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2006 Volume 23 Issue 11
2006, 23(6): 581-585
Abstract:
Thermo-sensitive poly(N-isopropylacrylamide)(PNIPA) hydrogel with a fast response rate was prepared by polymerization in aqueous solution of hydroxypropyl-methyl cellulose.The volume phase transition temperature of the PNIPA hydrogels was characterized by differential scanning calorimetry.The surface morphology of the PNIPA hydrogels was studied by scanning electron microscopy.The swelling ratios of the hydrogels at different temperatures were measured.Furthermore,the deswelling kinetics of the hydrogels was studied.In comparision with a conventional PNIPA hydrogel prepared in water,the hydrogel synthesized in hydroxypropyl-methyl cellulose aqueous solution has higher swelling ratios at temperatures below the lower critical solution temperature and exhibits a much faster response rate to temperature changes.For example,the hydrogel prepared in hydroxypropyl-methyl cellulose aqueous solution loses 89% water within 1min and about 93% water within 4 min,whereas the conventional hydrogel loses only about 66% water within 15 min.
Thermo-sensitive poly(N-isopropylacrylamide)(PNIPA) hydrogel with a fast response rate was prepared by polymerization in aqueous solution of hydroxypropyl-methyl cellulose.The volume phase transition temperature of the PNIPA hydrogels was characterized by differential scanning calorimetry.The surface morphology of the PNIPA hydrogels was studied by scanning electron microscopy.The swelling ratios of the hydrogels at different temperatures were measured.Furthermore,the deswelling kinetics of the hydrogels was studied.In comparision with a conventional PNIPA hydrogel prepared in water,the hydrogel synthesized in hydroxypropyl-methyl cellulose aqueous solution has higher swelling ratios at temperatures below the lower critical solution temperature and exhibits a much faster response rate to temperature changes.For example,the hydrogel prepared in hydroxypropyl-methyl cellulose aqueous solution loses 89% water within 1min and about 93% water within 4 min,whereas the conventional hydrogel loses only about 66% water within 15 min.
2006, 23(6): 586-590
Abstract:
Photocatalyst Cu/Fe2O3-TiO2 was prepared with sol-gel method.The surface structure,photon absorption and photocatalysis properties of the solid materials were assessed by XRD,Raman,TPR,IR,TEM,UV-Vis DRS and photocatalytic reaction experiments,respectively.The results showed that Fe2O3 was dispersed on the surface of TiO2 support as a monolayer at 10% content.Blue shift of the photon absorption edge of TiO2 was observed after the addition of Fe2O3.When the amount of Fe2O3 exceeded 10%,crystalline Fe2O3 appeared and the photon absorption decreased.The formation of the Fe-O-Ti bond strengthened the interaction between the semiconductors and promoted the transfer of photoexcited electron-hole pairs.Metal Cu broadened the photon absorption edge of the coupled materials toward visible region.The photocatalysis activity of the materials was related with photon absorption property closely.In the photocatalysis of reaction between CO2 and CH2NH2 to produce glycine directly,10% of Fe2O3 showed the best photocatalysis perfor-mance.Under the conditions of 120℃,normal pressure,space velocity 200 h-1 ,n(CO2):n(CH3NH2)=1:1 and UV light intensity 6.5×10-4 W/cm2,the conversion of CH3NH2 was 1.35% and the selectivity to glycine reached 92.0%.
Photocatalyst Cu/Fe2O3-TiO2 was prepared with sol-gel method.The surface structure,photon absorption and photocatalysis properties of the solid materials were assessed by XRD,Raman,TPR,IR,TEM,UV-Vis DRS and photocatalytic reaction experiments,respectively.The results showed that Fe2O3 was dispersed on the surface of TiO2 support as a monolayer at 10% content.Blue shift of the photon absorption edge of TiO2 was observed after the addition of Fe2O3.When the amount of Fe2O3 exceeded 10%,crystalline Fe2O3 appeared and the photon absorption decreased.The formation of the Fe-O-Ti bond strengthened the interaction between the semiconductors and promoted the transfer of photoexcited electron-hole pairs.Metal Cu broadened the photon absorption edge of the coupled materials toward visible region.The photocatalysis activity of the materials was related with photon absorption property closely.In the photocatalysis of reaction between CO2 and CH2NH2 to produce glycine directly,10% of Fe2O3 showed the best photocatalysis perfor-mance.Under the conditions of 120℃,normal pressure,space velocity 200 h-1 ,n(CO2):n(CH3NH2)=1:1 and UV light intensity 6.5×10-4 W/cm2,the conversion of CH3NH2 was 1.35% and the selectivity to glycine reached 92.0%.
2006, 23(6): 591-596
Abstract:
(NH4)4[PMo11VO40]·4H2O nanometer powders were prepared by solid state reaction between H4PMo11VO40·13H2O and(NH4)2C2O4·H2O at room temperature and characterized by elemental analysis,FTIR,XRD,TEM,TG-DTA and BET techniques.The experimental results indicate that the nanometer powders remain Keggin structure and have a mean grain size of 25 nm and BET specific surface area of 157.82 m2/g.The heteropolyanion shows good thermal stability up to 390℃.Using so-obtained nanomaterial as catalyst for the dehydration of cyclohexanol,the yield of cyclohexene could reach 77.98%,which is higher than those of currently widely used catalyst as well as its bulk counterpart.The yield was achived under optimized catalytic reaction conditions with the mass ratio (catalyst/cyclohexanol) of 8.31%,0.5 h reaction duration and 160℃ reaction temperature.
(NH4)4[PMo11VO40]·4H2O nanometer powders were prepared by solid state reaction between H4PMo11VO40·13H2O and(NH4)2C2O4·H2O at room temperature and characterized by elemental analysis,FTIR,XRD,TEM,TG-DTA and BET techniques.The experimental results indicate that the nanometer powders remain Keggin structure and have a mean grain size of 25 nm and BET specific surface area of 157.82 m2/g.The heteropolyanion shows good thermal stability up to 390℃.Using so-obtained nanomaterial as catalyst for the dehydration of cyclohexanol,the yield of cyclohexene could reach 77.98%,which is higher than those of currently widely used catalyst as well as its bulk counterpart.The yield was achived under optimized catalytic reaction conditions with the mass ratio (catalyst/cyclohexanol) of 8.31%,0.5 h reaction duration and 160℃ reaction temperature.
2006, 23(6): 597-601
Abstract:
Six Quaternary Ammonium tetraphenyl borates salt photobase generators were synthesized with the use of p-methoxy phenacylmethylene or 2-naphthoymethylene as chromophore,and triethylene diamine, pyridine or 3-methyl pyridine as tertiary amine.Their fluorescence emission properties were studied and their photolysis kinetics was investigated in different media by means of steady state photolysis method.The results show that their photolysis kinetics follows the first order reaction.
Six Quaternary Ammonium tetraphenyl borates salt photobase generators were synthesized with the use of p-methoxy phenacylmethylene or 2-naphthoymethylene as chromophore,and triethylene diamine, pyridine or 3-methyl pyridine as tertiary amine.Their fluorescence emission properties were studied and their photolysis kinetics was investigated in different media by means of steady state photolysis method.The results show that their photolysis kinetics follows the first order reaction.
2006, 23(6): 602-606
Abstract:
The preparation of supported liquid-phase platinum catalyst,and its catalytic property for hydro-silylation reaction of 3-chloropropene were studied.The catalyst displays a high activity and stability under atmospheric pressure for hydrosilylation of 3-chloropropene.The effects of temperature,feeding rate of reactants,and quantity of catalyst used on the hydrosilylation reaction were investigated.At 90℃,the single conversion of 3-chloropropene can be 96.2%,while the selectivity and yield of (3-chloropropyl)methyldichlorosilane can reach 86.9% and 83.6% respectively.The catalyst can be used for 15 h without too loss in term of catalytic activity.The catalytic activity for the hydrosilylation can be improved when modified by Gd.
The preparation of supported liquid-phase platinum catalyst,and its catalytic property for hydro-silylation reaction of 3-chloropropene were studied.The catalyst displays a high activity and stability under atmospheric pressure for hydrosilylation of 3-chloropropene.The effects of temperature,feeding rate of reactants,and quantity of catalyst used on the hydrosilylation reaction were investigated.At 90℃,the single conversion of 3-chloropropene can be 96.2%,while the selectivity and yield of (3-chloropropyl)methyldichlorosilane can reach 86.9% and 83.6% respectively.The catalyst can be used for 15 h without too loss in term of catalytic activity.The catalytic activity for the hydrosilylation can be improved when modified by Gd.
2006, 23(6): 607-611
Abstract:
With the presence of KI,Cd(Ⅱ) can react with I- to form metal complex anions CdI3- and CdI42- at pH 1.0~6.0,which can be well adsorbed on microcrystalline phenolphthalein modified by ethyl violet.Cd(Ⅱ) can be completely separated from Zn(Ⅱ),Fe(Ⅱ),Co(Ⅱ),Ni(Ⅱ),Mn(Ⅱ),Cr(Ⅲ) and Al(Ⅲ) under optimized conditions.This method was successfully applied to the concentration and determination of trace cadmium in environmental aqueous samples.The preconcentration factor can reach 100~200 times.Cadmium in natural water samples was concentrated prior to determination by FAAS.The recovery is above 96%.The detection limit is 0.018 μg/L.
With the presence of KI,Cd(Ⅱ) can react with I- to form metal complex anions CdI3- and CdI42- at pH 1.0~6.0,which can be well adsorbed on microcrystalline phenolphthalein modified by ethyl violet.Cd(Ⅱ) can be completely separated from Zn(Ⅱ),Fe(Ⅱ),Co(Ⅱ),Ni(Ⅱ),Mn(Ⅱ),Cr(Ⅲ) and Al(Ⅲ) under optimized conditions.This method was successfully applied to the concentration and determination of trace cadmium in environmental aqueous samples.The preconcentration factor can reach 100~200 times.Cadmium in natural water samples was concentrated prior to determination by FAAS.The recovery is above 96%.The detection limit is 0.018 μg/L.
