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2009 Volume 26 Issue 4
2009, 26(4): 373-377
Abstract:
A new cement dispersant for oil well cement,gelatin with sulfonated side chains,was synthesized by sulfonation grafting reaction of gelatin with formaldehyde,acetone and sodium pyrosulfite.FT-IR was utilized to confirm the presence of the sulfonated side chains on the gelatin.When the concentration of the synthesized dispersant reached 1%,the fluidity index,the consistency coefficient and the thickening time ratio of cement slurry were 1.124,0.014 and 1.02 respectively,and the corresponding compression-strength ratio was larger than 1.0.Meanwhile,with the same loading of the synthesized dispersant,the fluidity indexes and consistency coefficients of the saline cement slurries with 18%NaCl,37%NaCl or 2%CaCl2 were 1.021,1.087,0.914,and 0.035,0.025,0.063,respectively.Test results verified that the modified gelatin had an excellent dispersivity,strong brine tolerance and no side effect of retardation on cement slurry,as well as similar properties of conventional dispersants in the form of sulfonated aldehyde and ketone condensate.The gelatin with sulfonated side chains is expected to be a new kind of biodegradable dispersant.
A new cement dispersant for oil well cement,gelatin with sulfonated side chains,was synthesized by sulfonation grafting reaction of gelatin with formaldehyde,acetone and sodium pyrosulfite.FT-IR was utilized to confirm the presence of the sulfonated side chains on the gelatin.When the concentration of the synthesized dispersant reached 1%,the fluidity index,the consistency coefficient and the thickening time ratio of cement slurry were 1.124,0.014 and 1.02 respectively,and the corresponding compression-strength ratio was larger than 1.0.Meanwhile,with the same loading of the synthesized dispersant,the fluidity indexes and consistency coefficients of the saline cement slurries with 18%NaCl,37%NaCl or 2%CaCl2 were 1.021,1.087,0.914,and 0.035,0.025,0.063,respectively.Test results verified that the modified gelatin had an excellent dispersivity,strong brine tolerance and no side effect of retardation on cement slurry,as well as similar properties of conventional dispersants in the form of sulfonated aldehyde and ketone condensate.The gelatin with sulfonated side chains is expected to be a new kind of biodegradable dispersant.
2009, 26(4): 378-382
Abstract:
A series of surfactants,a,b,c,d,e and their acrylates,A,B,C,D and E,were synthesized with poly(ethylene oxide)(PEO)(Mw:200,600,1 000,2 000,6 000) and sterate chloride as the main starting materials.Their chemical structures were characterized by means of FTIR and 1H NMR.The surface activity and surface tension(γ) of surfactants a,b,c,d and e were evaluated by maximum bubble pressure method.Surfactants A,B,C,D and E were adopted as the grafting monomers of linear low density poly-ethylene(LLDPE),and grafting reaction was carried out via melt reactive extrusion procedure.Their surface properties were characterized with measuring contact angle.The surface tensions of sterates containing PEO with different molecular mass are individually 30.19,32.22,35.30,38.39 and 43.37 mN/m.The contact angles are individually 81.06°,70.10°,72.25°,76.40° and 95.55°.Thermal properties of grafted copo-lymers were studied by DSC.The crystalline temperatures of grafted copolymers are individually 109.30 ℃,109.08 ℃,110.18 ℃,109.74 ℃ and 109.74 ℃.The surface tension was found to increase with the length of PEO and the hydrophilic property of the grafted copolymers was better than that of pure LLDPE(103°).The crystalline temperatures of grafted copolymers were higher than that of pure LLDPE(104.95 ℃).
A series of surfactants,a,b,c,d,e and their acrylates,A,B,C,D and E,were synthesized with poly(ethylene oxide)(PEO)(Mw:200,600,1 000,2 000,6 000) and sterate chloride as the main starting materials.Their chemical structures were characterized by means of FTIR and 1H NMR.The surface activity and surface tension(γ) of surfactants a,b,c,d and e were evaluated by maximum bubble pressure method.Surfactants A,B,C,D and E were adopted as the grafting monomers of linear low density poly-ethylene(LLDPE),and grafting reaction was carried out via melt reactive extrusion procedure.Their surface properties were characterized with measuring contact angle.The surface tensions of sterates containing PEO with different molecular mass are individually 30.19,32.22,35.30,38.39 and 43.37 mN/m.The contact angles are individually 81.06°,70.10°,72.25°,76.40° and 95.55°.Thermal properties of grafted copo-lymers were studied by DSC.The crystalline temperatures of grafted copolymers are individually 109.30 ℃,109.08 ℃,110.18 ℃,109.74 ℃ and 109.74 ℃.The surface tension was found to increase with the length of PEO and the hydrophilic property of the grafted copolymers was better than that of pure LLDPE(103°).The crystalline temperatures of grafted copolymers were higher than that of pure LLDPE(104.95 ℃).
2009, 26(4): 383-387
Abstract:
Attapulgite was firstly purified and modified by silane coupling agent KH-570,and then silicone rubber(SR)/organic-attapulgite(OAT) nanocomposites were prepared in a two-roll mill.Fourier transform infrared(FTIR) spectrometry and transmission electron microscopy(TEM) were used to characterize the modification of AT.The vulcanization behavior,mechanical properties,and thermal stability of the SR/OAT nanocomposites were studied.The results show that OAT could reduce the optimum cure time of the SR and increase the minimum and maximum torque values,behaving like a vulcanizing accelerator for the SR.The tensile strength of the nanocomposites increased with OAT content increasing;however,the elongation at break achieved the optimum value at 20 phr OAT loading,which indicates that attapulgite can serve as an effective reinforcing agent for silicone rubber.In addition,thermogravimetric analysis(TGA) results show the incorporation of OAT could improve the thermal stability of the SR/OAT nanocomposites.
