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2005 Volume 22 Issue 8
2005, 22(8): 813-817
Abstract:
Simultaneous treatment of Cr(Ⅵ) and OrangeⅡ in wastewater was investigated with a metal halide lamp as light source.The affecting factors on the photoreaction were discussed,including pH and the initial concentrations of Cr(Ⅵ) and OrangeⅡ.The reaction mechanism was preliminarily studied.Under the irradiation of the metal halide lamp,the photoreduction of (Cr(Ⅵ)) and photooxidation of Orange occurred simultaneously in wastewater mixtures.It is beneficial to the treatment of Cr(Ⅵ) and OrangeⅡ to increase the concentrations of Cr(Ⅵ) and Orange.The photoreduction rate of (Cr(Ⅵ)) and the discoloration rate of Orange increase with increasing acidity.The higher the concentration of Cr(Ⅵ),the lower the photoreduction rate of Cr(Ⅵ).The higher the initial rate,the higher the discoloration rate of OrangeⅡ;the higher the concentration of Orange,the higher the photoreduction rate of (Cr(Ⅵ)),the discoloration rate of Orange and the initial rate.Orange is the dominant species influencing the reaction rate.The reaction mechanism may be that Orange is activated by absorbing energy first,and then reacts with Cr(Ⅵ) via redox.Simultaneous treatment of Cr(Ⅵ) and organic compounds in water can be induced by UV-Vis light.These findings suggest that the method may be a new approach to remove high valent heavy metals and organic compounds simultaneously.
Simultaneous treatment of Cr(Ⅵ) and OrangeⅡ in wastewater was investigated with a metal halide lamp as light source.The affecting factors on the photoreaction were discussed,including pH and the initial concentrations of Cr(Ⅵ) and OrangeⅡ.The reaction mechanism was preliminarily studied.Under the irradiation of the metal halide lamp,the photoreduction of (Cr(Ⅵ)) and photooxidation of Orange occurred simultaneously in wastewater mixtures.It is beneficial to the treatment of Cr(Ⅵ) and OrangeⅡ to increase the concentrations of Cr(Ⅵ) and Orange.The photoreduction rate of (Cr(Ⅵ)) and the discoloration rate of Orange increase with increasing acidity.The higher the concentration of Cr(Ⅵ),the lower the photoreduction rate of Cr(Ⅵ).The higher the initial rate,the higher the discoloration rate of OrangeⅡ;the higher the concentration of Orange,the higher the photoreduction rate of (Cr(Ⅵ)),the discoloration rate of Orange and the initial rate.Orange is the dominant species influencing the reaction rate.The reaction mechanism may be that Orange is activated by absorbing energy first,and then reacts with Cr(Ⅵ) via redox.Simultaneous treatment of Cr(Ⅵ) and organic compounds in water can be induced by UV-Vis light.These findings suggest that the method may be a new approach to remove high valent heavy metals and organic compounds simultaneously.
2005, 22(8): 818-822
Abstract:
Distribution behavior of terbutaline enantiomorph was investigated in a aqueous/organic two-phase system containing a chiral selector (L-dihexyltartrate).The influences of organic solvents,lipophilic anions and pH value on the distribution coefficient (k) and the separation factor (α) were investigated.The results show that tetraphenylborate lipophilic anion and terbutaline enantiomorph form two lipophilic salt complexes,which facilitates the solubilization of the enantiomorph in the organic phase.The extraction performance of the two kinds of organic solvent is different,and n-heptane is a better organic solvent.However,pH value of the aqueous phase also influences the extraction performance obviously.Under the determined extraction conditions,a new process of countercurrent liquid membrane extraction technology was adopted to separate terbutaline enantiomorph.To demonstrate the feasibility of the system,mass transfer experiments were performed,in which terbutaline enantiomorph of 99% optical purity can be obtained.
Distribution behavior of terbutaline enantiomorph was investigated in a aqueous/organic two-phase system containing a chiral selector (L-dihexyltartrate).The influences of organic solvents,lipophilic anions and pH value on the distribution coefficient (k) and the separation factor (α) were investigated.The results show that tetraphenylborate lipophilic anion and terbutaline enantiomorph form two lipophilic salt complexes,which facilitates the solubilization of the enantiomorph in the organic phase.The extraction performance of the two kinds of organic solvent is different,and n-heptane is a better organic solvent.However,pH value of the aqueous phase also influences the extraction performance obviously.Under the determined extraction conditions,a new process of countercurrent liquid membrane extraction technology was adopted to separate terbutaline enantiomorph.To demonstrate the feasibility of the system,mass transfer experiments were performed,in which terbutaline enantiomorph of 99% optical purity can be obtained.
2005, 22(8): 823-828
Abstract:
The oriented growth of glycine crystals beneath compressed Langmuir monolayers of dipalmitoylphosphatidylcholine (DPPC) was studied by means of electron probing microscopy (EPM),scan electron micro-scopy (SEM) and X-ray diffractometry (XRD).It was found that the morphology and the orientation of the formed crystals beneath the DPPC monolayer template changed with the pH of the glycine supersaturated solution.These changes are attributed to the glycine molecules with different charges and the mode of glycine molecules approaching the template at different pH values.These results are very important to the research of interactions between lipoprotein and amino acids or nucleic acids.
