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2002 Volume 19 Issue 2
2002, 19(2): 104-108
Abstract:
The recent achievements in the functionalization of [60] fullerene are reviewed. The properties and potential applications of the functional materials obtained from [60] fullerene derivatives in materials science and technology are summarized briefly.
The recent achievements in the functionalization of [60] fullerene are reviewed. The properties and potential applications of the functional materials obtained from [60] fullerene derivatives in materials science and technology are summarized briefly.
2002, 19(2): 109-112
Abstract:
The viscosity behavior of the aqueous complex solution of hydrophobically modified amphoteric cellulosic graft copolymer and hydrophobically modified polyacrylamide have been investigated as a function of complex ratio, complex concentration, NaCl concentration, temperature, shear rate and pH by means of Haake Rheometer. The results show that the complex solution exhibits better synergistic viscosity than the single constituent, excellent resistances to salt, temperature and shear rate, and has a maximum viscosity at pH=7.
The viscosity behavior of the aqueous complex solution of hydrophobically modified amphoteric cellulosic graft copolymer and hydrophobically modified polyacrylamide have been investigated as a function of complex ratio, complex concentration, NaCl concentration, temperature, shear rate and pH by means of Haake Rheometer. The results show that the complex solution exhibits better synergistic viscosity than the single constituent, excellent resistances to salt, temperature and shear rate, and has a maximum viscosity at pH=7.
2002, 19(2): 113-116
Abstract:
The binaphthol enantiomers were resolved by capillary electrophoresis combined with conductance detection. The U-cyclodextrin(U-CD) was used as a chiral reagent in sodium hydroxide solution. The Pt wire with diameter of 80 μm was used as working electrode. The separation parameters, such as concentration of running buffer and U-CD, applied voltage, have been studied in detail. Under the optimum conditions, baseline separation of the enantiomers could be completed in 15 minutes. The separation mechanism has been studied by using methylated U-CD as a chiral reagent. It was found that the H bonding is an important factor determining the interaction between molecules.
The binaphthol enantiomers were resolved by capillary electrophoresis combined with conductance detection. The U-cyclodextrin(U-CD) was used as a chiral reagent in sodium hydroxide solution. The Pt wire with diameter of 80 μm was used as working electrode. The separation parameters, such as concentration of running buffer and U-CD, applied voltage, have been studied in detail. Under the optimum conditions, baseline separation of the enantiomers could be completed in 15 minutes. The separation mechanism has been studied by using methylated U-CD as a chiral reagent. It was found that the H bonding is an important factor determining the interaction between molecules.
2002, 19(2): 117-120
Abstract:
Ten α-arylamino-phosphonate have been synthesized by addition reaction of diethyl phosphite with corresponding Schiff bases of arylmethylene-3 amino-1,2,4-triazole. Their structures were characterized by IR, 1H NMR and elemental analysis. Biological tests show that some α-arylamino phosphonates obtained from triazolyl Schiff bases of 4-chlorobenzaldehyde, 4-nitrobenzaldehyde and 2,4-dichlorobenzaldehyde have better auxetic activity as plant hormone.
Ten α-arylamino-phosphonate have been synthesized by addition reaction of diethyl phosphite with corresponding Schiff bases of arylmethylene-3 amino-1,2,4-triazole. Their structures were characterized by IR, 1H NMR and elemental analysis. Biological tests show that some α-arylamino phosphonates obtained from triazolyl Schiff bases of 4-chlorobenzaldehyde, 4-nitrobenzaldehyde and 2,4-dichlorobenzaldehyde have better auxetic activity as plant hormone.
2002, 19(2): 121-125
Abstract:
Nanoparticles of gelatin-γ-iron oxide composite have been prepared by a reverse microemulsion chemical tailoring method.The XRD?SEM?TEM and IR results showed that the ultrafine particles sized in 15 nm were coated by gelatin spheroid, sized in 1.2~3.2 μm and one spheroid contained about 80~213 iron oxide particles. The specific saturation magnetization of particles was es=30.34/(4c)×103A/m, the coercive force Hc=6 207 A/m and residual magnetism Br=2.94/(4c)×103 A/m. All these indicate that the composite nanoparticles exhibit hard magnet properties.
