Login In
2011 Volume 28 Issue 5
2011, 28(5): 489-499
doi: 10.3724/SP.J.1095.2011.00481
Abstract:
This paper summarized the progress of supercapacitors electrode materials based on carbon nanotubes and their composites.The capacitor's characteristics will be effectively improved when carbon nanotubes are modified or the carbon nanotubes composite with other materials.The article focuses on the recent development of the supercapacitor electrode materials using carbon nanotubes with the techniques of modification,activation,and dispersion,as well as nanotubes-transition metal oxide composites,carbon nanotubes-conductive polymer composites,and carbon nanotubes-graphene composites.
This paper summarized the progress of supercapacitors electrode materials based on carbon nanotubes and their composites.The capacitor's characteristics will be effectively improved when carbon nanotubes are modified or the carbon nanotubes composite with other materials.The article focuses on the recent development of the supercapacitor electrode materials using carbon nanotubes with the techniques of modification,activation,and dispersion,as well as nanotubes-transition metal oxide composites,carbon nanotubes-conductive polymer composites,and carbon nanotubes-graphene composites.
2011, 28(5): 500-503
doi: 10.3724/SP.J.1095.2011.00521
Abstract:
High density polyethylene was toughened by calcium carbonate(CaCO3) with different particle sizes.The relationship between critical interparticle distance(IDc) and CaCO3 content and particle size was studied at different temperatures.The purpose is to clarify that temperature is one of the important parameters for applicability of Wu's criterion.The results indicate that the IDc is almost independent of CaCO3 content and particle size at 17℃,that is,the criterion is applicable to this case.With an increase in the temperature,the results clearly show that IDc depends on the CaCO3 particle size at higher temperatures,that is,the criterion is inapplicable at higher temperatures.
High density polyethylene was toughened by calcium carbonate(CaCO3) with different particle sizes.The relationship between critical interparticle distance(IDc) and CaCO3 content and particle size was studied at different temperatures.The purpose is to clarify that temperature is one of the important parameters for applicability of Wu's criterion.The results indicate that the IDc is almost independent of CaCO3 content and particle size at 17℃,that is,the criterion is applicable to this case.With an increase in the temperature,the results clearly show that IDc depends on the CaCO3 particle size at higher temperatures,that is,the criterion is inapplicable at higher temperatures.
2011, 28(5): 504-509
doi: 10.3724/SP.J.1095.2011.00385
Abstract:
The alloys of polyethylene terephthalate(PET)/styrene ethylene butylene styrene(SEBS)/trimethylol propane trimethylacrylate(TMPTA) and PET/SEBS-g-MAH(maleic anhydride)/TMPTA were prepared by melting blending with a twin-screw extruder and irradiated by a Co-60 source.The effects of irradiation on the structure and properties of blends were studied through characterizations of mechanical properties,phase morphology and gel content analysis.The results of scanning electron microscopy(SEM) and gel extraction indicated that irradiation effectively improved the compatibility of PET/SEBS blends in the presence of an appropriate amount of TMPTA,which was ascribed to the generation of a new copolymer comprising both chains of SEBS and PET at the interface area.The compatibility was confirmed by the changes of impact strength as well.When the mass fraction of SEBS and TMPTA were 20% and 1% respectively,the impact strength of the blend reached 17.3 kJ/m2 after irradiation at 50 kGy.The introduction of maleic anhydride groups to SEBS chains did not change the phase structure obviously,but the maximum of impact strength was only 11.5 kJ/m2 in this case,significantly lower than that of the blends without maleic anhydride groups.
The alloys of polyethylene terephthalate(PET)/styrene ethylene butylene styrene(SEBS)/trimethylol propane trimethylacrylate(TMPTA) and PET/SEBS-g-MAH(maleic anhydride)/TMPTA were prepared by melting blending with a twin-screw extruder and irradiated by a Co-60 source.The effects of irradiation on the structure and properties of blends were studied through characterizations of mechanical properties,phase morphology and gel content analysis.The results of scanning electron microscopy(SEM) and gel extraction indicated that irradiation effectively improved the compatibility of PET/SEBS blends in the presence of an appropriate amount of TMPTA,which was ascribed to the generation of a new copolymer comprising both chains of SEBS and PET at the interface area.The compatibility was confirmed by the changes of impact strength as well.When the mass fraction of SEBS and TMPTA were 20% and 1% respectively,the impact strength of the blend reached 17.3 kJ/m2 after irradiation at 50 kGy.The introduction of maleic anhydride groups to SEBS chains did not change the phase structure obviously,but the maximum of impact strength was only 11.5 kJ/m2 in this case,significantly lower than that of the blends without maleic anhydride groups.
