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1997 Volume 14 Issue 1
1997, 14(1): 1-5
Abstract:
Three dichromogenic compounds containing both phenoxynaphthacenequinone and azobenzene photochromes, 6-[4-(phenylazo)phenoxy]-5,12-naphthacenequinone(5), 6-[4-(p-ethoxyphenylazo) phenoxy]-5,12-naphthacenequinone(6) and 6-[4-(p-nitrophenylazo) phenoxy]-5,12-naphthacene quinone(7), were synthesized by reacting 6-chloro-5,12-naphthacene-quinone with 4-hydroxyazobenzene and its derivatives. It was found that the phenoxynaphthacenequinone photochromes of all these dichromogenic compounds showed slight UV-induced photochromism. Based on the irreversible reaction of ammonia with the colored phenoxy-ana-naphthacenequinone, the concentrations of the ana forms of 5 and 6 in DMSO at the photostationary state(PSS) under 365 nm irradiation were estimated to be only 22% and 17% respectively. The results indicate the strong effect of phenylazo-group on the photochromic properties of phenoxynaphthacenequinone photochrome. On the other hand, unlike the 4-hydroxyazobenzene precursors, the cis isomers of azobenzene photochromes in the dichromogenic compounds were relatively stable in DMSO solution.
Three dichromogenic compounds containing both phenoxynaphthacenequinone and azobenzene photochromes, 6-[4-(phenylazo)phenoxy]-5,12-naphthacenequinone(5), 6-[4-(p-ethoxyphenylazo) phenoxy]-5,12-naphthacenequinone(6) and 6-[4-(p-nitrophenylazo) phenoxy]-5,12-naphthacene quinone(7), were synthesized by reacting 6-chloro-5,12-naphthacene-quinone with 4-hydroxyazobenzene and its derivatives. It was found that the phenoxynaphthacenequinone photochromes of all these dichromogenic compounds showed slight UV-induced photochromism. Based on the irreversible reaction of ammonia with the colored phenoxy-ana-naphthacenequinone, the concentrations of the ana forms of 5 and 6 in DMSO at the photostationary state(PSS) under 365 nm irradiation were estimated to be only 22% and 17% respectively. The results indicate the strong effect of phenylazo-group on the photochromic properties of phenoxynaphthacenequinone photochrome. On the other hand, unlike the 4-hydroxyazobenzene precursors, the cis isomers of azobenzene photochromes in the dichromogenic compounds were relatively stable in DMSO solution.
1997, 14(1): 6-10
Abstract:
Ni-ZrO2 composite plating was prepared by composite electrodeposition method, and the change of crystal preferential orientation and lattice parameter of matrix metal Ni caused by ZrO2 particles and its effect on the hydrogen evolution activity were investigated from the view of interaction between matrix metal and particles. The presence of ZrO2 particles has significant effect on the crystal structure of electrodeposited matrix metal Ni, and leads to a new crystal preferential orientation along (220) crystal face. This new crystal preferential orientation is unfavorable to the hydrogen evolution reaction. These results show that in the course of electrodeposition, Ni and ZrO2 particles enter into composite plating in a definite interfacial coupling relation, which is also proved by the data of the change in the lattice parameter of matrix metal Ni.
Ni-ZrO2 composite plating was prepared by composite electrodeposition method, and the change of crystal preferential orientation and lattice parameter of matrix metal Ni caused by ZrO2 particles and its effect on the hydrogen evolution activity were investigated from the view of interaction between matrix metal and particles. The presence of ZrO2 particles has significant effect on the crystal structure of electrodeposited matrix metal Ni, and leads to a new crystal preferential orientation along (220) crystal face. This new crystal preferential orientation is unfavorable to the hydrogen evolution reaction. These results show that in the course of electrodeposition, Ni and ZrO2 particles enter into composite plating in a definite interfacial coupling relation, which is also proved by the data of the change in the lattice parameter of matrix metal Ni.
1997, 14(1): 11-15
Abstract:
The catalytic properties of La1-xCuxMnO3 perovskite-type catalysts prepared by coprecipitation have been studied by means of XRD, TPR, TEM, SEM, EMPA, activity evaluation and etc. The results reveal that the activation energy of La1-xCuxMnO3 catalysts decreases with the increase of x from 0 to 0.6 and the activity of the catalysts for CO and CH4 oxidation has a maximum point (for CO oxidation x=0.4 and for CH4 oxidation x=0.2). It is considered that the above behaviour is caused by the increase of lattice defects and chemical potential of lattice oxygen in catalysts with the increase of x.