2006, 23(6): 612-616
Abstract:
HA/ZrO2 composite coatings were successfully prepared on titanium electrode by means of the hydrothermal electrodeposition method via adding ZrO2 powder in the electrolyte in an autoclave.The bonding strength,bioactivity and thermal stability of the coatings were investigated.The results obtained show that the bonding strength of HA/ZrO2 composite coating is obviously higher than that of pure HA coating.HA/ZrO2 composite coating surfaces are covered by carbonate-apatite coating after immersion in simulate body fluid for 7 d,which indicates that the bonding strength of the coating is improved without the decrease of the bioactivity by the addition of the ZrO2 in HA coating.Tetragonal phase ZrO2(t-ZrO2) underwent a martensitic transformation to monoclinic phase ZrO2(m-ZrO2) after sintering treatment.At sintering temperature above 700℃,HA partially decomposed which causes the ZrO2 transformation to β-calcium phosphate(β-TCP).when sintering at 1 200℃,HA decomposed to α-calcium phosphate(α-TCP) and gave CaO,cubic phases ZrO2 (c-ZrO2) and yields CaZrO3.
HA/ZrO2 composite coatings were successfully prepared on titanium electrode by means of the hydrothermal electrodeposition method via adding ZrO2 powder in the electrolyte in an autoclave.The bonding strength,bioactivity and thermal stability of the coatings were investigated.The results obtained show that the bonding strength of HA/ZrO2 composite coating is obviously higher than that of pure HA coating.HA/ZrO2 composite coating surfaces are covered by carbonate-apatite coating after immersion in simulate body fluid for 7 d,which indicates that the bonding strength of the coating is improved without the decrease of the bioactivity by the addition of the ZrO2 in HA coating.Tetragonal phase ZrO2(t-ZrO2) underwent a martensitic transformation to monoclinic phase ZrO2(m-ZrO2) after sintering treatment.At sintering temperature above 700℃,HA partially decomposed which causes the ZrO2 transformation to β-calcium phosphate(β-TCP).when sintering at 1 200℃,HA decomposed to α-calcium phosphate(α-TCP) and gave CaO,cubic phases ZrO2 (c-ZrO2) and yields CaZrO3.
2006, 23(6): 617-621
Abstract:
A new crosslinking agent containing silicon-hydrogen atoms and trimethoxylsilicon groups was synthesized by controlling the molar ratio of 2,4,6,8-tetramethylcyclotetrasiloxane to vinyltrimethoxyl-siloxane to be 1:2.A PMDS hybrid membrane was also prepared by using the crosslinking agent,a silicone rubber containing vinyl groups of 10% (molar fraction) and tetraethoxysilicone(TEOS) were chosen as the matrix materials.There were three types of the crosslinking reactions involved in the membrane-forming process.These included an addition reaction between the silicon-hydrogen atom and the vinyl group,hydrolyzation and condensation between trimethoxylsiloxane and TEOS and their self hydrolyzation and condensation.The chemical structures and morphologies of the hybrid membranes were characterized by using FTIR and SEM.The mechanical properties were also measured.The hybrid membrane containing a mass fraction of 25.0% of TEOS showed a good membrane-forming property,better optimal mechanical performance and oxygen-enriching property.For example,at 30℃ and 0.05 MPa,PO2 and αO2/N2 were 3.7×107 Pa Barrer and 3.45,respectively,which are higher than the target of modified silicone rubber membranes at present: PO2 >1.0×107 Pa,αO2/N2 >3.0.
A new crosslinking agent containing silicon-hydrogen atoms and trimethoxylsilicon groups was synthesized by controlling the molar ratio of 2,4,6,8-tetramethylcyclotetrasiloxane to vinyltrimethoxyl-siloxane to be 1:2.A PMDS hybrid membrane was also prepared by using the crosslinking agent,a silicone rubber containing vinyl groups of 10% (molar fraction) and tetraethoxysilicone(TEOS) were chosen as the matrix materials.There were three types of the crosslinking reactions involved in the membrane-forming process.These included an addition reaction between the silicon-hydrogen atom and the vinyl group,hydrolyzation and condensation between trimethoxylsiloxane and TEOS and their self hydrolyzation and condensation.The chemical structures and morphologies of the hybrid membranes were characterized by using FTIR and SEM.The mechanical properties were also measured.The hybrid membrane containing a mass fraction of 25.0% of TEOS showed a good membrane-forming property,better optimal mechanical performance and oxygen-enriching property.For example,at 30℃ and 0.05 MPa,PO2 and αO2/N2 were 3.7×107 Pa Barrer and 3.45,respectively,which are higher than the target of modified silicone rubber membranes at present: PO2 >1.0×107 Pa,αO2/N2 >3.0.
2006, 23(6): 622-625
Abstract:
CeO2 nano-powders were synthesized by coupling homogeneous precipitation and carbon adsorption method. The effect of the amount of added carbon on the nano-powder size was investigated. The optimal carbon to Ce(NO3)3 mole ratio is 3. The phase,particle shape,particle size and specific surface area of CeO2 particles were characterized by XRD,TEM and BET. CeO2 powder calcined at 700℃ is cubic fluorite and has a surface area of 53.6 m2/g. The average particle size is about 18 nm. The structures of the products calcined at 800~900℃ remain stable and no agglomeration could be observed.
CeO2 nano-powders were synthesized by coupling homogeneous precipitation and carbon adsorption method. The effect of the amount of added carbon on the nano-powder size was investigated. The optimal carbon to Ce(NO3)3 mole ratio is 3. The phase,particle shape,particle size and specific surface area of CeO2 particles were characterized by XRD,TEM and BET. CeO2 powder calcined at 700℃ is cubic fluorite and has a surface area of 53.6 m2/g. The average particle size is about 18 nm. The structures of the products calcined at 800~900℃ remain stable and no agglomeration could be observed.
2006, 23(6): 626-631
Abstract:
Sodium alginate and anion polyacrylamide were crossed by HCHO.The effects of the viscosity of the preparation solution,water ratio,total ion exchange capacity,temperature and acid-base concentration on the swelling ratio of membrane SA-APMA were investigated.SA-APAM membrane was characterized by means of FTIR and SEM and applied in electro-generated ferrate.The experiment results show that SA-APAM membrane of 1%PAM-3%SA could prevent FeO42- diffusion to cathode chamber and the OH- consumed in the anode chamber could be continuously feeded from cathode chamber.
Sodium alginate and anion polyacrylamide were crossed by HCHO.The effects of the viscosity of the preparation solution,water ratio,total ion exchange capacity,temperature and acid-base concentration on the swelling ratio of membrane SA-APMA were investigated.SA-APAM membrane was characterized by means of FTIR and SEM and applied in electro-generated ferrate.The experiment results show that SA-APAM membrane of 1%PAM-3%SA could prevent FeO42- diffusion to cathode chamber and the OH- consumed in the anode chamber could be continuously feeded from cathode chamber.
2006, 23(6): 632-636
Abstract:
The performances of MEG,including shale inhibition,water activity,toxicity and its effect on shale membrane efficiency and high density drilling fluid rheological and filtrating properties,were studied in laboratory.With the addition of 25% MEG,the inhibiting expansion ratio of shale is just about 10.55%,the water activity can be lowered to below 0.85 and the shale membrane efficiency can be increased by 202%.The major anti-collapse mechanism of MEG is believed to be originated from decreasing drilling fluid loss through osmosis.Using MEG to prepare drilling fluids possesses virtues,besides nontoxic and improvement in terms of rheological properties,suchas simple components,high temperature stability and good resistance to clay and gypsum.
The performances of MEG,including shale inhibition,water activity,toxicity and its effect on shale membrane efficiency and high density drilling fluid rheological and filtrating properties,were studied in laboratory.With the addition of 25% MEG,the inhibiting expansion ratio of shale is just about 10.55%,the water activity can be lowered to below 0.85 and the shale membrane efficiency can be increased by 202%.The major anti-collapse mechanism of MEG is believed to be originated from decreasing drilling fluid loss through osmosis.Using MEG to prepare drilling fluids possesses virtues,besides nontoxic and improvement in terms of rheological properties,suchas simple components,high temperature stability and good resistance to clay and gypsum.
2006, 23(6): 637-640
Abstract:
11 1,4-dioxide quinoxaline formaldehyde semicarbazones and imines were synthesized by the reactions of 1,4-dioxide quinoxaline formaldehyde with aminourea or substituted anilines.The structures were characterized by IR,MS,H NMR and elemental analysis.The bacteriostatic activities of the new compounds were assessed by 5 fungies.The results are as follow: the bacteriostatic effects of semicarbazones and formaldehyde imines are below 20% and in the range of 30%~40% at a dosage of 80 mg/L,di-aldehydethe imines have no effect,while those of formaldehyde imines g and h having o-electron donating group substituted anilines can reach 50% or higher.
11 1,4-dioxide quinoxaline formaldehyde semicarbazones and imines were synthesized by the reactions of 1,4-dioxide quinoxaline formaldehyde with aminourea or substituted anilines.The structures were characterized by IR,MS,H NMR and elemental analysis.The bacteriostatic activities of the new compounds were assessed by 5 fungies.The results are as follow: the bacteriostatic effects of semicarbazones and formaldehyde imines are below 20% and in the range of 30%~40% at a dosage of 80 mg/L,di-aldehydethe imines have no effect,while those of formaldehyde imines g and h having o-electron donating group substituted anilines can reach 50% or higher.
2006, 23(6): 641-645
Abstract:
The precursor of bismuth stannate(Bi2Sn2O7) was prepared by precipitation reaction in the nanodroplets of water/TX100/n-hexanol/cyclohexane microemulsion system.Some factors that affected the size and shape of the precursor were investigated.Spherical bismuth stannate particles with single pyrochlore structure were obtained when the precursor was calcined at a temperature as low as 500℃.The particle size was in the range of 10~20 nm with a mean size close to 10 nm.The IR bands were broadened when calcined at 500℃.