2011, 28(5): 510-515
doi: 10.3724/SP.J.1095.2011.00383
Abstract:
The starch(St) graft sodium acrylate was synthesized by solvent method.It has a high viscosity and a strong shear-resistance.The copolymerization was carried out using N,N'-methylene bisacrylamid as the crosslinker and ammonium persulfate as the initiator.Effects such as the amount of monomer,initiator and crosslinking agent,neutralization degree of the acrylic acid(AA),reaction time and temperature on the apparent viscosity were discussed.Through orthogonal experiment,the optimum graft copolymerization condition was obtained as the follows:the mass ratio of starch to acrylic acid is 1:1.5,the mass fraction of alcohol is 80%,initiator is 1% and crosslinker is 0.6% on the basis of the mass of starch,the reaction time is 2.5 h,the reaction temperature is 55℃,and the neutralization degree of the acrylic acid is 70%.The experiments showed that the graft starch paste has an excellent thixotropy.When 14.0 g/L slurry was dissolved in 4% salt water and base fluid,the apparent viscosity of the slurry was 26 mPa·s and the filtration loss was 7.2 mL.When the dosage of slurry was added up to 23.5 g/L in saturated salt water and base fluid,the apparent viscosity of the slurry was 54.5 mPa·s and the filtration loss was 3.1 mL.Additionally,the apparent viscosity and the filtration loss of the slurry were essentially remained the same after the slurry was treated for 16 h at 80℃.The experimental results show that the graft starch copolymer has good capacities of increasing viscosity and depressing the filtration loss,and it has excellent properties of aging-resistance and salt-resistance.
The starch(St) graft sodium acrylate was synthesized by solvent method.It has a high viscosity and a strong shear-resistance.The copolymerization was carried out using N,N'-methylene bisacrylamid as the crosslinker and ammonium persulfate as the initiator.Effects such as the amount of monomer,initiator and crosslinking agent,neutralization degree of the acrylic acid(AA),reaction time and temperature on the apparent viscosity were discussed.Through orthogonal experiment,the optimum graft copolymerization condition was obtained as the follows:the mass ratio of starch to acrylic acid is 1:1.5,the mass fraction of alcohol is 80%,initiator is 1% and crosslinker is 0.6% on the basis of the mass of starch,the reaction time is 2.5 h,the reaction temperature is 55℃,and the neutralization degree of the acrylic acid is 70%.The experiments showed that the graft starch paste has an excellent thixotropy.When 14.0 g/L slurry was dissolved in 4% salt water and base fluid,the apparent viscosity of the slurry was 26 mPa·s and the filtration loss was 7.2 mL.When the dosage of slurry was added up to 23.5 g/L in saturated salt water and base fluid,the apparent viscosity of the slurry was 54.5 mPa·s and the filtration loss was 3.1 mL.Additionally,the apparent viscosity and the filtration loss of the slurry were essentially remained the same after the slurry was treated for 16 h at 80℃.The experimental results show that the graft starch copolymer has good capacities of increasing viscosity and depressing the filtration loss,and it has excellent properties of aging-resistance and salt-resistance.
2011, 28(5): 516-520
doi: 10.3724/SP.J.1095.2011.00422
Abstract:
Biodegradable porous aliphatic poly(butylene succinate-co-ethylene succinate) s(PBES) was prepared through a direct polycondensation method in supercritical carbon dioxide(scCO2).The effects of reaction pressure,temperatures and duration time of scCO2 on the foaming behaviors of PBES were investigated.The obtained porous PBES were characterized by scanning electron micrograph(SEM),X-ray diffraction(XRD).The results showed that the porosity can reach over 55% and the diameter of the pores was in the range 50~200 μm.The crystallinity of PBES was decreased after scCO2 treatment.
Biodegradable porous aliphatic poly(butylene succinate-co-ethylene succinate) s(PBES) was prepared through a direct polycondensation method in supercritical carbon dioxide(scCO2).The effects of reaction pressure,temperatures and duration time of scCO2 on the foaming behaviors of PBES were investigated.The obtained porous PBES were characterized by scanning electron micrograph(SEM),X-ray diffraction(XRD).The results showed that the porosity can reach over 55% and the diameter of the pores was in the range 50~200 μm.The crystallinity of PBES was decreased after scCO2 treatment.
2011, 28(5): 521-525
doi: 10.3724/SP.J.1095.2011.00402
Abstract:
A new synthetic route to 5-amino-6-nitro-[1,2,5] oxadiazolo [3,4-b] pyridine-1-oxide was developed using 2,6-dichloropyridine as starting materials via four steps,including hydrazinolysis,reduction,nitration and Nietzki-Dietschy cyclization.The effects of these reactions were investigated based on their reaction mechanisms.On the basis of these results,the reaction was optimized and the overall yield of target product was up to 59.2%.The product was characterized by 1HNMR,MS and IR.
A new synthetic route to 5-amino-6-nitro-[1,2,5] oxadiazolo [3,4-b] pyridine-1-oxide was developed using 2,6-dichloropyridine as starting materials via four steps,including hydrazinolysis,reduction,nitration and Nietzki-Dietschy cyclization.The effects of these reactions were investigated based on their reaction mechanisms.On the basis of these results,the reaction was optimized and the overall yield of target product was up to 59.2%.The product was characterized by 1HNMR,MS and IR.
2011, 28(5): 526-530
doi: 10.3724/SP.J.1095.2011.00391
Abstract:
Heck reaction was employed to synthesize stilbene derivatives by utilizing 1,3-divinyl-1,1,3,3-tetramethyldisiloxane(DVS) as the ethylene source.The effects of the starting material molar ratio,reaction temperature and reaction time on the yield were investigated.A possible reaction mechanism was proposed.The results show that in DMF/H2O at 120℃,with the starting material molar ratio of R-Br:DVS at 5:1,and reaction time=48 h,the reaction produces 4-vinyl-bis-benzocyclobutene(V-bisBCB) and 1,2-diphenylethene(V-bisPh) with a yield of 45.1% and 48.6%,respectively.