The catalytic properties of La1-xCuxMnO3 perovskite-type catalysts prepared by coprecipitation have been studied by means of XRD, TPR, TEM, SEM, EMPA, activity evaluation and etc. The results reveal that the activation energy of La1-xCuxMnO3 catalysts decreases with the increase of x from 0 to 0.6 and the activity of the catalysts for CO and CH4 oxidation has a maximum point (for CO oxidation x=0.4 and for CH4 oxidation x=0.2). It is considered that the above behaviour is caused by the increase of lattice defects and chemical potential of lattice oxygen in catalysts with the increase of x.
1997, 14(1): 16-20
Abstract:
The relation between the catalytic ability for hydrogen evolution reaction and the conditions of electrodeposition (electrode-position temperature, electrolysis time, electrodeposition current density, electrolyte composition in the bath) has been studied using steady-state polarization and ac impedance techniques. The morphology of the composite coating surface of the electrodes and the composition of the composite coating are measured by SEM and EDS. The low hydrogen overpotential is obtained if the electrodes are prepared from the electrolyte containing molybdenum at 30℃, and by using a higher electrodeposition current density and a longer electrolysis time.e.g, 7200 seconds.
The relation between the catalytic ability for hydrogen evolution reaction and the conditions of electrodeposition (electrode-position temperature, electrolysis time, electrodeposition current density, electrolyte composition in the bath) has been studied using steady-state polarization and ac impedance techniques. The morphology of the composite coating surface of the electrodes and the composition of the composite coating are measured by SEM and EDS. The low hydrogen overpotential is obtained if the electrodes are prepared from the electrolyte containing molybdenum at 30℃, and by using a higher electrodeposition current density and a longer electrolysis time.e.g, 7200 seconds.
1997, 14(1): 21-24
Abstract:
Surface pressure/monomolecular area (c-A) isotherm of octa-tetrahydrofuryloxy Nd-bisphthalocyanine monolayer on the water subphase has been investigated. LB films have been prepared and characterized using UV-Vis absorption spectroscopy. LB films on highly oriented pyrolytic graphite (HOPG) were investigated using STM. It can be seen from the micrograph that Nd-bisphthalocyanine molecules distributed randomly in multimers on HOPG, but uniformly and dispersively in an ordered form when a layer of stearic acid has been deposited on HOPG before LB preparation. All results showed that Nd-bisphthalocyanine macrocycles oriented perpendicular to the substrate.
Surface pressure/monomolecular area (c-A) isotherm of octa-tetrahydrofuryloxy Nd-bisphthalocyanine monolayer on the water subphase has been investigated. LB films have been prepared and characterized using UV-Vis absorption spectroscopy. LB films on highly oriented pyrolytic graphite (HOPG) were investigated using STM. It can be seen from the micrograph that Nd-bisphthalocyanine molecules distributed randomly in multimers on HOPG, but uniformly and dispersively in an ordered form when a layer of stearic acid has been deposited on HOPG before LB preparation. All results showed that Nd-bisphthalocyanine macrocycles oriented perpendicular to the substrate.
1997, 14(1): 25-28
Abstract:
A new spiro ortho carbonate 3,9-di(p-methoxybenzyl)-1,5,7,11-tetroxaspiro[5,5] undecane(1) was prepared. Its cationic polymerization was carried out. The 1H NMR, 13C NMR and IR data as well as elemental analysis of the obtained polymers indicated that it underwent double ring-opening polymerization. The polymerization mechanism was discussed. DSC and IR were used to trace the curing process of epoxy resin with or without this monomer. The effects of curing agent and curing condition on curing reaction were investigated.
A new spiro ortho carbonate 3,9-di(p-methoxybenzyl)-1,5,7,11-tetroxaspiro[5,5] undecane(1) was prepared. Its cationic polymerization was carried out. The 1H NMR, 13C NMR and IR data as well as elemental analysis of the obtained polymers indicated that it underwent double ring-opening polymerization. The polymerization mechanism was discussed. DSC and IR were used to trace the curing process of epoxy resin with or without this monomer. The effects of curing agent and curing condition on curing reaction were investigated.
1997, 14(1): 29-32
Abstract:
It is shown in this paper that KCl and AlCl3 affect the colloidal properties of the mixed suspension consisting of montmorillonite(Mt) particles (possessing permanent negative charges) and aluminum magnesium hydroxide(possessing permanent positive charges)/glycerol particles by measuring electrophoretic mobilities(U), rheological parameters and middle pressure fluid loss(FL). With increase of KCl concentration, U in absolute value, apparent viscosity (AV) and Bingham yield point (YP) of the mixed suspension increase first, then decrease, showing a maximum value at KCl content about 1.0%, and change no longer at KCl content above 4.0%. With increase of AlCl3 concentration, U decreases in absolute value, and AV and YP decrease first and then increase and then decrease again. The FL increases with the increase of KCl and AlCl3 contents, indicating that aggregation in the mixed suspension is aggravated.