Attapulgite was firstly purified and modified by silane coupling agent KH-570,and then silicone rubber(SR)/organic-attapulgite(OAT) nanocomposites were prepared in a two-roll mill.Fourier transform infrared(FTIR) spectrometry and transmission electron microscopy(TEM) were used to characterize the modification of AT.The vulcanization behavior,mechanical properties,and thermal stability of the SR/OAT nanocomposites were studied.The results show that OAT could reduce the optimum cure time of the SR and increase the minimum and maximum torque values,behaving like a vulcanizing accelerator for the SR.The tensile strength of the nanocomposites increased with OAT content increasing;however,the elongation at break achieved the optimum value at 20 phr OAT loading,which indicates that attapulgite can serve as an effective reinforcing agent for silicone rubber.In addition,thermogravimetric analysis(TGA) results show the incorporation of OAT could improve the thermal stability of the SR/OAT nanocomposites.
2009, 26(4): 388-391
Abstract:
Twelve new N'-5-aryl-oxiadiazol-2-yl-N-sulfonylbenzoyl-imino acetylthiourea derivatives with sulfonylbenzoyl and 1,3,4-oxiadiazol were prepared.Their structures were determined by IR,1H NMR and elemental analysis.The biological activity tests show that most of these compounds have a good fungicidal activity to botrytis cinereapers and sclerotinia sclerotiorum,especially,fungicidal activities of compounds 5b and 5l can reach to 87% to 100% respectively.
Twelve new N'-5-aryl-oxiadiazol-2-yl-N-sulfonylbenzoyl-imino acetylthiourea derivatives with sulfonylbenzoyl and 1,3,4-oxiadiazol were prepared.Their structures were determined by IR,1H NMR and elemental analysis.The biological activity tests show that most of these compounds have a good fungicidal activity to botrytis cinereapers and sclerotinia sclerotiorum,especially,fungicidal activities of compounds 5b and 5l can reach to 87% to 100% respectively.
2009, 26(4): 392-395
Abstract:
The cationic copolymer was prepared from monomer acylamide(AM) and 2-(acyloyloxy)ethyl trimethylammonium chloride(DAC) by solution polymerization.The cationic degree of the copolymer was determined by the titration,the reactivity ratios of the cationic copolymer were obtained by the Fineman-Ross method,Kelen-Tudos method and Yezrielev-Brokhina-Roskin method,respectively.The results show that the values of the reactivity ratios determined by K-T method and YBR method are more accurate.The reactivity ratios of AM and DAC are rDAC=0.383 5,rAM=2.286 4 calculated by K-T method and YBR method.
The cationic copolymer was prepared from monomer acylamide(AM) and 2-(acyloyloxy)ethyl trimethylammonium chloride(DAC) by solution polymerization.The cationic degree of the copolymer was determined by the titration,the reactivity ratios of the cationic copolymer were obtained by the Fineman-Ross method,Kelen-Tudos method and Yezrielev-Brokhina-Roskin method,respectively.The results show that the values of the reactivity ratios determined by K-T method and YBR method are more accurate.The reactivity ratios of AM and DAC are rDAC=0.383 5,rAM=2.286 4 calculated by K-T method and YBR method.
2009, 26(4): 396-400
Abstract:
Europium(Ⅲ) doped silica gel composite was prepared by the sol-gel method,and the magnetic powder EMO for fingerprint detection was designed.Its application to the development of latent fingerprints left on some porous or nonporous surfaces and likely in crime scene was investigated.The effects of the aging of fingerprints and the stability of the labeled prints were discussed.The UV-Vis and fluorescence characterizations as well as the basic principle to detect fingerprints were presented.The results show that this EMO powder is an excellent development powder for the latent fingerprint detection.
Europium(Ⅲ) doped silica gel composite was prepared by the sol-gel method,and the magnetic powder EMO for fingerprint detection was designed.Its application to the development of latent fingerprints left on some porous or nonporous surfaces and likely in crime scene was investigated.The effects of the aging of fingerprints and the stability of the labeled prints were discussed.The UV-Vis and fluorescence characterizations as well as the basic principle to detect fingerprints were presented.The results show that this EMO powder is an excellent development powder for the latent fingerprint detection.
2009, 26(4): 401-404
Abstract:
Eight N'-phenoxyacetyl-N-(5-benzoylfurane-2-formy)-hydrazine derivatives were synthesized by the reaction of 5-substituted phenyl-2-furoyl chloride with substituted phenoxy acethydrazine.Their structures were confirmed by IR,1H NMR and elemental analysis.The preliminary bioassay shows that most of the title compounds exhibited some insecticidal activity to Aphis and Acarid.
Eight N'-phenoxyacetyl-N-(5-benzoylfurane-2-formy)-hydrazine derivatives were synthesized by the reaction of 5-substituted phenyl-2-furoyl chloride with substituted phenoxy acethydrazine.Their structures were confirmed by IR,1H NMR and elemental analysis.The preliminary bioassay shows that most of the title compounds exhibited some insecticidal activity to Aphis and Acarid.
2009, 26(4): 405-408
Abstract:
With paratoluenesulfonic acid(pTsOH) or trifluoroacetic acid(TFA) as catalyst,3β-acetoxy-androsta-5,15-dien-17-one(Ⅰ) was conveniently and efficiently obtained from o-iodoxybenzoic acid(IBX) selective dehydrogenation to dehydroepiandrosterone acetate in Tol-DMSO at 40~45 ℃in the yields of 77% and 89%,respectively.The synthetic routes avoided the disadvantages of bromination-debromination and fermentation route,i.e.,too many reaction steps,higher toxicity,larger costs,as well as the shortcomings of simple IBX selective dehydrogenation such as higher reaction temperature,longer reaction time.Hydrolysis of compoundⅠ by strong base gave 3β-hydroxyl-androsta-5,15-dien-17-one(Ⅱ) in a yield of 92%.The target 15β,16β-methylen-androsta-5-en-3β-ol-17-one(Ⅲ) was synthesized from Compound Ⅱ through Michaels' conjugate addition with trime-thylsulfoxonium iodide in THF-DMSO at 12~20 ℃ in a yield of 89%.The chemical structures of intermediates and target product were characterized by UV,IR,1H NMR,MS,and elemental analysis.