Nanoparticles of gelatin-γ-iron oxide composite have been prepared by a reverse microemulsion chemical tailoring method.The XRD?SEM?TEM and IR results showed that the ultrafine particles sized in 15 nm were coated by gelatin spheroid, sized in 1.2~3.2 μm and one spheroid contained about 80~213 iron oxide particles. The specific saturation magnetization of particles was es=30.34/(4c)×103A/m, the coercive force Hc=6 207 A/m and residual magnetism Br=2.94/(4c)×103 A/m. All these indicate that the composite nanoparticles exhibit hard magnet properties.
2002, 19(2): 126-129
Abstract:
BaO-TiO2-Nd2O3(BTN) precursor was prepared by sol-gel method. Its morphology and structure were characterized by XRD、IR and TEM. BTN powders were sintered and moulded to be ceramic material. The results indicated that the grain had a diameter of 30 nm, with a few agglomerations. The compound crystallized completely at 800℃, and the main crystal phase was Nd2Ti2O7. Compared with solid phase method, the material could be moulded at wider range of temperature(1 270~1 410℃), with steady dielectric constant(X) and small dielectric loss(tgW).
BaO-TiO2-Nd2O3(BTN) precursor was prepared by sol-gel method. Its morphology and structure were characterized by XRD、IR and TEM. BTN powders were sintered and moulded to be ceramic material. The results indicated that the grain had a diameter of 30 nm, with a few agglomerations. The compound crystallized completely at 800℃, and the main crystal phase was Nd2Ti2O7. Compared with solid phase method, the material could be moulded at wider range of temperature(1 270~1 410℃), with steady dielectric constant(X) and small dielectric loss(tgW).
2002, 19(2): 130-134
Abstract:
Ammonium nitrate has been modified by evaporative recrystallization from its mixture solution with hexadecyl trimethyl ammonium bromide and sodium dodecyl sulfate. The physical property of the modified compound has been investigated by SEM, DSC, specific surface area and explosibility measurements. The results show that in comparison with common ammonium nitrate, the modified ammonium nitrate has an irregular crystal shape, greater specific surface area, better particle size distribution, lower heat of crystal pattern transition and higher transition temperature. These indicate the modified ammonium nitrate has a mesoporous structure with good self-sensitizable, anti-hygroscopic and anticaking performance as an industrial explosive agent.
Ammonium nitrate has been modified by evaporative recrystallization from its mixture solution with hexadecyl trimethyl ammonium bromide and sodium dodecyl sulfate. The physical property of the modified compound has been investigated by SEM, DSC, specific surface area and explosibility measurements. The results show that in comparison with common ammonium nitrate, the modified ammonium nitrate has an irregular crystal shape, greater specific surface area, better particle size distribution, lower heat of crystal pattern transition and higher transition temperature. These indicate the modified ammonium nitrate has a mesoporous structure with good self-sensitizable, anti-hygroscopic and anticaking performance as an industrial explosive agent.
2002, 19(2): 135-139
Abstract:
A new type of proton exchange membrane modified with phosphoric acid is used as a solid electrolyte in the electrochemical gas sensor worked at the fixed potential. It was found that this type of membrane has advantages of high conductivity, good stickness, low price and good water preserving ability. The sensor prepared with this type of membrane possesses low background current and noise. The relationship between gas concentration and response signal is linear. Therefore, it is hopeful to obtain a new type of gas electrochemical sensor with solid electrolyte.
A new type of proton exchange membrane modified with phosphoric acid is used as a solid electrolyte in the electrochemical gas sensor worked at the fixed potential. It was found that this type of membrane has advantages of high conductivity, good stickness, low price and good water preserving ability. The sensor prepared with this type of membrane possesses low background current and noise. The relationship between gas concentration and response signal is linear. Therefore, it is hopeful to obtain a new type of gas electrochemical sensor with solid electrolyte.
2002, 19(2): 140-143
Abstract:
Six solid complexes of phenylcarboxymethyl sulfoxide(LH) with lanthanide(Ln=La,Ce,Pr,Nd,Sm,Eu) have been synthesized and characterized. Elemental analysis and 1H NMR results suggested that the complexes have a composition of RELCl2·3H2O·1.5C2H5OH(RE=La,Ce,Pr,Nd,Sm,Eu). The molar conductivities of the complexes in aqueous solution indicated that Cl-anions are not coordinated. IR results indicated the ligand is bonded with RE3+ ions through two oxygen atoms in carboxyl group as a symmetrical chelating bidentate group and one oxygen atom in sulfoxyl group. Fluorescence spectrum of Eu3+ complex revealed that there is no inversion symmetry at the site of Eu3+ ion.