The precursor of bismuth stannate(Bi2Sn2O7) was prepared by precipitation reaction in the nanodroplets of water/TX100/n-hexanol/cyclohexane microemulsion system.Some factors that affected the size and shape of the precursor were investigated.Spherical bismuth stannate particles with single pyrochlore structure were obtained when the precursor was calcined at a temperature as low as 500℃.The particle size was in the range of 10~20 nm with a mean size close to 10 nm.The IR bands were broadened when calcined at 500℃.
2006, 23(6): 646-650
Abstract:
Here we report a novel preparation method of Mn(Salen)/Al-HMS catalysts through host-guest interaction between Mn(Salen) complex and mesoporous Al-HMS under microwave irradiation(MWI).FT-IR,DR UV-Vis and TG measurement results indicate that Mn(Salen) complex could be successfully immobilized on mesoporous Al-HMS.Styrene epoxidation with PhIO as oxidant was carried out to test the effect of the catalyst prepared with different preparation methods on the catalytic activity and selectivity.It was found that the catalyst of Mn(Salen)/Al-HMS-IP1 shows a good conversion of styrene(74.6%) and the best selectivity for phenyloxirane(94.8%).Moreover,radiation time,quantity of oxidant and recycle times were investigated to investigate their effects on the catalytic performance.
Here we report a novel preparation method of Mn(Salen)/Al-HMS catalysts through host-guest interaction between Mn(Salen) complex and mesoporous Al-HMS under microwave irradiation(MWI).FT-IR,DR UV-Vis and TG measurement results indicate that Mn(Salen) complex could be successfully immobilized on mesoporous Al-HMS.Styrene epoxidation with PhIO as oxidant was carried out to test the effect of the catalyst prepared with different preparation methods on the catalytic activity and selectivity.It was found that the catalyst of Mn(Salen)/Al-HMS-IP1 shows a good conversion of styrene(74.6%) and the best selectivity for phenyloxirane(94.8%).Moreover,radiation time,quantity of oxidant and recycle times were investigated to investigate their effects on the catalytic performance.
2006, 23(6): 651-654
Abstract:
With TiCl4 and urea as the raw materials,the mix-crystals of rutile and anatase TiO2 were prepared at 100℃ by means of microwave irradiation method.The effect of pH on the ratio of the nanometer TiO2 mix- crystal was discussed.The crystal structure was determined by XRD.TEM indicated that the TiO2 was spherical particles,and the average diameter of the particles was 15 nm.The photocatalytic experiment showed that the mix-crystal material had better photocatalytic activity than the singleness TiO2.The compound could completely degrade the blue dye in 50 min under the sunlight.
With TiCl4 and urea as the raw materials,the mix-crystals of rutile and anatase TiO2 were prepared at 100℃ by means of microwave irradiation method.The effect of pH on the ratio of the nanometer TiO2 mix- crystal was discussed.The crystal structure was determined by XRD.TEM indicated that the TiO2 was spherical particles,and the average diameter of the particles was 15 nm.The photocatalytic experiment showed that the mix-crystal material had better photocatalytic activity than the singleness TiO2.The compound could completely degrade the blue dye in 50 min under the sunlight.
2006, 23(6): 655-658
Abstract:
Nine N1-furanidin-2'-yl-N3-alkylsulphonylalkyl-5-fluorouracils were synthesized via the oxidations of N1-furanidin-2'-yl-N3-alkylthioalkyl-5-fluorouracils 2.The intermediates 2 were prepared by the reactions of N1-furanidin-2'-yl-N3-bromoalkyl-5-fluorouracil 1 with sodium alkylsulfide.The structures of the products were confirmed by means of 1H NMR,IR,MS and elemental analysis.The inhibitory activities of compounds 3 to A549,HCT-8 and Bel-7402 cancer cells were tested in vitro.
Nine N1-furanidin-2'-yl-N3-alkylsulphonylalkyl-5-fluorouracils were synthesized via the oxidations of N1-furanidin-2'-yl-N3-alkylthioalkyl-5-fluorouracils 2.The intermediates 2 were prepared by the reactions of N1-furanidin-2'-yl-N3-bromoalkyl-5-fluorouracil 1 with sodium alkylsulfide.The structures of the products were confirmed by means of 1H NMR,IR,MS and elemental analysis.The inhibitory activities of compounds 3 to A549,HCT-8 and Bel-7402 cancer cells were tested in vitro.
2006, 23(6): 659-662
Abstract:
In the solid-phase synthesis of oligosaccharides,1,2-isopropyl-5,6-dehydrate-α,d-furan glucose was linked to the carriers styrene-diphenyl ethylene with sizes of 100~200 nm by dimethyldichlorosilane coupling agent.The saccharide chains were prolonged by the linkage of 1,2-isopropyl-5,6-dehydrate-α,d-furan glucose.In principle,the epoxy of the glucose unit on the carrier could react with the hydroxyl of another 1,2-isopropyl-5,6-dehydrate-α,d-furan glucose to make the target oligosaccharide.The resulant oligosaccharides were deattached from the carrier by tetrabutylammonium fluoride(TBAF) buffered with acetic acid and their structure was confirmed based on the results of UV,FT-IR,NMR and MS.
In the solid-phase synthesis of oligosaccharides,1,2-isopropyl-5,6-dehydrate-α,d-furan glucose was linked to the carriers styrene-diphenyl ethylene with sizes of 100~200 nm by dimethyldichlorosilane coupling agent.The saccharide chains were prolonged by the linkage of 1,2-isopropyl-5,6-dehydrate-α,d-furan glucose.In principle,the epoxy of the glucose unit on the carrier could react with the hydroxyl of another 1,2-isopropyl-5,6-dehydrate-α,d-furan glucose to make the target oligosaccharide.The resulant oligosaccharides were deattached from the carrier by tetrabutylammonium fluoride(TBAF) buffered with acetic acid and their structure was confirmed based on the results of UV,FT-IR,NMR and MS.
2006, 23(6): 663-667
Abstract:
(PEO)8LiClO4-modified SiO2 composite polymer electrolyte was prepared by the reaction of Si(OC2H5)4 in (PEO)8LiClO4) matrix and simultaneous modification of SiO2 by silane-coupling agent KH560.The morphology and ionic conductivity of the polymer electrolytes were investigated by means of SEM,AFM,DSC and A.C.impedance spectroscopy.The results showed that the modified SiO2 particles with the sizes of 35 nm were dispered uniformly in PEO matrix.Compared with unmodified SiO2,the addition of modified SiO2 in (PEO)8LiClO4 polymer electrolyte effectively leads to higher enhancement in ionic conductivity.When mass ratio of SiO2 reaches 10%,a maximum conductivity of 4.8×10-5 S/cm could be achieved.
(PEO)8LiClO4-modified SiO2 composite polymer electrolyte was prepared by the reaction of Si(OC2H5)4 in (PEO)8LiClO4) matrix and simultaneous modification of SiO2 by silane-coupling agent KH560.The morphology and ionic conductivity of the polymer electrolytes were investigated by means of SEM,AFM,DSC and A.C.impedance spectroscopy.The results showed that the modified SiO2 particles with the sizes of 35 nm were dispered uniformly in PEO matrix.Compared with unmodified SiO2,the addition of modified SiO2 in (PEO)8LiClO4 polymer electrolyte effectively leads to higher enhancement in ionic conductivity.When mass ratio of SiO2 reaches 10%,a maximum conductivity of 4.8×10-5 S/cm could be achieved.
2006, 23(6): 668-671
Abstract:
DL-tryptophan was synthesizd by condensing gramine with hydantoin and subsequent hydrolyzation of 5-(3-indole-methyl)hydantoin intermediate.The yield of DL-tryptophan to gramine was up to 41.6%.The optimum conditions of condensation were: 10 h reaction time,1.2:0.8:1 molar ratio of CH3I to C2H5ONa to gramine,0.9:1 molar ratio of gramine to hydantoin.The optimum conditions of hydrolysis were: 1.5 mol/L NaOH,10 h hydrolysis time,0.2 mol/L 5-(3-indolemethyl)hydantoin,and 100℃ reaction temperature.
DL-tryptophan was synthesizd by condensing gramine with hydantoin and subsequent hydrolyzation of 5-(3-indole-methyl)hydantoin intermediate.The yield of DL-tryptophan to gramine was up to 41.6%.The optimum conditions of condensation were: 10 h reaction time,1.2:0.8:1 molar ratio of CH3I to C2H5ONa to gramine,0.9:1 molar ratio of gramine to hydantoin.The optimum conditions of hydrolysis were: 1.5 mol/L NaOH,10 h hydrolysis time,0.2 mol/L 5-(3-indolemethyl)hydantoin,and 100℃ reaction temperature.
2006, 23(6): 672-675
Abstract:
Vinylbenzene sulfonate(VBS) pillared hydrotalcite(VBS-HT) was obtained by the ion-exchange reaction of VBS with nitrate anion pillared HT(NO3-HT),which was previously prepared by a co-precipitation method.The polymerization of pillaring VBS was conducted.The structure of VBS pillared HT and its polymerization product were characterized by means of X-ray diffraction,infrared spectrum and elemental analysis.It was found that well pillaring of VBS in HT could be achieved via ion-exchange reaction,and the interlayer spacing increased from 0.90 nm for NO3-HT to 1.83 nm for VBS pillared HT.The interlayer spacing was further increased to 1.94 nm after VBS was polymerized in the interspace of HT.
Vinylbenzene sulfonate(VBS) pillared hydrotalcite(VBS-HT) was obtained by the ion-exchange reaction of VBS with nitrate anion pillared HT(NO3-HT),which was previously prepared by a co-precipitation method.The polymerization of pillaring VBS was conducted.The structure of VBS pillared HT and its polymerization product were characterized by means of X-ray diffraction,infrared spectrum and elemental analysis.It was found that well pillaring of VBS in HT could be achieved via ion-exchange reaction,and the interlayer spacing increased from 0.90 nm for NO3-HT to 1.83 nm for VBS pillared HT.The interlayer spacing was further increased to 1.94 nm after VBS was polymerized in the interspace of HT.