Heck reaction was employed to synthesize stilbene derivatives by utilizing 1,3-divinyl-1,1,3,3-tetramethyldisiloxane(DVS) as the ethylene source.The effects of the starting material molar ratio,reaction temperature and reaction time on the yield were investigated.A possible reaction mechanism was proposed.The results show that in DMF/H2O at 120℃,with the starting material molar ratio of R-Br:DVS at 5:1,and reaction time=48 h,the reaction produces 4-vinyl-bis-benzocyclobutene(V-bisBCB) and 1,2-diphenylethene(V-bisPh) with a yield of 45.1% and 48.6%,respectively.
2011, 28(5): 531-536
doi: 10.3724/SP.J.1095.2011.00418
Abstract:
Molecular imprinting technology was employed to produce one kind of rhodamine B(RhB) molecularly imprinted polymer(MIP) microspheres by precipitation polymerization using RhB,acrylamide,ethylene glycol dimethacrylatea(EGDMA),azobisisobutyronitrile(AIBN),and acetonitrile as template,functional monomer,cross-linking agent,initiator and porogen,respectively.The resultant microspheres were characterized by scanning electron microscopy.The binding constant and chemical combination ratio of the complex formed between the template and the functional monomer were obtained by UV spectrophotometry,which showed that the RhB-monomer forms 1:1 complexes and the binding constant is 5.3×103 L/mol.The effects of types and volumes of the porogen on the size and the uniformity of microspheres were also discussed.After packing the microspheres into column,it was used to absorb RhB from red pepper.The extraction conditions of molecular imprinting solid phase extraction(MISPE) column for RhB were optimized.Pepper samples spiked with RhB were extracted by MISPE column and analyzed by high performance liquid chromatography.The recoveries of MISPE column for RhB extraction were found to be 91.7%~103.5%,indicating the feasibility of the prepared MIPs for RhB extraction.
Molecular imprinting technology was employed to produce one kind of rhodamine B(RhB) molecularly imprinted polymer(MIP) microspheres by precipitation polymerization using RhB,acrylamide,ethylene glycol dimethacrylatea(EGDMA),azobisisobutyronitrile(AIBN),and acetonitrile as template,functional monomer,cross-linking agent,initiator and porogen,respectively.The resultant microspheres were characterized by scanning electron microscopy.The binding constant and chemical combination ratio of the complex formed between the template and the functional monomer were obtained by UV spectrophotometry,which showed that the RhB-monomer forms 1:1 complexes and the binding constant is 5.3×103 L/mol.The effects of types and volumes of the porogen on the size and the uniformity of microspheres were also discussed.After packing the microspheres into column,it was used to absorb RhB from red pepper.The extraction conditions of molecular imprinting solid phase extraction(MISPE) column for RhB were optimized.Pepper samples spiked with RhB were extracted by MISPE column and analyzed by high performance liquid chromatography.The recoveries of MISPE column for RhB extraction were found to be 91.7%~103.5%,indicating the feasibility of the prepared MIPs for RhB extraction.
2011, 28(5): 537-541
doi: 10.3724/SP.J.1095.2011.00415
Abstract:
The ionic liquids have been known as "green" or "environmentally friendly" solvents and show potentials to replace traditional solvents.A new approach was set up for the extraction and separation of isoflavonoids from the Rhynchosia volubilis Lour using the 1-butyl-3-methyl tetrafluoroborate([Bmim]BF4) ionic liquid.Three isoflavonoids were obtained from the 70% alcohol extract of Rhynchosia volubilis.Based on the spectra analysis,their structures have been confirmed to be cajanone,3-[4'-(1"-methoxy)-propoxy]-phenyl-5,7-dihydroxy-isoflavone and Biochanin A,in which the 3-[4'-(1"-methoxy)-propoxy]-phenyl-5,7-dihydroxy-isoflavone is a novel compound.The result had shown that the[Bmim]BF4 could extract isoflavones effectively and selectively.A protocol for determining the content of each component in the isoflavonoid was established.The overall pharmacognosical content of isoflavone was 0.73% using cajanone as the standard and its maximum absorption(270 nm) as the determination wavelength.The average recovery rate and relative standard deviation was 99.94% and 3.66%,respectively.The recycling rate of the ionic liquid was 76.7%.
