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1996 Volume 13 Issue 4
1996, 13(4): 1-4
Abstract:
In this paper the advancement in the preparation and bioactivity study of some water-soluble C60 derivatives,such as fullerene-C60-γ-cyclodextrin inclusion complexes and fullerols,is reviewed.
In this paper the advancement in the preparation and bioactivity study of some water-soluble C60 derivatives,such as fullerene-C60-γ-cyclodextrin inclusion complexes and fullerols,is reviewed.
1996, 13(4): 5-9
Abstract:
The current applications of cyclodextrins in pharmaceuticals,food,environmental protection,deodorizer,biomedical science,cosmetics and electrochemistry have been reviewed in this paper.
The current applications of cyclodextrins in pharmaceuticals,food,environmental protection,deodorizer,biomedical science,cosmetics and electrochemistry have been reviewed in this paper.
1996, 13(4): 10-13
Abstract:
Plasma-induced graft copolymers of methyl methacrylate onto polypropylene (PP-g-PMMAI were used as compatilizers in the blend system of PP and polyvinylidene fluoride (PVDF).SEM and FTIR showed that it was the dipole-dipole interaction between the fluorine of PVDF and the carbonyl of PMMA of the compatilizer that made the polymers compatible. Mechanical property studies of the blend system showed that PP-g-PMMA copolymers with grafting yields of 7.7%~300% from various plasma treatment time or of 30%~80% from different post-polymerization time had the best compatibility effect.
Plasma-induced graft copolymers of methyl methacrylate onto polypropylene (PP-g-PMMAI were used as compatilizers in the blend system of PP and polyvinylidene fluoride (PVDF).SEM and FTIR showed that it was the dipole-dipole interaction between the fluorine of PVDF and the carbonyl of PMMA of the compatilizer that made the polymers compatible. Mechanical property studies of the blend system showed that PP-g-PMMA copolymers with grafting yields of 7.7%~300% from various plasma treatment time or of 30%~80% from different post-polymerization time had the best compatibility effect.
1996, 13(4): 14-16
Abstract:
The present paper describes the qualitative and quantitative analysis of γ-glycidoxypropyltrimethoxy-silane by GC for its purity control and for monitoring its concentration change vs time in the bonding reaction.The velocity of both bonding reaction and self-poly-condensation of this silanizing agent is examined. As a result,the optimum condition for the bonding reaction is obtained.
The present paper describes the qualitative and quantitative analysis of γ-glycidoxypropyltrimethoxy-silane by GC for its purity control and for monitoring its concentration change vs time in the bonding reaction.The velocity of both bonding reaction and self-poly-condensation of this silanizing agent is examined. As a result,the optimum condition for the bonding reaction is obtained.
1996, 13(4): 17-20
Abstract:
Layered double hydroxides pillared by tungstoferrate heteropolyanion with substituted transition metal Ni, ZnAl-FeW11Ni, has been synthesized by means of hydrothermal ion exchange method. Powder X-ray diffraction shows that the anionic clay precursor possesses a regular layered structure and a good crystallinity, and the pillared derivative has 2θ of 4.96° and gallery height of 1.325 nm. IR spectra indicate that the vibrational frequency and band shape of heteropolyanion existing in the layered regions of anionic clay are similar to those of the authentic heteropoly salt. So we can draw the conclusion that the Keggin structure of the gallery heteropoly anions is maintained. ESR results indicate that the heteropolyainons are of ordered arrangement in layered clay region.Tests show that the new pillared compound has a higher catalytic activity than that of anionic clay and heteronoly salts for dioctyl phthalate synthesis.
Layered double hydroxides pillared by tungstoferrate heteropolyanion with substituted transition metal Ni, ZnAl-FeW11Ni, has been synthesized by means of hydrothermal ion exchange method. Powder X-ray diffraction shows that the anionic clay precursor possesses a regular layered structure and a good crystallinity, and the pillared derivative has 2θ of 4.96° and gallery height of 1.325 nm. IR spectra indicate that the vibrational frequency and band shape of heteropolyanion existing in the layered regions of anionic clay are similar to those of the authentic heteropoly salt. So we can draw the conclusion that the Keggin structure of the gallery heteropoly anions is maintained. ESR results indicate that the heteropolyainons are of ordered arrangement in layered clay region.Tests show that the new pillared compound has a higher catalytic activity than that of anionic clay and heteronoly salts for dioctyl phthalate synthesis.
