO2-graphene compared to the neat TiO2.
TiO2 graphene composite was obtained by a one step hydrothermal method,using graphite oxide and commercial TiO2 as precursors.The morphology and structure of the composite were examined by scanning electron microscopy,transition electron microscopy,X-ray diffraction,N2 adsorption-desorption and Raman spectrum.The as-prepared TiO2-graphene photocatalyst possessed great adsorptivity of dyes,extended light absorption range,and efficient charge separation properties.Hence,in the photodegradation of methylene blue,a significant enhancement in efficiency was observed with TiO2-graphene compared to the neat TiO2.
2012, 29(8): 948-953
doi: 10.3724/SP.J.1095.2012.00372
Abstract:
Highly ordered TiO2 nanotube arrays(TiO2NTs) fabricated by anodization were employed as a substrate and loaded with Ni nanoparticles by pulse electrodeposition.The morphology and composites of titanium dioxide nanotubes and Ni/TiO2NTs electrodes were investigated using scanning electron microscopy and energy-dispersive X-ray spectroscopy,respectively.The Ni/TiO2NTs was used as an amperometric detector for electrocatalytic oxidation and determination of insulin.The results show that Ni/TiO2NTs electrode enables the oxidative detection of insulin at this modified electrode.The linear dynamic range of the detection is 0.8~1.6 μmol/L in 0.1 mol/L NaOH electrolyte,with a good sensitivity(0.49×10-3 A/(μmol·L-1·cm-2) and low detection limit(0.28 μmol/L).
Highly ordered TiO2 nanotube arrays(TiO2NTs) fabricated by anodization were employed as a substrate and loaded with Ni nanoparticles by pulse electrodeposition.The morphology and composites of titanium dioxide nanotubes and Ni/TiO2NTs electrodes were investigated using scanning electron microscopy and energy-dispersive X-ray spectroscopy,respectively.The Ni/TiO2NTs was used as an amperometric detector for electrocatalytic oxidation and determination of insulin.The results show that Ni/TiO2NTs electrode enables the oxidative detection of insulin at this modified electrode.The linear dynamic range of the detection is 0.8~1.6 μmol/L in 0.1 mol/L NaOH electrolyte,with a good sensitivity(0.49×10-3 A/(μmol·L-1·cm-2) and low detection limit(0.28 μmol/L).
2012, 29(8): 954-961
doi: 10.3724/SP.J.1095.2012.00405
Abstract:
A novel modified compound photoelectrode(Eu-Fe-Mo/CuInSe2) was prepared successfully by electrodeposition of CuInSe2 semiconductor materials on the glassy carbon electrode,which was modified beforehand with cyanide-bridged mixed complexes.With the electroplating solution that contained Cu2+,In3+,SeO32- and sodium citrate in acidic aqueous solution,we found that there existed the best Cu: In: Se concentration ratio of added chemicals by optimizing procedure.The methods of SEM and EDS were employed to characterize the surface morphology of the modified compound photoelectrode and the elemental composite of CuInSe2 materials.Furthermore,with the ordinary daylight of 60 watts incandescent lamp as the light source,the photovoltaic properties of modified compound photoelectrode were investigated by means of open circuit potential and chronoamperometry,and its photovoltage and photocurrent density responses for the photoelectrode were measured to be more than 30 mV and 8.9×10-6 A/cm2,respectively.In addition,the experimental results showed that the photoelectrode had a typical p-type semiconductor photovoltaic property and had excellent photovoltaic response time.
A novel modified compound photoelectrode(Eu-Fe-Mo/CuInSe2) was prepared successfully by electrodeposition of CuInSe2 semiconductor materials on the glassy carbon electrode,which was modified beforehand with cyanide-bridged mixed complexes.With the electroplating solution that contained Cu2+,In3+,SeO32- and sodium citrate in acidic aqueous solution,we found that there existed the best Cu: In: Se concentration ratio of added chemicals by optimizing procedure.The methods of SEM and EDS were employed to characterize the surface morphology of the modified compound photoelectrode and the elemental composite of CuInSe2 materials.Furthermore,with the ordinary daylight of 60 watts incandescent lamp as the light source,the photovoltaic properties of modified compound photoelectrode were investigated by means of open circuit potential and chronoamperometry,and its photovoltage and photocurrent density responses for the photoelectrode were measured to be more than 30 mV and 8.9×10-6 A/cm2,respectively.In addition,the experimental results showed that the photoelectrode had a typical p-type semiconductor photovoltaic property and had excellent photovoltaic response time.
