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2010 Volume 27 Issue 11
2010, 27(11): 1241-1251
doi: 10.3724/SP.J.1095.2010.00028
Abstract:
The applications of polyhydroxyl terephthalic acids in medicines and functional materials have captured much research attentions.This article reviews the synthesis and application of four typical chemicals with utmost importance and value.The preparation process of polyhydroxyl terephthalic acid substances through Koble-Schmitt reaction with phenol-type substances as starting materials has advantages such as simple operation,low production cost and environment benign,and so on.
The applications of polyhydroxyl terephthalic acids in medicines and functional materials have captured much research attentions.This article reviews the synthesis and application of four typical chemicals with utmost importance and value.The preparation process of polyhydroxyl terephthalic acid substances through Koble-Schmitt reaction with phenol-type substances as starting materials has advantages such as simple operation,low production cost and environment benign,and so on.
2010, 27(11): 1252-1255
doi: 10.3724/SP.J.1095.2010.00077
Abstract:
Merrifield resin microspheres immobilized by methoxycarbonylethyl imidazolium ionic liquid(IL) with magnetism were successfully prepared.We chose FeOOH and γ-Fe2O3 as the magnetic resource and employed the simple co-precipitation method to realize the synthesis,which is feasible and will lower the overall cost for further industrial scale application if possible.In the standpoint of comparison,the IL loaded on the merrifield resin with non-magnetic was also synthesized.The structures and properties of these two kinds of microspheres were investigated by vibrating sample magnetometer(VSM),Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),thermogravimetric analysis(TGA),as well as other performance tests.The testing results validate the structures of the two microspheres with our expectation,and indicate that the thermal stability of magnetic microspheres is superior to the non-magnetic one,so its decomposition does not occur below 200℃.The magnetic microspheres showed super-paramagnetic and did not form aggregates when the external magnetic field was absent.Magnetic separation of the magnetic microspheres has also been carried out in a 3.0 × 10-4 T single direction electromagnetic field to illustrate the predominant separation efficiency of the magnetic one.The results showed that the magnetic particles could be completely separated from water within 10 s in 3.0 × 10-4 T electromagnetic field.
Merrifield resin microspheres immobilized by methoxycarbonylethyl imidazolium ionic liquid(IL) with magnetism were successfully prepared.We chose FeOOH and γ-Fe2O3 as the magnetic resource and employed the simple co-precipitation method to realize the synthesis,which is feasible and will lower the overall cost for further industrial scale application if possible.In the standpoint of comparison,the IL loaded on the merrifield resin with non-magnetic was also synthesized.The structures and properties of these two kinds of microspheres were investigated by vibrating sample magnetometer(VSM),Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),thermogravimetric analysis(TGA),as well as other performance tests.The testing results validate the structures of the two microspheres with our expectation,and indicate that the thermal stability of magnetic microspheres is superior to the non-magnetic one,so its decomposition does not occur below 200℃.The magnetic microspheres showed super-paramagnetic and did not form aggregates when the external magnetic field was absent.Magnetic separation of the magnetic microspheres has also been carried out in a 3.0 × 10-4 T single direction electromagnetic field to illustrate the predominant separation efficiency of the magnetic one.The results showed that the magnetic particles could be completely separated from water within 10 s in 3.0 × 10-4 T electromagnetic field.
2010, 27(11): 1256-1259
doi: 10.3724/SP.J.1095.2010.00033
Abstract:
Tannin in Casuarina equisetifolia bark was in-situ immobilized by reaction of aldehydes and tannin. The adsorption behavior of the in-situ immobilized modified bark to Cr(Ⅵ) in aqueous solution was investigated. The results showed that the recovery yields of the modified barks were higher than 95% when the mass ratios of the bark to fomaldehyde,glyoxal and glutraldehyde were 1:20,1:4 and 3:25,respectively. The maximal adsorption capacity of the bark to Cr(Ⅵ) was achieved at pH=2.01.The equilibrium adsorption capacity of the barks modified with fomaldehyde,glyoxal and glutraldehyde was 68.0 mg/g,83.3 mg/g and 82.0 mg/g,respectively. The pseudo-second-order rate constant decreased with increases in the equilibrium adsorption capacity.
Tannin in Casuarina equisetifolia bark was in-situ immobilized by reaction of aldehydes and tannin. The adsorption behavior of the in-situ immobilized modified bark to Cr(Ⅵ) in aqueous solution was investigated. The results showed that the recovery yields of the modified barks were higher than 95% when the mass ratios of the bark to fomaldehyde,glyoxal and glutraldehyde were 1:20,1:4 and 3:25,respectively. The maximal adsorption capacity of the bark to Cr(Ⅵ) was achieved at pH=2.01.The equilibrium adsorption capacity of the barks modified with fomaldehyde,glyoxal and glutraldehyde was 68.0 mg/g,83.3 mg/g and 82.0 mg/g,respectively. The pseudo-second-order rate constant decreased with increases in the equilibrium adsorption capacity.
2010, 27(11): 1260-1264
doi: 10.3724/SP.J.1095.2010.00066
Abstract:
Ethylenediamine-grafted silica gel materials(EDA/SiO2) for the adsorption of Zn2+ were prepared with the use of γ-chloropropyltrichlorosilane as coupling reagent and ethylenediamine as a surface-modifying reagent.The adsorption behavior of EDA/SiO2 for Zn2+ and the effects of pH in Zn2+ solution,initial concentration,adsorption temperature and time were studied.The experimental results show that the pH value of Zn2+ solution affected the adsorption capacity of EDA/SiO2 significantly,and the suitable pH range was pH 3.0~5.5 for the adsorption of Zn2+.The adsorption equilibrium data for Zn2+ could be fitted according to the Langmuir model.The results of the thermodynamic parameters of the adsorption of Zn2+ on EDA/SiO2 show that this adsorption is an endothermic spontaneous process and increasing temperature is conducive to the adsorption.An interpretation was given for this,adsorption behavior of Zn2+ on EDA/SiO2.Adsorption kinetic data could be fitted by the pseudo-second-order kinetic equation,and the fitting kinetic constants were related with the initial solution concentration.