The ionic liquids have been known as "green" or "environmentally friendly" solvents and show potentials to replace traditional solvents.A new approach was set up for the extraction and separation of isoflavonoids from the Rhynchosia volubilis Lour using the 1-butyl-3-methyl tetrafluoroborate([Bmim]BF4) ionic liquid.Three isoflavonoids were obtained from the 70% alcohol extract of Rhynchosia volubilis.Based on the spectra analysis,their structures have been confirmed to be cajanone,3-[4'-(1"-methoxy)-propoxy]-phenyl-5,7-dihydroxy-isoflavone and Biochanin A,in which the 3-[4'-(1"-methoxy)-propoxy]-phenyl-5,7-dihydroxy-isoflavone is a novel compound.The result had shown that the[Bmim]BF4 could extract isoflavones effectively and selectively.A protocol for determining the content of each component in the isoflavonoid was established.The overall pharmacognosical content of isoflavone was 0.73% using cajanone as the standard and its maximum absorption(270 nm) as the determination wavelength.The average recovery rate and relative standard deviation was 99.94% and 3.66%,respectively.The recycling rate of the ionic liquid was 76.7%.
2011, 28(5): 542-548
doi: 10.3724/SP.J.1095.2011.00273
Abstract:
To study on the formation mechanism of organic sulfides,simulated experiments for the reaction between gasoline and magnesium sulfate were carried out to study the effect of water on the formation of organic sulfides in petroleum.The products were analyzed by some advanced analytical methods including gas chromatography,microcoulometry,capillary gas chromatography combined with a pulsed flame photometric detector(GC-PFPD),FT-IR and X-ray diffraction.Moreover,the kinetics of the reactions between gasoline and magnesium sulfate were investigated.It is shown that solid magnesium sulfate could react with gasoline to produce magnesium oxide,hydrogen sulfide,coke,carbon dioxide,and organic sulfides as the main products.With the increase of reaction temperature,the oxidation effect of magnesium sulfate were enhanced,the average molecular mass of hydrocarbon components dropped and the overall trend of inorganic sulfur transformed into organic ones were enhanced in the system.With temperature growing,sulfur was prone to convert to thiophenes with higher thermal stability.According to the kinetic results,the conversion in hydrous system is high than that of anhydrous system.The apparent activation energies for hydrous system and anhydrous system are 68.9 kJ/mol and 78.5 kJ/mol,respectively.
To study on the formation mechanism of organic sulfides,simulated experiments for the reaction between gasoline and magnesium sulfate were carried out to study the effect of water on the formation of organic sulfides in petroleum.The products were analyzed by some advanced analytical methods including gas chromatography,microcoulometry,capillary gas chromatography combined with a pulsed flame photometric detector(GC-PFPD),FT-IR and X-ray diffraction.Moreover,the kinetics of the reactions between gasoline and magnesium sulfate were investigated.It is shown that solid magnesium sulfate could react with gasoline to produce magnesium oxide,hydrogen sulfide,coke,carbon dioxide,and organic sulfides as the main products.With the increase of reaction temperature,the oxidation effect of magnesium sulfate were enhanced,the average molecular mass of hydrocarbon components dropped and the overall trend of inorganic sulfur transformed into organic ones were enhanced in the system.With temperature growing,sulfur was prone to convert to thiophenes with higher thermal stability.According to the kinetic results,the conversion in hydrous system is high than that of anhydrous system.The apparent activation energies for hydrous system and anhydrous system are 68.9 kJ/mol and 78.5 kJ/mol,respectively.
2011, 28(5): 549-554
doi: 10.3724/SP.J.1095.2011.00398
Abstract:
Polyaniline/attapulgite(PANI/ATP) nanofiber composites doped with hydrochloric acid were prepared by an in situ polymerization method and used for the absorbent of trace Cr(Ⅵ) in effluents of various wastewater.The effects of the mass ratio of the nanocomposite to the aqueous solution,the quality of the PANI/ATP nanofiber composite,adsorptive time and temperature as well as pH value in the solution on the adsorptive performance of PANI/ATP nanofiber composite were investigated.The results indicated that nearly 99.8% of Cr(Ⅵ) could be removed from the solution by PANI/ATP nanofiber composite when the mass ratio of the materials is 2:1,the quality is 0.4 g,the time is 50 min.The adsorption follows the Langmuir adsorption isotherm.Having the synergetic adsorption capacity originated from its organic and inorganic components,PANI/ATP nanofiber composite is a promising adsorbent for Cr(Ⅵ) because of its high efficiency,cost efficiency and regeneracy.
Polyaniline/attapulgite(PANI/ATP) nanofiber composites doped with hydrochloric acid were prepared by an in situ polymerization method and used for the absorbent of trace Cr(Ⅵ) in effluents of various wastewater.The effects of the mass ratio of the nanocomposite to the aqueous solution,the quality of the PANI/ATP nanofiber composite,adsorptive time and temperature as well as pH value in the solution on the adsorptive performance of PANI/ATP nanofiber composite were investigated.The results indicated that nearly 99.8% of Cr(Ⅵ) could be removed from the solution by PANI/ATP nanofiber composite when the mass ratio of the materials is 2:1,the quality is 0.4 g,the time is 50 min.The adsorption follows the Langmuir adsorption isotherm.Having the synergetic adsorption capacity originated from its organic and inorganic components,PANI/ATP nanofiber composite is a promising adsorbent for Cr(Ⅵ) because of its high efficiency,cost efficiency and regeneracy.