It is shown in this paper that KCl and AlCl3 affect the colloidal properties of the mixed suspension consisting of montmorillonite(Mt) particles (possessing permanent negative charges) and aluminum magnesium hydroxide(possessing permanent positive charges)/glycerol particles by measuring electrophoretic mobilities(U), rheological parameters and middle pressure fluid loss(FL). With increase of KCl concentration, U in absolute value, apparent viscosity (AV) and Bingham yield point (YP) of the mixed suspension increase first, then decrease, showing a maximum value at KCl content about 1.0%, and change no longer at KCl content above 4.0%. With increase of AlCl3 concentration, U decreases in absolute value, and AV and YP decrease first and then increase and then decrease again. The FL increases with the increase of KCl and AlCl3 contents, indicating that aggregation in the mixed suspension is aggravated.
1997, 14(1): 33-36
Abstract:
Ar+ laser-induced selective electroplating of copper on p-type silicon was studied in the present paper. Influences of surface oxide film, cathodic voltage as well as the laser power on the cathodic photocurrent and selectivity of plating were investigated. The results show that both native film and anodic passive film existed on silicon can reduce the photocurrent by one order of magnitude; however, a small amount of oxide film can improve the selectivity of deposition. When cathodic bias voltage and laser power are increased, the photocurrent is enhanced and the selectivity reduced. By utilizing weaker laser beam, selective copper deposit can be obtained on p-silicon which has been etched in 1:1 HF acid and then laid in the bath for 10~20 min preliminarily.
Ar+ laser-induced selective electroplating of copper on p-type silicon was studied in the present paper. Influences of surface oxide film, cathodic voltage as well as the laser power on the cathodic photocurrent and selectivity of plating were investigated. The results show that both native film and anodic passive film existed on silicon can reduce the photocurrent by one order of magnitude; however, a small amount of oxide film can improve the selectivity of deposition. When cathodic bias voltage and laser power are increased, the photocurrent is enhanced and the selectivity reduced. By utilizing weaker laser beam, selective copper deposit can be obtained on p-silicon which has been etched in 1:1 HF acid and then laid in the bath for 10~20 min preliminarily.
1997, 14(1): 37-40
Abstract:
The dispersion of Co and Mo on phosphorus and potassium modified V-Al2O3 was investigated by X-ray diffraction, BET surface areas and magnetic susceptibility analysis. It was found that molybdenum can no longer reach a single-layered dispersion as it does on V-Al2O3 support, but forms large crystallite of MoO3 on the H3PO4 treated V-Al2O3 support. While, cobalt oxide is highly dispersed with the help of phosphorus treatment. The resulting surface cobalt compound was recognized as staying in the tetrahedral coordination state. A AlPO4-like surface compound on the phosphorus modified V-Al2O3 was supposed and the influence of phosphorus on the dispersion of Co and Mo was explained accordingly. Effects of potassium on the dispersion of Co and Mo were also reported and discussed here in.
The dispersion of Co and Mo on phosphorus and potassium modified V-Al2O3 was investigated by X-ray diffraction, BET surface areas and magnetic susceptibility analysis. It was found that molybdenum can no longer reach a single-layered dispersion as it does on V-Al2O3 support, but forms large crystallite of MoO3 on the H3PO4 treated V-Al2O3 support. While, cobalt oxide is highly dispersed with the help of phosphorus treatment. The resulting surface cobalt compound was recognized as staying in the tetrahedral coordination state. A AlPO4-like surface compound on the phosphorus modified V-Al2O3 was supposed and the influence of phosphorus on the dispersion of Co and Mo was explained accordingly. Effects of potassium on the dispersion of Co and Mo were also reported and discussed here in.
1997, 14(1): 41-44
Abstract:
In this paper the chlorinated polyethylene(CPE) elastomer is synthesized by a solid state method. Results show that the chlorine distribution of CPE prepared by the solid state method is more homogeneous than that of CPE prepared by an aqueous suspension method. The chlorine distribution in the molecular chain, the residual crystallinity and the chlorination speed are affected by the reaction temperature. The degree of chlorination on the surface and in the bulk of polyethylene grains depends on the chlorination speed. The chlorine substitution on the macro molecular chain obstructs the chlorination of neighboring H-atoms.