With paratoluenesulfonic acid(pTsOH) or trifluoroacetic acid(TFA) as catalyst,3β-acetoxy-androsta-5,15-dien-17-one(Ⅰ) was conveniently and efficiently obtained from o-iodoxybenzoic acid(IBX) selective dehydrogenation to dehydroepiandrosterone acetate in Tol-DMSO at 40~45 ℃in the yields of 77% and 89%,respectively.The synthetic routes avoided the disadvantages of bromination-debromination and fermentation route,i.e.,too many reaction steps,higher toxicity,larger costs,as well as the shortcomings of simple IBX selective dehydrogenation such as higher reaction temperature,longer reaction time.Hydrolysis of compoundⅠ by strong base gave 3β-hydroxyl-androsta-5,15-dien-17-one(Ⅱ) in a yield of 92%.The target 15β,16β-methylen-androsta-5-en-3β-ol-17-one(Ⅲ) was synthesized from Compound Ⅱ through Michaels' conjugate addition with trime-thylsulfoxonium iodide in THF-DMSO at 12~20 ℃ in a yield of 89%.The chemical structures of intermediates and target product were characterized by UV,IR,1H NMR,MS,and elemental analysis.
2009, 26(4): 409-412
Abstract:
Precursor of complex materials was synthesized by sol-gel method from TiCl4 and PVC.The nano-meter TiO2/conjugated polymer(TiO2/CP) composite photocatalyst was prepared by calcinating the precursor at 260 ℃.TEM,XRD,FTIR and UV-Vis were used to characterize the composite photocatalyst and its photocatalytic activity for the degradation of dye methylene blue(MB) was studied.The results show that under the irradiation of natural light,when the calcination temperature was 260 ℃ and the TiO2 content was 66.36%,MB could be degraded more efficiently on the TiO2/CP than on pure nanometer TiO2.The average size of the composite photocatalyst was about 30 nm.The crystalline structure of TiO2 in the composite was in anatase form.Doping of CP could extended the photoresponse of TiO2 to the light in the whole UV-Vis region(λ=190~800 nm),resulting in efficient separation of photogenerated charges,hence the photocatalytic activity of composite photocatalyst was greatly enhanced.
Precursor of complex materials was synthesized by sol-gel method from TiCl4 and PVC.The nano-meter TiO2/conjugated polymer(TiO2/CP) composite photocatalyst was prepared by calcinating the precursor at 260 ℃.TEM,XRD,FTIR and UV-Vis were used to characterize the composite photocatalyst and its photocatalytic activity for the degradation of dye methylene blue(MB) was studied.The results show that under the irradiation of natural light,when the calcination temperature was 260 ℃ and the TiO2 content was 66.36%,MB could be degraded more efficiently on the TiO2/CP than on pure nanometer TiO2.The average size of the composite photocatalyst was about 30 nm.The crystalline structure of TiO2 in the composite was in anatase form.Doping of CP could extended the photoresponse of TiO2 to the light in the whole UV-Vis region(λ=190~800 nm),resulting in efficient separation of photogenerated charges,hence the photocatalytic activity of composite photocatalyst was greatly enhanced.
2009, 26(4): 413-420
Abstract:
Polypyrolle/SnO2(PPy/SnO2) nanocomposite particles(~30 nm) was synthesized by the emulsion polymerization in the presence of (NH4)2S2O8 as oxidant.PPy/SnO2/cellulose acetate(PPy/SnO2/CA) nanocomposite film was prepared with cellulose acetate as film former and acetone as solvent.The crystal structure,surface morphology,absorption spectra and the thermic stability of the products were investigated by TG,XRD,TEM,SEM,AFM,FT-IR,and DRS techniques.The photocatalytic activities of the products were evaluated by the polymerization of MMA.The average diameter and mass-average molecular mass of poly(methyl methacrylate)(PMMA) particles are 18 nm and 1.42×105,respectively.
Polypyrolle/SnO2(PPy/SnO2) nanocomposite particles(~30 nm) was synthesized by the emulsion polymerization in the presence of (NH4)2S2O8 as oxidant.PPy/SnO2/cellulose acetate(PPy/SnO2/CA) nanocomposite film was prepared with cellulose acetate as film former and acetone as solvent.The crystal structure,surface morphology,absorption spectra and the thermic stability of the products were investigated by TG,XRD,TEM,SEM,AFM,FT-IR,and DRS techniques.The photocatalytic activities of the products were evaluated by the polymerization of MMA.The average diameter and mass-average molecular mass of poly(methyl methacrylate)(PMMA) particles are 18 nm and 1.42×105,respectively.
2009, 26(4): 421-425
Abstract:
Six solid energetic complexes,M(ATZ)(bpy)m·nH2O((1)M=Mn,m=2,n=3;(2)M=Co,m=2,n=7;(3)M=Ni,m=2,n=0;(4)M=Cu,m=1,n=0;(5)M=Pb,m=1,n=3;(6)M=Zn,m=1,n=1;ATZ=5,5''-azotetrazole,bpy=2,2'-bipyridine),were synthesized and characterized.The enthalpy changes of the liquid phase reactions,ΔrHmθ,investigated by microcalorimetry,were ΔrHmθ(1)=-241.245±0.060 kJ/mol,ΔrHmθ(2)=-256.875±0.050 kJ/mol,ΔrHmθ(3)=-265.172±0.038 kJ/mol,ΔrHmθ(4)=-236.538±0.038 kJ/mol,ΔrHmθ(5)=-249.698±0.038 kJ/mol,ΔrHmθ(6)=-185.072±0.048 kJ/mol,respectively.In addition,thermokinetics of the liquid phase formation reactions was studied,and the activation enthalpy(ΔH≠θ),the activation entropy(ΔS≠θ),the activation free energy(ΔG≠θ),the apparent reaction rate constant(k),the apparent activation energy(E),the pre-exponential constant(A),and the reaction order(n) were calculated by the combination of the thermochemical data of the reaction and kinetic equations with the data of thermokinetic experiments,which will supply the necessary thermodynamic data for the application of these complexes.