2006, 23(6): 676-681
Abstract:
The inhibition corrosion behavior of 2-amido(1-phenyl-3-butyl)-5-methyl-thiadiazole and 2-amido(1,4-diphenyl-3-butyl)-5-methyl-thiadiazole on A3 steel in 1 mol/L HCl solution was investigated by means of mass loss and AC impedance.It has been shown that the two inhibitors have good inhibition performance for A3 steel in 1 mol/L HCl solution with optimal concentration of 400 mg/L.And inhibition efficiency of 2-amido(1,4-diphenyl-3-butyl)-5-methyl-thiadiazole is better than that of 2-amido(1-phenyl-3-butyl)-5-methyl-thiadiazole.The adsorption processes are exothermic reactions and belongs to the physical adsorptions and the Langmuir isotherm is followed.
The inhibition corrosion behavior of 2-amido(1-phenyl-3-butyl)-5-methyl-thiadiazole and 2-amido(1,4-diphenyl-3-butyl)-5-methyl-thiadiazole on A3 steel in 1 mol/L HCl solution was investigated by means of mass loss and AC impedance.It has been shown that the two inhibitors have good inhibition performance for A3 steel in 1 mol/L HCl solution with optimal concentration of 400 mg/L.And inhibition efficiency of 2-amido(1,4-diphenyl-3-butyl)-5-methyl-thiadiazole is better than that of 2-amido(1-phenyl-3-butyl)-5-methyl-thiadiazole.The adsorption processes are exothermic reactions and belongs to the physical adsorptions and the Langmuir isotherm is followed.
2006, 23(11): 1185-1189
Abstract:
The adsorption of cadmium(Ⅱ) on the extracellular polymers of natural biofilm was investigated.The exopolysaccharide and extracellular protein were obtained from the extracellular polymers of superiority bacteria of natural biofilm cultivated in Changchun South Lake.The results show that both Langmuir and Freundlich isotherm equations could describe the thermodynamic adsorption processes of Cd2+ on the extracellular polymers,exopolysaccharide and extracellular protein.The existence of Pb2+ affects the adsorption of Cd2+ while pH affect the adsorption processes.The mechanism of Cd2+ adsorption was studied by means of infrared spectra and the functional groups participated in the adsorption were identified.These groups could be acetylamino group(-NHCOCH3) and amino-group(-NH2)of protein,hydroxyl group(-OH) of exopolysaccharide,etc.The results show that the biosorption ability of the exopolysaccharide is much higher than that of the extracellular protein in the extracellular polymers
The adsorption of cadmium(Ⅱ) on the extracellular polymers of natural biofilm was investigated.The exopolysaccharide and extracellular protein were obtained from the extracellular polymers of superiority bacteria of natural biofilm cultivated in Changchun South Lake.The results show that both Langmuir and Freundlich isotherm equations could describe the thermodynamic adsorption processes of Cd2+ on the extracellular polymers,exopolysaccharide and extracellular protein.The existence of Pb2+ affects the adsorption of Cd2+ while pH affect the adsorption processes.The mechanism of Cd2+ adsorption was studied by means of infrared spectra and the functional groups participated in the adsorption were identified.These groups could be acetylamino group(-NHCOCH3) and amino-group(-NH2)of protein,hydroxyl group(-OH) of exopolysaccharide,etc.The results show that the biosorption ability of the exopolysaccharide is much higher than that of the extracellular protein in the extracellular polymers
2006, 23(11): 1190-1194
Abstract:
In an attempt to find novel herbicidal compounds,a series of pyrimidiny(thio) ether derivatives was synthesized by nucleophilic substitution of the chlorine at the 4-and 2-positions of 2,4-dichloropyrimidine in turn.The structures of the title compounds were confirmed by elemental analysis,1H NMR and X-ray diffraction methods.The preliminary bioassay results indicate that some of them have herbicidal activity to a certain degree.For example,compounds 7c,7j,7k and 7m exhibit excellent activities against Rape at a dosage of 1×10-4 g/mL(inhibitory ratio 80%).
In an attempt to find novel herbicidal compounds,a series of pyrimidiny(thio) ether derivatives was synthesized by nucleophilic substitution of the chlorine at the 4-and 2-positions of 2,4-dichloropyrimidine in turn.The structures of the title compounds were confirmed by elemental analysis,1H NMR and X-ray diffraction methods.The preliminary bioassay results indicate that some of them have herbicidal activity to a certain degree.For example,compounds 7c,7j,7k and 7m exhibit excellent activities against Rape at a dosage of 1×10-4 g/mL(inhibitory ratio 80%).
2006, 23(11): 1195-1199
Abstract:
Four chiral P,N-ligands were synthesized in high yields from natural cinchona alkaloids under mild conditions.Their Ir,Rh,Ru complexes were applied as asymmetric catalysts in asymmetric transfer hydroge-nation.The results show that high chemical yields(up to 95%) and moderate ee could be obtained(up to 75.3%).
Four chiral P,N-ligands were synthesized in high yields from natural cinchona alkaloids under mild conditions.Their Ir,Rh,Ru complexes were applied as asymmetric catalysts in asymmetric transfer hydroge-nation.The results show that high chemical yields(up to 95%) and moderate ee could be obtained(up to 75.3%).
2006, 23(11): 1200-1203
Abstract:
Seven novel N-(4,6-disubstitutedpyrimidin-2-yl)-2-(2,4-dichlorophenoxy) propionamides were synthesized through coupling of 2,4-dichlorophenoxypropionyl chloride with 4,6-disubstituted-2-amino-pyrimidine.All these compounds were characterized by 1H NMR,IR,MS and elemental analysis.The preliminary herbicidal tests showed that most of the compounds possessed inhibitory activity against selected weeds in a concentration of 100 mg/L.Among these compounds,6c exhibited 70%,85%,95% inhibitory rates against root growth of Echinochloa crusgallis L.,Sorghum bicolort,Digitaria sanguinalis(L.) scop(monocotyledon plant),and 98%,80%,80% inhibitory rates against root growth of Amaranthus retroflexus L.,Cucumis Sativus L.,Brassica campestris L.(dicotyledon plant).The title compounds also showed selective inhibitory activities against root and stalk growth for monocotyledon plant.In addition,95% inhibitory rate was observed for compound 6c against root and stalk growth of Amaranthus retroflexus L.and Digitaria sanguinalis(L.) Scop. and for compound 6f against root and stalk growth of Amaranthus retroflexus L. indicating their potential as candidates for herbicide application.
Seven novel N-(4,6-disubstitutedpyrimidin-2-yl)-2-(2,4-dichlorophenoxy) propionamides were synthesized through coupling of 2,4-dichlorophenoxypropionyl chloride with 4,6-disubstituted-2-amino-pyrimidine.All these compounds were characterized by 1H NMR,IR,MS and elemental analysis.The preliminary herbicidal tests showed that most of the compounds possessed inhibitory activity against selected weeds in a concentration of 100 mg/L.Among these compounds,6c exhibited 70%,85%,95% inhibitory rates against root growth of Echinochloa crusgallis L.,Sorghum bicolort,Digitaria sanguinalis(L.) scop(monocotyledon plant),and 98%,80%,80% inhibitory rates against root growth of Amaranthus retroflexus L.,Cucumis Sativus L.,Brassica campestris L.(dicotyledon plant).The title compounds also showed selective inhibitory activities against root and stalk growth for monocotyledon plant.In addition,95% inhibitory rate was observed for compound 6c against root and stalk growth of Amaranthus retroflexus L.and Digitaria sanguinalis(L.) Scop. and for compound 6f against root and stalk growth of Amaranthus retroflexus L. indicating their potential as candidates for herbicide application.
2006, 23(11): 1204-1208
Abstract:
A new AB2monomer,2-(3,5-diaminobenzamido)benzoic acid,was synthesized from 3,5-dinitrobenzoyl chloride and o-aminobenzoic acid.A hyperbranched aromatic polyamide(a) was prepared from this new monomer by self-polycondensation,and seven hyperbranched polymers(b~h) with various end-groups were also prepared by end-capping reactions with acid chlorides.These polymers were characterized by(FT-IR),1H NMR,GPC and DSC.Through the modification of the end-groups,the solubilities of the polymers synthesized were improved. The Mw's of polymers b~h were between 3.36 kg/mol and 3.96 kg/mol,the ηinh's of polymers a~h were between 0.061 dL/g and 0.078 dL/g,and the Tgs were between 56℃ and 185℃.The longer the aliphatic chain of the capping agent,the lower the Tg of the polymer;the higher the polarity of the capping agent,the higher the Tg of the polymer.
A new AB2monomer,2-(3,5-diaminobenzamido)benzoic acid,was synthesized from 3,5-dinitrobenzoyl chloride and o-aminobenzoic acid.A hyperbranched aromatic polyamide(a) was prepared from this new monomer by self-polycondensation,and seven hyperbranched polymers(b~h) with various end-groups were also prepared by end-capping reactions with acid chlorides.These polymers were characterized by(FT-IR),1H NMR,GPC and DSC.Through the modification of the end-groups,the solubilities of the polymers synthesized were improved. The Mw's of polymers b~h were between 3.36 kg/mol and 3.96 kg/mol,the ηinh's of polymers a~h were between 0.061 dL/g and 0.078 dL/g,and the Tgs were between 56℃ and 185℃.The longer the aliphatic chain of the capping agent,the lower the Tg of the polymer;the higher the polarity of the capping agent,the higher the Tg of the polymer.
2006, 23(11): 1209-1213
Abstract:
By employing Al-Ferron timed complexation colorimetry,Alb polymer from polyaluminum chloride (PAC) prepared by the partial alkalization of an AlCl3 solution varied with solution temperature, slaking time and basicity was investigated in detail.The results show that increasing slaking temperature or time could lead to the decrease of Alb content.Especially,when the temperature was higher than 80℃,it was disadvantageous to stabilize Alb polymer,which quickly decreased after slaking at 100℃ for 3 h.Because of the influences of the dual factors,the distribution of Al species in solution was subjected to the alkalization equilibrium of polyaluminum ions and unstable Alb polymer,the clear liquid containing as high as 83.19% Alb could be obtained through slaking treatment for 3 h at 80℃ from the PAC sample of B=80% prepared and aged at room temperature.For the PAC samples prepared by means of dropping alkali slowly at room temperature,the change extent of mass fraction of their Alb polymer could maximally reach 67.15% under different aging or slaking conditions.It was indicated by XRD and SEM that the crystallinity of the samples at room temperature were relatively high among the precipitates formed by the reaction of polyaluminum ions and sulfate radical,and that the tetrahedron crystal of Al13 could be prepared.After samples were processed at high temperature,their sulfate precipitates got gelatinous modality.