Ethylenediamine-grafted silica gel materials(EDA/SiO2) for the adsorption of Zn2+ were prepared with the use of γ-chloropropyltrichlorosilane as coupling reagent and ethylenediamine as a surface-modifying reagent.The adsorption behavior of EDA/SiO2 for Zn2+ and the effects of pH in Zn2+ solution,initial concentration,adsorption temperature and time were studied.The experimental results show that the pH value of Zn2+ solution affected the adsorption capacity of EDA/SiO2 significantly,and the suitable pH range was pH 3.0~5.5 for the adsorption of Zn2+.The adsorption equilibrium data for Zn2+ could be fitted according to the Langmuir model.The results of the thermodynamic parameters of the adsorption of Zn2+ on EDA/SiO2 show that this adsorption is an endothermic spontaneous process and increasing temperature is conducive to the adsorption.An interpretation was given for this,adsorption behavior of Zn2+ on EDA/SiO2.Adsorption kinetic data could be fitted by the pseudo-second-order kinetic equation,and the fitting kinetic constants were related with the initial solution concentration.
2010, 27(11): 1265-1271
doi: 10.3724/SP.J.1095.2010.00037
Abstract:
Chitosan cross-linked with 2,5-bis(formic acid)-3,4-diolthiophene(DTCC) was prepared with ethyl chloroacetate,sodium sulfide,diethyl oxalate and chitosan(CTS) as raw materials.The antibacterial effect of cross-linked polymer was studied against a series of test bacterial cultures by quantitative suspension method. Relation between storage time and variation of white peach mass-loss ratio,decomposition ratio,chlorophyll content,film penetration ratio and total saccharine content was examined thoroughly after freshkeeping process with synthesized cross-linked polymer as over-coat film.Results obtained from experiments indicated that partially cross-linked DTCC had a relatively strong antibacterial effect against Gram-positive and Gram-negative bacteria.The mean anti-bacterial ratios of DTCC for pseudomonas aeruginosa(MSH),pseudomonas fluorescens(ATCC13525),bacillus cereus(CIP6624),bacillus subtilis(ATCC6633) are 96.7%,95.8%,97.9% and 98.2%,respectively,after 20 min treatment.The minimal inhibited concentrations(MIC) for 4 bacteia are 25.0,25.0,3.1 and 3.1 g/L,respectively. DTCC also demonstrates strong antibacterial effect on aspergillus niger and penicillium italium:mean antibacterial ratios for above bacteria are 99.0% and 28.4%,respectively,with corresponding MIC of 25.0 and 12.5 g/L after 20 min treatment.DTCC with concentration of 1.0 g/L coated on the outer skin of white peaches shows a good preservation effect after 12 d storage under(27 ± 0.5)℃. The mass-loss,decomposition and film penetration ratios are 8.1%,40% and 34.1%,respectively. The total saccharine content is around 75.1 mg/g.
Chitosan cross-linked with 2,5-bis(formic acid)-3,4-diolthiophene(DTCC) was prepared with ethyl chloroacetate,sodium sulfide,diethyl oxalate and chitosan(CTS) as raw materials.The antibacterial effect of cross-linked polymer was studied against a series of test bacterial cultures by quantitative suspension method. Relation between storage time and variation of white peach mass-loss ratio,decomposition ratio,chlorophyll content,film penetration ratio and total saccharine content was examined thoroughly after freshkeeping process with synthesized cross-linked polymer as over-coat film.Results obtained from experiments indicated that partially cross-linked DTCC had a relatively strong antibacterial effect against Gram-positive and Gram-negative bacteria.The mean anti-bacterial ratios of DTCC for pseudomonas aeruginosa(MSH),pseudomonas fluorescens(ATCC13525),bacillus cereus(CIP6624),bacillus subtilis(ATCC6633) are 96.7%,95.8%,97.9% and 98.2%,respectively,after 20 min treatment.The minimal inhibited concentrations(MIC) for 4 bacteia are 25.0,25.0,3.1 and 3.1 g/L,respectively. DTCC also demonstrates strong antibacterial effect on aspergillus niger and penicillium italium:mean antibacterial ratios for above bacteria are 99.0% and 28.4%,respectively,with corresponding MIC of 25.0 and 12.5 g/L after 20 min treatment.DTCC with concentration of 1.0 g/L coated on the outer skin of white peaches shows a good preservation effect after 12 d storage under(27 ± 0.5)℃. The mass-loss,decomposition and film penetration ratios are 8.1%,40% and 34.1%,respectively. The total saccharine content is around 75.1 mg/g.
2010, 27(11): 1272-1275
doi: 10.3724/SP.J.1095.2010.00098
Abstract:
Conversion of α-pinene to campholenic aldehyde was directly carried out with aqueous hydrogen peroxide as oxidant catalyzed by VO(acac)2.The effects of reaction conditions such as solvents,temperature,dosage of catalyst and time on this reaction were investigated.The results showed that high valent V5+ obtained from VO(acac)2 and H2O2 is a good redox-Lewis acid bi-functional catalyst for the transformation of α-pinene to campholenic aldehyde via oxidation and isomerization of 2,3-epoxy pinane intermediate.Under optimal reaction conditions of n(H2O2):n(α-pinene):n(VO(acac)2)=2.5:1:0.01,reaction temperature 20℃,using acetone as solvent,58.7% selectivity of campholenic aldehyde was achieved at 50.2% conversion of α-pinene after 2 h reaction.Reacting for 6 h under the conditions described above,conversion of α-pinene can reach up to 73.0% and selectivity of major products campholenic aldehyde and verbenone were 47.2% and 13.2%,respectively.