Six solid energetic complexes,M(ATZ)(bpy)m·nH2O((1)M=Mn,m=2,n=3;(2)M=Co,m=2,n=7;(3)M=Ni,m=2,n=0;(4)M=Cu,m=1,n=0;(5)M=Pb,m=1,n=3;(6)M=Zn,m=1,n=1;ATZ=5,5''-azotetrazole,bpy=2,2'-bipyridine),were synthesized and characterized.The enthalpy changes of the liquid phase reactions,ΔrHmθ,investigated by microcalorimetry,were ΔrHmθ(1)=-241.245±0.060 kJ/mol,ΔrHmθ(2)=-256.875±0.050 kJ/mol,ΔrHmθ(3)=-265.172±0.038 kJ/mol,ΔrHmθ(4)=-236.538±0.038 kJ/mol,ΔrHmθ(5)=-249.698±0.038 kJ/mol,ΔrHmθ(6)=-185.072±0.048 kJ/mol,respectively.In addition,thermokinetics of the liquid phase formation reactions was studied,and the activation enthalpy(ΔH≠θ),the activation entropy(ΔS≠θ),the activation free energy(ΔG≠θ),the apparent reaction rate constant(k),the apparent activation energy(E),the pre-exponential constant(A),and the reaction order(n) were calculated by the combination of the thermochemical data of the reaction and kinetic equations with the data of thermokinetic experiments,which will supply the necessary thermodynamic data for the application of these complexes.
2009, 26(4): 426-430
Abstract:
According to standard addition method a series of samples of known water-containing ionic liquid(IL) [C5mim][BF4](1-methyl-3-pentylimidazolium tetrafluoroborate) were prepared and their densityexhibited a good linear relationship with the water content in a temperature range of278.15 to 338.15 K.Byextrapolation,the density values of the ionic liquid at various temperatures were determined.The empericalequation,lnρ=0.1201 1-5.79×10-4(T-298.15),and the thermal expansion coefficient of the IL,α=5.79×10-4K-1,were obtained.On the basis of Glasser's theory,the standard molar entropy,the surfaceexcess energy,and crystal energy of the IL were estimated.In terms of the interstice model,the thermalexpansion coefficient of the IL,α(calculated),was calculated,which was in good agreement with the experi-mentalα.This result means that the interstice model is reasonable.
According to standard addition method a series of samples of known water-containing ionic liquid(IL) [C5mim][BF4](1-methyl-3-pentylimidazolium tetrafluoroborate) were prepared and their densityexhibited a good linear relationship with the water content in a temperature range of278.15 to 338.15 K.Byextrapolation,the density values of the ionic liquid at various temperatures were determined.The empericalequation,lnρ=0.1201 1-5.79×10-4(T-298.15),and the thermal expansion coefficient of the IL,α=5.79×10-4K-1,were obtained.On the basis of Glasser's theory,the standard molar entropy,the surfaceexcess energy,and crystal energy of the IL were estimated.In terms of the interstice model,the thermalexpansion coefficient of the IL,α(calculated),was calculated,which was in good agreement with the experi-mentalα.This result means that the interstice model is reasonable.
2009, 26(4): 431-434
Abstract:
The hydrolysis process of dioscin catalyzed by ion exchange resin was studied systematically.The effects of reaction temperature,reaction time,catalyst dosage on the hydrolysis of dioscin were examined via orthogonal design and single-factor experiments.The optimum hydrolysis conditions were found to be:reaction temperature 80 ℃,reaction time 9 h,catalyst dosage 6 g.The result indicates that the concentration of H+ in the hydrolyzed solution catalyzed by ion exchange resin was only 0.2% of that by HCl,although the yield of diosgenin obtained under the catalysis of ion exchange resin is(about 70%) lower than that under the catalysis of HCl,it shows a great potential as a kind of green catalyst for the hydrolysis of dioscin.
The hydrolysis process of dioscin catalyzed by ion exchange resin was studied systematically.The effects of reaction temperature,reaction time,catalyst dosage on the hydrolysis of dioscin were examined via orthogonal design and single-factor experiments.The optimum hydrolysis conditions were found to be:reaction temperature 80 ℃,reaction time 9 h,catalyst dosage 6 g.The result indicates that the concentration of H+ in the hydrolyzed solution catalyzed by ion exchange resin was only 0.2% of that by HCl,although the yield of diosgenin obtained under the catalysis of ion exchange resin is(about 70%) lower than that under the catalysis of HCl,it shows a great potential as a kind of green catalyst for the hydrolysis of dioscin.
2009, 26(4): 435-438
Abstract:
Alginate is a kind of Kelp polysaccharide which can be degraded to oligomeric alginate.Oligomeric alginate was reacted with FeCl3,and a series of Fe(Ⅲ)-oligoalginate complexes were obtained.When pH12,the complexes are stable in aqueous solution and reduced by Vitamin C and readily absorbed by human body.Meanwhile,the Fe(Ⅲ)-oligoalginate complexes prepared from oligomeric alginate with molecular mass of 21.4 kDa and 9.8 kDa contained 34% Fe.At 6~8 h after feeding the mouse with the complexes,the serum iron concentration of the mice rose obviously and the bioavailability of the complexes was 1.067.So they can be used as iron supplement.
Alginate is a kind of Kelp polysaccharide which can be degraded to oligomeric alginate.Oligomeric alginate was reacted with FeCl3,and a series of Fe(Ⅲ)-oligoalginate complexes were obtained.When pH12,the complexes are stable in aqueous solution and reduced by Vitamin C and readily absorbed by human body.Meanwhile,the Fe(Ⅲ)-oligoalginate complexes prepared from oligomeric alginate with molecular mass of 21.4 kDa and 9.8 kDa contained 34% Fe.At 6~8 h after feeding the mouse with the complexes,the serum iron concentration of the mice rose obviously and the bioavailability of the complexes was 1.067.So they can be used as iron supplement.