By employing Al-Ferron timed complexation colorimetry,Alb polymer from polyaluminum chloride (PAC) prepared by the partial alkalization of an AlCl3 solution varied with solution temperature, slaking time and basicity was investigated in detail.The results show that increasing slaking temperature or time could lead to the decrease of Alb content.Especially,when the temperature was higher than 80℃,it was disadvantageous to stabilize Alb polymer,which quickly decreased after slaking at 100℃ for 3 h.Because of the influences of the dual factors,the distribution of Al species in solution was subjected to the alkalization equilibrium of polyaluminum ions and unstable Alb polymer,the clear liquid containing as high as 83.19% Alb could be obtained through slaking treatment for 3 h at 80℃ from the PAC sample of B=80% prepared and aged at room temperature.For the PAC samples prepared by means of dropping alkali slowly at room temperature,the change extent of mass fraction of their Alb polymer could maximally reach 67.15% under different aging or slaking conditions.It was indicated by XRD and SEM that the crystallinity of the samples at room temperature were relatively high among the precipitates formed by the reaction of polyaluminum ions and sulfate radical,and that the tetrahedron crystal of Al13 could be prepared.After samples were processed at high temperature,their sulfate precipitates got gelatinous modality.
2006, 23(11): 1214-1217
Abstract:
Poly(L-isoleucine) modified glassy carbon electrode was successfully was prepared.The electrochemical behavior of dopamine studied at the poly(L-isoleucine) modified electrode and a cyclic voltammetric determination method for dopamine has been set up.In pH=7.5 phosphate buffer solution,a couple of redox peaks was observed by cyclic sweeping between -0.4 V and 0.6 V at 250 mV/s with the peak potential Epa=0.206 V and Epc=0.104 V(vs Ag/AgCl),respectively.The peak current is proportional to the concentration of dopamine,the linear range for the determination of dopamine is from 1.0×10-8 to 5.0×10-4 mol/L.The detection limit is 5.0×10-9 mol/L.The relative standard deviation is 3.2%(n=9,5.0×10-5 mol/L dopamine).The method was applied to the determination of dopamine in medicine with satisfactory results.
Poly(L-isoleucine) modified glassy carbon electrode was successfully was prepared.The electrochemical behavior of dopamine studied at the poly(L-isoleucine) modified electrode and a cyclic voltammetric determination method for dopamine has been set up.In pH=7.5 phosphate buffer solution,a couple of redox peaks was observed by cyclic sweeping between -0.4 V and 0.6 V at 250 mV/s with the peak potential Epa=0.206 V and Epc=0.104 V(vs Ag/AgCl),respectively.The peak current is proportional to the concentration of dopamine,the linear range for the determination of dopamine is from 1.0×10-8 to 5.0×10-4 mol/L.The detection limit is 5.0×10-9 mol/L.The relative standard deviation is 3.2%(n=9,5.0×10-5 mol/L dopamine).The method was applied to the determination of dopamine in medicine with satisfactory results.
2006, 23(11): 1218-1222
Abstract:
TiO2/AC(ω(AC)=5%) composite photocatalysts prepared via TiCl4 hydrolysis method were calcinate at different temperatures.XRD,DRS,FTIR,SEM and N2 adsorption isotherm were used for crystal structure,spectral characteristics and surface properties measurement.Phenol was used as a probe compound for the photocatalytic activity test.Effect of activated carbon modification on the structure chracteristics and photocatalytic activity of TiO2 photocatalyst was investigated.The results show that TiO2/AC exhibits a higher activity than TiO2 within a wide range of calcination temperatures.AC was beneficial to TiO2 size control and phase transformation retardment.
TiO2/AC(ω(AC)=5%) composite photocatalysts prepared via TiCl4 hydrolysis method were calcinate at different temperatures.XRD,DRS,FTIR,SEM and N2 adsorption isotherm were used for crystal structure,spectral characteristics and surface properties measurement.Phenol was used as a probe compound for the photocatalytic activity test.Effect of activated carbon modification on the structure chracteristics and photocatalytic activity of TiO2 photocatalyst was investigated.The results show that TiO2/AC exhibits a higher activity than TiO2 within a wide range of calcination temperatures.AC was beneficial to TiO2 size control and phase transformation retardment.
2006, 23(11): 1223-1227
Abstract:
The colloidal carbon nano-spheres synthesized by means of the hydrothermal method were used as support and reductant to synthesize Nano-Pd/C material.This Nano-Pd/C material could be used as catalyst in the synthese of 5,6-diamino-1,10-phenanthroline and its catalytic activity was studied systematically.The experiment results show that the Nano-Pd/C catalyst can decrease the reaction time from 12 h to 6 h while increase the yield from 83% to 90%.
The colloidal carbon nano-spheres synthesized by means of the hydrothermal method were used as support and reductant to synthesize Nano-Pd/C material.This Nano-Pd/C material could be used as catalyst in the synthese of 5,6-diamino-1,10-phenanthroline and its catalytic activity was studied systematically.The experiment results show that the Nano-Pd/C catalyst can decrease the reaction time from 12 h to 6 h while increase the yield from 83% to 90%.
2006, 23(11): 1228-1232
Abstract:
The homopolymer of benzyl L-glutamate was prepared through ring opening polymerization of N-carboxy-α-amino acid anhydride(NCA) and the mechanism of the polymerization of NCA was discussed.The product was characterized by IR spectroscopy and differential scanning calorimetry(DSC).The effect of temperature and time on the molecular weight of the poly(γ-benzyl-L-glutamate) was studied.With the increase of treatment time,the molecular weight of the product increased linearly.THF was used to prepare the film.The density of PBLG was 1.098 g/cm3.The influence of immersion time on the water absorption ratio was discussed.The result suggests that the water absorption ratio of PBLG increased with time,from 2.64% to 5.58%.The water absorption ratio tended to be stable within 48 h.Under identical conditions,the water absorption at the interface was likely to be much higher than those at other parts.
The homopolymer of benzyl L-glutamate was prepared through ring opening polymerization of N-carboxy-α-amino acid anhydride(NCA) and the mechanism of the polymerization of NCA was discussed.The product was characterized by IR spectroscopy and differential scanning calorimetry(DSC).The effect of temperature and time on the molecular weight of the poly(γ-benzyl-L-glutamate) was studied.With the increase of treatment time,the molecular weight of the product increased linearly.THF was used to prepare the film.The density of PBLG was 1.098 g/cm3.The influence of immersion time on the water absorption ratio was discussed.The result suggests that the water absorption ratio of PBLG increased with time,from 2.64% to 5.58%.The water absorption ratio tended to be stable within 48 h.Under identical conditions,the water absorption at the interface was likely to be much higher than those at other parts.
2006, 23(11): 1233-1236
Abstract:
A new chiral quaternary ammonium salt 1a was synthesized by the reaction of cinchonine and 2,4,6-trimethyl benzyl chloride.Etherification between 1a and benzyl bromide,allyl chloride,or methyl iodide give corresponding etherified quaternary ammonium salts 1b,1c,and 1d.In the presence of 1b,1c,or 1d(5%,molar fraction),chalcone was stereoselectively epoxidized by sodium hypochlorite with yields range from 89% to 92% and ee range from 58% to 63%.
A new chiral quaternary ammonium salt 1a was synthesized by the reaction of cinchonine and 2,4,6-trimethyl benzyl chloride.Etherification between 1a and benzyl bromide,allyl chloride,or methyl iodide give corresponding etherified quaternary ammonium salts 1b,1c,and 1d.In the presence of 1b,1c,or 1d(5%,molar fraction),chalcone was stereoselectively epoxidized by sodium hypochlorite with yields range from 89% to 92% and ee range from 58% to 63%.
2006, 23(11): 1237-1242
Abstract:
Novel polymer films comprising of epoxidized natural rubber(ENR) and styrene butadiene rubber(SBR) were prepared by means of phase-inversion.Thermogravimetric(TG) analysis indicated that the polymer films possessed good thermal stability with a decomposition temperature higher than 300℃.Scanning electron microscopy(SEM) and atomic force microscopy(AFM) techniques were used to evaluate the microstructure.Gel polymer electrolytes(GPEs) were prepared by dipping ENR/SBR based polymer films in 1 mol/L LiClO4/(propylene carbonate(PC))/(ethylene carbonate(EC)) liquid electrolyte solutions with V(PC):V(EC) being 1:1.Mechanical strength of the GPEs with V(ENR):V(SBR) being 1:1 and ENR at different epoxidized numbers(20%,40% and 60%) reach 184,397,and 243 kg/cm2,respectively.Electrochemical properties were investigated systematically via AC impedance and Liner Sweep Voltammetry(LSV).The results show that GPE prepared with 40%ENR had the highest conductivity of 1.9×10-3 S/cm and a broad electrochemical stability window of 4.7 V at room temperature.Additionally,excellent interfacial stability between GPE and lithium electrode was obtained.
