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2005 Volume 22 Issue 1
2005, 22(1): 1-4
Abstract:
A method for the evaluation of the autoignition hazard from organic peroxides is proposed based on the calculation of the self-accelerating decomposition temperature(SADT) via the experiment by means of a C80Ⅱ microcalorimeter. The chemical kinetic parameters of some organic peroxides were calculated using heat flux data measured by virtue of the C80 microcalorimeter, and their SADTs were obtained based on the Semenov model. The SADTs estimated from the C80 data are in good agreement with the US-TEST results.
A method for the evaluation of the autoignition hazard from organic peroxides is proposed based on the calculation of the self-accelerating decomposition temperature(SADT) via the experiment by means of a C80Ⅱ microcalorimeter. The chemical kinetic parameters of some organic peroxides were calculated using heat flux data measured by virtue of the C80 microcalorimeter, and their SADTs were obtained based on the Semenov model. The SADTs estimated from the C80 data are in good agreement with the US-TEST results.
2005, 22(1): 5-8
Abstract:
By blending chitosan(CTS) with polyvinyl alcohol(PVA) and crosslinking them with glutaraldehyde, a modified chitosan pervaporation membrane with better selectivity and higher permeation flux was prepared. The effects of methodology of membrane formation, pervaporation temperature and the composition of feed solution on the separation performance for tert-butyl alcohol(TBA)-water mixtures were examined in com parison with the polyvinyl alcohol/polyacrylonitrile composite membranes. Experimental results show that the modified chitosan composite membrane displayed the best separation factor of 3 500 and the total flux was 132 g/(m2·h) when the pervaporation temperature was 343 K and the amount of TBA in feed solution was in the range of 80% to 92%.
By blending chitosan(CTS) with polyvinyl alcohol(PVA) and crosslinking them with glutaraldehyde, a modified chitosan pervaporation membrane with better selectivity and higher permeation flux was prepared. The effects of methodology of membrane formation, pervaporation temperature and the composition of feed solution on the separation performance for tert-butyl alcohol(TBA)-water mixtures were examined in com parison with the polyvinyl alcohol/polyacrylonitrile composite membranes. Experimental results show that the modified chitosan composite membrane displayed the best separation factor of 3 500 and the total flux was 132 g/(m2·h) when the pervaporation temperature was 343 K and the amount of TBA in feed solution was in the range of 80% to 92%.
2005, 22(1): 9-13
Abstract:
The renaturation of polyphenol oxidase from Tobacco denatured in 6.0 mol/L guanidine hydrochloride(GdnHCl) was investigated. In the absence of additives(s), the optimal renaturation conditions, with 63.36% of activity recovered, are as follows:1.5 mol/L GdnHCl, denaturation time 30 min, renaturation temperature 4℃ and enzyme concentration 1.5×10-4 g/mL. 1.0 mol/L (NH4)2SO4 showed a limited effect on the recovering of PPO activity. Using both 1.0 mol/L (NH4)2SO4 and 100 μmol/L CuSO4 was the most effective method, and the renaturation system with both CTAB and β-CD together showed a more favorable effect on the enzyme renaturation, than that with the single β-CD.
The renaturation of polyphenol oxidase from Tobacco denatured in 6.0 mol/L guanidine hydrochloride(GdnHCl) was investigated. In the absence of additives(s), the optimal renaturation conditions, with 63.36% of activity recovered, are as follows:1.5 mol/L GdnHCl, denaturation time 30 min, renaturation temperature 4℃ and enzyme concentration 1.5×10-4 g/mL. 1.0 mol/L (NH4)2SO4 showed a limited effect on the recovering of PPO activity. Using both 1.0 mol/L (NH4)2SO4 and 100 μmol/L CuSO4 was the most effective method, and the renaturation system with both CTAB and β-CD together showed a more favorable effect on the enzyme renaturation, than that with the single β-CD.
2005, 22(1): 14-18
Abstract:
A series of liquid crystals containing naphthalene 1~13 was synthesized by the reaction of carbonyl compound with Grignard reagent and coupling reaction between phenyl boronic acid and halogen naphthalene. The yields of the compounds were from 7.3% to 75.9%. The structure of the compounds were identified by IR, 1H NMR, 13C NMR, MS and their phase transition behavior was measured by DSC. The isomerization mechanism of cyclohexane derivatives under base catalysis is briefly discussed.
A series of liquid crystals containing naphthalene 1~13 was synthesized by the reaction of carbonyl compound with Grignard reagent and coupling reaction between phenyl boronic acid and halogen naphthalene. The yields of the compounds were from 7.3% to 75.9%. The structure of the compounds were identified by IR, 1H NMR, 13C NMR, MS and their phase transition behavior was measured by DSC. The isomerization mechanism of cyclohexane derivatives under base catalysis is briefly discussed.