Conversion of α-pinene to campholenic aldehyde was directly carried out with aqueous hydrogen peroxide as oxidant catalyzed by VO(acac)2.The effects of reaction conditions such as solvents,temperature,dosage of catalyst and time on this reaction were investigated.The results showed that high valent V5+ obtained from VO(acac)2 and H2O2 is a good redox-Lewis acid bi-functional catalyst for the transformation of α-pinene to campholenic aldehyde via oxidation and isomerization of 2,3-epoxy pinane intermediate.Under optimal reaction conditions of n(H2O2):n(α-pinene):n(VO(acac)2)=2.5:1:0.01,reaction temperature 20℃,using acetone as solvent,58.7% selectivity of campholenic aldehyde was achieved at 50.2% conversion of α-pinene after 2 h reaction.Reacting for 6 h under the conditions described above,conversion of α-pinene can reach up to 73.0% and selectivity of major products campholenic aldehyde and verbenone were 47.2% and 13.2%,respectively.
2010, 27(11): 1276-1281
doi: 10.3724/SP.J.1095.2010.00076
Abstract:
Simultaneous synthesis of poly(ethylene glycol succinate) oligomers and dimethyl carbonate(DMC) was achieved by coupling reaction of ethylene carbonate(EC) and dimethyl succinate(DS) over various metal acetate catalysts.The effluent of coupling reaction was confirmed by GC-MS qualitative analysis.The structure of poly(ethylene glycol succinate) oligomeric product was characterized and assured by 1H NMR and FTIR spectra,and the intrinsic viscosity of poly(ethylene glycol succinate) oligomers was tested by the Ubbelohde type viscometer.The yield of DMC was gained by gas chromatography quantitative analysis,and the extent of coupling reaction could be calculated by the yield of DMC.Results showed that the lithium acetate has the highest catalytic activity.Using this compound as catalyst,the effects of experimental parameters including the molar ratio of EC to DS,reaction temperature,reaction time and amount of catalyst on the coupling reaction were investigated.The optimized reaction conditions are as follows:reaction temperature is in the range of 195 to 200℃,molar ratio of EC to DS is 2:1,the molar fraction of catalyst is about 2%,reaction time is 2 h.Under these conditions,the yield of DMC was 48.0%;the intrinsic viscosity[η]of poly(ethylene glycol succinate) oligomers was 0.3787 dL/g.
Simultaneous synthesis of poly(ethylene glycol succinate) oligomers and dimethyl carbonate(DMC) was achieved by coupling reaction of ethylene carbonate(EC) and dimethyl succinate(DS) over various metal acetate catalysts.The effluent of coupling reaction was confirmed by GC-MS qualitative analysis.The structure of poly(ethylene glycol succinate) oligomeric product was characterized and assured by 1H NMR and FTIR spectra,and the intrinsic viscosity of poly(ethylene glycol succinate) oligomers was tested by the Ubbelohde type viscometer.The yield of DMC was gained by gas chromatography quantitative analysis,and the extent of coupling reaction could be calculated by the yield of DMC.Results showed that the lithium acetate has the highest catalytic activity.Using this compound as catalyst,the effects of experimental parameters including the molar ratio of EC to DS,reaction temperature,reaction time and amount of catalyst on the coupling reaction were investigated.The optimized reaction conditions are as follows:reaction temperature is in the range of 195 to 200℃,molar ratio of EC to DS is 2:1,the molar fraction of catalyst is about 2%,reaction time is 2 h.Under these conditions,the yield of DMC was 48.0%;the intrinsic viscosity[η]of poly(ethylene glycol succinate) oligomers was 0.3787 dL/g.
2010, 27(11): 1282-1285
doi: 10.3724/SP.J.1095.2010.00015
Abstract:
Using recycled lamp tungsten filament as the precursor of catalyst,adipic acid was synthesized from the oxidation of cyclohexanone by 30% H2O2 without the presence of any organic solvent,acidic additives and phase transfer agents.The IR and TG results indicate that nascent peroxotungstic acid is the active catalytic component obtained from the oxidation of recycled lamp tungsten filament by H2O2.It converts to tungstic acid finally.After 6h refluxing,a 63.7% yield of adipic acid could be attained using the above catalyst in optimized reaction system consisting of 100 mmol of cyclohexanone in 50 mL 30% H2O2,and with 1.5% molar fraction of catalyst in cyclohexanone.Under identical conditions the yield is 10%~18% higher than those from using tungstic acid or WO3 as the catalyst.
Using recycled lamp tungsten filament as the precursor of catalyst,adipic acid was synthesized from the oxidation of cyclohexanone by 30% H2O2 without the presence of any organic solvent,acidic additives and phase transfer agents.The IR and TG results indicate that nascent peroxotungstic acid is the active catalytic component obtained from the oxidation of recycled lamp tungsten filament by H2O2.It converts to tungstic acid finally.After 6h refluxing,a 63.7% yield of adipic acid could be attained using the above catalyst in optimized reaction system consisting of 100 mmol of cyclohexanone in 50 mL 30% H2O2,and with 1.5% molar fraction of catalyst in cyclohexanone.Under identical conditions the yield is 10%~18% higher than those from using tungstic acid or WO3 as the catalyst.