1996, 13(4): 21-24
Abstract:
A composite film with water-resistance was prepared by curing polyurethane-acry-late on regenerated cellulose film (from bagasse pulp) under UV-irradiation. The structures of films were studied by IR and SEM. The water-resistance, mechanical properties, water vapor permeability and size stability of the films were measured.The experimental results showed that when polyurethane/arcylate is 40:55 by mass,the composite film prepared under 400 W UV irradiation for 5 min possesses dense surface structure and good mechanical properties. After being soaked in water,the tensile strength retained 90% that of dry film,the shrinkage and swelling were less than 2.5%,and the water vapor permeability was a quarter of that of uncured cellulose film. The water-resistance and size stability of the composite film were improved significantly.In addition,its transmittance in visible range is 80%~90% and it can shield UV light.
A composite film with water-resistance was prepared by curing polyurethane-acry-late on regenerated cellulose film (from bagasse pulp) under UV-irradiation. The structures of films were studied by IR and SEM. The water-resistance, mechanical properties, water vapor permeability and size stability of the films were measured.The experimental results showed that when polyurethane/arcylate is 40:55 by mass,the composite film prepared under 400 W UV irradiation for 5 min possesses dense surface structure and good mechanical properties. After being soaked in water,the tensile strength retained 90% that of dry film,the shrinkage and swelling were less than 2.5%,and the water vapor permeability was a quarter of that of uncured cellulose film. The water-resistance and size stability of the composite film were improved significantly.In addition,its transmittance in visible range is 80%~90% and it can shield UV light.
1996, 13(4): 25-29
Abstract:
Cobalt phthalocyanine(CoPc)-didodecyldimethylammonium bromide (DDAB) surfactant film electrode could be prepared by casting the mixture of CoPc with DDAB chloroform solution on the surface of pyrolytic graphite electrode and then removing the chloroform by evaporation. Cyclic voltammetric experiments showed that the film electrode in KBr solution had a pair of well-defined and stable reduction and oxidation peaks at Epc=0.40 V and Epa=-0.36 V(vs. SCE),respectively.The electrochemistry of this system was studied and the electrochemical parameters were estimated. The CoPc-DDAB film electrode could be used to catalyze electrochemical reduction of halogenated acetic acids.
Cobalt phthalocyanine(CoPc)-didodecyldimethylammonium bromide (DDAB) surfactant film electrode could be prepared by casting the mixture of CoPc with DDAB chloroform solution on the surface of pyrolytic graphite electrode and then removing the chloroform by evaporation. Cyclic voltammetric experiments showed that the film electrode in KBr solution had a pair of well-defined and stable reduction and oxidation peaks at Epc=0.40 V and Epa=-0.36 V(vs. SCE),respectively.The electrochemistry of this system was studied and the electrochemical parameters were estimated. The CoPc-DDAB film electrode could be used to catalyze electrochemical reduction of halogenated acetic acids.
1996, 13(4): 30-33
Abstract:
The electroreduction process of nitrobenzene (NB) in 0.5 mol/L sulfuric acid solution was studied by cyclic voltammetry by using palladium implanted glassy carbon(GC) eletrodes.The surface composition of implanted electrode and concentration depth profiles of various elements were measured by AES. Implantation of palladium into GC at 40 keV to a fluence of 1×1017 ions·cm-2 produced a surface-near region with a maximum atomic concentration of 20% palladium.The implanted substrates are much more active than the untreated ones in the electroreduction of NB. Aniline was detected as a reduction product of NB by using gas chromatographic methods. The electroreduction mechanism of NB in acidic solution is discussed.
The electroreduction process of nitrobenzene (NB) in 0.5 mol/L sulfuric acid solution was studied by cyclic voltammetry by using palladium implanted glassy carbon(GC) eletrodes.The surface composition of implanted electrode and concentration depth profiles of various elements were measured by AES. Implantation of palladium into GC at 40 keV to a fluence of 1×1017 ions·cm-2 produced a surface-near region with a maximum atomic concentration of 20% palladium.The implanted substrates are much more active than the untreated ones in the electroreduction of NB. Aniline was detected as a reduction product of NB by using gas chromatographic methods. The electroreduction mechanism of NB in acidic solution is discussed.