Novel polymer films comprising of epoxidized natural rubber(ENR) and styrene butadiene rubber(SBR) were prepared by means of phase-inversion.Thermogravimetric(TG) analysis indicated that the polymer films possessed good thermal stability with a decomposition temperature higher than 300℃.Scanning electron microscopy(SEM) and atomic force microscopy(AFM) techniques were used to evaluate the microstructure.Gel polymer electrolytes(GPEs) were prepared by dipping ENR/SBR based polymer films in 1 mol/L LiClO4/(propylene carbonate(PC))/(ethylene carbonate(EC)) liquid electrolyte solutions with V(PC):V(EC) being 1:1.Mechanical strength of the GPEs with V(ENR):V(SBR) being 1:1 and ENR at different epoxidized numbers(20%,40% and 60%) reach 184,397,and 243 kg/cm2,respectively.Electrochemical properties were investigated systematically via AC impedance and Liner Sweep Voltammetry(LSV).The results show that GPE prepared with 40%ENR had the highest conductivity of 1.9×10-3 S/cm and a broad electrochemical stability window of 4.7 V at room temperature.Additionally,excellent interfacial stability between GPE and lithium electrode was obtained.
2006, 23(11): 1243-1248
Abstract:
Self-crosslinking copolymers based on 2-(N-propylperfluorooctanesulfoamido) ethyl acrylate(FA),methyl methacrylate(MMA),n-butyl acrylate(n-BA) and sodium 2-acrylamide-2-methyl propanesulfonate(AMPSNa) were synthesized via soap-free emulsion polymerization with vinyl triethoxysilane(VTES) as a crosslinking agent.The structure and surface morphology of the copolymers were characterized by FT-IR,NMR,DSC and SPM,respectively.Further studies focused on the influence of cross-linking on the physical properties of perfluorinated acrylate copolymers.It was found that the water-and solvent-resistance properites were dramatically improved with increase of the extent of cross-linking.With VTES amount increasing,the values of the contact angle for water and oil first increased and then decreased,and the contact angle hysteresis was alleviated.The surface free energy of the FA copolymer films decreased from 27.2 mN/m to about 14.8 mN/m after cross-linking.
Self-crosslinking copolymers based on 2-(N-propylperfluorooctanesulfoamido) ethyl acrylate(FA),methyl methacrylate(MMA),n-butyl acrylate(n-BA) and sodium 2-acrylamide-2-methyl propanesulfonate(AMPSNa) were synthesized via soap-free emulsion polymerization with vinyl triethoxysilane(VTES) as a crosslinking agent.The structure and surface morphology of the copolymers were characterized by FT-IR,NMR,DSC and SPM,respectively.Further studies focused on the influence of cross-linking on the physical properties of perfluorinated acrylate copolymers.It was found that the water-and solvent-resistance properites were dramatically improved with increase of the extent of cross-linking.With VTES amount increasing,the values of the contact angle for water and oil first increased and then decreased,and the contact angle hysteresis was alleviated.The surface free energy of the FA copolymer films decreased from 27.2 mN/m to about 14.8 mN/m after cross-linking.
2006, 23(11): 1249-1252
Abstract:
Adipic acid was synthesized by WO3-catalyzed oxidation of cyclohexanone with 30% hydrogen peroxide in the absence of organic solvent and phase-transfer catalyst.The influence of reaction conditions such as catalyst amount,hydrogen peroxide amount,reaction temperature and time on the oxidation was investigated.Under the optimal conditions,i.e.when n(cyclohexanone):n(hydrogen peroxide):n(tungsten trioxide) was 100:500:2,and the reaction temperature was 120℃,the reaction time was 6 h,the isolated yield of adipic acid could reach 80.3% and its purity was 99.8%.The catalyst could be reused for 5 times and the isolated yield of adipic acid was still above 70.2%.
Adipic acid was synthesized by WO3-catalyzed oxidation of cyclohexanone with 30% hydrogen peroxide in the absence of organic solvent and phase-transfer catalyst.The influence of reaction conditions such as catalyst amount,hydrogen peroxide amount,reaction temperature and time on the oxidation was investigated.Under the optimal conditions,i.e.when n(cyclohexanone):n(hydrogen peroxide):n(tungsten trioxide) was 100:500:2,and the reaction temperature was 120℃,the reaction time was 6 h,the isolated yield of adipic acid could reach 80.3% and its purity was 99.8%.The catalyst could be reused for 5 times and the isolated yield of adipic acid was still above 70.2%.
2006, 23(11): 1253-1258
Abstract:
A new solid complex of rare earth Eu(Ⅲ) with N-acetyl-DL-alanine(C5H9NO3,Ac-Ala) and imidazole(C3H4N2,Im) was synthesized and characterized by means of chemical and elemental analyses,FTIR,UV,1H NMR,13C NMR and XRD.The composition of the complex was confirmed to be Eu(C5H8NO3)2(C3H5N2)2Cl3·3H2O.The thermal decomposition of the complex was studied via TG-DTG curve.By means of the Achar method and the Coats-Redfern method,the non-isothermal kinetic data of the dehydration stage of the complex was analyzed.The most probable reaction mechanism was suggested by comparing the kinetic parameters.The kinetic equation for the dehydration stage could be expressed as dα/dt=A/β·e-E/RT{(1-α)[-ln(1-α)]-1/2}.Luminescence measurement showed that the complex emits fluorescence.
A new solid complex of rare earth Eu(Ⅲ) with N-acetyl-DL-alanine(C5H9NO3,Ac-Ala) and imidazole(C3H4N2,Im) was synthesized and characterized by means of chemical and elemental analyses,FTIR,UV,1H NMR,13C NMR and XRD.The composition of the complex was confirmed to be Eu(C5H8NO3)2(C3H5N2)2Cl3·3H2O.The thermal decomposition of the complex was studied via TG-DTG curve.By means of the Achar method and the Coats-Redfern method,the non-isothermal kinetic data of the dehydration stage of the complex was analyzed.The most probable reaction mechanism was suggested by comparing the kinetic parameters.The kinetic equation for the dehydration stage could be expressed as dα/dt=A/β·e-E/RT{(1-α)[-ln(1-α)]-1/2}.Luminescence measurement showed that the complex emits fluorescence.
2006, 23(11): 1259-1263
Abstract:
The viscosity of dilute alginate solution as a function of Ca2+ concentration was studied by viscosity measurement.The effect of polymer concentration,temperature and NaCl on the viscosity was investigated.The results show that for 0.125% and 0.15% alginate solutions,the viscosities firstly declined to certain minimum values with increasing the amount of Ca2+ added,and then rapidly rised until gel occurred;for a 0.075% alginate solution,the viscosity slightly changed as the amount of Ca2+ increased;In ηrel~1/T had a good linearity in the temperature range of 15~35℃;the viscosity decreased as NaCl was added.Thermal stability and the structure of calcium alginate complex were analyzed by means of DSC and FTIR.
The viscosity of dilute alginate solution as a function of Ca2+ concentration was studied by viscosity measurement.The effect of polymer concentration,temperature and NaCl on the viscosity was investigated.The results show that for 0.125% and 0.15% alginate solutions,the viscosities firstly declined to certain minimum values with increasing the amount of Ca2+ added,and then rapidly rised until gel occurred;for a 0.075% alginate solution,the viscosity slightly changed as the amount of Ca2+ increased;In ηrel~1/T had a good linearity in the temperature range of 15~35℃;the viscosity decreased as NaCl was added.Thermal stability and the structure of calcium alginate complex were analyzed by means of DSC and FTIR.
2006, 23(11): 1264-1268
Abstract:
10-Methacryloyloxydecyl-2-thiouracil-5-carboxylate was synthesized from the reaction of thiouracil with diethyl ethoxymethylene malonate and ω-hydroxy-decyl-methacrylate.The structure of the product was characterized by 1H NMR,MS and FT-IR,and the effect of this product on the bond durability between composite resin with Au alloy,Ti alloy or Co-Cr alloy was evaluated.The product significantly elevated the bonding strength between composite resin and Au alloy,and the shear strength was 22.4 MPa when the mass fraction of this product was 0.5%.But this product could not enhance the bonding strength of the composite resin with Ti alloy and Co-Cr alloy;the shear strength was 12.1 MPa,13.7 MPa respectively.
10-Methacryloyloxydecyl-2-thiouracil-5-carboxylate was synthesized from the reaction of thiouracil with diethyl ethoxymethylene malonate and ω-hydroxy-decyl-methacrylate.The structure of the product was characterized by 1H NMR,MS and FT-IR,and the effect of this product on the bond durability between composite resin with Au alloy,Ti alloy or Co-Cr alloy was evaluated.The product significantly elevated the bonding strength between composite resin and Au alloy,and the shear strength was 22.4 MPa when the mass fraction of this product was 0.5%.But this product could not enhance the bonding strength of the composite resin with Ti alloy and Co-Cr alloy;the shear strength was 12.1 MPa,13.7 MPa respectively.
2006, 23(11): 1269-1272
Abstract:
The influence of β-nucleating agent(N,N'-dicyclohexylterephthalicamide) on the mechanical and crystallization characteristics of polypropylene(PP) was studied.The β-nucleating agent displayed an outstanding effect on increasing the PP toughness.The impact strength rised from 36.09 J/m2 to 65.79 J/m2 by adding 0.3% β-nucleating agent.DSC showed that the addition of a small amount of the β-nucleating agent to PP induced a rather high proportion of β modification.The effect of cooling rate on the peak crystallization temperature and the crystallinity was also studied.When the cooling rate was 10℃/min,the peak temperature increased from 118.38℃ to 124.53℃.Nucleated PP showed a higher crystallization temperature and a faster crystallization rate.
The influence of β-nucleating agent(N,N'-dicyclohexylterephthalicamide) on the mechanical and crystallization characteristics of polypropylene(PP) was studied.The β-nucleating agent displayed an outstanding effect on increasing the PP toughness.The impact strength rised from 36.09 J/m2 to 65.79 J/m2 by adding 0.3% β-nucleating agent.DSC showed that the addition of a small amount of the β-nucleating agent to PP induced a rather high proportion of β modification.The effect of cooling rate on the peak crystallization temperature and the crystallinity was also studied.When the cooling rate was 10℃/min,the peak temperature increased from 118.38℃ to 124.53℃.Nucleated PP showed a higher crystallization temperature and a faster crystallization rate.
2006, 23(11): 1273-1277
Abstract:
Two new organotin compounds have been synthesized and characterized by means of IR,1H NMR and elemental analysis.They were used as efficient Lewis acid catalysts for esterification reactions of carbo-xylic acids with alcohols to afford corresponding saturated esters with 87%~98% yields and unsaturated and tertiary ones with 90%~94% and 54%~68% yields,respectively.The catalysts could be easily filtrated from the reaction mixture and reused.