2011, 28(5): 555-559
doi: 10.3724/SP.J.1095.2011.00412
Abstract:
A zwitterionic monomer of 3-(N,N-dimethylamino-N-sulfopropane propyl acrylamide)(DMAPAAS) was prepared by the ring opening reaction of 1,3-cyclopropanesultone with N,N-dimethylamino propyl acrylamide(DMAPAA) at 55℃ for 20 h.Zwitterionic copolymers P(AM-DMAPAAS) containing sulfobetaine groups were synthesized by copolymerization of AM and DMAPAAS in aqueous solution.The copolymers were characterized and the solubility of copolymers P(AM-DMAPAAS) was evaluated.The viscosity of the copolymers was determined.The results show that the viscosity of the copolymers in brine solution is greater than that in deionized water,and the viscosity in Mg2+ and Ca2+ salt solution is increased as the salt concentration is increased.The copolymers exhibit a typical antipolyelectrolyte behavior.Under the situation where the same temperature is increased,the viscosity retention of the zwitterionic copolymer is 1.4 times of that of PAM.
A zwitterionic monomer of 3-(N,N-dimethylamino-N-sulfopropane propyl acrylamide)(DMAPAAS) was prepared by the ring opening reaction of 1,3-cyclopropanesultone with N,N-dimethylamino propyl acrylamide(DMAPAA) at 55℃ for 20 h.Zwitterionic copolymers P(AM-DMAPAAS) containing sulfobetaine groups were synthesized by copolymerization of AM and DMAPAAS in aqueous solution.The copolymers were characterized and the solubility of copolymers P(AM-DMAPAAS) was evaluated.The viscosity of the copolymers was determined.The results show that the viscosity of the copolymers in brine solution is greater than that in deionized water,and the viscosity in Mg2+ and Ca2+ salt solution is increased as the salt concentration is increased.The copolymers exhibit a typical antipolyelectrolyte behavior.Under the situation where the same temperature is increased,the viscosity retention of the zwitterionic copolymer is 1.4 times of that of PAM.
2011, 28(5): 560-564
doi: 10.3724/SP.J.1095.2011.00409
Abstract:
The abilities of sodium alkyl aryl sulfonate,which had high-purity and defined structure,to emulsify alkanes,were investigated by a water diversion method.Using liquid paraffin wax as the oil phase,the effects of the concentration of emulsion,length of alkyl chain,structures and locations of aryl groups in alkyl chain on emulsion stability were studied,and the best concentration of emulsion were determined.Meanwhile,the effects of different oil phases to emulsion stability were discussed.The experimental data showed that the best mass fraction of emulsion was 0.1%.With definite structures of aryl group,emulsion stability increased linearly with the increasing of the length of carbonic chain.When the length of alkyl chain on alkyl group was set,the emulsion stability was enhanced with the increasing of the length of alkyl chain on aryl group.With the aromatic ring shifts from the terminal to the center of the long alkyl chain,the emulsion stability increased.With the increase of molecular mass of oil phases,the molecular mass of emulsifier to achieve stable emulsifying liquid increased.
The abilities of sodium alkyl aryl sulfonate,which had high-purity and defined structure,to emulsify alkanes,were investigated by a water diversion method.Using liquid paraffin wax as the oil phase,the effects of the concentration of emulsion,length of alkyl chain,structures and locations of aryl groups in alkyl chain on emulsion stability were studied,and the best concentration of emulsion were determined.Meanwhile,the effects of different oil phases to emulsion stability were discussed.The experimental data showed that the best mass fraction of emulsion was 0.1%.With definite structures of aryl group,emulsion stability increased linearly with the increasing of the length of carbonic chain.When the length of alkyl chain on alkyl group was set,the emulsion stability was enhanced with the increasing of the length of alkyl chain on aryl group.With the aromatic ring shifts from the terminal to the center of the long alkyl chain,the emulsion stability increased.With the increase of molecular mass of oil phases,the molecular mass of emulsifier to achieve stable emulsifying liquid increased.
2011, 28(5): 565-570
doi: 10.3724/SP.J.1095.2011.00414
Abstract:
Four kinds of quaternary ammonium salt cationic surfactants(dodecyl benzyl dimethyl ammonium chloride(1227),tetradecyl dimethyl benzyl ammonium(1427),hexadecyl trimethyl ammonium bromide(1631) and octadecyl trimethyl ammonium bromide(1831)) were used to modify sodium bentonite(Na-Ben).The prepared organic bentonites(1227-Ben,1427-Ben,1631-Ben,1831-Ben) were characterized by Fourier transform infrared spectroscopy(FT-IR) and X-ray diffraction(XRD),and used as subsidence-resistance for preparing suspensions containing 5% hexaconazole.The suspension capability of bentonite modified by above four organic additives in water and the effects of these bentonites on the physical stability of suspensions were examined.FT-IR spectra and XRD analysis results showed that these four cationic surfactants were intercalated into the layer of bentonite.Suspension capability results indicated that 1831-Ben has a better suspension than the other three.Subsidence-resistance tests showed that bentonites modified by organic additives could improve the physical stability of suspensions.The water segregation ratio of samples prepared by 1831-Ben was the lowest,while the viscosity,yield value and suspension rate were the highest.So 1831-Ben could be used as a suspension-additive for the preparation of suspensions containing 5% hexaconazole.