2009, 26(4): 439-442
Abstract:
Coordination compounds were synthesized from D-glucosamine hydrochloride and LaCl3 or NdCl3.Their structures were characterized by elemental analysis,molar conductivity,IR,UV-Vis,and X-ray photoelectron spectroscopy.The scavenging effects of D-glucosamine and the rare earth complexes on superoxide anion free radical were studied.The results show that rare earth ion La3+ or Nd3+ and D-glucosamine formed the coordination compounds.In the two coordination compounds the rare earth ions were coordinated with the N atom in the amino groups and the O atom in the secondary hydroxyl groups of D-glucosamine as well as Cl-ion.The D-glucosamine and complexes all had significant scavenging effects on the superoxide anion free radical.The rare earth complexes displayed the highest scavenging effects on the superoxide anion free radical.
Coordination compounds were synthesized from D-glucosamine hydrochloride and LaCl3 or NdCl3.Their structures were characterized by elemental analysis,molar conductivity,IR,UV-Vis,and X-ray photoelectron spectroscopy.The scavenging effects of D-glucosamine and the rare earth complexes on superoxide anion free radical were studied.The results show that rare earth ion La3+ or Nd3+ and D-glucosamine formed the coordination compounds.In the two coordination compounds the rare earth ions were coordinated with the N atom in the amino groups and the O atom in the secondary hydroxyl groups of D-glucosamine as well as Cl-ion.The D-glucosamine and complexes all had significant scavenging effects on the superoxide anion free radical.The rare earth complexes displayed the highest scavenging effects on the superoxide anion free radical.
2009, 26(4): 443-446
Abstract:
α-MnO2 with a tunnel structure was fabricated via a hydrothermal oxidation-reduction method.When α-MnO2 was treated in a 0.5 mol/L HCl solution for 4 days,it was transformed into H-α-MnO2.The obtained H-α-MnO2 sample was soaked in a 0.9% NaCl solution for 4 days.92% of K+ ions in the solution was selectively adsorbed,while the structure of α-MnO2 was not changed.
α-MnO2 with a tunnel structure was fabricated via a hydrothermal oxidation-reduction method.When α-MnO2 was treated in a 0.5 mol/L HCl solution for 4 days,it was transformed into H-α-MnO2.The obtained H-α-MnO2 sample was soaked in a 0.9% NaCl solution for 4 days.92% of K+ ions in the solution was selectively adsorbed,while the structure of α-MnO2 was not changed.
2009, 26(4): 447-450
Abstract:
A novel method was developed for the determination of dichloroacetic acid,trichloroacetic acid and glyphosate in environmental water by ion chromatography with large volume direct injection.With a high capacity anion exchange column,IonPac AS9-HC column,and 25 mmol/L sodium carbonate and 2 mmol/L sodium hydroxide as eluent,the glyphosate could be well separated from trichloroacetic acid,and dichloroacetic acid could be well separated from other anions(such as F-,Cl-,NO3-,SO42-),too,and they can be determined within 22 min at a flow rate of 1.0 mL/min.A 500 μL sample loop was used.The detection limits for dichloroacetic acid,trichloroacetic acid and glyphosate were 0.005 mg/L,0.014 mg/L,and 0.03 mg/L respectively.The recoveries of the method for glyphosate,DCAA,and TCAA were between 92.6%~103.9%.The new method was applied to detecting dichloroacetic acid,trichloroacetic acid and glyphosate in river water and treated water samples of Canton with satisfactory result.
A novel method was developed for the determination of dichloroacetic acid,trichloroacetic acid and glyphosate in environmental water by ion chromatography with large volume direct injection.With a high capacity anion exchange column,IonPac AS9-HC column,and 25 mmol/L sodium carbonate and 2 mmol/L sodium hydroxide as eluent,the glyphosate could be well separated from trichloroacetic acid,and dichloroacetic acid could be well separated from other anions(such as F-,Cl-,NO3-,SO42-),too,and they can be determined within 22 min at a flow rate of 1.0 mL/min.A 500 μL sample loop was used.The detection limits for dichloroacetic acid,trichloroacetic acid and glyphosate were 0.005 mg/L,0.014 mg/L,and 0.03 mg/L respectively.The recoveries of the method for glyphosate,DCAA,and TCAA were between 92.6%~103.9%.The new method was applied to detecting dichloroacetic acid,trichloroacetic acid and glyphosate in river water and treated water samples of Canton with satisfactory result.
2009, 26(4): 451-455
Abstract:
In a pH 6.2 Na2HPO4-NaH2PO4 buffer solution,the immune reaction of goat anti-human fibrinogen serum and human fibrinogen(Fg) forms immune complex particles that exhibit a stronger resonance scattering peak at 340 nm.The resonance scattering intensity at 340 nm was enhanced with the increase of concentration of Fg.There is a linear relation in resonance scattering intensity ΔI340 nm to the Fg concentration c in a range of 1.33×10-7~5.33×10-6 g/mL.The regressed linear equation is ΔI340 nm=12.17c+3.35,the relation coefficient is 0.998 6.The detection limit(3σ) is achieved at 2.8×10-8 g/mL Fg.Influence of 18 substances on the determination was examined.Results indicate that this assay has a good selectivity.The proposed method was applied to the determination of Fg in plasma,with a relative standard deviation of 2.2%~2.3%.The result is in agreement with the Fg content in normal plasma.
In a pH 6.2 Na2HPO4-NaH2PO4 buffer solution,the immune reaction of goat anti-human fibrinogen serum and human fibrinogen(Fg) forms immune complex particles that exhibit a stronger resonance scattering peak at 340 nm.The resonance scattering intensity at 340 nm was enhanced with the increase of concentration of Fg.There is a linear relation in resonance scattering intensity ΔI340 nm to the Fg concentration c in a range of 1.33×10-7~5.33×10-6 g/mL.The regressed linear equation is ΔI340 nm=12.17c+3.35,the relation coefficient is 0.998 6.The detection limit(3σ) is achieved at 2.8×10-8 g/mL Fg.Influence of 18 substances on the determination was examined.Results indicate that this assay has a good selectivity.The proposed method was applied to the determination of Fg in plasma,with a relative standard deviation of 2.2%~2.3%.The result is in agreement with the Fg content in normal plasma.