Six solid complexes of phenylcarboxymethyl sulfoxide(LH) with lanthanide(Ln=La,Ce,Pr,Nd,Sm,Eu) have been synthesized and characterized. Elemental analysis and 1H NMR results suggested that the complexes have a composition of RELCl2·3H2O·1.5C2H5OH(RE=La,Ce,Pr,Nd,Sm,Eu). The molar conductivities of the complexes in aqueous solution indicated that Cl-anions are not coordinated. IR results indicated the ligand is bonded with RE3+ ions through two oxygen atoms in carboxyl group as a symmetrical chelating bidentate group and one oxygen atom in sulfoxyl group. Fluorescence spectrum of Eu3+ complex revealed that there is no inversion symmetry at the site of Eu3+ ion.
2002, 19(2): 144-148
Abstract:
The crystal structure of a mixed valence compound,[C10H10N]4PMo9W3O40·2DMF is reported. The crystal is monoclinic with space group P21/n, a=1.490 6(4)nm, b=1.249 6(1) nm, c=1.765 2(5) nm, U=98.16(1)°, V=3.254 7(13) nm3, Z=2, Dc=2.791 g/nm3,Mr=2.735 84, R=0.053 1 and Rw=0.136 2. A certain change in bond distance is found for all of anions and the PO4 tetrahedron is markedly distorted after displacement of molybdenum atom by tungsten. The reduced electrons are delocalized among the molybdenum atoms and the degree of delocalization decreases with the decrease in temperature. The compound exhibits the third order nonlinear optical properties,with the third order susceptibility being i(3)=1.48×10-13esu.
The crystal structure of a mixed valence compound,[C10H10N]4PMo9W3O40·2DMF is reported. The crystal is monoclinic with space group P21/n, a=1.490 6(4)nm, b=1.249 6(1) nm, c=1.765 2(5) nm, U=98.16(1)°, V=3.254 7(13) nm3, Z=2, Dc=2.791 g/nm3,Mr=2.735 84, R=0.053 1 and Rw=0.136 2. A certain change in bond distance is found for all of anions and the PO4 tetrahedron is markedly distorted after displacement of molybdenum atom by tungsten. The reduced electrons are delocalized among the molybdenum atoms and the degree of delocalization decreases with the decrease in temperature. The compound exhibits the third order nonlinear optical properties,with the third order susceptibility being i(3)=1.48×10-13esu.
2002, 19(2): 149-152
Abstract:
6-Methoxy-2-propionyl naphthalene was halogenated with cupric halide, then ketalated with 1,2-propanediol, catalytically rearranged by Zn(OAc)2 or ZnO to give dl-naproxen in yield of 85%~90.4% based on 6-methoxy-2-propionyl naphthalene. All reactions were carried out in "one pot" without additional separation of the intermediates. The route of catalytic rearrangement by using cupric chloride as halogenating agent and zine oxide as catalyst via 2-chloro-2-(6-methoxy-2'-naphthyl)-4 methy-1,3-dioxolane appeared more economical due to the cheapness of reagents and simplicity in separation.
6-Methoxy-2-propionyl naphthalene was halogenated with cupric halide, then ketalated with 1,2-propanediol, catalytically rearranged by Zn(OAc)2 or ZnO to give dl-naproxen in yield of 85%~90.4% based on 6-methoxy-2-propionyl naphthalene. All reactions were carried out in "one pot" without additional separation of the intermediates. The route of catalytic rearrangement by using cupric chloride as halogenating agent and zine oxide as catalyst via 2-chloro-2-(6-methoxy-2'-naphthyl)-4 methy-1,3-dioxolane appeared more economical due to the cheapness of reagents and simplicity in separation.