Four kinds of quaternary ammonium salt cationic surfactants(dodecyl benzyl dimethyl ammonium chloride(1227),tetradecyl dimethyl benzyl ammonium(1427),hexadecyl trimethyl ammonium bromide(1631) and octadecyl trimethyl ammonium bromide(1831)) were used to modify sodium bentonite(Na-Ben).The prepared organic bentonites(1227-Ben,1427-Ben,1631-Ben,1831-Ben) were characterized by Fourier transform infrared spectroscopy(FT-IR) and X-ray diffraction(XRD),and used as subsidence-resistance for preparing suspensions containing 5% hexaconazole.The suspension capability of bentonite modified by above four organic additives in water and the effects of these bentonites on the physical stability of suspensions were examined.FT-IR spectra and XRD analysis results showed that these four cationic surfactants were intercalated into the layer of bentonite.Suspension capability results indicated that 1831-Ben has a better suspension than the other three.Subsidence-resistance tests showed that bentonites modified by organic additives could improve the physical stability of suspensions.The water segregation ratio of samples prepared by 1831-Ben was the lowest,while the viscosity,yield value and suspension rate were the highest.So 1831-Ben could be used as a suspension-additive for the preparation of suspensions containing 5% hexaconazole.
2011, 28(5): 571-575
doi: 10.3724/SP.J.1095.2011.00182
Abstract:
Ti/PbO2 electrodes doped with Fe or Co were prepared by an electro-codeposition method.The effects of the Fe or Co on Ti/PbO2 electrodes were investigated by the X-ray diffraction(XRD),scanning electron microscope(SEM) and cyclic voltammetry(CV).Compared with the pure Ti/PbO2 electrode,the morphology of Ti/PbO2 electrode doped with either Fe or Co remained nearly unchanged while their structures and performances were varied.The activities of oxygen evolution reaction(OER) were improved in Co doped electrode.The dissolution,re-deposition or crystalline transforming of PbO2 took place during the electroreaction process.In addition,the lifetime of the electrodes might be influenced by such dissolution and re-deposition.
Ti/PbO2 electrodes doped with Fe or Co were prepared by an electro-codeposition method.The effects of the Fe or Co on Ti/PbO2 electrodes were investigated by the X-ray diffraction(XRD),scanning electron microscope(SEM) and cyclic voltammetry(CV).Compared with the pure Ti/PbO2 electrode,the morphology of Ti/PbO2 electrode doped with either Fe or Co remained nearly unchanged while their structures and performances were varied.The activities of oxygen evolution reaction(OER) were improved in Co doped electrode.The dissolution,re-deposition or crystalline transforming of PbO2 took place during the electroreaction process.In addition,the lifetime of the electrodes might be influenced by such dissolution and re-deposition.
2011, 28(5): 576-582
doi: 10.3724/SP.J.1095.2011.00404
Abstract:
A Ru0.7Si0.3O2/Ti electrode is used as the anode and stainless steel as the cathode,to decompose nitrobenzene in wastewater.The optimal conditions are as follows when the original concentration is 220 mg/L,J(current density)=25×10-3 A/cm2,ρ(Na2SO4)=8 g/L,pH=2.Under the optimal conditions,the removal efficiencies of nitrobenzene and TOC are above 85% and 50% respectively.The result shows Ru0.7Si0.3O2/Ti anode can effectively remove the organic pollutants in wastewater.The result of the intermediates detection shows that the nitrobenzene degradation is a synergistic process of the anode and the cathode.
A Ru0.7Si0.3O2/Ti electrode is used as the anode and stainless steel as the cathode,to decompose nitrobenzene in wastewater.The optimal conditions are as follows when the original concentration is 220 mg/L,J(current density)=25×10-3 A/cm2,ρ(Na2SO4)=8 g/L,pH=2.Under the optimal conditions,the removal efficiencies of nitrobenzene and TOC are above 85% and 50% respectively.The result shows Ru0.7Si0.3O2/Ti anode can effectively remove the organic pollutants in wastewater.The result of the intermediates detection shows that the nitrobenzene degradation is a synergistic process of the anode and the cathode.
2011, 28(5): 583-589
doi: 10.3724/SP.J.1095.2011.00410
Abstract:
A Pb-Zn coating was electroplated from methyisulfonic acid bath.The coating was then corroded by 10% H2SO4(volume fraction) solution to dissolve zinc.A porous Pb-Zn electrode was therefore successfully prepared.The Pb-Zn coating was composed of Pb(Fm3m) and Zn(P663/mmc).Electrochemical reduction characteristics of maleic acid(MA) on porous Pb-Zn and Pb electrodes were investigated by voltammetry,cathode polarization,chronocoulometry,and electrochemical impedance spectrum(EIS).As a result,MA was absorbed on the electrode surface,and then underwent irreversible electron-transfer reaction.The corresponding diffusion coefficients for MA in H2SO4 solution on a Pb and porous Pb-Zn electrode was 1.2×10-7 and 1.7×10-7 cm2/s,respectively.The apparent exchange current density(i0) of MA on a porous PbZn electrode was steadier than that on a Pb electrode.The i0 of MA on the porous Pb-Zn electrode had a linear relationship with temperature in low temperature,and increased sharply above 50℃,while decreased rapidly when reached to 65℃.The best electrochemical-reduction temperature for MA on porous Pb-Zn electrode was 50~60℃.The catalytic activity of MA on porous Pb-Zn electrode was higher than that on lead electrode.