2005, 22(1): 19-23
Abstract:
Four nano heteropolymolybdovanadophosphates H3MPMo10V2O40·xH2O(M=Co2+,Ni2+,Cu2+,Zn2+) were synthesized by solid-state reaction at room temperature. The catalytic activity of the nano heteropoly compound catalysts for the hydroxylation of benzene to phenol with H2O2 and the effects of reaction conditions were studied. The experimental results show that the yield of phenol was over 50% and the selectivity for phenol was over 98% under the optimum conditions, i.e.,H2O2/C6H6 (molar ratio)=1.5 C6H6/catalyst(mass ratio)=25, reaction time 2 h, temperature 70℃. The four nano catalysts exhibited high activity for the hydroxylation of benzene to phenol.
Four nano heteropolymolybdovanadophosphates H3MPMo10V2O40·xH2O(M=Co2+,Ni2+,Cu2+,Zn2+) were synthesized by solid-state reaction at room temperature. The catalytic activity of the nano heteropoly compound catalysts for the hydroxylation of benzene to phenol with H2O2 and the effects of reaction conditions were studied. The experimental results show that the yield of phenol was over 50% and the selectivity for phenol was over 98% under the optimum conditions, i.e.,H2O2/C6H6 (molar ratio)=1.5 C6H6/catalyst(mass ratio)=25, reaction time 2 h, temperature 70℃. The four nano catalysts exhibited high activity for the hydroxylation of benzene to phenol.
2005, 22(1): 24-29
Abstract:
Macroporous hypercrosslinked resin(Rf18) was synthesized from styrene and decorated by loading methyiamine(Rs3), N-methylacetamido(Rs4), dimethylamine(Rs5) and trimethylamine(Rs6) respectively. The adsorption and chromatographic separation of camptothecin and Vincoside-Lactam(VCS-LT) by the synthesized resins were compared. Their adsorption capacity and adsorption selectivity for camptothecin and vincoside-lactam were found to be remarkably increased. For quaternary ammonium resin(Rs6), the separation impact(αc/v) was 114. Camptothecin and vincoside-lactam could be effectively separated with resins Rf18 (Rs3, Rs5). But camptothecin could not be washed out from Rs6 with organic solvent, it could be easily washed out with acidic solution of 80% ethanol-water(pH=4).
Macroporous hypercrosslinked resin(Rf18) was synthesized from styrene and decorated by loading methyiamine(Rs3), N-methylacetamido(Rs4), dimethylamine(Rs5) and trimethylamine(Rs6) respectively. The adsorption and chromatographic separation of camptothecin and Vincoside-Lactam(VCS-LT) by the synthesized resins were compared. Their adsorption capacity and adsorption selectivity for camptothecin and vincoside-lactam were found to be remarkably increased. For quaternary ammonium resin(Rs6), the separation impact(αc/v) was 114. Camptothecin and vincoside-lactam could be effectively separated with resins Rf18 (Rs3, Rs5). But camptothecin could not be washed out from Rs6 with organic solvent, it could be easily washed out with acidic solution of 80% ethanol-water(pH=4).
2005, 22(1): 30-34
Abstract:
The life of each of Pd/C catalysts prepared at different temperatures was tested on a continuous gas-solid fixed bed reactor at 145℃. The results show that the deactivation rates of catalysts were speeded up with increasing the preparation temperature. When the as-prepared and used catalysts were characterized by XRD and DTA, it was found that carbonaceous deposit was the main factor of the deactivation of catalysts. As the preparation temperature increased, the rates of the carbonaceous deposits were speeded up due to the formation of big active particles of metal. During the preparations of catalysts and the hydrodechlorination reaction, the supports of catalysts were apparently hydrogenated. With the preparation temperature increasing, the burning temperature of the supports of Pd/C catalysts lowered from 610~625℃ of pure supports to about 589℃. When the preparation temperature was over 450℃, a new burning peak of the supports appeared at about 530℃. The degree of hydrogenations of supports was greater with the reaction time increasing. The burning peaks of all the supports appeared at 490~500℃ after deactivation of catalysts. And the hydrogenation degrees were related to the deactivation of catalysts.