In this paper the chlorinated polyethylene(CPE) elastomer is synthesized by a solid state method. Results show that the chlorine distribution of CPE prepared by the solid state method is more homogeneous than that of CPE prepared by an aqueous suspension method. The chlorine distribution in the molecular chain, the residual crystallinity and the chlorination speed are affected by the reaction temperature. The degree of chlorination on the surface and in the bulk of polyethylene grains depends on the chlorination speed. The chlorine substitution on the macro molecular chain obstructs the chlorination of neighboring H-atoms.
1997, 14(1): 45-48
Abstract:
The mixed catalytic rate(νmix) of the reaction between I3- and Ti3+ ions on reduced Pt surface has been calculated through the electrochemical study on electrode reactions of I3-/I- and Ti3+/Ti4+. When the mixed potential(Emix) lies in the limiting current region, νmix is independent of Ti3+ concentration and is first-order to[I3-]. νmix is also proportional to the square root of the rotating speed of electrode. There is only small differences in νmix as the H+ concentration changes. Results obtained by electrochemistry agree with the results measured by kinetic method. The results of this heterogeneous catalysis in solution have been predicted and explained by pure electrochemistry.
The mixed catalytic rate(νmix) of the reaction between I3- and Ti3+ ions on reduced Pt surface has been calculated through the electrochemical study on electrode reactions of I3-/I- and Ti3+/Ti4+. When the mixed potential(Emix) lies in the limiting current region, νmix is independent of Ti3+ concentration and is first-order to[I3-]. νmix is also proportional to the square root of the rotating speed of electrode. There is only small differences in νmix as the H+ concentration changes. Results obtained by electrochemistry agree with the results measured by kinetic method. The results of this heterogeneous catalysis in solution have been predicted and explained by pure electrochemistry.
1997, 14(1): 49-52
Abstract:
The oxidation activity of CuO supported on CeO2 and Al2O3 was investigated using the oxidation of carbon monoxide as a model reaction. The reducibility and Cu oxide species of the catalysts were studied by XRD and TPR techniques. The susceptibility of CO to oxidation strongly depends on the support:the catalytic activity of CuO/CeO2 is much higher than that of CuO/Al2O3. It is found that the existing forms of copper species, crystal particle size of CuO, the reducibility and activity of catalysts are affected by thermal treatment. The formation of CuAl2O4 spinal species at high temperature is the main reason for activity decrease of CuO/Al2O3 catalyst, and the increase of crystal particle size of CuO is the main reason for activity decrease of CuO/CeO2.
The oxidation activity of CuO supported on CeO2 and Al2O3 was investigated using the oxidation of carbon monoxide as a model reaction. The reducibility and Cu oxide species of the catalysts were studied by XRD and TPR techniques. The susceptibility of CO to oxidation strongly depends on the support:the catalytic activity of CuO/CeO2 is much higher than that of CuO/Al2O3. It is found that the existing forms of copper species, crystal particle size of CuO, the reducibility and activity of catalysts are affected by thermal treatment. The formation of CuAl2O4 spinal species at high temperature is the main reason for activity decrease of CuO/Al2O3 catalyst, and the increase of crystal particle size of CuO is the main reason for activity decrease of CuO/CeO2.
1997, 14(1): 53-55
Abstract:
The photo-initiation activity of two kinds of cationic initiators, sulphonium salts and aryl cyclopentadienylferrocenium salts, and their composites with free radical initiators has been studied in the present paper. The enhanced initiation efficiency of aryl cyclopentadienylferrocenium salts by the strong oxidant cumene hydroperoxide and the enhanced crosslinking of cationic curing systems by the addition of suitable amount of polyfunctional alcohols are also discussed.
The photo-initiation activity of two kinds of cationic initiators, sulphonium salts and aryl cyclopentadienylferrocenium salts, and their composites with free radical initiators has been studied in the present paper. The enhanced initiation efficiency of aryl cyclopentadienylferrocenium salts by the strong oxidant cumene hydroperoxide and the enhanced crosslinking of cationic curing systems by the addition of suitable amount of polyfunctional alcohols are also discussed.
1997, 14(1): 56-58
Abstract:
2,5-Dimethoxybenzene-p-dichloromethyl sulphonium salt as the monomer of poly(2,5-dimethoxy-p-phenylene vinylene) was obtained with a yield over 75% through improved methoxylation, chloromethylation and sulphonization procedures from hydroquinone. The reaction conditions were studied in detail and the synthesized products in each step were confirmed by GC/MS and 1H NMR.