2010, 27(11): 1286-1290
doi: 10.3724/SP.J.1095.2010.90880
Abstract:
Enantioenriched(S)-3-chloro-1,2-propanediol and(R)-epichlorohydrin were obtained from the kinetic hydrolysis resolution of racemic epichlorohydrin by(S,S)-salen Co(Ⅲ) OAc.(S)-Metoprolol with optical purity higher than 99% could be prepared via the reaction of 4-(2-methoxyethyl) phenol with(S)-3chloro-1,2-propanediol followed by an amination reaction using isopropyl amine.When (R)-epichlorohydrin was used as the chiral precursor,(S)-metoprolol could be also prepared but with less optical purity(>92%). The overall yield of(S)-metoprolol was 53.9%.The structure of the product was determined by IR,1H NMR,13C NMR and MS.This procedure is effective,simple and has a high utilization rate of raw material.The optical purity and yield of the product are satisfactory.The process is promising for scaling-up industrial potential applications.
Enantioenriched(S)-3-chloro-1,2-propanediol and(R)-epichlorohydrin were obtained from the kinetic hydrolysis resolution of racemic epichlorohydrin by(S,S)-salen Co(Ⅲ) OAc.(S)-Metoprolol with optical purity higher than 99% could be prepared via the reaction of 4-(2-methoxyethyl) phenol with(S)-3chloro-1,2-propanediol followed by an amination reaction using isopropyl amine.When (R)-epichlorohydrin was used as the chiral precursor,(S)-metoprolol could be also prepared but with less optical purity(>92%). The overall yield of(S)-metoprolol was 53.9%.The structure of the product was determined by IR,1H NMR,13C NMR and MS.This procedure is effective,simple and has a high utilization rate of raw material.The optical purity and yield of the product are satisfactory.The process is promising for scaling-up industrial potential applications.
2010, 27(11): 1291-1295
doi: 10.3724/SP.J.1095.2010.90869
Abstract:
Six different imidazoline quaternary ammonium salts were synthesized with the use of valeric acid,decanoic acid,oleic acid,diethylenetriamine,benzyl chloride and thiourea as raw materials.The corrosion inhibition performances of quaternary ammonium salts of thioureido alkyl imidazoline and alkyl imidazoline on carbon steel in 1.0 mol/L HCl medium were compared at 80℃ via both static mass loss and polarization curve methods.The synergies between each of these two corrosion inhibitors and each of the inorganic anions or anionic surfactants were also investigated.The results show that the inhibition effect of quaternary ammonium salt of thioureido alkyl imidazoline reaches a 98.3% rate of corrosion inhibition and is significantly superior to that of quaternary ammonium salt of alkyl imidazoline.The best corrosion inhibition effect is achieved when the mass ratio of quaternary ammonium salt of thioureido alkyl imidazoline to I- is 1:1 during preparation process.This gives a corrosion inhibition effect 1.5% higher than that of quaternary ammonium salt of thioureido alkyl imidazoline compounds used alone.
Six different imidazoline quaternary ammonium salts were synthesized with the use of valeric acid,decanoic acid,oleic acid,diethylenetriamine,benzyl chloride and thiourea as raw materials.The corrosion inhibition performances of quaternary ammonium salts of thioureido alkyl imidazoline and alkyl imidazoline on carbon steel in 1.0 mol/L HCl medium were compared at 80℃ via both static mass loss and polarization curve methods.The synergies between each of these two corrosion inhibitors and each of the inorganic anions or anionic surfactants were also investigated.The results show that the inhibition effect of quaternary ammonium salt of thioureido alkyl imidazoline reaches a 98.3% rate of corrosion inhibition and is significantly superior to that of quaternary ammonium salt of alkyl imidazoline.The best corrosion inhibition effect is achieved when the mass ratio of quaternary ammonium salt of thioureido alkyl imidazoline to I- is 1:1 during preparation process.This gives a corrosion inhibition effect 1.5% higher than that of quaternary ammonium salt of thioureido alkyl imidazoline compounds used alone.
2010, 27(11): 1296-1300
doi: 10.3724/SP.J.1095.2010.00018
Abstract:
Iron nanoparticles were uniformly deposited on glassy carbon electrode by electrochemical cyclic voltammetry,and Fe core/Pt shell nanoparticles(nano-PtFe) were further obtained through "galvanic replacement". SEM observation illustrated that cuboid nanoparticles with average sizes,ca.60 nm,dispersing uniformly on GC electrode surfaces. The electrocatalytical activities for nitrite reduction by nano-Fe/GC,nano-Pt/GC and nano-PtFe/GC electrodes were studied by cyclic voltammetry(CV). The catalytic activity is in the order of:nano-Fe/GC < nano-Pt/GC < nano-PtFe/GC. The onset potential(Ei) of nitrite reduction on nano-PtFe/GC electrode is positively shifted 0.14V,and the steady reduction current density(ip) is about 3 times of that from nano-Pt/GC electrode.
Iron nanoparticles were uniformly deposited on glassy carbon electrode by electrochemical cyclic voltammetry,and Fe core/Pt shell nanoparticles(nano-PtFe) were further obtained through "galvanic replacement". SEM observation illustrated that cuboid nanoparticles with average sizes,ca.60 nm,dispersing uniformly on GC electrode surfaces. The electrocatalytical activities for nitrite reduction by nano-Fe/GC,nano-Pt/GC and nano-PtFe/GC electrodes were studied by cyclic voltammetry(CV). The catalytic activity is in the order of:nano-Fe/GC < nano-Pt/GC < nano-PtFe/GC. The onset potential(Ei) of nitrite reduction on nano-PtFe/GC electrode is positively shifted 0.14V,and the steady reduction current density(ip) is about 3 times of that from nano-Pt/GC electrode.
2010, 27(11): 1301-1305
doi: 10.3724/SP.J.1095.2010.00070
Abstract:
The mCMC/TiO2-Oxine/mCS bipolar membrane(BPM) was prepared by using carboxymethyl cellulose(CMC) as the anodic layer,chitosan(CS) as the cathodic layer,and Cr3+ and glutaraldehyde as the linking reagents. Nano-TiO2 was taken as an interlayer. The BPM showed a sandwich composition. TiO2 was modified with the photosensitizer,oxine as a photocatalyst to enhance the photocatalytic properties for splitting the water in the interlayer of the BPM. The bipolar membrane exhibited an excellent hydrophilic performance,lower impedance and working voltage. When the working current density was as high as 0.12 A/cm2,the working voltage was as low as 5.0 V with UV irradiation.