The oriented growth of glycine crystals beneath compressed Langmuir monolayers of dipalmitoylphosphatidylcholine (DPPC) was studied by means of electron probing microscopy (EPM),scan electron micro-scopy (SEM) and X-ray diffractometry (XRD).It was found that the morphology and the orientation of the formed crystals beneath the DPPC monolayer template changed with the pH of the glycine supersaturated solution.These changes are attributed to the glycine molecules with different charges and the mode of glycine molecules approaching the template at different pH values.These results are very important to the research of interactions between lipoprotein and amino acids or nucleic acids.
2005, 22(8): 829-834
Abstract:
Seventeen new carboxylic pyrazolyl oxime esters containing chlorine were prepared.Their structures were confirmed by virtue of 1H NMR,IR and elemental analysis.Some of them were also confirmed by means of EI-Ms or LC/MS/MS.The preliminary bioassay for these compounds showed that some of them displayed good herbicidal and pesticidal as well as fungicidal activities.
Seventeen new carboxylic pyrazolyl oxime esters containing chlorine were prepared.Their structures were confirmed by virtue of 1H NMR,IR and elemental analysis.Some of them were also confirmed by means of EI-Ms or LC/MS/MS.The preliminary bioassay for these compounds showed that some of them displayed good herbicidal and pesticidal as well as fungicidal activities.
2005, 22(8): 835-839
Abstract:
Porous silica was prepared from tetraethyl orthosilicate (TEOS) coated activated carbon in supercritical CO2.The pore structure of the porous silica was determined.The multipoint BET surface area,total pore volume,and average pore size of the product prepared via supercritical CO2 coating were 1 147 m2/g),1.4 cm3/g and 2.20 nm,respectively.These results were better than that of the porous silica material prepared via simple immersion coating.In addition,the effects of various factors on the coating in supercritical fluids (SCF) were studied,and improved coating conditions were explored.
Porous silica was prepared from tetraethyl orthosilicate (TEOS) coated activated carbon in supercritical CO2.The pore structure of the porous silica was determined.The multipoint BET surface area,total pore volume,and average pore size of the product prepared via supercritical CO2 coating were 1 147 m2/g),1.4 cm3/g and 2.20 nm,respectively.These results were better than that of the porous silica material prepared via simple immersion coating.In addition,the effects of various factors on the coating in supercritical fluids (SCF) were studied,and improved coating conditions were explored.
2005, 22(8): 840-843
Abstract:
In the present work,suspended Ag/TiO2 was used as the catalyst,Ti mesh as the electrode,and a three-dimension electrode of Ti/Ag/TiO2 was constructed.The effect of enforced electric field was observed,and the electro-photocatalytic degradation of phenol in aqueous solution at the prepared electrode were evaluated.The results show that the anode potential bias favors the photocatalytic degradation of phenol.The maximum phenol removal efficiency was achieved when TiO2 ith 1.5% silver loading was used.Two optimal voltage values for the Ag/TiO2 electro-photocatalysis reaction were 20 and 10 V,respectively.Addition of electrolyte NaCl increased the phenol removal efficiency of Ag/TiO2 electro-photocatalysis from 49.7% to 93.6%.Enforced electric field can drive photogenerated electrons away from the photocatalyst surface,and the enhanced photocatalytic activity is mainly caused by the low recombination rate of electrons and holes and the higher rate of electron transfer to adsorbed oxygen.
In the present work,suspended Ag/TiO2 was used as the catalyst,Ti mesh as the electrode,and a three-dimension electrode of Ti/Ag/TiO2 was constructed.The effect of enforced electric field was observed,and the electro-photocatalytic degradation of phenol in aqueous solution at the prepared electrode were evaluated.The results show that the anode potential bias favors the photocatalytic degradation of phenol.The maximum phenol removal efficiency was achieved when TiO2 ith 1.5% silver loading was used.Two optimal voltage values for the Ag/TiO2 electro-photocatalysis reaction were 20 and 10 V,respectively.Addition of electrolyte NaCl increased the phenol removal efficiency of Ag/TiO2 electro-photocatalysis from 49.7% to 93.6%.Enforced electric field can drive photogenerated electrons away from the photocatalyst surface,and the enhanced photocatalytic activity is mainly caused by the low recombination rate of electrons and holes and the higher rate of electron transfer to adsorbed oxygen.
2005, 22(8): 844-847
Abstract:
The photocrosslinkable copolymers,poly (N-vinyl pyrrolidone-2-hydropropyl acrylate)(P(NVP-co-HEA)),were synthesized from N-vinyl pyrrolidone and 2-hydropropyl acrylate via radical copolymerization.After cinnamoylation,the copolymers were not only temperature sensitive in aqueous solution,but also photoactive.The properties of the cinnamoylated P(NVP-co-HEA) were studied.The results show that the low critical solution temperature (LCST) of cinnamoylated P (NVP-co-HEA) was 55,50,45,36 at degree of cinnamoylation of 10%,15%,20%,25% in aqueous solution,respectively.At 30% cinnamoylation the aqueous solution of the copolymer was blue translucent due to micellization,and at 35% cinnamoylation the copolymer became insoluble in water.A film of cinnamoylated P(NVP-co-HEA) crosslinks and becomes insoluble under the irradiation of UV light,but it swells in water and becomes a hydrogel.