2,5-Dimethoxybenzene-p-dichloromethyl sulphonium salt as the monomer of poly(2,5-dimethoxy-p-phenylene vinylene) was obtained with a yield over 75% through improved methoxylation, chloromethylation and sulphonization procedures from hydroquinone. The reaction conditions were studied in detail and the synthesized products in each step were confirmed by GC/MS and 1H NMR.
1997, 14(1): 59-61
Abstract:
The aluminate phosphor, Ce0.67 Tb0.33 MgAl12O20.5, has been synthesized by the combustion of mixtures of respective metal nitrates and urea. The process is energy-saving, instantaneous and safe. The reaction can be completed at 600℃ furnace temperature, which is much lower than that used in traditional solid-state reaction process. The phosphor was characterized by XRD, SEM, fluorescence spectra, particle size distribution, density and relative brightness measurements. The effects of different preparation conditions on the properties, especially the brightness, of the phosphor were inspected.
The aluminate phosphor, Ce0.67 Tb0.33 MgAl12O20.5, has been synthesized by the combustion of mixtures of respective metal nitrates and urea. The process is energy-saving, instantaneous and safe. The reaction can be completed at 600℃ furnace temperature, which is much lower than that used in traditional solid-state reaction process. The phosphor was characterized by XRD, SEM, fluorescence spectra, particle size distribution, density and relative brightness measurements. The effects of different preparation conditions on the properties, especially the brightness, of the phosphor were inspected.
1997, 14(1): 62-64
Abstract:
The tea polyphenol(TP) germanium has been synthesized by reacting Ge4+ with TP, which is extracted from green tea. Reaction conditions and characterizations were studied by UV and IR spectroscopy. The toxicity tests show that the median lethal dose is 2343±297 mg/kgBW.
The tea polyphenol(TP) germanium has been synthesized by reacting Ge4+ with TP, which is extracted from green tea. Reaction conditions and characterizations were studied by UV and IR spectroscopy. The toxicity tests show that the median lethal dose is 2343±297 mg/kgBW.
1997, 14(1): 65-67
Abstract:
The influence of some non-ionic surfactants on anodic oxidation of zinc powder electrodeposited from 10 mol/L KOH-0.5 mol/L ZnO solution is considered. The inhibition mechanism for zinc powder electrode was given by electrochemical impedance spectrum and polarization curve measurements.
The influence of some non-ionic surfactants on anodic oxidation of zinc powder electrodeposited from 10 mol/L KOH-0.5 mol/L ZnO solution is considered. The inhibition mechanism for zinc powder electrode was given by electrochemical impedance spectrum and polarization curve measurements.
1997, 14(1): 68-70
Abstract:
Conditions of phase separation in polyethylene glycol-salt-extractant two-phase aqueous systems and factors affecting extraction yield of metal ions were investigated. Results indicated that Fe(Ⅲ), Al(Ⅲ) and Cd(Ⅱ) were quantitatively separated from some mixed ions under suitable extraction conditions.
Conditions of phase separation in polyethylene glycol-salt-extractant two-phase aqueous systems and factors affecting extraction yield of metal ions were investigated. Results indicated that Fe(Ⅲ), Al(Ⅲ) and Cd(Ⅱ) were quantitatively separated from some mixed ions under suitable extraction conditions.
1997, 14(1): 71-73
Abstract:
The p-alkoxybenzaldehydes are key intermediates for synthesis of liquid crystalline materials. This paper reports a new method for synthesizing p-alkoxybenzaldehydes from sodium p-acylphenolate with n-alkyl bromide or chloride at certain temperature in EtOH. By using this method, some compounds have been obtained in good yield. Some synthetic routes are illustrated and evaluated.
The p-alkoxybenzaldehydes are key intermediates for synthesis of liquid crystalline materials. This paper reports a new method for synthesizing p-alkoxybenzaldehydes from sodium p-acylphenolate with n-alkyl bromide or chloride at certain temperature in EtOH. By using this method, some compounds have been obtained in good yield. Some synthetic routes are illustrated and evaluated.
1997, 14(1): 74-76
Abstract:
A new type of supported complex catalysts, zirconium glycine-N,N-dimethylph-osphonate-palladium was prepared for the first time. The catalytic activity of title catalysts for hydrogenation of several substrates under atmospheric pressure was studied. The catalytic activity is greatly affected by the NCH2CO2H/Pd ratio, catalyst amount, reaction temperature, substrates and solvents. At 40℃ and under atmospheric pressure, the hydrogenation activity of the catalysts for various substituted olefins and nitrobenzene is very high and with high selectivity. The catalyst can be reused.