The life of each of Pd/C catalysts prepared at different temperatures was tested on a continuous gas-solid fixed bed reactor at 145℃. The results show that the deactivation rates of catalysts were speeded up with increasing the preparation temperature. When the as-prepared and used catalysts were characterized by XRD and DTA, it was found that carbonaceous deposit was the main factor of the deactivation of catalysts. As the preparation temperature increased, the rates of the carbonaceous deposits were speeded up due to the formation of big active particles of metal. During the preparations of catalysts and the hydrodechlorination reaction, the supports of catalysts were apparently hydrogenated. With the preparation temperature increasing, the burning temperature of the supports of Pd/C catalysts lowered from 610~625℃ of pure supports to about 589℃. When the preparation temperature was over 450℃, a new burning peak of the supports appeared at about 530℃. The degree of hydrogenations of supports was greater with the reaction time increasing. The burning peaks of all the supports appeared at 490~500℃ after deactivation of catalysts. And the hydrogenation degrees were related to the deactivation of catalysts.
2005, 22(1): 35-39
Abstract:
Three iron materials, low-carbon steel, high-carbon steel and gray cast iron were used respectively as the anode in the electrolysis production of ferrate(Ⅵ). The results show that their current efficiencies were remarkably different with the carbon content, the gray cast iron showed the highest FeO42- current efficiency. An intermittent negative square wave pulsed on the anode was capable of effectively improving the oxide film elimination on the anode surface, with distinct increase of current efficiency. The removal rate of CODCr was more than 85% when the freshly produced ferrate(Ⅵ) via electrolysis was used to degrade sodium dodecyl benzene sulfonate (SDBS) which was in a synthetic waste-water sample.
Three iron materials, low-carbon steel, high-carbon steel and gray cast iron were used respectively as the anode in the electrolysis production of ferrate(Ⅵ). The results show that their current efficiencies were remarkably different with the carbon content, the gray cast iron showed the highest FeO42- current efficiency. An intermittent negative square wave pulsed on the anode was capable of effectively improving the oxide film elimination on the anode surface, with distinct increase of current efficiency. The removal rate of CODCr was more than 85% when the freshly produced ferrate(Ⅵ) via electrolysis was used to degrade sodium dodecyl benzene sulfonate (SDBS) which was in a synthetic waste-water sample.
2005, 22(1): 40-44
Abstract:
Eight title compounds were synthesized in yields of 43.2%~56.5% by chlorination of 1-methoxynaphthalene in CF3COOH/CH3COOH mixtures(volume ratio,1:9) at 25℃ with Cl- as chlorine source, O2 and catalytic amount of NO+ BF4- as the oxidant. Their structures were confirmed by virtue of elemental analysis, IR, 1H NMR and MS. The plant growth regulating activities of the compounds were examined. Most of the compounds have a remarkable plant growth regulating activity, for compounds 6f and 6h the inhibiting activities are -20.3%(6f) and -15.3%(6h) respectively on wheat coleoptile at the concentration of 0.1 g/L, and promoting activities 2.58%(6f) and 2.04%(6h) at the concentration of 0.01 g/L. The inhibition rates of compounds 6a~6h on wheat coleoptile are increased compared with those of 1 hydroxyalkanephosphonic esters (5a~5h) by 2.3%~4.5%, and promotion rates are also increased by 0.24%~0.58%. Chlorine in naphthalene ring appears in favor of improving biological activity of these compounds.
Eight title compounds were synthesized in yields of 43.2%~56.5% by chlorination of 1-methoxynaphthalene in CF3COOH/CH3COOH mixtures(volume ratio,1:9) at 25℃ with Cl- as chlorine source, O2 and catalytic amount of NO+ BF4- as the oxidant. Their structures were confirmed by virtue of elemental analysis, IR, 1H NMR and MS. The plant growth regulating activities of the compounds were examined. Most of the compounds have a remarkable plant growth regulating activity, for compounds 6f and 6h the inhibiting activities are -20.3%(6f) and -15.3%(6h) respectively on wheat coleoptile at the concentration of 0.1 g/L, and promoting activities 2.58%(6f) and 2.04%(6h) at the concentration of 0.01 g/L. The inhibition rates of compounds 6a~6h on wheat coleoptile are increased compared with those of 1 hydroxyalkanephosphonic esters (5a~5h) by 2.3%~4.5%, and promotion rates are also increased by 0.24%~0.58%. Chlorine in naphthalene ring appears in favor of improving biological activity of these compounds.
2005, 22(1): 45-49
Abstract:
Supported catalysts for ethylene polymerization were prepared by the interaction of nickel diimine complex (C6H5-N=C(CH3)C(CH3)=N-C6H5)NiCl2 with MgCl2(THF)2, silica and their bisupport,and branched polyethylenes were obtained with AlEt2Cl as cocatalyst. Supports and polymerization temperature have pronounced effects on catalytic activity of the catalysts and the properties of polyethylene products. The highest catalytic activity of 2.5×105 g/(mol·h) was obtained at 14℃ over MgCl2/SiO2 bisupport, and the branching degree of polyethylene product was 1.7%. 13C NMR analysis reveals there are methyl, butyl and long branches at polyethylene backbone. Branching degree of the polyethylenes and the content of methyl branch rise quickly with reaction temperature, but the content of long branches drops remarkably. Particle size analysis reveals that the size of polymer microspheres presents a Gaussian distribution.