1996, 13(4): 34-37
Abstract:
The title compound was synthesized by three methods from naphthopyrone. The structures of this compound and its precursors were fully characterized by 1H NMR, MS, IR and elemental analysis.Its DNA-intercalative activity was investigated in DMSO-Tris HCl system by fluorescence quenching technique and the apparent Scatchard binding constant was estimated. Results showed that it efficiently intercalated into DNA.The spectral properties and DNA-intercalative activity have been compared with those of its analogues.
The title compound was synthesized by three methods from naphthopyrone. The structures of this compound and its precursors were fully characterized by 1H NMR, MS, IR and elemental analysis.Its DNA-intercalative activity was investigated in DMSO-Tris HCl system by fluorescence quenching technique and the apparent Scatchard binding constant was estimated. Results showed that it efficiently intercalated into DNA.The spectral properties and DNA-intercalative activity have been compared with those of its analogues.
1996, 13(4): 38-40
Abstract:
The morphology structure of nylon-1010/PP-g-MAH blend systems,as well as nylon-1010/PP blends were studied. The Molau experiments and the IR analysis of the xylene extraction fractions of the blends showed that the reactions between -NH2 or -NH- groups of nylon-1010 and maleic anhydride groups of PP-g-MAH took place during the melt blending, and the PP-g-NY1010 copolymer formed by the reactions acted as a compatibilizer. Also it could be found from the SEM photographs that the affinity between the nylon-1010 and PP-g-MAH was improved to some extent as compared with that of nylon-1010lPP blends.
The morphology structure of nylon-1010/PP-g-MAH blend systems,as well as nylon-1010/PP blends were studied. The Molau experiments and the IR analysis of the xylene extraction fractions of the blends showed that the reactions between -NH2 or -NH- groups of nylon-1010 and maleic anhydride groups of PP-g-MAH took place during the melt blending, and the PP-g-NY1010 copolymer formed by the reactions acted as a compatibilizer. Also it could be found from the SEM photographs that the affinity between the nylon-1010 and PP-g-MAH was improved to some extent as compared with that of nylon-1010lPP blends.
1996, 13(4): 41-44
Abstract:
The solutions of relative molecular mass distribution functions for free radical polymerizations are given in terms of implicit functions and by use of Monte Carlo method. After analyzing the properties of the integrals,the effective integration area for the solution equations is established,so the speed of calculation is increased. Theoretical data for the relative molecular mass distribution of styrene bulk polymerization have been obtained in good agreement with experimental results.
The solutions of relative molecular mass distribution functions for free radical polymerizations are given in terms of implicit functions and by use of Monte Carlo method. After analyzing the properties of the integrals,the effective integration area for the solution equations is established,so the speed of calculation is increased. Theoretical data for the relative molecular mass distribution of styrene bulk polymerization have been obtained in good agreement with experimental results.
1996, 13(4): 45-48
Abstract:
The complexes of rare earth elements with disalicylic acid-borate were synthesized. The composition and structure of these complexes were determined by chemical analysis, IR and UV spectra and their antibacterial activities were examined.
The complexes of rare earth elements with disalicylic acid-borate were synthesized. The composition and structure of these complexes were determined by chemical analysis, IR and UV spectra and their antibacterial activities were examined.
1996, 13(4): 49-51
Abstract:
Natural rubber is epoxidized with peracetic acid. When epoxy group is introduced into the double bonds of the main molecular chain, the molecular polarity is enhanced,while the high elongation character remains essentially. The glass transition temperature,oil resistance,air tightness and adhesion increase significantly,but the impact elasticity decreases.Its applicability approaches to those of certain special synthetic rubbers,thus the application scope of natural rubber is broadened.
Natural rubber is epoxidized with peracetic acid. When epoxy group is introduced into the double bonds of the main molecular chain, the molecular polarity is enhanced,while the high elongation character remains essentially. The glass transition temperature,oil resistance,air tightness and adhesion increase significantly,but the impact elasticity decreases.Its applicability approaches to those of certain special synthetic rubbers,thus the application scope of natural rubber is broadened.
1996, 13(4): 52-55
Abstract:
The chitosan/polyether semi-IPN hydrogel based on glutaraldehyde-crosslinked chitosan and polyether interpenetrating polymer network(semi-IPN) has been prepared.The physical state of water in the semi-IPN hydrogel swollen in distilled water or PH=l.25 buffer solution was studied with differential scanning calorimetry(DSC).Infrared spectroscopy was also used to provide information on the interactions of water molecules with the gel network.