2009, 26(4): 456-461
Abstract:
In a pH=8.0 BR buffer solution,some flavones such as morin,quercetin,and rutin,can react with Fe(phen)32+ to form ion association complexes.As a result,the Resonance Rayleigh scattering(RRS) is enhanced greatly.The maximum RRS wavelengths of the three ion association complexes are all located at 310 nm.In a certain concentrations range,there is a linear relationship between the RRS intensity and the flavones concentration.So,a new RRS method for the determination of some flavones with Fe(phen)32+ as a probe was established.The method had a high sensitivity and selectivity,with the detection limit(3σ/K) of 1.25×10-7 mol/L(37.74 μg/L) for morin,1.80×10-7 mol/L(54.42 μg/L) for quercetin and 2.72×10-7 mol/L(167.30 μg/L) for rutin,respectively.The optimum reaction conditions and the effects of foreign substances were investigated.The contents of total flavones were determined in Hawthorn Fruit and Ramulus Mori with rutin and morin as the reference compounds respectively.In addition,the reaction mechanism was discussed.
In a pH=8.0 BR buffer solution,some flavones such as morin,quercetin,and rutin,can react with Fe(phen)32+ to form ion association complexes.As a result,the Resonance Rayleigh scattering(RRS) is enhanced greatly.The maximum RRS wavelengths of the three ion association complexes are all located at 310 nm.In a certain concentrations range,there is a linear relationship between the RRS intensity and the flavones concentration.So,a new RRS method for the determination of some flavones with Fe(phen)32+ as a probe was established.The method had a high sensitivity and selectivity,with the detection limit(3σ/K) of 1.25×10-7 mol/L(37.74 μg/L) for morin,1.80×10-7 mol/L(54.42 μg/L) for quercetin and 2.72×10-7 mol/L(167.30 μg/L) for rutin,respectively.The optimum reaction conditions and the effects of foreign substances were investigated.The contents of total flavones were determined in Hawthorn Fruit and Ramulus Mori with rutin and morin as the reference compounds respectively.In addition,the reaction mechanism was discussed.
2009, 26(4): 462-466
Abstract:
A novel and simple spectrophotometric method for determination of hydroquinone with 1,2-naphthoquinone-4-sulfonate reagent was developed.The method was based on 2-hydroxy-1,4-naphthoquinone(lawsone) formed from hydroxyl ion and NQS in a buffer solution of pH=13.00 with hydroquinone as a catalyst.Absorbency was linearly proportional to the concentration of hydroquinone in a range of 1.3×10-7~1.32×10-5 g/mL at the maximal absorption wavelength of 454 nm.The equation of linear regression was A=0.025 61+0.073 28c(1×105 mol/L),with a correlation coefficient of 0.995 5.The detection limit was 9×10-8 g/mL(3σ/k),and the recovery was in a range of 96.5%~103%.The method has been successfully applied to the determination of hydroquinone in water.
A novel and simple spectrophotometric method for determination of hydroquinone with 1,2-naphthoquinone-4-sulfonate reagent was developed.The method was based on 2-hydroxy-1,4-naphthoquinone(lawsone) formed from hydroxyl ion and NQS in a buffer solution of pH=13.00 with hydroquinone as a catalyst.Absorbency was linearly proportional to the concentration of hydroquinone in a range of 1.3×10-7~1.32×10-5 g/mL at the maximal absorption wavelength of 454 nm.The equation of linear regression was A=0.025 61+0.073 28c(1×105 mol/L),with a correlation coefficient of 0.995 5.The detection limit was 9×10-8 g/mL(3σ/k),and the recovery was in a range of 96.5%~103%.The method has been successfully applied to the determination of hydroquinone in water.
2009, 26(4): 467-470
Abstract:
In view of background interference and weak signals in practice,a method for analyzing passive remote sensing FTIR signals with interferogram was built based on different attenuation rates of background and sample interferogram.With a bandwidth of FIR filter of 20 cm-1,the signal of benzene was acquired from the passive remote sensing FTIR interferogram while parameters were optimized as follows:interferogram length was 100 points,and the start point of interferogram was 50 points apart from the centerburst.Then PLS was utilized to build a calibration model and recognize 26 unknown samples with a recognition rate of 96%.The work indicates that the responses of passive remote sensing FTIR were intensified and the background effect was avoided with this technique.Combination of this technique with chemometric method makes if possible to monitor the environmental pollution automatically.
In view of background interference and weak signals in practice,a method for analyzing passive remote sensing FTIR signals with interferogram was built based on different attenuation rates of background and sample interferogram.With a bandwidth of FIR filter of 20 cm-1,the signal of benzene was acquired from the passive remote sensing FTIR interferogram while parameters were optimized as follows:interferogram length was 100 points,and the start point of interferogram was 50 points apart from the centerburst.Then PLS was utilized to build a calibration model and recognize 26 unknown samples with a recognition rate of 96%.The work indicates that the responses of passive remote sensing FTIR were intensified and the background effect was avoided with this technique.Combination of this technique with chemometric method makes if possible to monitor the environmental pollution automatically.
2009, 26(4): 471-474
Abstract:
A novel and facile photoreduction technique to synthesize Au core/Ag shell nanoparticles has been proposed with Keggin structure polyoxotungstosilicate H4SiW12O40(short for SiW12) as a reducing reagent,photocatalyst,and stabilizer.The nanoparticles capped with Keggin ions could obviate the possibility of nucleation of fresh Ag nanoparticles in solution.The resulted Au core/Ag shell(SiW12-(Au/Ag) nanoparticles) were of polydisperse and spheric morphology with size ranged from 30 to 40 nm.Through the electrostatic attraction of the PVP polymer film on the glassy carbon electrode surface,a SiW12-(Au/Ag) nanoparticles multilayer films modified electrode(SiW12-(Au/Ag)-PVP/GCE) was obtained.The results show that three pairs of reversible redox peaks of SiW12 at the modified electrode have been obtained by cyclic voltammetry in a 0.5 mol/L H2SO4 solution,with good sensitivity and excellent stability.The electrocatalysis of H2O2 at SiW12-(Au/Ag)-PVP/GCE shows a higher activity than that of it at SiW12-Ag-PVP/GCE.It suggests that the interaction between Au core and Ag shell could enhance the electrocatalysis of SiW12-modified electrode.