Supported catalysts for ethylene polymerization were prepared by the interaction of nickel diimine complex (C6H5-N=C(CH3)C(CH3)=N-C6H5)NiCl2 with MgCl2(THF)2, silica and their bisupport,and branched polyethylenes were obtained with AlEt2Cl as cocatalyst. Supports and polymerization temperature have pronounced effects on catalytic activity of the catalysts and the properties of polyethylene products. The highest catalytic activity of 2.5×105 g/(mol·h) was obtained at 14℃ over MgCl2/SiO2 bisupport, and the branching degree of polyethylene product was 1.7%. 13C NMR analysis reveals there are methyl, butyl and long branches at polyethylene backbone. Branching degree of the polyethylenes and the content of methyl branch rise quickly with reaction temperature, but the content of long branches drops remarkably. Particle size analysis reveals that the size of polymer microspheres presents a Gaussian distribution.
2005, 22(1): 50-54
Abstract:
Eight solanesyl derivatives including N-solanesylamides(5a~5d) and N-acyl-N'-solanesylpiperazines(6a~6d) were synthesized with solanesol as starting material and four commercial drugs as the sources of acyl groups. All the products were characterized by 1H NMR, IR, MS and elemental analyses. The inhibition activities of 5a~5d and 6a~6d to KB, Bel-7402, HCT-8 cells were biologically evaluated in vitro, the results show these compounds only have poor anti-tumor activity.
Eight solanesyl derivatives including N-solanesylamides(5a~5d) and N-acyl-N'-solanesylpiperazines(6a~6d) were synthesized with solanesol as starting material and four commercial drugs as the sources of acyl groups. All the products were characterized by 1H NMR, IR, MS and elemental analyses. The inhibition activities of 5a~5d and 6a~6d to KB, Bel-7402, HCT-8 cells were biologically evaluated in vitro, the results show these compounds only have poor anti-tumor activity.
2005, 22(1): 55-58
Abstract:
Thermal decomposition kinetics of glycine complexes with light rare earth bromides was studied under non-isothermal conditions by DSC technique. Their kinetic parameters(activation energy E, pre-expontial factor A) were obtained from the analysis of the DSC results by the Ozawa method, the Kissinger method, the Achar method and the Coats-Redfern method, respectively. The most probable kinetic functions of thermal decomposition for the first, the second and the fourth stages were suggested and their kinetic equations could be expressed as dα/dt=A/β·e-E/RT(1-α), dα/dt=A/β·e-E/RT(1-α)2 and dα/dt=A/β·e-E/RT(1-α)2, respectively.
Thermal decomposition kinetics of glycine complexes with light rare earth bromides was studied under non-isothermal conditions by DSC technique. Their kinetic parameters(activation energy E, pre-expontial factor A) were obtained from the analysis of the DSC results by the Ozawa method, the Kissinger method, the Achar method and the Coats-Redfern method, respectively. The most probable kinetic functions of thermal decomposition for the first, the second and the fourth stages were suggested and their kinetic equations could be expressed as dα/dt=A/β·e-E/RT(1-α), dα/dt=A/β·e-E/RT(1-α)2 and dα/dt=A/β·e-E/RT(1-α)2, respectively.
2005, 22(1): 59-62
Abstract:
Multi-walled carbon nanotubes(MWNTs) were oxidized and cut in a mixture of concentrated sulfuric and nitric acids under sonication to introduce carboxyl and hydroxyl groups onto MWNTs. TEM|resistance measurement and 1H NMR were used to study the effect of oxidation on the length|resistivity and the amount of hydrogen in the oxidized MWNTs. The results show that 10 h of oxidation may be the most favorite condition to shorten the carbon nanotubes and introduce enough functional groups with inherent properties of MWNTs being remained as much as possible.
Multi-walled carbon nanotubes(MWNTs) were oxidized and cut in a mixture of concentrated sulfuric and nitric acids under sonication to introduce carboxyl and hydroxyl groups onto MWNTs. TEM|resistance measurement and 1H NMR were used to study the effect of oxidation on the length|resistivity and the amount of hydrogen in the oxidized MWNTs. The results show that 10 h of oxidation may be the most favorite condition to shorten the carbon nanotubes and introduce enough functional groups with inherent properties of MWNTs being remained as much as possible.