The chitosan/polyether semi-IPN hydrogel based on glutaraldehyde-crosslinked chitosan and polyether interpenetrating polymer network(semi-IPN) has been prepared.The physical state of water in the semi-IPN hydrogel swollen in distilled water or PH=l.25 buffer solution was studied with differential scanning calorimetry(DSC).Infrared spectroscopy was also used to provide information on the interactions of water molecules with the gel network.
1996, 13(4): 56-58
Abstract:
The dissolution and transformation mechanism of carnallite in Na2SO4 solution has been studied.The kinetic equations of dissolution and crystallization have been fitted by the variation of ion concentration vs time.The apparent activation energy has been obtained.
The dissolution and transformation mechanism of carnallite in Na2SO4 solution has been studied.The kinetic equations of dissolution and crystallization have been fitted by the variation of ion concentration vs time.The apparent activation energy has been obtained.
1996, 13(4): 59-61
Abstract:
The catalytic activities of four organotin compounds BuSnCl3(Ⅰ),Bu2SnCl2(Ⅱ), Bu2SnO(Ⅲ) and ClBu2SnOSnBu2Cl(Ⅳ) for the reaction of ethyl hexylate with allyl alcohol were reported. A series of acrylic esters was synthesized by catalytic transesterification of methyl acrylate and alcohols with (Ⅳ).It was found that methyl 3-trichlorostannylpropionate readily undergoes an autocatalysed transesterification with alcohols, forming the correspounding propionate analogs.The catalytic activity of organotins for transesterification possibly comes from the coordination of the carbonyl oxygen in ester to the tin atom.
The catalytic activities of four organotin compounds BuSnCl3(Ⅰ),Bu2SnCl2(Ⅱ), Bu2SnO(Ⅲ) and ClBu2SnOSnBu2Cl(Ⅳ) for the reaction of ethyl hexylate with allyl alcohol were reported. A series of acrylic esters was synthesized by catalytic transesterification of methyl acrylate and alcohols with (Ⅳ).It was found that methyl 3-trichlorostannylpropionate readily undergoes an autocatalysed transesterification with alcohols, forming the correspounding propionate analogs.The catalytic activity of organotins for transesterification possibly comes from the coordination of the carbonyl oxygen in ester to the tin atom.
1996, 13(4): 62-64
Abstract:
Microdomain morphology in styrene-butadiene-styrene triblock copolymer (SBS) and polystyrene (PS) blends was investigated by small angle X-ray scattering. The homopolystyrenes having molecular weight of 500 and 12000,respectively, were blended with SBS up to a concentration of 25%.As the homopolymer concentration increased,the size of the PS microdomains increased.The size of polybutadiene (PB)microdomains,on the other hand,decreased if the added polystyrene was with low molecular weight and increased if the molecular weight of the added polystyrene was large. In the blends containing low molecular weight PS, the area per junction increased with the addition of PS, while it kept almost constant for the blends containing high molecular weight PS. In the fixed PS concentration,increasing the homopolymer molecular weight increased the size of PS and PB microdomains and decreased the area per junction. The swelling in the PS microdomains became dramatically asymmetric with an increase in the homopolymer concentration and/or the homopolymer molecular weight.Over the cylinder-lamellar transition induced by the addition of thepolystyrene,the lateral expansion increased dramatically.
Microdomain morphology in styrene-butadiene-styrene triblock copolymer (SBS) and polystyrene (PS) blends was investigated by small angle X-ray scattering. The homopolystyrenes having molecular weight of 500 and 12000,respectively, were blended with SBS up to a concentration of 25%.As the homopolymer concentration increased,the size of the PS microdomains increased.The size of polybutadiene (PB)microdomains,on the other hand,decreased if the added polystyrene was with low molecular weight and increased if the molecular weight of the added polystyrene was large. In the blends containing low molecular weight PS, the area per junction increased with the addition of PS, while it kept almost constant for the blends containing high molecular weight PS. In the fixed PS concentration,increasing the homopolymer molecular weight increased the size of PS and PB microdomains and decreased the area per junction. The swelling in the PS microdomains became dramatically asymmetric with an increase in the homopolymer concentration and/or the homopolymer molecular weight.Over the cylinder-lamellar transition induced by the addition of thepolystyrene,the lateral expansion increased dramatically.
1996, 13(4): 65-67
Abstract:
The variation of crystallinity of PEEKK samples treated at various temperatures has been studied by using wide-angle X-ray diffraction (WAXD). Based on X-ray scattering intensity theory and by using the graphic multipeak resolution method,the formula of crystallinity (Wc,x) for PEEKK is derived.The results calculated are compatible with the density and calorimetry measurements.