A novel and facile photoreduction technique to synthesize Au core/Ag shell nanoparticles has been proposed with Keggin structure polyoxotungstosilicate H4SiW12O40(short for SiW12) as a reducing reagent,photocatalyst,and stabilizer.The nanoparticles capped with Keggin ions could obviate the possibility of nucleation of fresh Ag nanoparticles in solution.The resulted Au core/Ag shell(SiW12-(Au/Ag) nanoparticles) were of polydisperse and spheric morphology with size ranged from 30 to 40 nm.Through the electrostatic attraction of the PVP polymer film on the glassy carbon electrode surface,a SiW12-(Au/Ag) nanoparticles multilayer films modified electrode(SiW12-(Au/Ag)-PVP/GCE) was obtained.The results show that three pairs of reversible redox peaks of SiW12 at the modified electrode have been obtained by cyclic voltammetry in a 0.5 mol/L H2SO4 solution,with good sensitivity and excellent stability.The electrocatalysis of H2O2 at SiW12-(Au/Ag)-PVP/GCE shows a higher activity than that of it at SiW12-Ag-PVP/GCE.It suggests that the interaction between Au core and Ag shell could enhance the electrocatalysis of SiW12-modified electrode.
2009, 26(4): 475-478
Abstract:
TiO2-CuO/Cu composite electrode was fabricated and used to investigate the photoelectrochemical reduction of CO2.The photoelectrochemical measurements show that TiO2 could effectively absorb light energy and release abundant electrons to enhance the reduction of CO2.The TiO2-CuO/Cu composite electrode has a good catalytic activity for reducing CO2 under light radiation.The onset reduction potential was shifted positively from-0.9 V to-0.8 V,and at the same time,the decomposition of water was greatly suppressed.The Mott-Schottky profiles showed the composite electrode was n-type semiconductor and the flat-band potential was shifted negatively as the radiation time increased.The FT-IR and GC-MS spectroscopies proved the reducted products were mainly HCOOH and HCHO,along with a small amount of CH4 and C2H4.At-1.2 V for 3 h under light radiation,the conversion rate for CO2 reached to 32%.Based on the experimental data,the free radical reduction mechanism was proposed.
TiO2-CuO/Cu composite electrode was fabricated and used to investigate the photoelectrochemical reduction of CO2.The photoelectrochemical measurements show that TiO2 could effectively absorb light energy and release abundant electrons to enhance the reduction of CO2.The TiO2-CuO/Cu composite electrode has a good catalytic activity for reducing CO2 under light radiation.The onset reduction potential was shifted positively from-0.9 V to-0.8 V,and at the same time,the decomposition of water was greatly suppressed.The Mott-Schottky profiles showed the composite electrode was n-type semiconductor and the flat-band potential was shifted negatively as the radiation time increased.The FT-IR and GC-MS spectroscopies proved the reducted products were mainly HCOOH and HCHO,along with a small amount of CH4 and C2H4.At-1.2 V for 3 h under light radiation,the conversion rate for CO2 reached to 32%.Based on the experimental data,the free radical reduction mechanism was proposed.
2009, 26(4): 479-482
Abstract:
Acrylamide(AM)/Octadecyl methacrylate(OM) hydrophobically associating water-soluble copolymer were synthesized by free-radical micellar copolymerization.The copolymer structures were determined by FT-IR spectroscopy.The effects of copolymer concentration,salt concentration,rate of shear and temperature on the apparent viscosity of the copolymer have been studied.The results showed that the solution apparent viscosity increase sharply when the mass fraction of the copolymer was higher than critical associating concentration(2%).With an increasing of NaCl concentration,the copolymer solution apparent viscosity increased.
Acrylamide(AM)/Octadecyl methacrylate(OM) hydrophobically associating water-soluble copolymer were synthesized by free-radical micellar copolymerization.The copolymer structures were determined by FT-IR spectroscopy.The effects of copolymer concentration,salt concentration,rate of shear and temperature on the apparent viscosity of the copolymer have been studied.The results showed that the solution apparent viscosity increase sharply when the mass fraction of the copolymer was higher than critical associating concentration(2%).With an increasing of NaCl concentration,the copolymer solution apparent viscosity increased.
2009, 26(4): 483-485
Abstract:
A new energetic complex of copper(Ⅱ) was prepared and identified as CuATZ·2H2O(ATZ2-=5,5'-azotetrazolate) by chemical analysis.The solubility of the complex was determined.The enthalpy change of the liquid-phase reaction for the formation of the complex,ΔrHmθ(l),was determined to be(-39.182±0.097) kJ/mol at 298.15 K by microcalorimetry.On the basis of experimental and calculated results,the thermodynamic and kinetic parameters of the liquid-phase reaction for the formation of the complex were obtained at different temperatures.The lower apparent activation energy E(24.880 5 kJ/mol) benefited the proceeding of the reaction under ordinary experimental conditions.However the complex can not be used as a component in solid propellants due to its sensitivity to shock and impact at room temperature at mg quantity and increased risk of explosion upon friction and static charge at about 60 ℃.
A new energetic complex of copper(Ⅱ) was prepared and identified as CuATZ·2H2O(ATZ2-=5,5'-azotetrazolate) by chemical analysis.The solubility of the complex was determined.The enthalpy change of the liquid-phase reaction for the formation of the complex,ΔrHmθ(l),was determined to be(-39.182±0.097) kJ/mol at 298.15 K by microcalorimetry.On the basis of experimental and calculated results,the thermodynamic and kinetic parameters of the liquid-phase reaction for the formation of the complex were obtained at different temperatures.The lower apparent activation energy E(24.880 5 kJ/mol) benefited the proceeding of the reaction under ordinary experimental conditions.However the complex can not be used as a component in solid propellants due to its sensitivity to shock and impact at room temperature at mg quantity and increased risk of explosion upon friction and static charge at about 60 ℃.