The photocrosslinkable copolymers,poly (N-vinyl pyrrolidone-2-hydropropyl acrylate)(P(NVP-co-HEA)),were synthesized from N-vinyl pyrrolidone and 2-hydropropyl acrylate via radical copolymerization.After cinnamoylation,the copolymers were not only temperature sensitive in aqueous solution,but also photoactive.The properties of the cinnamoylated P(NVP-co-HEA) were studied.The results show that the low critical solution temperature (LCST) of cinnamoylated P (NVP-co-HEA) was 55,50,45,36 at degree of cinnamoylation of 10%,15%,20%,25% in aqueous solution,respectively.At 30% cinnamoylation the aqueous solution of the copolymer was blue translucent due to micellization,and at 35% cinnamoylation the copolymer became insoluble in water.A film of cinnamoylated P(NVP-co-HEA) crosslinks and becomes insoluble under the irradiation of UV light,but it swells in water and becomes a hydrogel.
2005, 22(8): 848-851
Abstract:
Reactions of 4 substituted 3-formyl chromones with 4 aroacetohydrazides,catalyzed by ice acetic acid,gave 16 corresponding Schiff Base compounds.Then 3-(3-acetyl-5-aroxymethylene-2,3-dihydro-1,3,4-oxadiazol-2-yl) chromones were prepared by heating and refluxing the Schiff base with Ac2O.All the target compounds were characterized by means of elemental analysis,IR,LC-MS,and 1H NMR.
Reactions of 4 substituted 3-formyl chromones with 4 aroacetohydrazides,catalyzed by ice acetic acid,gave 16 corresponding Schiff Base compounds.Then 3-(3-acetyl-5-aroxymethylene-2,3-dihydro-1,3,4-oxadiazol-2-yl) chromones were prepared by heating and refluxing the Schiff base with Ac2O.All the target compounds were characterized by means of elemental analysis,IR,LC-MS,and 1H NMR.
2005, 22(8): 852-856
Abstract:
In a NH3-NH4Cl buffer solution (pH=10.5) and in the presence of a surfactant zephiran chloride,Ag(Ⅰ) and sodium diethyldithiocarbamate (DDTC) form a complex molecule,which can self-aggregate to form stable colorless (Ag-DDTC)n chelate particles.They exhibit a resonance scattering (RS) peak at 361 nm and a synchronous scattering peak at 464 nm.There are two fluorescence peaks at 400 and 466 nm when the exciting wavelength is 260 nm.The RS intensity at 361 nm and that of fluorescence at 400 nm change linearly with Ag(Ⅰ) concentration over a concentration range of 4.3×10-8~3.24×10-6 g/mL.A new resonance scattering method for the determination of Ag with DDTC is thus afforded with a detection limit of 1.0×10-8 g/mL.The method was used to determine the trace silver in photograph and fixation waste water with satisfactory results.
In a NH3-NH4Cl buffer solution (pH=10.5) and in the presence of a surfactant zephiran chloride,Ag(Ⅰ) and sodium diethyldithiocarbamate (DDTC) form a complex molecule,which can self-aggregate to form stable colorless (Ag-DDTC)n chelate particles.They exhibit a resonance scattering (RS) peak at 361 nm and a synchronous scattering peak at 464 nm.There are two fluorescence peaks at 400 and 466 nm when the exciting wavelength is 260 nm.The RS intensity at 361 nm and that of fluorescence at 400 nm change linearly with Ag(Ⅰ) concentration over a concentration range of 4.3×10-8~3.24×10-6 g/mL.A new resonance scattering method for the determination of Ag with DDTC is thus afforded with a detection limit of 1.0×10-8 g/mL.The method was used to determine the trace silver in photograph and fixation waste water with satisfactory results.
2005, 22(8): 857-860
Abstract:
An electrochemical method was developed for the determination of ethynylestradiol based on the electrocatalytic activity of multi-wall carbon nanotube (MWNT).Owing to the unique and extraordinary properties of MWNT,the oxidation peak current of ethynylestradiol increases remarkably on a MWNT-modified glassy carbon electrode (GCE),accompanied by the lowering of oxidation overpotential.The oxidation peak current varies linearly with the concentration of ethynylestradiol in the range from 1×10-7 to 4×10-5 mol/L.The detection limit is 3×10-8 mol/L after open-circuit accumulation for 3 min.The relative standard deviation (RSD) of ten measurements is 6.2% for 1×10-6 mol/L ethynylestradiol,indicating the good reproducibility.This proposed method was successfully employed in detecting ethynylestradiol in ethynylestradiol tablets.