2012, 29(8): 962-968
doi: 10.3724/SP.J.1095.2012.00398
Abstract:
The inhibition effect of Yushania polytricha leaves extract(YPLE) on the corrosion of aluminum in 1.0 mol/L HCl media was studied by mass loss,potentiodynamic polarization curves,electrochemical impedance spectroscopy,Fourier transform infrared spectroscopy,ultraviolet spectrophotometry and scanning electron microscope methods.The results show that YPLE is a good inhibitor,and the inhibition efficiency increases with the inhibitor concentration.The adsorption of YPLE on aluminum surface obeys Langmuir adsorption isotherm.YPLE behaves as a cathodic inhibitor.EIS spectra exhibit one capacitive loop at high frequencies followed by an inductive one at low frequency values,and the impedance value increases with the inhibitor concentration.SEM results confirm the corrosion of aluminum is retarded remarkably by the addition of YPLE.
The inhibition effect of Yushania polytricha leaves extract(YPLE) on the corrosion of aluminum in 1.0 mol/L HCl media was studied by mass loss,potentiodynamic polarization curves,electrochemical impedance spectroscopy,Fourier transform infrared spectroscopy,ultraviolet spectrophotometry and scanning electron microscope methods.The results show that YPLE is a good inhibitor,and the inhibition efficiency increases with the inhibitor concentration.The adsorption of YPLE on aluminum surface obeys Langmuir adsorption isotherm.YPLE behaves as a cathodic inhibitor.EIS spectra exhibit one capacitive loop at high frequencies followed by an inductive one at low frequency values,and the impedance value increases with the inhibitor concentration.SEM results confirm the corrosion of aluminum is retarded remarkably by the addition of YPLE.
2012, 29(8): 969-973
doi: 10.3724/SP.J.1095.2012.00387
Abstract:
The interaction of bovine serum albumin(BSA) with perfluorooctane sulfonate(PFOS) was investigated with resonance light scattering(RLS) spectroscopy.A RLS method for the determination of PFOS was established.In pH=4.1 Britton-Robinson buffer solution,perfluorooctane sulfonate anions reacted with the protonated BSA by electrostatic forces and hydrophobic interactions to form ion-association complexes and resulted in greatly enhanced resonance light scattering signals characterized by a peak at 285.0 nm.The RLS intensity of system was proportional to the content of PFOS in the range of 0.2~25.0 μmol/L,and the limit of detection was 20.0 nmol/L.The optimum reaction conditions and interference of foreign substances were investigated.This RLS method was applied to the determination of PFOS in environmental samples with RSD≤4.4%.
The interaction of bovine serum albumin(BSA) with perfluorooctane sulfonate(PFOS) was investigated with resonance light scattering(RLS) spectroscopy.A RLS method for the determination of PFOS was established.In pH=4.1 Britton-Robinson buffer solution,perfluorooctane sulfonate anions reacted with the protonated BSA by electrostatic forces and hydrophobic interactions to form ion-association complexes and resulted in greatly enhanced resonance light scattering signals characterized by a peak at 285.0 nm.The RLS intensity of system was proportional to the content of PFOS in the range of 0.2~25.0 μmol/L,and the limit of detection was 20.0 nmol/L.The optimum reaction conditions and interference of foreign substances were investigated.This RLS method was applied to the determination of PFOS in environmental samples with RSD≤4.4%.
2012, 29(8): 974-976
doi: 10.3724/SP.J.1095.2012.00369
Abstract:
Taking advantage of the hydrophilicity of zeolite A membrane,it was used as a vapor permeation membrane to remove the water generated from the esterification between acrylic acid and ethanol with the presence of p-toluene sulphonic acid as catalyst.This allowed to efficiently separate in situ formed water from the reactor,shift the esterification toward right side and hence substantially enhance the conversion of acrylic acid.Up to 100% conversion could be achieved within 15 h.
Taking advantage of the hydrophilicity of zeolite A membrane,it was used as a vapor permeation membrane to remove the water generated from the esterification between acrylic acid and ethanol with the presence of p-toluene sulphonic acid as catalyst.This allowed to efficiently separate in situ formed water from the reactor,shift the esterification toward right side and hence substantially enhance the conversion of acrylic acid.Up to 100% conversion could be achieved within 15 h.