2009, 26(4): 486-488
Abstract:
4,6-Bis(difluoromethoxy)-2-aminopyrimdine(Ⅵ) and its intermediates Ⅰ,Ⅱ,Ⅲ,Ⅳ,Ⅴ were synthesized by cyclization,methylation,difluoromethoxidation,oxidation and ammonolysis reactions in sequence with thiourea and diethyl malonate as materials.The total yield is 30%.In methanol sodium,compound Ⅰ was obtained by the cyclization of thiourea and diethyl malonate.Compound Ⅱ was obtained by the reaction of sulfenyl of compound Ⅰ with dimethyl sulfate,compound Ⅲ was obtained by the reaction of hydroxy of compound Ⅱ with chlorodifuoromethane,compound Ⅳ was obtained by the oxidation of sulfur of compound Ⅲ using hydrogen peroxide,compound Ⅴ was obtained by the substitution of methylsulfone group of compound Ⅳ with amino,compound Ⅵ was obtained from compound Ⅴ by reaction with o-methoxycarbo-nylbenzenylsulfylisocyanate.The structures of compounds Ⅰ,Ⅱ,Ⅲ,Ⅳ,Ⅴ,Ⅵ were characterized by 1H NMR,MS,and the purities were detected by HPLC.
4,6-Bis(difluoromethoxy)-2-aminopyrimdine(Ⅵ) and its intermediates Ⅰ,Ⅱ,Ⅲ,Ⅳ,Ⅴ were synthesized by cyclization,methylation,difluoromethoxidation,oxidation and ammonolysis reactions in sequence with thiourea and diethyl malonate as materials.The total yield is 30%.In methanol sodium,compound Ⅰ was obtained by the cyclization of thiourea and diethyl malonate.Compound Ⅱ was obtained by the reaction of sulfenyl of compound Ⅰ with dimethyl sulfate,compound Ⅲ was obtained by the reaction of hydroxy of compound Ⅱ with chlorodifuoromethane,compound Ⅳ was obtained by the oxidation of sulfur of compound Ⅲ using hydrogen peroxide,compound Ⅴ was obtained by the substitution of methylsulfone group of compound Ⅳ with amino,compound Ⅵ was obtained from compound Ⅴ by reaction with o-methoxycarbo-nylbenzenylsulfylisocyanate.The structures of compounds Ⅰ,Ⅱ,Ⅲ,Ⅳ,Ⅴ,Ⅵ were characterized by 1H NMR,MS,and the purities were detected by HPLC.
2009, 26(4): 489-491
Abstract:
2,4,7-Triaminofluorene was synthesized via the nitration and reduction of fluorene,which was then respectively condensed with a series of aldehydes to give the corresponding novel schiff bases(a～i).Their structures were confirmed by IR,1H NMR,MS and elemental analysis,and most of them displayed antibacterial activities.
2,4,7-Triaminofluorene was synthesized via the nitration and reduction of fluorene,which was then respectively condensed with a series of aldehydes to give the corresponding novel schiff bases(a～i).Their structures were confirmed by IR,1H NMR,MS and elemental analysis,and most of them displayed antibacterial activities.
2009, 26(4): 492-494
Abstract:
The binding constant between aloe-emodin and β-cyclodextrin was determined by capillary electrophoresis.In a 0.015 mol/L sodium borate buffer(pH=9.7) at 25 ℃,the binding constant obtained by the proposed method was 27.5 L/mol.
The binding constant between aloe-emodin and β-cyclodextrin was determined by capillary electrophoresis.In a 0.015 mol/L sodium borate buffer(pH=9.7) at 25 ℃,the binding constant obtained by the proposed method was 27.5 L/mol.
2009, 26(4): 495-497
Abstract:
Electroless plating of nickel was used to plate nickel on expanded graphite surface.The plated expanded graphite was characterized by SEM,EDS,X-ray Diffraction,IR,vibrating sample magnetometer.The results indicate that an even layer of nickel was plated on expanded graphite.Ni accounted for 94.12% and P accounted for 5.88%.The reflectivity was increased in the near infrared region.The magnetism capability was enhanced.The magnetization and the retentivity were 26.3 A·m2/kg and 8.1 A·m2/kg respectively.The σr/σs was 0.31.The obtained material belongs to soft magnetism material.
Electroless plating of nickel was used to plate nickel on expanded graphite surface.The plated expanded graphite was characterized by SEM,EDS,X-ray Diffraction,IR,vibrating sample magnetometer.The results indicate that an even layer of nickel was plated on expanded graphite.Ni accounted for 94.12% and P accounted for 5.88%.The reflectivity was increased in the near infrared region.The magnetism capability was enhanced.The magnetization and the retentivity were 26.3 A·m2/kg and 8.1 A·m2/kg respectively.The σr/σs was 0.31.The obtained material belongs to soft magnetism material.
2009, 26(4): 498-500
Abstract:
Samples were treated via solid-phase micro-extraction(SPME) and analyzed by HPLC equipped with a fluorescence detector to detect carbamate pesticide residues in vegetables.The effects of fiber coatings on the extracting efficiency,factors influencing the extraction process and treatment for the vegetables were investigated.LOD of the method for different pesticides ranged from 0.4×10-9 to 40×10-9 g/g.Linear range was from 0.05 to 1 mg/L.The recovery rate was from 74.4% to 108.4%.RSD was from 4.26% to 13.97%.
Samples were treated via solid-phase micro-extraction(SPME) and analyzed by HPLC equipped with a fluorescence detector to detect carbamate pesticide residues in vegetables.The effects of fiber coatings on the extracting efficiency,factors influencing the extraction process and treatment for the vegetables were investigated.LOD of the method for different pesticides ranged from 0.4×10-9 to 40×10-9 g/g.Linear range was from 0.05 to 1 mg/L.The recovery rate was from 74.4% to 108.4%.RSD was from 4.26% to 13.97%.