A new type of supported complex catalysts, zirconium glycine-N,N-dimethylph-osphonate-palladium was prepared for the first time. The catalytic activity of title catalysts for hydrogenation of several substrates under atmospheric pressure was studied. The catalytic activity is greatly affected by the NCH2CO2H/Pd ratio, catalyst amount, reaction temperature, substrates and solvents. At 40℃ and under atmospheric pressure, the hydrogenation activity of the catalysts for various substituted olefins and nitrobenzene is very high and with high selectivity. The catalyst can be reused.
1997, 14(1): 77-79
Abstract:
The enolate, obtained by treatment of methyl 3-(diethylamino) propionate with lithium diisopropylamide, reacts with epoxides to give products which may be considered to be protected acrylate esters. T-Methylene-V-butyrolactones were synthesized by lactonization after the one-pot deamination procedure.
The enolate, obtained by treatment of methyl 3-(diethylamino) propionate with lithium diisopropylamide, reacts with epoxides to give products which may be considered to be protected acrylate esters. T-Methylene-V-butyrolactones were synthesized by lactonization after the one-pot deamination procedure.
1997, 14(1): 80-82
Abstract:
The catalytic behaviour of poly(styrene-4-vinylpyridine) (PS4V Py) neodymium complex[(NdCl3)n·PS4V Py] for butadiene polymerization was described. The catalytic activity of (NdCl3)n·PS4V Py was much greater than that of similar small molecule catalysts. The catalytic efficiency of (NdCl3)n·PS4V Py was up to 11.7 kg polybutadiene/g Nd, about 25 times that of NdCl3·1.5DPy which exhibited the highest activity among the corresponding small molecule catalysts. The relationship between the activity of (NdCl3)n·PS4V Py and its constitution was discussed. The activity of (NdCl3)n·PS4V Py increased as the molar ratio of 4-vinylpyridine(4V Py)/Nd decreased. High activity was found at 4VPy/Nd ratio about 2 with 88~96% conversion. It is likely that uncoordinated 4VPy units remaining in the complex interact with the alkyl aluminium or active species to decrease the activity.
The catalytic behaviour of poly(styrene-4-vinylpyridine) (PS4V Py) neodymium complex[(NdCl3)n·PS4V Py] for butadiene polymerization was described. The catalytic activity of (NdCl3)n·PS4V Py was much greater than that of similar small molecule catalysts. The catalytic efficiency of (NdCl3)n·PS4V Py was up to 11.7 kg polybutadiene/g Nd, about 25 times that of NdCl3·1.5DPy which exhibited the highest activity among the corresponding small molecule catalysts. The relationship between the activity of (NdCl3)n·PS4V Py and its constitution was discussed. The activity of (NdCl3)n·PS4V Py increased as the molar ratio of 4-vinylpyridine(4V Py)/Nd decreased. High activity was found at 4VPy/Nd ratio about 2 with 88~96% conversion. It is likely that uncoordinated 4VPy units remaining in the complex interact with the alkyl aluminium or active species to decrease the activity.
1997, 14(1): 83-85
Abstract:
A series of carbamates containing aryloxyphenoxypropionate group were synthesized by condensation of aromatic amines with 4-(1-methoxycarbonyl-1-ethoxyl) phenyl-chloroformate. The preparation of the new compounds and intermediates were discussed. The preliminary bioassay showed that some compounds exhibited a selective herbicidal activity against broadleaf weeds at 1.5 kg/ha.
A series of carbamates containing aryloxyphenoxypropionate group were synthesized by condensation of aromatic amines with 4-(1-methoxycarbonyl-1-ethoxyl) phenyl-chloroformate. The preparation of the new compounds and intermediates were discussed. The preliminary bioassay showed that some compounds exhibited a selective herbicidal activity against broadleaf weeds at 1.5 kg/ha.
1997, 14(1): 86-88
Abstract:
The title complex was prepared by the reaction of (t-BuCp)2 YCl in THF with ether solution of CH3Li at -78℃. The complex was characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. The complex [(t-BuCp)2YCH3]2 was used as a catalyst for polymerization of MMA and the influence of polymerization conditions on its catalytic activity was investigated.
The title complex was prepared by the reaction of (t-BuCp)2 YCl in THF with ether solution of CH3Li at -78℃. The complex was characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. The complex [(t-BuCp)2YCH3]2 was used as a catalyst for polymerization of MMA and the influence of polymerization conditions on its catalytic activity was investigated.