2005, 22(1): 63-66
Abstract:
A "soft chemistry" method was adopted to prepare ultrafine particles of K2La2Ti3O10. The synthesis process was monitored by FT-IR analysis. The product obtained was characterized by means of XRD, TEM, BET surface area analysis and tested for its acid-exchanging property. Compared with the traditional solid-state method, the results show that this method lower the reaction temperature(from 1 100℃ to 800℃) and is time-saving (11 h to 2 h). K2La2Ti3O10 with the particle size from several micron to 350 nm×300 nm and BET surface area more than 11.83 m2/g could be obtained. It can be easily exfoliated in a 2 mol/L HNO3 solution, and the exfoliated monodisperse sheets could scroll to 20 nm×100 nm nanotubes automatically.
A "soft chemistry" method was adopted to prepare ultrafine particles of K2La2Ti3O10. The synthesis process was monitored by FT-IR analysis. The product obtained was characterized by means of XRD, TEM, BET surface area analysis and tested for its acid-exchanging property. Compared with the traditional solid-state method, the results show that this method lower the reaction temperature(from 1 100℃ to 800℃) and is time-saving (11 h to 2 h). K2La2Ti3O10 with the particle size from several micron to 350 nm×300 nm and BET surface area more than 11.83 m2/g could be obtained. It can be easily exfoliated in a 2 mol/L HNO3 solution, and the exfoliated monodisperse sheets could scroll to 20 nm×100 nm nanotubes automatically.
2005, 22(1): 67-70
Abstract:
A novel fluorenone derivative, fluorenone-4-(methoxy) benzaldehyde dihydrazon, which has optical limiting capability, was synthesized and characterized by IR, electronic spectra, elemental analysis, and single crystal X-ray diffraction analysis. The crystal determination results show the molecule has well planarity with high delocalization of π electrons in the system. Optical limiting capability of this compound was measured by means of the Z-scan technique. The result shows that this compound has good optical limiting to 532 nm wavelength light of Nd:YAG pumping laser. The two photon absorption cross-section σ is 3.96×10-46 cm4s/photon.
A novel fluorenone derivative, fluorenone-4-(methoxy) benzaldehyde dihydrazon, which has optical limiting capability, was synthesized and characterized by IR, electronic spectra, elemental analysis, and single crystal X-ray diffraction analysis. The crystal determination results show the molecule has well planarity with high delocalization of π electrons in the system. Optical limiting capability of this compound was measured by means of the Z-scan technique. The result shows that this compound has good optical limiting to 532 nm wavelength light of Nd:YAG pumping laser. The two photon absorption cross-section σ is 3.96×10-46 cm4s/photon.
2005, 22(1): 71-74
Abstract:
In the presence of phase-transfer catalyst tetrabutylammouium bromide and with the mixture of NaOH(or KOH) and K2CO3 powder as base, ethyl acetate as solvent, 2-[N-(tert-butoxycarbonyl)amino] thiophene, 2-[N-(tert-butoxycarbonyl)amino-5-methylthiophene and diethyl N-[5-[N-(tert-butoxycar-bonyl)amino]-2-thenoyl]-L-glutamate were conveniently N-alkylated with different alkyl halides in yields of 70%~97%. The structures of the products were confirmed by IR，ESI-MS，1H NMR and elemental analysis. The method has the advantages of mild reaction condition, short reaction time and high yield.
In the presence of phase-transfer catalyst tetrabutylammouium bromide and with the mixture of NaOH(or KOH) and K2CO3 powder as base, ethyl acetate as solvent, 2-[N-(tert-butoxycarbonyl)amino] thiophene, 2-[N-(tert-butoxycarbonyl)amino-5-methylthiophene and diethyl N-[5-[N-(tert-butoxycar-bonyl)amino]-2-thenoyl]-L-glutamate were conveniently N-alkylated with different alkyl halides in yields of 70%~97%. The structures of the products were confirmed by IR，ESI-MS，1H NMR and elemental analysis. The method has the advantages of mild reaction condition, short reaction time and high yield.
2005, 22(1): 75-78
Abstract:
2-Fluoroindolizines and 2-fluoro-benzo[d]indolizines 4 were synthesized in yields of 50%~70% via a 1,3-dipolar reaction of fluorinated vinyl tosylate 2 with N-ylides of pyridinium or isoquinolinium for 24 h in the presence of K2CO3 and Et3N in DMF. Their structures were confirmed by 1H NMR, 19F NMR, IR, MS and elemental analyses. A reaction mechanism is proposed.