The variation of crystallinity of PEEKK samples treated at various temperatures has been studied by using wide-angle X-ray diffraction (WAXD). Based on X-ray scattering intensity theory and by using the graphic multipeak resolution method,the formula of crystallinity (Wc,x) for PEEKK is derived.The results calculated are compatible with the density and calorimetry measurements.
1996, 13(4): 68-70
Abstract:
The tails of small angle X-ray scattering curves of polyethylene irradiated with different dos age have been analysed and found to agree with Porod's linearity relations of two-phase model. After irradiation the two-phase demarcation of polyethylene remains unchanged. The correlation length estimated from integral invariant and the intercept of a straight line does not change with dose remarkably. These results agree with the prediction of "lamellar core damage mechanism" and do not coincide with the prediction of "lamellar surface damage mechanism".
The tails of small angle X-ray scattering curves of polyethylene irradiated with different dos age have been analysed and found to agree with Porod's linearity relations of two-phase model. After irradiation the two-phase demarcation of polyethylene remains unchanged. The correlation length estimated from integral invariant and the intercept of a straight line does not change with dose remarkably. These results agree with the prediction of "lamellar core damage mechanism" and do not coincide with the prediction of "lamellar surface damage mechanism".
1996, 13(4): 71-73
Abstract:
Blends of polypropylene and nylon-1010 in 50:50 ratio were prepared using a polyethylene-based ionomer as a compatibilizer.The effects of the addition of this compatibilizer on the morphology,melting and crystallization behavior and the dynamic mechanical properties of the blends were examined. The compatibilization of the ionomer in the blends was measured. The size of dispersed particles reduced in PPlnylon1010 lionomer blends. The crystallization temperatures,melting points and the degree of crystallinity of polypropylene were decreased by the addition of ionomer.
Blends of polypropylene and nylon-1010 in 50:50 ratio were prepared using a polyethylene-based ionomer as a compatibilizer.The effects of the addition of this compatibilizer on the morphology,melting and crystallization behavior and the dynamic mechanical properties of the blends were examined. The compatibilization of the ionomer in the blends was measured. The size of dispersed particles reduced in PPlnylon1010 lionomer blends. The crystallization temperatures,melting points and the degree of crystallinity of polypropylene were decreased by the addition of ionomer.
1996, 13(4): 74-76
Abstract:
CdSO4 and (NH4)2S were separately dissolved in solvation layer of Triton X-100/C10H21OH/H2O lamellar liquid crystal. The mixing of the two liquid crystal systems resulted in the formation of ultrafine CdS particles in the solvation layer.The size of CdS particles was limited by the change of thickness of solvation layer in the lamellar liquid crystal to be less than 10 nm in diameter. Changing the related component concentrations did not considerably affect the size of ultrafine CdS particles.
CdSO4 and (NH4)2S were separately dissolved in solvation layer of Triton X-100/C10H21OH/H2O lamellar liquid crystal. The mixing of the two liquid crystal systems resulted in the formation of ultrafine CdS particles in the solvation layer.The size of CdS particles was limited by the change of thickness of solvation layer in the lamellar liquid crystal to be less than 10 nm in diameter. Changing the related component concentrations did not considerably affect the size of ultrafine CdS particles.
1996, 13(4): 77-79
Abstract:
Four kinds of active carbon were used to reduce NO as both supports and reducing agents. The cupric oxide and ferric oxide supported on the active carbon greatly enhanced the conversion of NO reduction.The conversion depended on the reducibility of active carbon and metallic ions impregnated.Cupric oxide exhibited better promotion than ferric oxide.The active carbon with greater reducing ability tends to produce a higher conversion of NO reduction. Additionally,the dispersion of cupric oxide on active carbon is also a factor influencing NO reduction.
Four kinds of active carbon were used to reduce NO as both supports and reducing agents. The cupric oxide and ferric oxide supported on the active carbon greatly enhanced the conversion of NO reduction.The conversion depended on the reducibility of active carbon and metallic ions impregnated.Cupric oxide exhibited better promotion than ferric oxide.The active carbon with greater reducing ability tends to produce a higher conversion of NO reduction. Additionally,the dispersion of cupric oxide on active carbon is also a factor influencing NO reduction.