The mCMC/TiO2-Oxine/mCS bipolar membrane(BPM) was prepared by using carboxymethyl cellulose(CMC) as the anodic layer,chitosan(CS) as the cathodic layer,and Cr3+ and glutaraldehyde as the linking reagents. Nano-TiO2 was taken as an interlayer. The BPM showed a sandwich composition. TiO2 was modified with the photosensitizer,oxine as a photocatalyst to enhance the photocatalytic properties for splitting the water in the interlayer of the BPM. The bipolar membrane exhibited an excellent hydrophilic performance,lower impedance and working voltage. When the working current density was as high as 0.12 A/cm2,the working voltage was as low as 5.0 V with UV irradiation.
2010, 27(11): 1306-1312
doi: 10.3724/SP.J.1095.2010.00026
Abstract:
The cross-linking SBS hybrid bipolar membrane(SBS BPM) was prepared by free radical reaction of SBS(styrene-butadiene-styrene triblock copolymer) with acrylic acid(AA),sulfonic styrene(StSO3H) and γ-methacryloxypropyltrimethoxysilane(KH-570) as the anode membrane,and reaction of SBS with dimethyl amino ethyl methacrylate(DMAEMA) and KH-570 as the cathode membrane.Cross-linking reaction was carried out through sol-gel reaction of trimethoxysilane group.SBS BPM exhibited high temperature tolerance(thermal degradation temperature in N2,Td was up to 186.5℃).The ion exchange capacities(IECs) of the anode and cathode membranes were 1.51 and 2.71 mmol/g,respectively.SBS hybrid bipolar membranes were used as the separator in the electrolysis cell,then using tungstate/pertungstate as the media to indirect electrooxidate maleic acid to prepare trans-2,3-oxiranedicarboxylic acid in the cathode chamber.Graphite was used as the anode and cathode electrode.At 50℃ and when the current density was 2.0 × 10-2 A/cm2 for 4 h,the yield and average current efficiency of trans-2,3-oxiranedicarboxylic acid were 53.0% and 40.8%,respectively.
The cross-linking SBS hybrid bipolar membrane(SBS BPM) was prepared by free radical reaction of SBS(styrene-butadiene-styrene triblock copolymer) with acrylic acid(AA),sulfonic styrene(StSO3H) and γ-methacryloxypropyltrimethoxysilane(KH-570) as the anode membrane,and reaction of SBS with dimethyl amino ethyl methacrylate(DMAEMA) and KH-570 as the cathode membrane.Cross-linking reaction was carried out through sol-gel reaction of trimethoxysilane group.SBS BPM exhibited high temperature tolerance(thermal degradation temperature in N2,Td was up to 186.5℃).The ion exchange capacities(IECs) of the anode and cathode membranes were 1.51 and 2.71 mmol/g,respectively.SBS hybrid bipolar membranes were used as the separator in the electrolysis cell,then using tungstate/pertungstate as the media to indirect electrooxidate maleic acid to prepare trans-2,3-oxiranedicarboxylic acid in the cathode chamber.Graphite was used as the anode and cathode electrode.At 50℃ and when the current density was 2.0 × 10-2 A/cm2 for 4 h,the yield and average current efficiency of trans-2,3-oxiranedicarboxylic acid were 53.0% and 40.8%,respectively.
2010, 27(11): 1313-1317
doi: 10.3724/SP.J.1095.2010.00013
Abstract:
The interactions between 1-Keto-2-(p-dimethylaminobenzal)-tetrohydronaphthalene(KDTN) and human serum albumin(HSA) have been studied by fluorescence and UV-Vis absorption spectra.The binding of KDTN to HSA quenches the tryptophan residue fluorescence and the results show that static quenching occurrs together with the complex formation.The binding constant and binding sites of KDTN to HSA at pH=7.43 are measured at different temperatures according to the double logarithm regression curve.In addition,the thermodynamic data show that KDTN molecules enter the hydrophobic cavity of HSA via Van der Waals force or hydrogen bond.Finally,the synchronous fluorescence spectra show that the microenvironment of the tryptophan residues does not show significant effect on the conformation.
The interactions between 1-Keto-2-(p-dimethylaminobenzal)-tetrohydronaphthalene(KDTN) and human serum albumin(HSA) have been studied by fluorescence and UV-Vis absorption spectra.The binding of KDTN to HSA quenches the tryptophan residue fluorescence and the results show that static quenching occurrs together with the complex formation.The binding constant and binding sites of KDTN to HSA at pH=7.43 are measured at different temperatures according to the double logarithm regression curve.In addition,the thermodynamic data show that KDTN molecules enter the hydrophobic cavity of HSA via Van der Waals force or hydrogen bond.Finally,the synchronous fluorescence spectra show that the microenvironment of the tryptophan residues does not show significant effect on the conformation.
2010, 27(11): 1318-1321
doi: 10.3724/SP.J.1095.2010.90891
Abstract:
With citrate as a stabilizing agent,CuS nanoparticles were synthesized in aqueous phase. This article is to study the effects of resonance light scattering between CuS nanoparticles and mercury ions under the conditions of different pH values and the ratios of sodium sulfide and copper sulfate.Under optimum conditions,the method to determine trace mercury in water was established. The results showed that in the optimum experimental conditions,the intensity of resonance light scattering has a good linearity(r=0.991) in the range of 0.01~100 μmol/L with a detection limit of 0.003 μmol/L.The recovery is in the range of 100.3%~103.4% for Hg2+ detection in environmental water sample.