2-Fluoroindolizines and 2-fluoro-benzo[d]indolizines 4 were synthesized in yields of 50%~70% via a 1,3-dipolar reaction of fluorinated vinyl tosylate 2 with N-ylides of pyridinium or isoquinolinium for 24 h in the presence of K2CO3 and Et3N in DMF. Their structures were confirmed by 1H NMR, 19F NMR, IR, MS and elemental analyses. A reaction mechanism is proposed.
2005, 22(1): 79-82
Abstract:
The thermal properties of four siloxane-acrylate copolymer microemulsions film were investigated by thermal methods as the function of siloxane content, presence of MMA and curing time. The results show that the difference of four siloxanes only slightly affects the Tg of the films when the siloxane content is 2%, but the Tg decreases with the increase of siloxane content. The residues of the films by heating at 400℃ increase from 0.16% to 9.67% with the change of the mass fraction of siloxane from 0 to 15%. Maximum decomposition temperature has increased by 56.7℃ when 3% MAA(mass fraction) is present in the copolymerization process, which indicates that carboxyl monomer greatly enhances the thermal stability of the films.
The thermal properties of four siloxane-acrylate copolymer microemulsions film were investigated by thermal methods as the function of siloxane content, presence of MMA and curing time. The results show that the difference of four siloxanes only slightly affects the Tg of the films when the siloxane content is 2%, but the Tg decreases with the increase of siloxane content. The residues of the films by heating at 400℃ increase from 0.16% to 9.67% with the change of the mass fraction of siloxane from 0 to 15%. Maximum decomposition temperature has increased by 56.7℃ when 3% MAA(mass fraction) is present in the copolymerization process, which indicates that carboxyl monomer greatly enhances the thermal stability of the films.
2005, 22(1): 83-86
Abstract:
Molecularly imprinted polymers(MIPs) of sulfamethazine(SM2) were prepared with silica gel as a sacrificial material, methacrylic acid(MAA) and 4-vinylpyridine(4-Vp) as functional monomers, glycol dimethacrylate(EDMA) as crosslinker. The polymer properties were investigated by static adsorption experiments. Scatchard analysis shows that the adsorption ability of MAA-MIP is superior to that of 4-Vp-MIP. The dissociation constant of MAA-MIP is 9.59×10-4 mol/L. The value of apparent binding ability is 307.0 μmol/g.
Molecularly imprinted polymers(MIPs) of sulfamethazine(SM2) were prepared with silica gel as a sacrificial material, methacrylic acid(MAA) and 4-vinylpyridine(4-Vp) as functional monomers, glycol dimethacrylate(EDMA) as crosslinker. The polymer properties were investigated by static adsorption experiments. Scatchard analysis shows that the adsorption ability of MAA-MIP is superior to that of 4-Vp-MIP. The dissociation constant of MAA-MIP is 9.59×10-4 mol/L. The value of apparent binding ability is 307.0 μmol/g.
2005, 22(1): 87-90
Abstract:
The composite powder of fibrous hydroxyapatite(HAP)/amorphous chitosan(CS) was prepared by the homogeneous coprecipitation with urea as the precipitant and characterised by XRD, SEM, IR and chemical composition (n(Ca)/n(P)). The n(Ca)/n(P) and phase structure of the powder were found to be affected by the pH value of the system during coprecipitation with urea. The inorganic phase of the composite powder predominately consisted of hydroxyapatite when its n(Ca)/n(P) was 1.64, the urea concentration was 1.0 mol/L and the pH value of system was 7.2. The inorganic phase of the composite powder in part is consisted of calcium phosphate dibasic(DCPA) when its n(Ca)/n(P) was 1.42, the urea concenration was 0.5 mol/L and the pH value of system was 6.1. Compared with mechanically mixed HAP/CS powders, the composite powders had new wave peaks at 1 654 cm-1 and 1 560 cm-1 in the IR spectrum.
The composite powder of fibrous hydroxyapatite(HAP)/amorphous chitosan(CS) was prepared by the homogeneous coprecipitation with urea as the precipitant and characterised by XRD, SEM, IR and chemical composition (n(Ca)/n(P)). The n(Ca)/n(P) and phase structure of the powder were found to be affected by the pH value of the system during coprecipitation with urea. The inorganic phase of the composite powder predominately consisted of hydroxyapatite when its n(Ca)/n(P) was 1.64, the urea concentration was 1.0 mol/L and the pH value of system was 7.2. The inorganic phase of the composite powder in part is consisted of calcium phosphate dibasic(DCPA) when its n(Ca)/n(P) was 1.42, the urea concenration was 0.5 mol/L and the pH value of system was 6.1. Compared with mechanically mixed HAP/CS powders, the composite powders had new wave peaks at 1 654 cm-1 and 1 560 cm-1 in the IR spectrum.