An electrochemical method was developed for the determination of ethynylestradiol based on the electrocatalytic activity of multi-wall carbon nanotube (MWNT).Owing to the unique and extraordinary properties of MWNT,the oxidation peak current of ethynylestradiol increases remarkably on a MWNT-modified glassy carbon electrode (GCE),accompanied by the lowering of oxidation overpotential.The oxidation peak current varies linearly with the concentration of ethynylestradiol in the range from 1×10-7 to 4×10-5 mol/L.The detection limit is 3×10-8 mol/L after open-circuit accumulation for 3 min.The relative standard deviation (RSD) of ten measurements is 6.2% for 1×10-6 mol/L ethynylestradiol,indicating the good reproducibility.This proposed method was successfully employed in detecting ethynylestradiol in ethynylestradiol tablets.
2005, 22(8): 861-864
Abstract:
The thermal degradations of polyether-polyurethane and polyester-polyurethane in air and nitrogen atmospheres were investigated via thermogravimetry analysis (TG).The kinetic constants of the polyurethanes were obtained with the model fitting method.The investigation shows that the first-stage of thermal degradation of the polyurethane is controlled by diffusion mechanism.The results show that the thermal stability of polyester-polyurethane is higher than that of polyether-polyurethane,and the presence of oxygen affects significantly the break of the polymeric chains.
The thermal degradations of polyether-polyurethane and polyester-polyurethane in air and nitrogen atmospheres were investigated via thermogravimetry analysis (TG).The kinetic constants of the polyurethanes were obtained with the model fitting method.The investigation shows that the first-stage of thermal degradation of the polyurethane is controlled by diffusion mechanism.The results show that the thermal stability of polyester-polyurethane is higher than that of polyether-polyurethane,and the presence of oxygen affects significantly the break of the polymeric chains.
2005, 22(8): 865-869
Abstract:
Zeolite 4A was rapidly synthesized under microwave heating,and the effect of the addition of lanthanum sulfate and sodium sulfate (LNS for short) on the synthesis was studied.It was found that with the addition of LNS the crystallization rate of zeolite 4A almost doubled,and the crystallization rate in microwave field was about ten times faster than that under conventional heating.The whiteness of the products obtained in microwave field was 94%,the calcium ions exchange capacity 310 mg CaCO3/g dry zeolite,and the average particle size 2.561 μm.With the addition of LNS,the whiteness was 96%,the calcium ion exchange capacity 318 mg CaCO3/g dry zeolite,and the average particle size 1.958 μm.Moreover,the LNS acts as a modulizer,and the crystal form of zeolite 4A became spherical with the addition of LNS.
Zeolite 4A was rapidly synthesized under microwave heating,and the effect of the addition of lanthanum sulfate and sodium sulfate (LNS for short) on the synthesis was studied.It was found that with the addition of LNS the crystallization rate of zeolite 4A almost doubled,and the crystallization rate in microwave field was about ten times faster than that under conventional heating.The whiteness of the products obtained in microwave field was 94%,the calcium ions exchange capacity 310 mg CaCO3/g dry zeolite,and the average particle size 2.561 μm.With the addition of LNS,the whiteness was 96%,the calcium ion exchange capacity 318 mg CaCO3/g dry zeolite,and the average particle size 1.958 μm.Moreover,the LNS acts as a modulizer,and the crystal form of zeolite 4A became spherical with the addition of LNS.
2005, 22(8): 870-873
Abstract:
Ethanol was used as a reducing agent instead of NH3 for the removal of NOx.A series of Copper-supported catalysts were prepared via impregnation method.The effects of temperature and the support were studied.The reduction activity and texture of the catalysts were examined by TPR and BET methods.It was found that 10% CuO/TYZp-3 exhibited good catalytic activity at high temperatures,and the NOx conversion reached 98.7% at 350;and 10% CuO/20% TiO2-γ-Al2O3 showed good catalyic activity at low temperatures,and the NOx conversion reached 46.4% at 250℃.And at above 400℃,the NOx conversion over other CuO catalysts reached 99%.
Ethanol was used as a reducing agent instead of NH3 for the removal of NOx.A series of Copper-supported catalysts were prepared via impregnation method.The effects of temperature and the support were studied.The reduction activity and texture of the catalysts were examined by TPR and BET methods.It was found that 10% CuO/TYZp-3 exhibited good catalytic activity at high temperatures,and the NOx conversion reached 98.7% at 350;and 10% CuO/20% TiO2-γ-Al2O3 showed good catalyic activity at low temperatures,and the NOx conversion reached 46.4% at 250℃.And at above 400℃,the NOx conversion over other CuO catalysts reached 99%.
2005, 22(8): 874-878
Abstract:
Ammonium carnallite was synthesized with a >85% yield by a process in which a mixture of hydrated magnesium chloride from the salt lake and ammonium chloride solution at a 11 molar ratio was dehydrated to some extent at 160℃ for about 4 h.Dehydrated ammonium carnallite and solid ammonium chloride were mixed at a 14 mass ratio,and the ammonium chloride in the mixture was decomposed into NH3 and HCl,in which the pressure of NH3 reached 30.5 kPa and dehydrated ammonium carnallite was dehydrated by NH3 at 410℃,and finally the anhydrous magnesium chloride was calcined at 700℃.The result shows that magnesium oxide in the anhydrous magnesium chloride was less than 0.1% by mass.The XRD pattern and SEM micrograph demonstrate that the ammonium carnallite and the anhydrous magnesium chloride crystals were respectively homogeneous,the grains of them big and well-distributed.The anhydrous magnesium chloride thus produced can be used for the production of magnesium metal through electrolysis.