1996, 13(4): 80-82
Abstract:
The composite fiber of ZrO2 nanocrystal compounded fleece fiber has been prepared from ZrO2·nH2O sol and fleece fiber using the sol-soaking and hydrothermal methods.The effects of the state of ZrO2 and the particle sizes of ZrO2·nH2O and ZrO2 nanocrystal on the ZrO2 content in the composite fiber have been studied, and the properties of the latter have been measured. Results show that the ZrO2 nanocrystals have a square phase and the tensile feature of composite fiber is fine.
The composite fiber of ZrO2 nanocrystal compounded fleece fiber has been prepared from ZrO2·nH2O sol and fleece fiber using the sol-soaking and hydrothermal methods.The effects of the state of ZrO2 and the particle sizes of ZrO2·nH2O and ZrO2 nanocrystal on the ZrO2 content in the composite fiber have been studied, and the properties of the latter have been measured. Results show that the ZrO2 nanocrystals have a square phase and the tensile feature of composite fiber is fine.
1996, 13(4): 83-85
Abstract:
Title compounds(4a~d) have been synthesized by the reaction of methylsulfonyl chloride with 3-dialkylaminomethylene-isobenzopran-4-one These compounds show some anti-inflammatory activity.
Title compounds(4a~d) have been synthesized by the reaction of methylsulfonyl chloride with 3-dialkylaminomethylene-isobenzopran-4-one These compounds show some anti-inflammatory activity.
1996, 13(4): 86-88
Abstract:
Two new novel binuclear cobalt (Ⅱ) complexes, namely,[Co2(4PT)(Phen)4](ClO4)2·3H2O (complex 1) and[Co2(4PT)(NPhen)4] (ClO4)2·2H2O (complex 2) (4PT=4-nitrophthalato, Phen=l,10-phenanthroline, NPhen=5-nitro-1,10-phenanthroline) have been synthesized. The complexes were characterized by elemental analysis, IR, UV-Vis spectra and electronic conductance. The variable-temperature magnetic susceptibility of the complexes was measured over 77~300 K. The data were analyzed by using the magnetic susceptibility equation based on Heisenberg spin-exchange operator, and the exchange integrals for complex 1 and complex 2 were found 2J=-8.6 cm-1 and 2J=-4.3 cm-1,respectively. Experiments of inhibiting human leukemia cell, stomach cancer cell and carcinoma of nasopharyngeal cancer cell in vitro were made,and found that the complexes exhibited a relatively strong function of inhibiting these three kinds of cancer cells.
Two new novel binuclear cobalt (Ⅱ) complexes, namely,[Co2(4PT)(Phen)4](ClO4)2·3H2O (complex 1) and[Co2(4PT)(NPhen)4] (ClO4)2·2H2O (complex 2) (4PT=4-nitrophthalato, Phen=l,10-phenanthroline, NPhen=5-nitro-1,10-phenanthroline) have been synthesized. The complexes were characterized by elemental analysis, IR, UV-Vis spectra and electronic conductance. The variable-temperature magnetic susceptibility of the complexes was measured over 77~300 K. The data were analyzed by using the magnetic susceptibility equation based on Heisenberg spin-exchange operator, and the exchange integrals for complex 1 and complex 2 were found 2J=-8.6 cm-1 and 2J=-4.3 cm-1,respectively. Experiments of inhibiting human leukemia cell, stomach cancer cell and carcinoma of nasopharyngeal cancer cell in vitro were made,and found that the complexes exhibited a relatively strong function of inhibiting these three kinds of cancer cells.
1996, 13(4): 89-91
Abstract:
A series of γ-Al2O3-supported Cr-Ag bimetallic and individual mono-metallic catalysts was prepared by wetness impregnation method.The oxidation activity of CO was determined in a gas flow system. The effect of promoter Ag was studied by BET, XRD and TPR. The activity of Cr/γ-Al2O3 catalyst for CO oxidation was relatively poor. As the silver loading increased, the temperature of 100% coversion of CO over Ag/γ-Al2O3 catalysts decreased rapidly. The oxidation activity of catalyst was evidently enhanced by the addition of Ag, and increased with the content of Ag. The result of TPR showed that Ag could substantially change the reducibility of catalyst, TM decreased about 75℃,and the oxidation activity of catalyst was promoted.