Two new organotin compounds have been synthesized and characterized by means of IR,1H NMR and elemental analysis.They were used as efficient Lewis acid catalysts for esterification reactions of carbo-xylic acids with alcohols to afford corresponding saturated esters with 87%~98% yields and unsaturated and tertiary ones with 90%~94% and 54%~68% yields,respectively.The catalysts could be easily filtrated from the reaction mixture and reused.
2006, 23(11): 1278-1281
Abstract:
Magnetic photocatalyst(Ag-TiO2/ZnO/γ-Fe2O3) was prepared by photoreducing Ag(Ⅰ)-EDTA to Ag metal on TiO2 surface with magnetite ZnO/γ-Fe2O3 as a matrix.The photocatalysts were characterized by means of XRD,EDX and TEM,respectively.The photocatalysis of the catalyst was tested with methylene blue as decomposition substance.The influence of the presence of ZnO and Ag content on the photocatalytic activity was investigated.The results show that 0.5%(mass fraction)Ag-TiO2/ZnO/γFe2Osub>3 (14:3:3) had the highest photocatalytic activity and its photocatalytic activity remained good even after three cycles.
Magnetic photocatalyst(Ag-TiO2/ZnO/γ-Fe2O3) was prepared by photoreducing Ag(Ⅰ)-EDTA to Ag metal on TiO2 surface with magnetite ZnO/γ-Fe2O3 as a matrix.The photocatalysts were characterized by means of XRD,EDX and TEM,respectively.The photocatalysis of the catalyst was tested with methylene blue as decomposition substance.The influence of the presence of ZnO and Ag content on the photocatalytic activity was investigated.The results show that 0.5%(mass fraction)Ag-TiO2/ZnO/γFe2Osub>3 (14:3:3) had the highest photocatalytic activity and its photocatalytic activity remained good even after three cycles.
2006, 23(11): 1282-1285
Abstract:
A novel acidic ionic liquid,[Hmim] HSO4,was prepared and used as solvent and catalyst in the esterification of acetic acid and alcohols.The esterification products could be easily separated in high yield from the reaction system via simple phase separation.The acidic ionic liquid phase after removal of water could be reused.The effect of reaction conditions on product yield for the esterification between acetic acid and n-Butanol was studied.Butyl acetate with a yield of 97% was obtained under optimal conditions.The acidic ionic liquid HSO4 was recycled 5 times and the yield of butyl acetate did not decrease remarkably.The structure of the acidic ionic liquid [Hmim] HSO4 was characterized by 1H NMR,IR,and elemental analysis,and it was found that HSO4 existed as monohydrate.Acidity determination of aquoes solutions of [Hmim] HSO4 showed that [Hmim] HSO4 possessed stronger acidity than CF3COO.
A novel acidic ionic liquid,[Hmim] HSO4,was prepared and used as solvent and catalyst in the esterification of acetic acid and alcohols.The esterification products could be easily separated in high yield from the reaction system via simple phase separation.The acidic ionic liquid phase after removal of water could be reused.The effect of reaction conditions on product yield for the esterification between acetic acid and n-Butanol was studied.Butyl acetate with a yield of 97% was obtained under optimal conditions.The acidic ionic liquid HSO4 was recycled 5 times and the yield of butyl acetate did not decrease remarkably.The structure of the acidic ionic liquid [Hmim] HSO4 was characterized by 1H NMR,IR,and elemental analysis,and it was found that HSO4 existed as monohydrate.Acidity determination of aquoes solutions of [Hmim] HSO4 showed that [Hmim] HSO4 possessed stronger acidity than CF3COO.
2006, 23(11): 1286-1290
Abstract:
Reaction of a resin PADC containing N,O,and S multifunctional groups with a PdCl2 solution produced a newtype of PADC-Pd catalyst,and its structure was confirmed with XPS,TG,and DTA.Thermal analysis showsed that the catalyst is stable at up to 280℃.PADC-Pd is an efficient catalyst and Heck arylations of acrylic acid or styrene with iodoarenes can be performed in the presence of a small amount of the catalyst in air,and substituted trans-cinnamic acid or trans-stilbene can be obtained.In the presence of PADC-Pd,Heck arylation of acrylic acid with iodobenzene could be carried out efficiently at a low temperature(85℃) and the yield was 95%,which indicated the high catalytic activity of PADC-Pd.The catalyst could be used repeatedly for 8 cycles after simple washing,and the yield was up to 81% at the 6th cycle.But the catalytic activity decreased with the cycle,which was probably due to leaching of palladium into the solvent.
Reaction of a resin PADC containing N,O,and S multifunctional groups with a PdCl2 solution produced a newtype of PADC-Pd catalyst,and its structure was confirmed with XPS,TG,and DTA.Thermal analysis showsed that the catalyst is stable at up to 280℃.PADC-Pd is an efficient catalyst and Heck arylations of acrylic acid or styrene with iodoarenes can be performed in the presence of a small amount of the catalyst in air,and substituted trans-cinnamic acid or trans-stilbene can be obtained.In the presence of PADC-Pd,Heck arylation of acrylic acid with iodobenzene could be carried out efficiently at a low temperature(85℃) and the yield was 95%,which indicated the high catalytic activity of PADC-Pd.The catalyst could be used repeatedly for 8 cycles after simple washing,and the yield was up to 81% at the 6th cycle.But the catalytic activity decreased with the cycle,which was probably due to leaching of palladium into the solvent.
2006, 23(11): 1291-1294
Abstract:
Mesoporous molecular sieves containing aluminum ions(Al-MCM-41) with Si/Al ratio of 30 were used to support 20% calcium metaborate (Ca(BO2)2) by microwave irradiation method.The samples,Ca(BO2)2/Al-MCM-41 were characterized by powder X-ray diffraction(XRD),nitrogen adsorption measurement(BET),Fourier transform infra red spectroscopy(FT-IR).The XRD patterns show that the Ca(BO2)2 was dispersed uniformly on Al-MCM-41 and the material,Ca(BO2)2/Al-MCM-41,had the indigenous Al-MCM-41 structure and ordered pore distribution.Ca(BO2)2/Al-MCM-41 samples were used as catalysts in the ethyloxylation of n-octyl alcohol.The results show that Ca(BO2)2/Al-MCM-41 has higher catalytic activity than Al-MCM-41 and Ca(BO2)2.The reaction was carried out at 140℃ in the presence of 5% catalyst with respect to the octanol.The homologue distribution of the ethoxylates was determined by means of GC and MS techniques,which showed the homologue distribution of octanolpolyoxyethylene ethers was narrowed for Ca(BO2)2/Al-MCM-41 catalyzed ethoxylation,and the selectivity coefficient(Cs) was 17.9.
Mesoporous molecular sieves containing aluminum ions(Al-MCM-41) with Si/Al ratio of 30 were used to support 20% calcium metaborate (Ca(BO2)2) by microwave irradiation method.The samples,Ca(BO2)2/Al-MCM-41 were characterized by powder X-ray diffraction(XRD),nitrogen adsorption measurement(BET),Fourier transform infra red spectroscopy(FT-IR).The XRD patterns show that the Ca(BO2)2 was dispersed uniformly on Al-MCM-41 and the material,Ca(BO2)2/Al-MCM-41,had the indigenous Al-MCM-41 structure and ordered pore distribution.Ca(BO2)2/Al-MCM-41 samples were used as catalysts in the ethyloxylation of n-octyl alcohol.The results show that Ca(BO2)2/Al-MCM-41 has higher catalytic activity than Al-MCM-41 and Ca(BO2)2.The reaction was carried out at 140℃ in the presence of 5% catalyst with respect to the octanol.The homologue distribution of the ethoxylates was determined by means of GC and MS techniques,which showed the homologue distribution of octanolpolyoxyethylene ethers was narrowed for Ca(BO2)2/Al-MCM-41 catalyzed ethoxylation,and the selectivity coefficient(Cs) was 17.9.
2006, 23(6): 682-684
Abstract:
NiO nanoparticles were successfully prepared by solid state thermal decomposition of NiCO3 (10 nm) precursor,which was synthesized by solid state reaction at room temperature.The crystal structure,particle-size and properties of the nanoparticles were characterized by means of XRD,TEM TG-DTA and BET.The results show that the NiO had an average particle size of 5.8 nm and highest BET specific surface area of 116.6 m2/g after annealling the precursor at 300℃ for 2 h.The formation mechanism of the nanoparticles were also discussed.
NiO nanoparticles were successfully prepared by solid state thermal decomposition of NiCO3 (10 nm) precursor,which was synthesized by solid state reaction at room temperature.The crystal structure,particle-size and properties of the nanoparticles were characterized by means of XRD,TEM TG-DTA and BET.The results show that the NiO had an average particle size of 5.8 nm and highest BET specific surface area of 116.6 m2/g after annealling the precursor at 300℃ for 2 h.The formation mechanism of the nanoparticles were also discussed.
2006, 23(6): 685-687
Abstract:
Based on the one-carbon unit transfer reaction of tetrahydrofolate coenzymes,α-naphthyl cyclo-hexyl ketone was synthesized successfully with benzoimidazolium salt as the tetrahydrofolate coenzyme model at formic acid oxidation level and Grignard reagent as a nucleophile to which one carbon unit was transferred via addition-hydrolysis reaction.This provides a new convenient biomimetic synthesis method to the title compound.The α-naphthyl cyclohexyl ketone was characterized by means of IR spectra,MS and 1H NMR.The reaction mechanism and the effects of reaction conditions on the yield were investigated.
Based on the one-carbon unit transfer reaction of tetrahydrofolate coenzymes,α-naphthyl cyclo-hexyl ketone was synthesized successfully with benzoimidazolium salt as the tetrahydrofolate coenzyme model at formic acid oxidation level and Grignard reagent as a nucleophile to which one carbon unit was transferred via addition-hydrolysis reaction.This provides a new convenient biomimetic synthesis method to the title compound.The α-naphthyl cyclohexyl ketone was characterized by means of IR spectra,MS and 1H NMR.The reaction mechanism and the effects of reaction conditions on the yield were investigated.