Ammonium carnallite was synthesized with a >85% yield by a process in which a mixture of hydrated magnesium chloride from the salt lake and ammonium chloride solution at a 11 molar ratio was dehydrated to some extent at 160℃ for about 4 h.Dehydrated ammonium carnallite and solid ammonium chloride were mixed at a 14 mass ratio,and the ammonium chloride in the mixture was decomposed into NH3 and HCl,in which the pressure of NH3 reached 30.5 kPa and dehydrated ammonium carnallite was dehydrated by NH3 at 410℃,and finally the anhydrous magnesium chloride was calcined at 700℃.The result shows that magnesium oxide in the anhydrous magnesium chloride was less than 0.1% by mass.The XRD pattern and SEM micrograph demonstrate that the ammonium carnallite and the anhydrous magnesium chloride crystals were respectively homogeneous,the grains of them big and well-distributed.The anhydrous magnesium chloride thus produced can be used for the production of magnesium metal through electrolysis.
2005, 22(8): 879-882
Abstract:
The precursors of S2O2-8/Fe2O3-SiO2 solid acids prepared via co-precipitation method were modified by microwave hydrothermal treatment.After being impregnated in a (NH4)2S2O8 solution and calcined at a certain temperature,solid acid catalysts were formed.The samples were characterized by XRD,TEM,N2 gas adsorption/desorption and chemical analysis.The catalytic activities of the solid acids were evaluated by esterification of acetic acid and butanol.In addition,the solid acid catalysts were compared with other catalysts prepared under normal conditions.The results show that adding SiO2 retards the formation and growth of Fe2O3 crystals.After the precursors were modified via 250 W microwave hydrothermal treatment,the solid acids had a moderate specific area (37.1 m2/g) and a narrow pore size distribution,and the sulphur content was 6.02%.The solid acid showed a high catalytic activity.At 3 h reaction time,the convertion of acetic acid reached 97.7%.
The precursors of S2O2-8/Fe2O3-SiO2 solid acids prepared via co-precipitation method were modified by microwave hydrothermal treatment.After being impregnated in a (NH4)2S2O8 solution and calcined at a certain temperature,solid acid catalysts were formed.The samples were characterized by XRD,TEM,N2 gas adsorption/desorption and chemical analysis.The catalytic activities of the solid acids were evaluated by esterification of acetic acid and butanol.In addition,the solid acid catalysts were compared with other catalysts prepared under normal conditions.The results show that adding SiO2 retards the formation and growth of Fe2O3 crystals.After the precursors were modified via 250 W microwave hydrothermal treatment,the solid acids had a moderate specific area (37.1 m2/g) and a narrow pore size distribution,and the sulphur content was 6.02%.The solid acid showed a high catalytic activity.At 3 h reaction time,the convertion of acetic acid reached 97.7%.
2005, 22(8): 883-886
Abstract:
Tungsten trioxide powder has been prepared from ammonium paratungstate via hydrothermal method using orthogonal and mono-level design of experiments.The effect of the preparation process on particle size,specific surface area,crystal form and crystalline morphology of the tungsten trioxide was investigated by TEM and XRD etc.It was found that the optimum conditions of the preparation are hydrothermal crystallization for 8 h at 180℃,followed by vacuum drying at 45℃ and calcination at 500℃ for 2 h.The blank reference experiment shows that hydrothermal crystallization treatment favors the formation of hexagonal tungsten trioxide,and the tungsten trioxide powder sample prepared by this method has a high degree of crystallinity.
Tungsten trioxide powder has been prepared from ammonium paratungstate via hydrothermal method using orthogonal and mono-level design of experiments.The effect of the preparation process on particle size,specific surface area,crystal form and crystalline morphology of the tungsten trioxide was investigated by TEM and XRD etc.It was found that the optimum conditions of the preparation are hydrothermal crystallization for 8 h at 180℃,followed by vacuum drying at 45℃ and calcination at 500℃ for 2 h.The blank reference experiment shows that hydrothermal crystallization treatment favors the formation of hexagonal tungsten trioxide,and the tungsten trioxide powder sample prepared by this method has a high degree of crystallinity.
2005, 22(8): 887-890
Abstract:
Nanometer carbon black with excellent dispersion in oily systems was obtained via surface grafting modification.TEM images show that surface grafting modification and ultrasonic field prevent carbon black from coagutation effectively.The particle size was about 24 nm to 300 nm and the parficles dispersed uniformly in the coating.Nanometer carbon black dispersion system in ultrasonic field was put into alkyd resin coating and alkyd resin antirust coating respectively,and then nanometer composite coating was obtained by means of ultrasonication and mechanical agitation.Corrosion experiment via gravimetric method and anode polarization experiment showed that the resistance to corrosion of the alkyd resin coating was improved by the nanometer carbon black,and its anodic corrosion current was reduced to about 1/10 that of alkyl resin coating without nanometer carbon black,and its corrosion potential increased by about 200 mV to 500 mV.