A series of γ-Al2O3-supported Cr-Ag bimetallic and individual mono-metallic catalysts was prepared by wetness impregnation method.The oxidation activity of CO was determined in a gas flow system. The effect of promoter Ag was studied by BET, XRD and TPR. The activity of Cr/γ-Al2O3 catalyst for CO oxidation was relatively poor. As the silver loading increased, the temperature of 100% coversion of CO over Ag/γ-Al2O3 catalysts decreased rapidly. The oxidation activity of catalyst was evidently enhanced by the addition of Ag, and increased with the content of Ag. The result of TPR showed that Ag could substantially change the reducibility of catalyst, TM decreased about 75℃,and the oxidation activity of catalyst was promoted.
1996, 13(4): 92-94
Abstract:
Nanometer-sized zinc oxide was synthesized by five different procedures without any surface activating agents. Their structures were characterized by X-ray powder diffraction,transmission electron microscope,infrared spectroscopy and extended X-ray absorption fine structure. The shape of ZnO grains is spheric and their diameter ranges from 10 nm to 80 nm. The influences of synthesis type,reaction conditions,processing procedures of inter mediates, thermodecomposition conditions on the grain size were discussed.
Nanometer-sized zinc oxide was synthesized by five different procedures without any surface activating agents. Their structures were characterized by X-ray powder diffraction,transmission electron microscope,infrared spectroscopy and extended X-ray absorption fine structure. The shape of ZnO grains is spheric and their diameter ranges from 10 nm to 80 nm. The influences of synthesis type,reaction conditions,processing procedures of inter mediates, thermodecomposition conditions on the grain size were discussed.
1996, 13(4): 95-97
Abstract:
Three different methods for extracting red pigment from lycium barbarum were compared and the stability of this red pigment was studied. The experimental results showed that the flooding extraction is superior to other two methods. The red pigment is resistant to heat, acid and base, and keeps stable in the presence of Cu2+ and Ca2+ ions.So this technique is expected to be used extensively.
Three different methods for extracting red pigment from lycium barbarum were compared and the stability of this red pigment was studied. The experimental results showed that the flooding extraction is superior to other two methods. The red pigment is resistant to heat, acid and base, and keeps stable in the presence of Cu2+ and Ca2+ ions.So this technique is expected to be used extensively.
1996, 13(4): 98-100
Abstract:
The condensed polynuclear aromatic hydrocarbon resin was prepared with naphthalene or α-naphthol as raw material and p-xylenediol as crosslinker. The reaction was monitored by IR and UV measurements.The reaction mechanism,influencing factors and curing conditions were investigated.
The condensed polynuclear aromatic hydrocarbon resin was prepared with naphthalene or α-naphthol as raw material and p-xylenediol as crosslinker. The reaction was monitored by IR and UV measurements.The reaction mechanism,influencing factors and curing conditions were investigated.
1996, 13(4): 101-103
Abstract:
PTMSP membrane was modified by CCl4 plasma, and the surface of modified membranes was studied by XPS and water contact angle measurements. The experimental results show that the CCl4 plasma modified membranes exhibit a significant increase in gas selectivity over the unmodified PTMSP.The oxygen-nitrogen separation factors αO2/N2 increased from 1.50 to 7.89 and the oxygen permeation coefficient PO2 decreased from 9×105 Barrer to 9×102 Barrer.
PTMSP membrane was modified by CCl4 plasma, and the surface of modified membranes was studied by XPS and water contact angle measurements. The experimental results show that the CCl4 plasma modified membranes exhibit a significant increase in gas selectivity over the unmodified PTMSP.The oxygen-nitrogen separation factors αO2/N2 increased from 1.50 to 7.89 and the oxygen permeation coefficient PO2 decreased from 9×105 Barrer to 9×102 Barrer.
1996, 13(4): 104-106
Abstract:
A novel 14 membered N-acetic acid substituted tetraazamacrocyclic ligand, 5,12-diphenyl-7,14-dimethyl-l,4,8,11-tetraazacyclotetradecane-N-acetic acid (HL) has been synthesized in dry methanol by the interaction of 5, 12-diphenyl-7, 14-dimethyl-1,4,8,11-tetraazacyclotetradecane with bromoacetic acid. Its Cu (Ⅱ) and Ni(Ⅱ) complexes have also been prepared. The ligand and the complexes have been characterized by elemental analysis. IR, 1H NMR,MS,UV-Vis spectra and conductivity measurements.