2005, 22(1): 91-94
Abstract:
Two DIAR couplers were synthesized with 2-(isopropylamino)-benzenethiol as timing group, which was synthesized from benzothiazole and triphosgene used as a substitute of phosgene, and good result was obtained. The structures of the two DIAR couplers were characterized by 1H NMR, elemental analysis, and mass spectrometry. Good interlayer effect was obtained in practical application.
Two DIAR couplers were synthesized with 2-(isopropylamino)-benzenethiol as timing group, which was synthesized from benzothiazole and triphosgene used as a substitute of phosgene, and good result was obtained. The structures of the two DIAR couplers were characterized by 1H NMR, elemental analysis, and mass spectrometry. Good interlayer effect was obtained in practical application.
2005, 22(1): 95-98
Abstract:
A simple, convenient and efficient procedure for synthesis of 1,1-diamino-2,2-dinitroethylene(FOX-7) was described. Nitrations of 2-methylimidazole at ambient temperature affords 2-(dinitromethylene)-5,5-dinitro-4-imidazolidinone(compound 1), which reacts with water to give FOX-7. The key step was ring cleavage of compound 1 by addition of water to the reaction mixture or vice versa. By this means the synthetic pathway of 2-methylimidazole to FOX-7 could be achieved in a continuous process. The overall yield was 35.8%. The structure of FOX-7 was characterized by IR, MS, NMR and elemental analysis.
A simple, convenient and efficient procedure for synthesis of 1,1-diamino-2,2-dinitroethylene(FOX-7) was described. Nitrations of 2-methylimidazole at ambient temperature affords 2-(dinitromethylene)-5,5-dinitro-4-imidazolidinone(compound 1), which reacts with water to give FOX-7. The key step was ring cleavage of compound 1 by addition of water to the reaction mixture or vice versa. By this means the synthetic pathway of 2-methylimidazole to FOX-7 could be achieved in a continuous process. The overall yield was 35.8%. The structure of FOX-7 was characterized by IR, MS, NMR and elemental analysis.
2005, 22(1): 99-102
Abstract:
The electrochemical performances of zinc electrodes were investigated as the functions of ZnO size and mass fraction of Zn to ZnO in 6.0 mol/L KOH solutions. The peak shapes and peak current in the CV curves were found differed for zinc electrodes with different compositions at a scan rate of 1 mV/s. The zinc electrode containing 50%(mass fraction) ZnO nanoparticles exhibited better electrochemical behavior due to better distribution of the electroactive species on the surface of the electrode, and improvement of the electrode structure in favor of the transfer of reaction particles and ionic charges compared with the zinc electrode containing common ZnO. The discharge capacities of the zinc electrode containing 50% ZnO nanoparticles were 220 mA·h/g and 198 mA·h/g at 25th and 30th charge-discharge cycles, respectively.
The electrochemical performances of zinc electrodes were investigated as the functions of ZnO size and mass fraction of Zn to ZnO in 6.0 mol/L KOH solutions. The peak shapes and peak current in the CV curves were found differed for zinc electrodes with different compositions at a scan rate of 1 mV/s. The zinc electrode containing 50%(mass fraction) ZnO nanoparticles exhibited better electrochemical behavior due to better distribution of the electroactive species on the surface of the electrode, and improvement of the electrode structure in favor of the transfer of reaction particles and ionic charges compared with the zinc electrode containing common ZnO. The discharge capacities of the zinc electrode containing 50% ZnO nanoparticles were 220 mA·h/g and 198 mA·h/g at 25th and 30th charge-discharge cycles, respectively.
2005, 22(1): 103-104
Abstract:
phenanthroline(1) was oxidized by a mixture of concentrated sulfuric acid and concentrated nitric acid in the presence of sodium bromide to yield 1,10-phenanthroline-5,6-dione(2) in 90%. Compound 2 gave a mono-oxime(3) hydrochloric salt in nearly quantitive amount by reacting with equal molar hydroxylamine hydrochloride. The structures of the compounds were characterized by IR and 1H NMR spectroscopy. The method is more simple and efficient.
phenanthroline(1) was oxidized by a mixture of concentrated sulfuric acid and concentrated nitric acid in the presence of sodium bromide to yield 1,10-phenanthroline-5,6-dione(2) in 90%. Compound 2 gave a mono-oxime(3) hydrochloric salt in nearly quantitive amount by reacting with equal molar hydroxylamine hydrochloride. The structures of the compounds were characterized by IR and 1H NMR spectroscopy. The method is more simple and efficient.