Nanometer carbon black with excellent dispersion in oily systems was obtained via surface grafting modification.TEM images show that surface grafting modification and ultrasonic field prevent carbon black from coagutation effectively.The particle size was about 24 nm to 300 nm and the parficles dispersed uniformly in the coating.Nanometer carbon black dispersion system in ultrasonic field was put into alkyd resin coating and alkyd resin antirust coating respectively,and then nanometer composite coating was obtained by means of ultrasonication and mechanical agitation.Corrosion experiment via gravimetric method and anode polarization experiment showed that the resistance to corrosion of the alkyd resin coating was improved by the nanometer carbon black,and its anodic corrosion current was reduced to about 1/10 that of alkyl resin coating without nanometer carbon black,and its corrosion potential increased by about 200 mV to 500 mV.
2005, 22(8): 891-894
Abstract:
Four new water-soluble α-aminopropiophenone hydrochlorides were synthesized from acetanilide.0.1 mol acetanilide was reacted with 0.26 mol aluminum chloride and 0.12 mol propionyl chloride for 5 h,and the yield was 57.3%.The structure of the products were identified,and all four products exhibited good water-solubility and activity as photoinitiators.
Four new water-soluble α-aminopropiophenone hydrochlorides were synthesized from acetanilide.0.1 mol acetanilide was reacted with 0.26 mol aluminum chloride and 0.12 mol propionyl chloride for 5 h,and the yield was 57.3%.The structure of the products were identified,and all four products exhibited good water-solubility and activity as photoinitiators.
2005, 22(8): 895-898
Abstract:
The interaction of horse heart hemoglobin with Hypocrellin A (HA) was studied by means of UV-Vis absorption spectroscopy and fluorescence spectroscropy under physiological condition.In the UV-Vis absorption spectrum,the intensity of the absorption peak of amino acid residues in the hemoglobin molecule decreases and the peak shifts bathochromically due to the hydrogen bonding between the amino acid residue in the hemoglobin molecule and HA.The synchronous fluorescence spectra show that the degree of the interaction of HA with different amino acid residues are different.For example,the fluorescence quenching kinetic constants of HA for tryptophane and tyrosine residues were 5.5×1012 and 1.7×1012 L/mol,respectively,which clearly demonstrates that the interaction between HA and tryptophane residue is more intense than that between HA and tyrosine residue.
The interaction of horse heart hemoglobin with Hypocrellin A (HA) was studied by means of UV-Vis absorption spectroscopy and fluorescence spectroscropy under physiological condition.In the UV-Vis absorption spectrum,the intensity of the absorption peak of amino acid residues in the hemoglobin molecule decreases and the peak shifts bathochromically due to the hydrogen bonding between the amino acid residue in the hemoglobin molecule and HA.The synchronous fluorescence spectra show that the degree of the interaction of HA with different amino acid residues are different.For example,the fluorescence quenching kinetic constants of HA for tryptophane and tyrosine residues were 5.5×1012 and 1.7×1012 L/mol,respectively,which clearly demonstrates that the interaction between HA and tryptophane residue is more intense than that between HA and tyrosine residue.
2005, 22(8): 899-903
Abstract:
Stable epoxy-styrene-acrylic aqueous dispersion modified with siloxane was prepared with a two-step synthetic method.FTIR,SEM and TGA were used to characterize the structure and property of the product.The results show that the epoxy was chemically modified by styrene-acyrlic and γ-aminopropyl methyl diethoxysilone (A-2100).Its microphase structure was formed before curing.The membrane has a fine microphase structure,and the size of the microphase region was 0.2~0.5 μm.At the same time it had similar thermal stability as the epoxy-styrene-acrylic copolymer,and the mass loss was 5% at 181.The membrane exhibited good chemical resistance.The viscosity of the dispersion did not change greatly after 180 d.
Stable epoxy-styrene-acrylic aqueous dispersion modified with siloxane was prepared with a two-step synthetic method.FTIR,SEM and TGA were used to characterize the structure and property of the product.The results show that the epoxy was chemically modified by styrene-acyrlic and γ-aminopropyl methyl diethoxysilone (A-2100).Its microphase structure was formed before curing.The membrane has a fine microphase structure,and the size of the microphase region was 0.2~0.5 μm.At the same time it had similar thermal stability as the epoxy-styrene-acrylic copolymer,and the mass loss was 5% at 181.The membrane exhibited good chemical resistance.The viscosity of the dispersion did not change greatly after 180 d.
2005, 22(8): 904-907
Abstract:
An amino-polycarbonate was synthesized,and the morphology features and properties of epoxy resin/amino-polycarbonate system cured by a tertiary amine were studied.The glass transition temperature,surface morphology,and mechanical properties of EP/amino-PC/BDMA were investigated by DSC,AFM and etc.The epoxy resin/amino-polycarbonate blend exhibited a single glass transition temperature.With the addition of the amino-polycarbonate,the glass transition temperature of the modified system decreased from 104.0℃ to 83.8℃.The mechanical properties of the modified epoxy resin system were improved and the impact toughness of the modified system increased by 11%.