With citrate as a stabilizing agent,CuS nanoparticles were synthesized in aqueous phase. This article is to study the effects of resonance light scattering between CuS nanoparticles and mercury ions under the conditions of different pH values and the ratios of sodium sulfide and copper sulfate.Under optimum conditions,the method to determine trace mercury in water was established. The results showed that in the optimum experimental conditions,the intensity of resonance light scattering has a good linearity(r=0.991) in the range of 0.01~100 μmol/L with a detection limit of 0.003 μmol/L.The recovery is in the range of 100.3%~103.4% for Hg2+ detection in environmental water sample.
2010, 27(11): 1322-1327
doi: 10.3724/SP.J.1095.2010.90856
Abstract:
A novel method was developed to produce a TiO2 film with circular pores on its surface.Macrospore structure can be obtained in the presence of two complexing agents of acetylacetone(acac) and diethanolamine(DEA) under a template-free condition.Notwithstanding,it has been found that irrespective of the kind of complexing agents,whether it is acac,or DEA,a common flat surface-formation process has been confirmed.In this account,acac or DEA added in the sols serve as stabilizers that impedes the hydrosis and polymerization among constituents during gel-forming reactions.But the situation has entirely changed when both acac and DEA were used as complexing agents.The hydrolysis is conducted under acidic conditions where a relatively narrow distribution of growing oligomers can be obtained.And the phase separation is driven by the reduction of miscibility between the polar solvent and polycondensed inorganic species.The phaseformation time would decline according the adding amount of DEA which triggers the process of hydrolysis under acidic conditions.The fluid phase of solvent mixture could oxidize and decompose to carbon dioxide which leaves numerous pores on the surface.The results show that the TiO2 film doped with two stabilizers exhibits superhydrophilic characteristic(6.5°) although it is not exposed to ultraviolet irradiation,comparing with flat ones(20° and 23°).Finally,the formation mechanism and the property-structure relationship were discussed in details.
A novel method was developed to produce a TiO2 film with circular pores on its surface.Macrospore structure can be obtained in the presence of two complexing agents of acetylacetone(acac) and diethanolamine(DEA) under a template-free condition.Notwithstanding,it has been found that irrespective of the kind of complexing agents,whether it is acac,or DEA,a common flat surface-formation process has been confirmed.In this account,acac or DEA added in the sols serve as stabilizers that impedes the hydrosis and polymerization among constituents during gel-forming reactions.But the situation has entirely changed when both acac and DEA were used as complexing agents.The hydrolysis is conducted under acidic conditions where a relatively narrow distribution of growing oligomers can be obtained.And the phase separation is driven by the reduction of miscibility between the polar solvent and polycondensed inorganic species.The phaseformation time would decline according the adding amount of DEA which triggers the process of hydrolysis under acidic conditions.The fluid phase of solvent mixture could oxidize and decompose to carbon dioxide which leaves numerous pores on the surface.The results show that the TiO2 film doped with two stabilizers exhibits superhydrophilic characteristic(6.5°) although it is not exposed to ultraviolet irradiation,comparing with flat ones(20° and 23°).Finally,the formation mechanism and the property-structure relationship were discussed in details.
2010, 27(11): 1328-1333
doi: 10.3724/SP.J.1095.2010.00091
Abstract:
Cu2O microcubes and nanospheres were prepared by solution-phase reducing method and hydrothermal treatment,respectively.The products were characterized via X-ray diffraction(XRD) and field emitted scanning electron microscopy(FESEM).The photocatalytic activities of as-synthesized Cu2O microcubes and nanospheres toward methyl orange were studied.The decoloration rates of methyl orange in assynthesized Cu2O microcubes and nanospheres system was 77.4% and 89.0%,respectively.In the Cu2O/Fenton composite system,the decoloration rate of methyl orange could reach 98.2%.In addition,a proposed photocatalytic degradation mechanism of Cu2O for methyl orange was provided.
Cu2O microcubes and nanospheres were prepared by solution-phase reducing method and hydrothermal treatment,respectively.The products were characterized via X-ray diffraction(XRD) and field emitted scanning electron microscopy(FESEM).The photocatalytic activities of as-synthesized Cu2O microcubes and nanospheres toward methyl orange were studied.The decoloration rates of methyl orange in assynthesized Cu2O microcubes and nanospheres system was 77.4% and 89.0%,respectively.In the Cu2O/Fenton composite system,the decoloration rate of methyl orange could reach 98.2%.In addition,a proposed photocatalytic degradation mechanism of Cu2O for methyl orange was provided.
2010, 27(11): 1334-1338
doi: 10.3724/SP.J.1095.2010.00034
Abstract:
A Schiff base ligand,N,N'-bis(3,5-dichlorosalicylaldehyde)-o-phenylenediamine,and its copper complex was synthesized.The compound was characterized by elemental analysis,FTIR,TG-DTG,single crystal X-ray diffraction,UV-Vis absorption spectroscopy,and fluorescence excitation and emission spectra.The high thermal decomposition temperature of 384℃ for the complex showed that it had high thermal stability.In its infrared spectrum,a strong band was observed at about 1616 cm-1. This band was due to the conjugated C=N stretching vibration,and was shifted to higher frequency compared with the free ligand of 3,5-dichlorosalicylaldehyde and o-phenylenediamine.The new band at 530 cm-1 was assigned to Cu-O stretching vibration.The crystal of the copper(Ⅱ) complex belongs to monoclinic system with space group,P2(1)/n,a=0.81316(8) nm,b=1.53101(18) nm,c=1.87819(19) nm,β=92.4530(10)°,Z=4, the final R1=0.058, and ωR2=0.148.The central copper ion of the complex coordinated with the two O and two N of the Schiff base to form a five-membered ring and two six-membered rings,which constituted a fourcoordinated planar conformation.The complex's UV absorption bands were at about 268,310 and 435 nm,where the absorption band at about 435 nm can be assigned to the intrinsic absorption of C=N.Its fluorescence excitation is in the range of 360~480 nm,and its DMF solution emitted intensive blue-green fluorescence at the peak wavelength of 507 nm.Its optical gap was about 2.59 eV,which was determined by the intrinsic absorption band edge of the complex in DMF solution.