A novel 14 membered N-acetic acid substituted tetraazamacrocyclic ligand, 5,12-diphenyl-7,14-dimethyl-l,4,8,11-tetraazacyclotetradecane-N-acetic acid (HL) has been synthesized in dry methanol by the interaction of 5, 12-diphenyl-7, 14-dimethyl-1,4,8,11-tetraazacyclotetradecane with bromoacetic acid. Its Cu (Ⅱ) and Ni(Ⅱ) complexes have also been prepared. The ligand and the complexes have been characterized by elemental analysis. IR, 1H NMR,MS,UV-Vis spectra and conductivity measurements.
1996, 13(4): 107-109
Abstract:
The thermogenesis curves of mitochondria isolated from fish liver tissue were determined by using an LKB-2277 bioactivity monitor. After isolation from fish liver,mitochondria still has activity and can live for a long time by utilyzing the stored nutrients. We calculated the recovery rate constants of mitochondria and found that the thermogenesis curves of mitochondria are similar to those obtained from procaryotic cells. It was found by studying the thermogenesis curves that if a fish is superior in breed or grow faster than another, the stagnant period of mitochondria metabolism will be shorter and the recovery rate constant will be bigger.
The thermogenesis curves of mitochondria isolated from fish liver tissue were determined by using an LKB-2277 bioactivity monitor. After isolation from fish liver,mitochondria still has activity and can live for a long time by utilyzing the stored nutrients. We calculated the recovery rate constants of mitochondria and found that the thermogenesis curves of mitochondria are similar to those obtained from procaryotic cells. It was found by studying the thermogenesis curves that if a fish is superior in breed or grow faster than another, the stagnant period of mitochondria metabolism will be shorter and the recovery rate constant will be bigger.
1996, 13(4): 110-112
Abstract:
Copolymerization of ethylene/octene-1 was investigated by using two types of supported zirconocene catalysts, Zr/MAO/SiO2 and Zr/MAO/SAA,where SiO2 and poly(styrene-acrylamide) (SAA) were used as carriers respectively. The results showed that the catalysts have high copolymerization ability. The triad sequence distribution and mean sequence lengths of monomers in the copolymers have been calculated by 13C NMR data.
Copolymerization of ethylene/octene-1 was investigated by using two types of supported zirconocene catalysts, Zr/MAO/SiO2 and Zr/MAO/SAA,where SiO2 and poly(styrene-acrylamide) (SAA) were used as carriers respectively. The results showed that the catalysts have high copolymerization ability. The triad sequence distribution and mean sequence lengths of monomers in the copolymers have been calculated by 13C NMR data.
1996, 13(4): 113-114
Abstract:
In this paper,the synthesis of blue luminescent dye 9,10-diphenylanthracene (DPA3 and the influence of some reducing agents on yield and quality of product have been examined in detail. Experimental results indicate that stannous chloride is the best reducing agent for this synthesis. Fluorescence and chemiluminescence spectra have been measured and found that DPA displays strong and long-time chemiluminescence in peroxyoxalate system (λmax=434 nm).
In this paper,the synthesis of blue luminescent dye 9,10-diphenylanthracene (DPA3 and the influence of some reducing agents on yield and quality of product have been examined in detail. Experimental results indicate that stannous chloride is the best reducing agent for this synthesis. Fluorescence and chemiluminescence spectra have been measured and found that DPA displays strong and long-time chemiluminescence in peroxyoxalate system (λmax=434 nm).
1996, 13(4): 115-116
Abstract:
By doping Ag on the surface of the SnOx gas sensing film, the sensitivity and selectivity are improved greatly, and the working temperature is decreased. The catalysis of Ag has been discussed based on the color change of the film during measuring procedure.
By doping Ag on the surface of the SnOx gas sensing film, the sensitivity and selectivity are improved greatly, and the working temperature is decreased. The catalysis of Ag has been discussed based on the color change of the film during measuring procedure.
1996, 13(4): 117-118
Abstract:
An improved direct extraction method for preparation of neodymium naphthenate with NaOH instead of NH4OH was proposed. In comparison with original method, the improved method has many advantages such as fast reaction rate' easy monitoring and operation as well as absence of irritative smell. The product obtained therewith can be used for formulation of diene stereospecific polymerization catalyst with good catalytic property.
An improved direct extraction method for preparation of neodymium naphthenate with NaOH instead of NH4OH was proposed. In comparison with original method, the improved method has many advantages such as fast reaction rate' easy monitoring and operation as well as absence of irritative smell. The product obtained therewith can be used for formulation of diene stereospecific polymerization catalyst with good catalytic property.