An amino-polycarbonate was synthesized,and the morphology features and properties of epoxy resin/amino-polycarbonate system cured by a tertiary amine were studied.The glass transition temperature,surface morphology,and mechanical properties of EP/amino-PC/BDMA were investigated by DSC,AFM and etc.The epoxy resin/amino-polycarbonate blend exhibited a single glass transition temperature.With the addition of the amino-polycarbonate,the glass transition temperature of the modified system decreased from 104.0℃ to 83.8℃.The mechanical properties of the modified epoxy resin system were improved and the impact toughness of the modified system increased by 11%.
2005, 22(8): 908-911
Abstract:
δ-Manganese dioxide (δ-MnO2) was prepared from a Mn(Ⅱ) salt oxidized by ammonium persulfate ((NH4)2S2O8).The crystalline form of the δ-MnO2 was affected by the molar ratio of Mn2+to OH-,reaction temperature,and the amount of (NH4)2S2O8.The structure of the δ-MnO2 was characterized by means of X-ray diffraction (XRD) and Infrared spectroscopy (IR).Its electrochemical performance was also studied via cyclic voltammetry and constant current charge/discharge experiments.The results indicate that as-prepared δ-MnO2 has a good layer-structure and a high discharge capacity (~160 mA·h/g,2.0~4.5 V).
δ-Manganese dioxide (δ-MnO2) was prepared from a Mn(Ⅱ) salt oxidized by ammonium persulfate ((NH4)2S2O8).The crystalline form of the δ-MnO2 was affected by the molar ratio of Mn2+to OH-,reaction temperature,and the amount of (NH4)2S2O8.The structure of the δ-MnO2 was characterized by means of X-ray diffraction (XRD) and Infrared spectroscopy (IR).Its electrochemical performance was also studied via cyclic voltammetry and constant current charge/discharge experiments.The results indicate that as-prepared δ-MnO2 has a good layer-structure and a high discharge capacity (~160 mA·h/g,2.0~4.5 V).
2005, 22(8): 912-914
Abstract:
4-(4-Bromobutyl) styrene was synthesized from p-chloroacetophenone.p-Chloroacetophenone was hydrogenized with potassium hydrogenborane to obtain p-chlorophenylethanol,which was then dehydrated to yield p-chlorostyrene in the presence of potassium bisulfate,and finally p-chlorostyrene was reacted with magnesium to get Grignard reagent,which was then reacted with 1,4-dibromobutane to synthesize 4-(4-bromobutyl) styrene.MS,1H NMR and FT-IR were used to characterize the product.The results are consistent with the structure of 4-(4-bromobutyl) styrene.
4-(4-Bromobutyl) styrene was synthesized from p-chloroacetophenone.p-Chloroacetophenone was hydrogenized with potassium hydrogenborane to obtain p-chlorophenylethanol,which was then dehydrated to yield p-chlorostyrene in the presence of potassium bisulfate,and finally p-chlorostyrene was reacted with magnesium to get Grignard reagent,which was then reacted with 1,4-dibromobutane to synthesize 4-(4-bromobutyl) styrene.MS,1H NMR and FT-IR were used to characterize the product.The results are consistent with the structure of 4-(4-bromobutyl) styrene.
2005, 22(8): 915-917
Abstract:
The effects of petroleum sulphonate,HPAM and pH value on the zeta potential of Na-montmo-rrillonite suspensions were investigated,and orthogonal design of experiment was used to study the effect of these factors on the zeta potential of montmorillonite suspensions when the three factors existed simultaneously.The results show that the zeta potential of montmorillonite becomes more negative with the increase of the concentration of petroleum sulphonate,that of HPAM,and the pH value.Moreover,FpH=13.3(>F0.01=9.78),FHPAM=7.73(>F0.05=4.76) and Fpetroleum sulfonate=3.05 when the three factors co-exist,thus the effect of pH value on the zeta potential of montmorillonite is the most prominent factor,the HPAM a less prominent factor,and the petroleum sulphonate is least prominent.
The effects of petroleum sulphonate,HPAM and pH value on the zeta potential of Na-montmo-rrillonite suspensions were investigated,and orthogonal design of experiment was used to study the effect of these factors on the zeta potential of montmorillonite suspensions when the three factors existed simultaneously.The results show that the zeta potential of montmorillonite becomes more negative with the increase of the concentration of petroleum sulphonate,that of HPAM,and the pH value.Moreover,FpH=13.3(>F0.01=9.78),FHPAM=7.73(>F0.05=4.76) and Fpetroleum sulfonate=3.05 when the three factors co-exist,thus the effect of pH value on the zeta potential of montmorillonite is the most prominent factor,the HPAM a less prominent factor,and the petroleum sulphonate is least prominent.
2005, 22(8): 918-919
Abstract:
A series of 2-aryl-4,5-diphenylimidazoles were synthesized by one-step condensation reaction of aromatic aldehyde,diphenyl diketone and ammonium acetate (molar ratio 1:1:2) in acetic acid under microwave irradiation.Products were characterized by mp,IR,1H NMR,MS and elemental analysis,and their melting points are identical to those of the known compounds reported in the literature.The reaction time was 4~11 min and the yield 70%~98%.It's a low energy consumption,environmentally benign,and easy process.