A Pb-Zn coating was electroplated from methyisulfonic acid bath.The coating was then corroded by 10% H2SO4(volume fraction) solution to dissolve zinc.A porous Pb-Zn electrode was therefore successfully prepared.The Pb-Zn coating was composed of Pb(Fm3m) and Zn(P663/mmc).Electrochemical reduction characteristics of maleic acid(MA) on porous Pb-Zn and Pb electrodes were investigated by voltammetry,cathode polarization,chronocoulometry,and electrochemical impedance spectrum(EIS).As a result,MA was absorbed on the electrode surface,and then underwent irreversible electron-transfer reaction.The corresponding diffusion coefficients for MA in H2SO4 solution on a Pb and porous Pb-Zn electrode was 1.2×10-7 and 1.7×10-7 cm2/s,respectively.The apparent exchange current density(i0) of MA on a porous PbZn electrode was steadier than that on a Pb electrode.The i0 of MA on the porous Pb-Zn electrode had a linear relationship with temperature in low temperature,and increased sharply above 50℃,while decreased rapidly when reached to 65℃.The best electrochemical-reduction temperature for MA on porous Pb-Zn electrode was 50~60℃.The catalytic activity of MA on porous Pb-Zn electrode was higher than that on lead electrode.
2011, 28(5): 590-596
doi: 10.3724/SP.J.1095.2011.00536
Abstract:
A poly(amino black 10B) modified glassy carbon electrode,prepared by electrochemical polymerization was developed for the direct determination of vitamin B6.The polymer thickness can be controlled by potential circles.The modified electrode shows obvious electrocatalytic activity toward the oxidation of vitamin B 6,since it decreases the oxidation overpotential as well as greatly enhances the oxidation peak current of vitamin B6.Differential pulse voltammetry and amperometric detection methods were utilized for the measurement of vitamin B 6.The method is very sensitive and simple,and the detection limit is 0.05 μmol/L.Compared with other known modified electrodes,the poly(amino black 10B) modified electrode possesses many advantages such as low detection limit,fast response,good repeatability,low cost and simplicity.The practical application of this modified electrode was demonstrated with vitamin B6 drugs.
A poly(amino black 10B) modified glassy carbon electrode,prepared by electrochemical polymerization was developed for the direct determination of vitamin B6.The polymer thickness can be controlled by potential circles.The modified electrode shows obvious electrocatalytic activity toward the oxidation of vitamin B 6,since it decreases the oxidation overpotential as well as greatly enhances the oxidation peak current of vitamin B6.Differential pulse voltammetry and amperometric detection methods were utilized for the measurement of vitamin B 6.The method is very sensitive and simple,and the detection limit is 0.05 μmol/L.Compared with other known modified electrodes,the poly(amino black 10B) modified electrode possesses many advantages such as low detection limit,fast response,good repeatability,low cost and simplicity.The practical application of this modified electrode was demonstrated with vitamin B6 drugs.
2011, 28(5): 597-601
doi: 10.3724/SP.J.1095.2011.00423
Abstract:
Bi(Ⅲ) modified Pt-electrode was prepared and the adsorption character of Bi(Ⅲ) on the electrode was studied by cyclic voltammetry.The mechanism of electrode response was discussed.A method using oscillo-potentiometry for the titration of Bi(Ⅲ) was described.In 0.1 mol/L nitric acid solution(pH=1.0),Bi(Ⅲ) was titrated with EDTA,and two modified Pt-electrodes were used as bi-indicator electrode system.The end point of titration was determined by an abrupt maximum displacement of the fluorescence spot observed on the screen of the cathodic oscillograph.When Bi(Ⅲ) content was in the range of 1.19×10-4~1.44×10-2 mol/L,the recovery was in the range of 99.8%~100.1% and the detection limit was 1.0×10-4 mol/L(S/N=3).Furthermore,the modified electrode showed excellent stability and reproducibility.In 1.0×10-2 mol/L Bi(Ⅲ) solution,the values of end point potentials obtained from 7 continuous determinations were all around 100 mV,and the relative standard deviation(RSD) was 0.04%.Moreover,the proposed method has been used in the determination of Bi(Ⅲ) contained in samples with recoveries of 99.5%~100.5% and RSD(n=7) less than 0.25%,which are in accordance with the indicator method.
Bi(Ⅲ) modified Pt-electrode was prepared and the adsorption character of Bi(Ⅲ) on the electrode was studied by cyclic voltammetry.The mechanism of electrode response was discussed.A method using oscillo-potentiometry for the titration of Bi(Ⅲ) was described.In 0.1 mol/L nitric acid solution(pH=1.0),Bi(Ⅲ) was titrated with EDTA,and two modified Pt-electrodes were used as bi-indicator electrode system.The end point of titration was determined by an abrupt maximum displacement of the fluorescence spot observed on the screen of the cathodic oscillograph.When Bi(Ⅲ) content was in the range of 1.19×10-4~1.44×10-2 mol/L,the recovery was in the range of 99.8%~100.1% and the detection limit was 1.0×10-4 mol/L(S/N=3).Furthermore,the modified electrode showed excellent stability and reproducibility.In 1.0×10-2 mol/L Bi(Ⅲ) solution,the values of end point potentials obtained from 7 continuous determinations were all around 100 mV,and the relative standard deviation(RSD) was 0.04%.Moreover,the proposed method has been used in the determination of Bi(Ⅲ) contained in samples with recoveries of 99.5%~100.5% and RSD(n=7) less than 0.25%,which are in accordance with the indicator method.