1997, 14(1): 89-91
Abstract:
A quarternary hydrogen storage alloy LaNi4Cu0.5Co0.5 was prepared using a coprecipitation-reduction-diffusion method. The alloy is activated easily. The surface species and composition of the alloy were derived from XPS measurements. SEM studies revealed many microcracks formed after activation, favoring rapid hydrogen absorption kinetics.
A quarternary hydrogen storage alloy LaNi4Cu0.5Co0.5 was prepared using a coprecipitation-reduction-diffusion method. The alloy is activated easily. The surface species and composition of the alloy were derived from XPS measurements. SEM studies revealed many microcracks formed after activation, favoring rapid hydrogen absorption kinetics.
1997, 14(1): 92-94
Abstract:
The exothermic behavior of curing reaction of epoxy resin toughened by hydroxyl-terminated butadiene-acrylonitrile was studied by DSC method. The kinetic parameters of curing reaction and then the relationship between conversion, time and temperature of reaction were obtained.
The exothermic behavior of curing reaction of epoxy resin toughened by hydroxyl-terminated butadiene-acrylonitrile was studied by DSC method. The kinetic parameters of curing reaction and then the relationship between conversion, time and temperature of reaction were obtained.
1997, 14(1): 95-97
Abstract:
The reaction mechanism of radiation-induced graft polymerization on MgO surface by mutual irradiation has been studied. It is proved by IR spectroscopy that PMMA has been grafted onto MgO surface. By studying grafting temperature, inhibitor, molecular weight and molecular weight distribution, we discover that both free radical and anion induced graft polymerizations take place under the action of high energy radiation. Comparing IR spectra of radiation-polymerized PMMA and graft link on MgO surface, we suggest that O- species trapped in oxide ion lattice on the solid surface is the active site initiating graft polymerization by high energy radiation.
The reaction mechanism of radiation-induced graft polymerization on MgO surface by mutual irradiation has been studied. It is proved by IR spectroscopy that PMMA has been grafted onto MgO surface. By studying grafting temperature, inhibitor, molecular weight and molecular weight distribution, we discover that both free radical and anion induced graft polymerizations take place under the action of high energy radiation. Comparing IR spectra of radiation-polymerized PMMA and graft link on MgO surface, we suggest that O- species trapped in oxide ion lattice on the solid surface is the active site initiating graft polymerization by high energy radiation.
1997, 14(1): 98-100
Abstract:
Pt/CdS catalysts were treated at high temperature in nitrogen gas containing 1.30 g/m3O2. The surface composition and structure of catalysts were studied by XPS, XRD and TEM. Results show that a regular change in the Pt valence and CdS surface composition takes place with treating time. It is verified that low concentration oxygen has an action of modifying Pt/CdS surface.
Pt/CdS catalysts were treated at high temperature in nitrogen gas containing 1.30 g/m3O2. The surface composition and structure of catalysts were studied by XPS, XRD and TEM. Results show that a regular change in the Pt valence and CdS surface composition takes place with treating time. It is verified that low concentration oxygen has an action of modifying Pt/CdS surface.
1997, 14(1): 101-103
Abstract:
Four novel ferrocenyl long-chain alkyl U-diketonato zinc(Ⅱ) complexes with a general formula ZnL2(L=C5H5FeC5H4COCHCOCnH2n+1, n=6~9) were prepared by reaction of ferrocenyl long-chain alkyl U-diketones with Zn(CH3COO)2·2H2O. These complexes were characterized by elemental analysis, IR, 1H NMR, MS and TG-DTA. The results studied by DSC and polarizing microscopy with a heating stage show that the four heteronuclear transition metal complexes have thermotropic liquid crystalline properties. This type of liquid crystalline complexes has not been reported so far.
Four novel ferrocenyl long-chain alkyl U-diketonato zinc(Ⅱ) complexes with a general formula ZnL2(L=C5H5FeC5H4COCHCOCnH2n+1, n=6~9) were prepared by reaction of ferrocenyl long-chain alkyl U-diketones with Zn(CH3COO)2·2H2O. These complexes were characterized by elemental analysis, IR, 1H NMR, MS and TG-DTA. The results studied by DSC and polarizing microscopy with a heating stage show that the four heteronuclear transition metal complexes have thermotropic liquid crystalline properties. This type of liquid crystalline complexes has not been reported so far.