Catalytic Asymmetric Epoxidation of Styrene with Chiral Mn(Ⅲ) Salen as Catalyst and NaOCl as Oxidant
2006, 23(6): 688-690
Abstract:
A new chiral Mn(Ⅲ) Salen complex was synthesized and characterized by FT-IR and elemental analysis.The complex was used as catalyst for enantioselective epoxidation of styrene with NaOCl as oxidant in the presence of axial base.The effects of pH value,solvents and axial bases on the asymmetric epoxidation of styrene were investigated.Conversion of styrene and ee of the epoxides could reach 100% and 42% respectively when the reaction was run at 0℃,the catalyst loading is 0.1 mmol,and pH value of 1.0 mmol 4-PPNO in buffered CH2Cl2 is 11.30.
A new chiral Mn(Ⅲ) Salen complex was synthesized and characterized by FT-IR and elemental analysis.The complex was used as catalyst for enantioselective epoxidation of styrene with NaOCl as oxidant in the presence of axial base.The effects of pH value,solvents and axial bases on the asymmetric epoxidation of styrene were investigated.Conversion of styrene and ee of the epoxides could reach 100% and 42% respectively when the reaction was run at 0℃,the catalyst loading is 0.1 mmol,and pH value of 1.0 mmol 4-PPNO in buffered CH2Cl2 is 11.30.
2006, 23(6): 691-693
Abstract:
New calix[4]arene poly(aza) derivatives 3,4 and bis-calix[4]arene 5 containing azo-groups,amido groups and Schiff-base groups were synthesized in yields of 87%,89%,84%,respectively.Their structures were confirmed by 1H NMR,ESI-MS and elemental analysis.Liquid-liquid extraction experiments showed they possessed excellent extraction capabilities for cations and their extraction percentages were higher than those of similar calix[4]arene derivatives containing amido and Schiff-base groups.
New calix[4]arene poly(aza) derivatives 3,4 and bis-calix[4]arene 5 containing azo-groups,amido groups and Schiff-base groups were synthesized in yields of 87%,89%,84%,respectively.Their structures were confirmed by 1H NMR,ESI-MS and elemental analysis.Liquid-liquid extraction experiments showed they possessed excellent extraction capabilities for cations and their extraction percentages were higher than those of similar calix[4]arene derivatives containing amido and Schiff-base groups.
2006, 23(6): 694-696
Abstract:
A narrow distribution low molecular weight chitosan(LMWCTS) was prepared by the oxide degradation system adjusted with trace amount of zinc sulfate.Fluorescence probe was used to investigate the polarity of micro-area of this degradation system,IR and GPC were utilized for measuring the physic-chemical properties of these LMWCTS samples.The system with 3.8 mmol ZnSO4 had a narrow distribution of LMWCTS (Mw=973,d=1.1) and the yield of LMWCTS was 85%.Those primary structure units of the chitosan have not been altered after degradation.
A narrow distribution low molecular weight chitosan(LMWCTS) was prepared by the oxide degradation system adjusted with trace amount of zinc sulfate.Fluorescence probe was used to investigate the polarity of micro-area of this degradation system,IR and GPC were utilized for measuring the physic-chemical properties of these LMWCTS samples.The system with 3.8 mmol ZnSO4 had a narrow distribution of LMWCTS (Mw=973,d=1.1) and the yield of LMWCTS was 85%.Those primary structure units of the chitosan have not been altered after degradation.
2006, 23(11): 1295-1297
Abstract:
The catalysts of rare earth(Ⅲ) perfluorooctanesulfonates (RE(OPf)3,RE=Sc,Y,La~Lu) were prepared and the synthesis of acetals(ketal) via condensation of aromatic aldehydes with diols catalyzed by RE(OPf)3 in fluorous solvents was investigated.Perfluorohexane(C6F14),perfluoromethylcyclohexane(C7F14),perfluorotoluene(C7F8),perfluorooctane(C8F18),perfluorooctyl bromide(C8F17Br) and per-fluorodecalin (C10F18,cis and trans-mixture) can be used as fluorous solvent for the reaction.The results show that Yb(OPf)3 and C10F18 were the best catalyst and fluorous solvent respectively.The yield of the condensation of benzaldehyde with ethylene glycol was 83% by using Yb(OPf)3 as the catalyst and C10F18 as the fluorous solvent.By simple phase-separation,the fluorous phase containing only catalyst could be re-utilized up to five times with a slight decrease in yield from 83% to 81%.
The catalysts of rare earth(Ⅲ) perfluorooctanesulfonates (RE(OPf)3,RE=Sc,Y,La~Lu) were prepared and the synthesis of acetals(ketal) via condensation of aromatic aldehydes with diols catalyzed by RE(OPf)3 in fluorous solvents was investigated.Perfluorohexane(C6F14),perfluoromethylcyclohexane(C7F14),perfluorotoluene(C7F8),perfluorooctane(C8F18),perfluorooctyl bromide(C8F17Br) and per-fluorodecalin (C10F18,cis and trans-mixture) can be used as fluorous solvent for the reaction.The results show that Yb(OPf)3 and C10F18 were the best catalyst and fluorous solvent respectively.The yield of the condensation of benzaldehyde with ethylene glycol was 83% by using Yb(OPf)3 as the catalyst and C10F18 as the fluorous solvent.By simple phase-separation,the fluorous phase containing only catalyst could be re-utilized up to five times with a slight decrease in yield from 83% to 81%.
2006, 23(11): 1298-1300
Abstract:
A novel flow injection chemiluminescence(FI-CL) system for the determination of isoprocarb is presented.It was based on the chemiluminescence reaction of sodium hydrosulfite with Ce(Ⅳ) in a vitriol acid solution.The emission intensity can be obviously enhanced by isoprocarb.The proposed method is very sensitive,simple and quick.The enhanced value of chemiluminescence intensity was proportional to isoprocarb concentration in the range of 0.1~10 mg/L(r=0.999 7).The detection limit was 80 μg/L and the relative standard deviation was 3.3% for 1.0 mg/L isoprocarb(n=11).This method was successfully applied to the determination of isoprocarb in rice and water.The recovery was 96.1%~99.4%.
A novel flow injection chemiluminescence(FI-CL) system for the determination of isoprocarb is presented.It was based on the chemiluminescence reaction of sodium hydrosulfite with Ce(Ⅳ) in a vitriol acid solution.The emission intensity can be obviously enhanced by isoprocarb.The proposed method is very sensitive,simple and quick.The enhanced value of chemiluminescence intensity was proportional to isoprocarb concentration in the range of 0.1~10 mg/L(r=0.999 7).The detection limit was 80 μg/L and the relative standard deviation was 3.3% for 1.0 mg/L isoprocarb(n=11).This method was successfully applied to the determination of isoprocarb in rice and water.The recovery was 96.1%~99.4%.
2006, 23(11): 1301-1303
Abstract:
Carbon black/vapor-grown carbon fibres/poly(butyl methacrylate)(CB/VGCF/PBMA) conductive composite was fabricated by polymerization filling.Conducting property and electrical resistance responsivity of the composite in saturated organic vapors were investigated.The experimental results indicate that 1%(mass fraction) of VGCF was able to decrease the electrical resistivity of the composite from 1 040 Ω·cm to 195 Ω·cm,probably due to an additional percolation process.Adding small amount of VGCF into the composites notably decrease the negative vapor coefficient(NVC) intensity of the composites from 15.6 to 2.2.
Carbon black/vapor-grown carbon fibres/poly(butyl methacrylate)(CB/VGCF/PBMA) conductive composite was fabricated by polymerization filling.Conducting property and electrical resistance responsivity of the composite in saturated organic vapors were investigated.The experimental results indicate that 1%(mass fraction) of VGCF was able to decrease the electrical resistivity of the composite from 1 040 Ω·cm to 195 Ω·cm,probably due to an additional percolation process.Adding small amount of VGCF into the composites notably decrease the negative vapor coefficient(NVC) intensity of the composites from 15.6 to 2.2.
2006, 23(11): 1304-1306
Abstract:
After extraction with hot water for several times,the leaf mustard was dried and then a polysaccharide named ALP-2 was isolated from the dried leaf mustard with dilute alkali extraction,alcohol precipitation,and DEAE-Sepharose FF column chromatography.ALP-2 was identified by means of cellulose acetate film electrophoresis and HPLC to be a homogeneous polysaccharide,a non-starch polysaccharide without any protein and nucleic acid.Its average molecular weight was 459 750.The analysis by virtue of HPLC after its complete hydrolysis by acid showed that ALP-2 mainly consisted of rhamnose, arabinose,glucose,galactose,and a unknown monosaccharide.
After extraction with hot water for several times,the leaf mustard was dried and then a polysaccharide named ALP-2 was isolated from the dried leaf mustard with dilute alkali extraction,alcohol precipitation,and DEAE-Sepharose FF column chromatography.ALP-2 was identified by means of cellulose acetate film electrophoresis and HPLC to be a homogeneous polysaccharide,a non-starch polysaccharide without any protein and nucleic acid.Its average molecular weight was 459 750.The analysis by virtue of HPLC after its complete hydrolysis by acid showed that ALP-2 mainly consisted of rhamnose, arabinose,glucose,galactose,and a unknown monosaccharide.
2006, 23(11): 1307-1308
Abstract:
Biphenyl was produced by direct oxidative coupling of benzene via activation of the(C-H) bond in the presence of palladium acetate as the catalyst and potassium persulfate as the oxidant in trifluoroacetic acid at room temperature.Effect of catalyst,oxidant,and acid etc.on this reaction was investigated.
Biphenyl was produced by direct oxidative coupling of benzene via activation of the(C-H) bond in the presence of palladium acetate as the catalyst and potassium persulfate as the oxidant in trifluoroacetic acid at room temperature.Effect of catalyst,oxidant,and acid etc.on this reaction was investigated.