2011, 28(5): 602-604
doi: 10.3724/SP.J.1095.2011.00430
Abstract:
The effects of N,N-dialkylimidazolium-based ionic liquids on the catalytic reaction of amylase were studied in this paper via the spectroscopy method.The results indicate that the ionic liquids show inhibitory activities on the catalytic reaction of amylase.1-Butyl-3-methylimidazolium chloride([HMIM]Cl) showed the highest inhibitory activity among all investigated ionic liquids in this study.Furthermore,the inhibition effect of ionic liquids having the same anion increases with the alkyl group length of the imidazolium ring.
The effects of N,N-dialkylimidazolium-based ionic liquids on the catalytic reaction of amylase were studied in this paper via the spectroscopy method.The results indicate that the ionic liquids show inhibitory activities on the catalytic reaction of amylase.1-Butyl-3-methylimidazolium chloride([HMIM]Cl) showed the highest inhibitory activity among all investigated ionic liquids in this study.Furthermore,the inhibition effect of ionic liquids having the same anion increases with the alkyl group length of the imidazolium ring.
2011, 28(5): 605-607
doi: 10.3724/SP.J.1095.2011.00436
Abstract:
A novel reactive flame retardant,5,5-dimethyl-2-phospha-1,3-dioxan-2-yl-allyl phosphate,was synthesized by reacting neopentyl glycol,phosphorus oxychloride,allyl alcohol with sodium through two steps.The title compound was characterized by elemental analysis,FTIR,MS and 1H NMR.The thermal properties of the title compound were studied by TG and DSC techniques.The results show that the synthesized compound is consistent with the expected structure.The yield of the compound is 55.5% with the molar ratio of allyl alcohol to sodium being 2:1,the reaction temperature being at 0℃ using an ice bath for 2 h at first,and then at 30℃ for 6 h.The TG curves show that the initial thermal decomposition temperature of the compound is about 130.2℃,and there is about 23% char residue left at 800℃,indicating that the title compound has a good thermal stability and a char forming capability.
A novel reactive flame retardant,5,5-dimethyl-2-phospha-1,3-dioxan-2-yl-allyl phosphate,was synthesized by reacting neopentyl glycol,phosphorus oxychloride,allyl alcohol with sodium through two steps.The title compound was characterized by elemental analysis,FTIR,MS and 1H NMR.The thermal properties of the title compound were studied by TG and DSC techniques.The results show that the synthesized compound is consistent with the expected structure.The yield of the compound is 55.5% with the molar ratio of allyl alcohol to sodium being 2:1,the reaction temperature being at 0℃ using an ice bath for 2 h at first,and then at 30℃ for 6 h.The TG curves show that the initial thermal decomposition temperature of the compound is about 130.2℃,and there is about 23% char residue left at 800℃,indicating that the title compound has a good thermal stability and a char forming capability.
2011, 28(5): 608-610
doi: 10.3724/SP.J.1095.2011.00434
Abstract:
Acid activated and kaolinite supported SO42-/ZrO2-TiO2 was prepared as a solid acid catalyst.The structure and acid strength of the catalyst was studied by FT-IR,XRD and NH3-TPD.The activity and stability of the catalyst for the synthesis of cyclohexanon ethylene ketal were investigated.The results showed that the acid amount of kaolinite was increased with increasing acid activation,and the acid strength was significantly enhanced after supporting SO42-/ZrO2-TiO2 and calcinations at 500℃ for 3 h.When the molar ratio of cyclohexanone to ethylene is 1:1.2,the loading of catalyst is 1.2 g and the volume of cyclohexane is 15 mL,the yield of cyclohexanone ethylene ketal from 0.2 mol cyclohexanon feed could reach 96.8% after 70 min reaction.The catalyst was used repeatedly for 5 times with the yield still larger than 90%.
Acid activated and kaolinite supported SO42-/ZrO2-TiO2 was prepared as a solid acid catalyst.The structure and acid strength of the catalyst was studied by FT-IR,XRD and NH3-TPD.The activity and stability of the catalyst for the synthesis of cyclohexanon ethylene ketal were investigated.The results showed that the acid amount of kaolinite was increased with increasing acid activation,and the acid strength was significantly enhanced after supporting SO42-/ZrO2-TiO2 and calcinations at 500℃ for 3 h.When the molar ratio of cyclohexanone to ethylene is 1:1.2,the loading of catalyst is 1.2 g and the volume of cyclohexane is 15 mL,the yield of cyclohexanone ethylene ketal from 0.2 mol cyclohexanon feed could reach 96.8% after 70 min reaction.The catalyst was used repeatedly for 5 times with the yield still larger than 90%.