1997, 14(1): 104-106
Abstract:
The compatibility and mechanical properties of linear low density polyethylene/ethylene-vinyl acetate copolymer blends are investigated by differential scanning calorimetry, wide angle X-ray diffraction, dynamic mechanical analysis (DMA) and static mechanical property measurements. Even DMA experiments show that the amorphous phase is miscible and no cocrystallization miscibility is found in the blend system. Nevertheless, some interactions may exist between these two components depending on the blend compositions.
The compatibility and mechanical properties of linear low density polyethylene/ethylene-vinyl acetate copolymer blends are investigated by differential scanning calorimetry, wide angle X-ray diffraction, dynamic mechanical analysis (DMA) and static mechanical property measurements. Even DMA experiments show that the amorphous phase is miscible and no cocrystallization miscibility is found in the blend system. Nevertheless, some interactions may exist between these two components depending on the blend compositions.
1997, 14(1): 107-109
Abstract:
Polystyrene-supported selenoethers were synthesized from chloromethylated crosslinked polystyrene and (HOCH2CH2)2 Se or EtOCH2CH2SeCH2CH2OH via Williamson reaction. They were reacted with potassium chloroplatinite in acetone under nitrogen atmosphere to give title complexes. It was found that the platinum complexes exhibited high catalytic activity in the hydrosilylation of olefins with triethoxysilane.
Polystyrene-supported selenoethers were synthesized from chloromethylated crosslinked polystyrene and (HOCH2CH2)2 Se or EtOCH2CH2SeCH2CH2OH via Williamson reaction. They were reacted with potassium chloroplatinite in acetone under nitrogen atmosphere to give title complexes. It was found that the platinum complexes exhibited high catalytic activity in the hydrosilylation of olefins with triethoxysilane.
1997, 14(1): 110-112
Abstract:
Cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) were used as surfactants and effects of micelles on the basic hydrolysis of aspirin (ASP) were studied spectrophotometrically. When the concentrations of CTAB are larger than 7.3×10-3 mol/L, there is an inhibition of basic hydrolysis of ASP, the best concentration being 3.25×10-3 mol/L. At a constant concentration of CTAB, the addition of a small amount of SDS causes the inhibition of CTAB to decrease, indicating that SDS takes part together with CTAB in the formation of mixed micelles.
Cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) were used as surfactants and effects of micelles on the basic hydrolysis of aspirin (ASP) were studied spectrophotometrically. When the concentrations of CTAB are larger than 7.3×10-3 mol/L, there is an inhibition of basic hydrolysis of ASP, the best concentration being 3.25×10-3 mol/L. At a constant concentration of CTAB, the addition of a small amount of SDS causes the inhibition of CTAB to decrease, indicating that SDS takes part together with CTAB in the formation of mixed micelles.
1997, 14(1): 113-114
Abstract:
An optical fiber ethanol sensor was reported using a polyvinylidene fluoride membrane. The sensor was applied to the rapid determination of ethanol in spirits in the range of 1~60% with satisfactory results.
An optical fiber ethanol sensor was reported using a polyvinylidene fluoride membrane. The sensor was applied to the rapid determination of ethanol in spirits in the range of 1~60% with satisfactory results.
1997, 14(1): 115-116
Abstract:
The electro deposition behaviour of Zn-Co-P alloy on Copper Electrode has been studied with cyclic voltammetry. It is shown that the cathodic polarization of Zn-Co alloy increases, if NaH2PO2 has been added into the electroplating solution and that the anodic dissolution peak potential of Zn-Co-P alloy has shifted to positive potential in comparison with those of Zn, Zn-P allo y and Zn-Co alloy, therefore, the corrosion resistance of Zn-Co-P alloy increases.
The electro deposition behaviour of Zn-Co-P alloy on Copper Electrode has been studied with cyclic voltammetry. It is shown that the cathodic polarization of Zn-Co alloy increases, if NaH2PO2 has been added into the electroplating solution and that the anodic dissolution peak potential of Zn-Co-P alloy has shifted to positive potential in comparison with those of Zn, Zn-P allo y and Zn-Co alloy, therefore, the corrosion resistance of Zn-Co-P alloy increases.
1997, 14(1): 117-118
Abstract:
Spherical and unagglomerant ZnS particles with submicrometer size were synthesized using W/O emulsions as reaction media. With nonionic-cationic mixed surfactants as emulsifiers for the emulsions, nanosized ZnS particles can be obtained in conventional emulsions.
Spherical and unagglomerant ZnS particles with submicrometer size were synthesized using W/O emulsions as reaction media. With nonionic-cationic mixed surfactants as emulsifiers for the emulsions, nanosized ZnS particles can be obtained in conventional emulsions.