A series of 2-aryl-4,5-diphenylimidazoles were synthesized by one-step condensation reaction of aromatic aldehyde,diphenyl diketone and ammonium acetate (molar ratio 1:1:2) in acetic acid under microwave irradiation.Products were characterized by mp,IR,1H NMR,MS and elemental analysis,and their melting points are identical to those of the known compounds reported in the literature.The reaction time was 4~11 min and the yield 70%~98%.It's a low energy consumption,environmentally benign,and easy process.
2005, 22(8): 920-922
Abstract:
Al-grafted mesoporous silica zeolite materials known as Al-MCM-41 were prepared with supercritical CO2 as the media.The X-ray diffraction (XRD) patterns and N2 adsorption/desorption isotherms indicate that Al-modified MCM-41 materials keep silica MCM-41 pore diameter of about 2.7 nm and the excellent structural ordering very well.The gel permeation chromatography (GPC) and 1H NMR show that the polymerization of ε-caprolactone went well with butanol.It was demonstrated that compared with conventional Al-MCM-41 materials,the aluminosilicate mesoporous zeolite prepared with the aid of supercritical CO2 is a novel useful catalyst for the polymerization of ε-caprolactone.
Al-grafted mesoporous silica zeolite materials known as Al-MCM-41 were prepared with supercritical CO2 as the media.The X-ray diffraction (XRD) patterns and N2 adsorption/desorption isotherms indicate that Al-modified MCM-41 materials keep silica MCM-41 pore diameter of about 2.7 nm and the excellent structural ordering very well.The gel permeation chromatography (GPC) and 1H NMR show that the polymerization of ε-caprolactone went well with butanol.It was demonstrated that compared with conventional Al-MCM-41 materials,the aluminosilicate mesoporous zeolite prepared with the aid of supercritical CO2 is a novel useful catalyst for the polymerization of ε-caprolactone.
2005, 22(8): 923-925
Abstract:
Ethyl cellulose (EC)/cellulose acetate (CA) blends were prepared by solution blending.The thermal stability of the blends was observed by TG,and the compatibility of them was also studied by visco-metry,refractive index,DSC and IR.The results show that the refractive index or the trait vicidity of the EC/CA solution is linearly dependent on the mass composition of the blend.At 50 and 0.01 g/mL concentration,EC and CA are almost completely miscible.A single Tg was observed for a series of blends,which was in between the Tg of pure EC and that of pure CA.The decomposition temperature of the EC/CA blend decreased with the increase of EC mass fraction in the blends.These results indicate that there is good compatibility between EC and CA,and the thermal stability of the blends is improved compared to that of pure EC.
Ethyl cellulose (EC)/cellulose acetate (CA) blends were prepared by solution blending.The thermal stability of the blends was observed by TG,and the compatibility of them was also studied by visco-metry,refractive index,DSC and IR.The results show that the refractive index or the trait vicidity of the EC/CA solution is linearly dependent on the mass composition of the blend.At 50 and 0.01 g/mL concentration,EC and CA are almost completely miscible.A single Tg was observed for a series of blends,which was in between the Tg of pure EC and that of pure CA.The decomposition temperature of the EC/CA blend decreased with the increase of EC mass fraction in the blends.These results indicate that there is good compatibility between EC and CA,and the thermal stability of the blends is improved compared to that of pure EC.
2005, 22(8): 926-928
Abstract:
SiO2 glassy materials with Ge crystals embedded were formed by heating GeO2/SiO2 glass at 700℃ in the presence of hydrogen.GeO2/SiO2 glass was prepared with the sol-gel technique.The Ge/SiO2 samples show a special photoluminescence property and exhibit strong luminescence at 392 nm (3.12 eV),secondary strong luminescence at 600 nm (2.05 eV) and weak luminescence at 770 nm (1.60 eV) when excited under 246 nm (5.01 eV) ultra-violet light at room temperature.The structure of this new luminescence material was studied with XRD,XPS,and TEM.The results show that the presence of nanometer sized (around 10 nm) Ge and GeO crystals in the SiO2 may cause the three-band photoluminescence.The GeO2/SiO2 glass without going through the reducing process only has GeO2 in the SiO2 glass,and does not show the photo-luminescence.
SiO2 glassy materials with Ge crystals embedded were formed by heating GeO2/SiO2 glass at 700℃ in the presence of hydrogen.GeO2/SiO2 glass was prepared with the sol-gel technique.The Ge/SiO2 samples show a special photoluminescence property and exhibit strong luminescence at 392 nm (3.12 eV),secondary strong luminescence at 600 nm (2.05 eV) and weak luminescence at 770 nm (1.60 eV) when excited under 246 nm (5.01 eV) ultra-violet light at room temperature.The structure of this new luminescence material was studied with XRD,XPS,and TEM.The results show that the presence of nanometer sized (around 10 nm) Ge and GeO crystals in the SiO2 may cause the three-band photoluminescence.The GeO2/SiO2 glass without going through the reducing process only has GeO2 in the SiO2 glass,and does not show the photo-luminescence.