2005, 22(1): 105-107
Abstract:
In the presence of catalyst BF3·OEt2, using ethylene glycol as initiator and CH2Cl2 as solvent hydroxylterminated poly(cyclohexene oxide)(PCHO) was synthesized by cationic ring opening polymerization of monomer cyclohexene oxide(CHO). The effect of catalyst amount, polymerization temperature and polymerization time on polymerization results were discussed. The best technical condition was:polymerization temperature 0℃, n(BF3·OEt2)/n(CHO)=0.02, n(EG)/n(CHO)=0.01, polymerization time 5 h. The average molecular weight of PCHO obtained was about 1 200, and the conversion of polymer could be up to 92%. The structure of the product was identified by IR and 1H NMR.
In the presence of catalyst BF3·OEt2, using ethylene glycol as initiator and CH2Cl2 as solvent hydroxylterminated poly(cyclohexene oxide)(PCHO) was synthesized by cationic ring opening polymerization of monomer cyclohexene oxide(CHO). The effect of catalyst amount, polymerization temperature and polymerization time on polymerization results were discussed. The best technical condition was:polymerization temperature 0℃, n(BF3·OEt2)/n(CHO)=0.02, n(EG)/n(CHO)=0.01, polymerization time 5 h. The average molecular weight of PCHO obtained was about 1 200, and the conversion of polymer could be up to 92%. The structure of the product was identified by IR and 1H NMR.
2005, 22(1): 108-110
Abstract:
Ten arylacyl-aryl diazene compounds were synthesized in yields of 89.6%~95.6% under mild conditions with 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxyl as phase-transfer catalyst in dehydrogenation of arylacyl-arylhydrazines. Their structures were confirmed by elemental analysis, IR and 1H NMR spectra. The reaction mechanism was discussed.
Ten arylacyl-aryl diazene compounds were synthesized in yields of 89.6%~95.6% under mild conditions with 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxyl as phase-transfer catalyst in dehydrogenation of arylacyl-arylhydrazines. Their structures were confirmed by elemental analysis, IR and 1H NMR spectra. The reaction mechanism was discussed.
2005, 22(1): 111-113
Abstract:
A new scale inhibitor, epoxysuccinic acid-2,3-epoxypropylsulfonic acid copolymer(PECS) was synthesized from disodium epoxysuccinate and sodium 2,3-epoxypropylsulfonate. The effects of the molar ratio of the monomers, the polymerization temperature, time, and the amount of initiator were studied. The optimal synthesis conditions were as follows:the polymerization temperature was at 70℃, the molar ratio of n(epoxysuccinic acid):n(2,3-epoxypropylsulfonic acid):n(initiator)=1:1:0.1, and the reaction time was 12 h. The results show that PECS is similar to polyepoxysuccinic acid(PESA) in inhibiting calcium carbonate scale and calcium sulfate scale, and superior to PESA in inhibiting calcium phosphate scale and stabilizing zinc salt.
A new scale inhibitor, epoxysuccinic acid-2,3-epoxypropylsulfonic acid copolymer(PECS) was synthesized from disodium epoxysuccinate and sodium 2,3-epoxypropylsulfonate. The effects of the molar ratio of the monomers, the polymerization temperature, time, and the amount of initiator were studied. The optimal synthesis conditions were as follows:the polymerization temperature was at 70℃, the molar ratio of n(epoxysuccinic acid):n(2,3-epoxypropylsulfonic acid):n(initiator)=1:1:0.1, and the reaction time was 12 h. The results show that PECS is similar to polyepoxysuccinic acid(PESA) in inhibiting calcium carbonate scale and calcium sulfate scale, and superior to PESA in inhibiting calcium phosphate scale and stabilizing zinc salt.
2005, 22(1): 114-116
Abstract:
A novel blue light emitting material, 9,10-bis(9,9-diphenylfluorenyl) anthracene(DPFA) was synthesized and it's optoelectronic properties were studied. Organic light-emitting diodes(OLEDs) has been fabricated and showed efficient blue emission at 445 nm with excellent color purity. The brightness of the device is up to 2 433 cd/cm2with a high luminescence efficiency of 3.53 cd/A(3.26 lm/W).
A novel blue light emitting material, 9,10-bis(9,9-diphenylfluorenyl) anthracene(DPFA) was synthesized and it's optoelectronic properties were studied. Organic light-emitting diodes(OLEDs) has been fabricated and showed efficient blue emission at 445 nm with excellent color purity. The brightness of the device is up to 2 433 cd/cm2with a high luminescence efficiency of 3.53 cd/A(3.26 lm/W).