A Schiff base ligand,N,N'-bis(3,5-dichlorosalicylaldehyde)-o-phenylenediamine,and its copper complex was synthesized.The compound was characterized by elemental analysis,FTIR,TG-DTG,single crystal X-ray diffraction,UV-Vis absorption spectroscopy,and fluorescence excitation and emission spectra.The high thermal decomposition temperature of 384℃ for the complex showed that it had high thermal stability.In its infrared spectrum,a strong band was observed at about 1616 cm-1. This band was due to the conjugated C=N stretching vibration,and was shifted to higher frequency compared with the free ligand of 3,5-dichlorosalicylaldehyde and o-phenylenediamine.The new band at 530 cm-1 was assigned to Cu-O stretching vibration.The crystal of the copper(Ⅱ) complex belongs to monoclinic system with space group,P2(1)/n,a=0.81316(8) nm,b=1.53101(18) nm,c=1.87819(19) nm,β=92.4530(10)°,Z=4, the final R1=0.058, and ωR2=0.148.The central copper ion of the complex coordinated with the two O and two N of the Schiff base to form a five-membered ring and two six-membered rings,which constituted a fourcoordinated planar conformation.The complex's UV absorption bands were at about 268,310 and 435 nm,where the absorption band at about 435 nm can be assigned to the intrinsic absorption of C=N.Its fluorescence excitation is in the range of 360~480 nm,and its DMF solution emitted intensive blue-green fluorescence at the peak wavelength of 507 nm.Its optical gap was about 2.59 eV,which was determined by the intrinsic absorption band edge of the complex in DMF solution.
2010, 27(11): 1339-1343
doi: 10.3724/SP.J.1095.2010.00081
Abstract:
A ternary complex with the formula of[Dy(p-MBA)3phen]2(p-MBA=p-methylbenzoic acid;phen=1,10-phenathroline) was synthesized via the solution method. Elemental analysis,infrared spectra,molar conductance,thermogravimetry and derivative thermogravimetry(TG-DTG) were used to characterize the title complex.The results show the Dy(Ⅲ) ion was coordinated to the oxygen atoms of p-methylbenzoic acid,and the nitrogen atoms of the 1,10-phenanthroline,and the title complex has a good thermal stability.Nonisothermal kinetics of the first thermal decomposition stage of Dy(Ⅲ) complex was studied in the static air atmosphere.Through the Popescu method and the nonlinear integral isoconversional(NL-INT) method,the kinetic equation was expressed as (dα)/(dT)=(15.55 × 1012)/(β) exp ((-19825.60)/(T))3(1-α)2/3, and the average activation energy and the pre-exponential factor were 164.83 kJ/mol and 15.55 × 1012 min-1,respectively.The thermal stability of a series of complexes was compared. The results may provide some valuable materials for the choice of functional materials of rare-earth complexes.
A ternary complex with the formula of[Dy(p-MBA)3phen]2(p-MBA=p-methylbenzoic acid;phen=1,10-phenathroline) was synthesized via the solution method. Elemental analysis,infrared spectra,molar conductance,thermogravimetry and derivative thermogravimetry(TG-DTG) were used to characterize the title complex.The results show the Dy(Ⅲ) ion was coordinated to the oxygen atoms of p-methylbenzoic acid,and the nitrogen atoms of the 1,10-phenanthroline,and the title complex has a good thermal stability.Nonisothermal kinetics of the first thermal decomposition stage of Dy(Ⅲ) complex was studied in the static air atmosphere.Through the Popescu method and the nonlinear integral isoconversional(NL-INT) method,the kinetic equation was expressed as (dα)/(dT)=(15.55 × 1012)/(β) exp ((-19825.60)/(T))3(1-α)2/3, and the average activation energy and the pre-exponential factor were 164.83 kJ/mol and 15.55 × 1012 min-1,respectively.The thermal stability of a series of complexes was compared. The results may provide some valuable materials for the choice of functional materials of rare-earth complexes.
2010, 27(11): 1344-1350
doi: 10.3724/SP.J.1095.2010.00007
Abstract:
Phytic acid was extracted from the waste detoxified liquor of rapeseed meal using trialkylamine(N235)-n-octanol/sulfonated kerosene. The effects of pH and the concentrations of phytic acid and N235 on partition coefficient were studied. The optimal conditions of extraction are as follows:the pH value is 3.0,the concentration of N235 is 0.17 mol/L,the concentration of n-octanol is 0.48 mol/L,the phase ratio is 5:1 and the extraction time is 5 min. Under the optimal operating conditions and at a concentration of 0.02 mol/L of phytic acid in the pre-extraction solution,the single extraction efficiency was 95.2%. The conditions of back extraction are as follows:the concentration of NaOH solution is 0.25 mol/L,the phase ratio is 5:2 and the back extraction time is 5 min. The overall yield was 82.6% after a three-stage back-extraction treatment. The results indicate that n-octanol could enhance the extraction ratio of phytic acid,which is probably caused by the N235-n-octanol molecular cluster.
Phytic acid was extracted from the waste detoxified liquor of rapeseed meal using trialkylamine(N235)-n-octanol/sulfonated kerosene. The effects of pH and the concentrations of phytic acid and N235 on partition coefficient were studied. The optimal conditions of extraction are as follows:the pH value is 3.0,the concentration of N235 is 0.17 mol/L,the concentration of n-octanol is 0.48 mol/L,the phase ratio is 5:1 and the extraction time is 5 min. Under the optimal operating conditions and at a concentration of 0.02 mol/L of phytic acid in the pre-extraction solution,the single extraction efficiency was 95.2%. The conditions of back extraction are as follows:the concentration of NaOH solution is 0.25 mol/L,the phase ratio is 5:2 and the back extraction time is 5 min. The overall yield was 82.6% after a three-stage back-extraction treatment. The results indicate that n-octanol could enhance the extraction ratio of phytic acid,which is probably caused by the N235-n-octanol molecular cluster.
2010, 27(11): 1351-1355
doi: 10.3724/SP.J.1095.2010.90882
Abstract:
The cloud point system containing Triton X-100 and NaCl at given temperatures was useed as an extracting medium. A detailed study on spectral characteristics and microstructures has been carried out to investigate the process of cloud point extraction of glycyrrhizic acid(GA). The results showed that the wave numbers of H-O and C-O stretching vibration bands in the Fourier transform infrared spectra increased with increasing temperature. Near the cloud point,this change has been strengthened. Main phase bodies in cloud point system have droplet-distribution characteristics and the micelle size in coacervate phase was enlarged after adsorping more GA. Under high concentration of GA,this phenomenon was attributed to the inter crosslinking of micelles in the coacervate phase.
The cloud point system containing Triton X-100 and NaCl at given temperatures was useed as an extracting medium. A detailed study on spectral characteristics and microstructures has been carried out to investigate the process of cloud point extraction of glycyrrhizic acid(GA). The results showed that the wave numbers of H-O and C-O stretching vibration bands in the Fourier transform infrared spectra increased with increasing temperature. Near the cloud point,this change has been strengthened. Main phase bodies in cloud point system have droplet-distribution characteristics and the micelle size in coacervate phase was enlarged after adsorping more GA. Under high concentration of GA,this phenomenon was attributed to the inter crosslinking of micelles in the coacervate phase.
2010, 27(11): 1356-1358
doi: 10.3724/SP.J.1095.2010.00185
Abstract:
With Fe(NO3)3·9H2O,LiNO3,NH4 H2PO4 and sucrose as raw materials, LiFePO4/C was synthesized by using supercritical carbon dioxide at 50℃ for 24 h,and then being annealed at 350℃ and 600℃. The particle size of synthesized LiFePO4/C is in the range of 0.5~1.0 μm. For the electrochemical performance of LiFePO4/C as the cathode material of lithium ion battery,the initial discharge capacity is 156.6 mA·h/g,and there is no obvious capacity fading after 50 cycles.
With Fe(NO3)3·9H2O,LiNO3,NH4 H2PO4 and sucrose as raw materials, LiFePO4/C was synthesized by using supercritical carbon dioxide at 50℃ for 24 h,and then being annealed at 350℃ and 600℃. The particle size of synthesized LiFePO4/C is in the range of 0.5~1.0 μm. For the electrochemical performance of LiFePO4/C as the cathode material of lithium ion battery,the initial discharge capacity is 156.6 mA·h/g,and there is no obvious capacity fading after 50 cycles.
2010, 27(11): 1359-1361
doi: 10.3724/SP.J.1095.2010.90885
Abstract:
The conductivity behaviors of water-in-toluene-alkanol(heptanol,decanol) reverse microemulsions stabilized solely by sodium bis(2-ethylhexyl) sulfosuccinate(AOT) with and without the additives(sodium chloride) were investigated through conductance measurements. The results showed that the percolation phenomenon was apparently inhibited by toluene in the water/AOT/decanol system,while no effect in the water/AOT/heptanol system. The conductance of water/AOT/heptanol/toulene and water/AOT/decanol/toulene systems had a hardly change in the present of sodium chloride.
The conductivity behaviors of water-in-toluene-alkanol(heptanol,decanol) reverse microemulsions stabilized solely by sodium bis(2-ethylhexyl) sulfosuccinate(AOT) with and without the additives(sodium chloride) were investigated through conductance measurements. The results showed that the percolation phenomenon was apparently inhibited by toluene in the water/AOT/decanol system,while no effect in the water/AOT/heptanol system. The conductance of water/AOT/heptanol/toulene and water/AOT/decanol/toulene systems had a hardly change in the present of sodium chloride.
2010, 27(11): 1362-1364
doi: 10.3724/SP.J.1095.2010.00002
Abstract:
A high performance liquid chromatographic method was developed for simultaneous determining the contents of galanthamine and lycorine in Lycoris Herb. The chromatographic analysis was carried out on a phenomenex-C18 column. The mobile phase was acetonitrile (A)-0.1% trifluoroacetic acid(TFA) (B) with gradient elution. The detection wavelength was set at 289 nm. The calibration curves for galanthamine and lycorine showed good linearity in the range of 0.5~10 mg/L(r=0.9999). The detection limits were 0.09 mg/L for galanthamine and 0.15 mg/L for lycorine at the signal-to-noise ratio of 3,and the average recoveries were 99.53% and 96.82%,respectively. The method is simple,rapid,accurate and suitable for the determination of galanthamine and lycorine in Lycoris Herb.
A high performance liquid chromatographic method was developed for simultaneous determining the contents of galanthamine and lycorine in Lycoris Herb. The chromatographic analysis was carried out on a phenomenex-C18 column. The mobile phase was acetonitrile (A)-0.1% trifluoroacetic acid(TFA) (B) with gradient elution. The detection wavelength was set at 289 nm. The calibration curves for galanthamine and lycorine showed good linearity in the range of 0.5~10 mg/L(r=0.9999). The detection limits were 0.09 mg/L for galanthamine and 0.15 mg/L for lycorine at the signal-to-noise ratio of 3,and the average recoveries were 99.53% and 96.82%,respectively. The method is simple,rapid,accurate and suitable for the determination of galanthamine and lycorine in Lycoris Herb.