2002, 19(2): 153-157
Abstract:
Hydroxyethyl cellulose/silicon dioxide gel composites(HEC/SiO2) prepared by a sol-gel method through the hydrolysis and polycondensation of tetramethoxy-silicane in a hydroxyethyl cellulose aqueous solution. The gel composites are used as carriers for immobilization of glucose oxidase(GOD). The effects of enzyme content given, phosphate buffer pH, and immobilizing temperature on the activity of immobilized GOD are discussed. The optimum conditions obtained as follows:enzyme content given 21 mg, phosphate buffer pH=6.5, immobilizing temperature 32℃. Under the optimum conditions, the bioactivity of the immobilized GOD was as high as 1 000 μmol/(min·g) (dried carrier), about 50 percentage of that of free GOD. The basic proporties of the immobilized GOD are also studied. The results showed that the optimum pH of resultant immobilized GOD and temperature for immobilization were 5.2 and 32℃, respectively. The Michaelis constant(Km) is 7.94 mmol/L.
Hydroxyethyl cellulose/silicon dioxide gel composites(HEC/SiO2) prepared by a sol-gel method through the hydrolysis and polycondensation of tetramethoxy-silicane in a hydroxyethyl cellulose aqueous solution. The gel composites are used as carriers for immobilization of glucose oxidase(GOD). The effects of enzyme content given, phosphate buffer pH, and immobilizing temperature on the activity of immobilized GOD are discussed. The optimum conditions obtained as follows:enzyme content given 21 mg, phosphate buffer pH=6.5, immobilizing temperature 32℃. Under the optimum conditions, the bioactivity of the immobilized GOD was as high as 1 000 μmol/(min·g) (dried carrier), about 50 percentage of that of free GOD. The basic proporties of the immobilized GOD are also studied. The results showed that the optimum pH of resultant immobilized GOD and temperature for immobilization were 5.2 and 32℃, respectively. The Michaelis constant(Km) is 7.94 mmol/L.
2002, 19(2): 158-162
Abstract:
Three 4-acyl bis(1,3-diphenyl-5-pyrazolone) have been synthesized:1,5 bis(1'-,3'-diphenyl-5'-pyrazolone-4'-yl)-1,5-pentanedione, 1,6-bis(1'-,3'-diphenyl-5'-pyrazolone-4'-yl)-1,6-hexanedione and 1,10-bis(1'-,3'-diphenyl-5'-pyrazolone-4'-yl)-1,10-decanedione. The composition of the products were characterized by elemental analysis, FT-IR and 1H NMR spectra. The binary and ternary complexes of Tb(Ⅲ) with the above compounds together with 1,10-phenanthroline(Phen) or 2,2-dipyridine(Dipy) have been prepared. The fluorescence properties of the complexes have been investigated. The characteristic fluorescence of Tb(Ⅲ) ion, and the energy level of the triplet state of the three 4-acyl bis(1,3-diphenyl-5-pyrazolone) ligands were found to be well matched with the lowest excited state(5D4) level of the Tb(Ⅲ) ion. The fluorescence intensities of the complexes decreased with the increase of the length of carbon chains between the two pyrazolone rings of 4-acyl bis(1,3-dipheny-5-pyrazolone) ligands. The second ligand, Phen and Dipy, enhanced the fluorescence intensity of the complexes, while the Phen appeared to be better than the Dipy.
Three 4-acyl bis(1,3-diphenyl-5-pyrazolone) have been synthesized:1,5 bis(1'-,3'-diphenyl-5'-pyrazolone-4'-yl)-1,5-pentanedione, 1,6-bis(1'-,3'-diphenyl-5'-pyrazolone-4'-yl)-1,6-hexanedione and 1,10-bis(1'-,3'-diphenyl-5'-pyrazolone-4'-yl)-1,10-decanedione. The composition of the products were characterized by elemental analysis, FT-IR and 1H NMR spectra. The binary and ternary complexes of Tb(Ⅲ) with the above compounds together with 1,10-phenanthroline(Phen) or 2,2-dipyridine(Dipy) have been prepared. The fluorescence properties of the complexes have been investigated. The characteristic fluorescence of Tb(Ⅲ) ion, and the energy level of the triplet state of the three 4-acyl bis(1,3-diphenyl-5-pyrazolone) ligands were found to be well matched with the lowest excited state(5D4) level of the Tb(Ⅲ) ion. The fluorescence intensities of the complexes decreased with the increase of the length of carbon chains between the two pyrazolone rings of 4-acyl bis(1,3-dipheny-5-pyrazolone) ligands. The second ligand, Phen and Dipy, enhanced the fluorescence intensity of the complexes, while the Phen appeared to be better than the Dipy.
2002, 19(2): 163-167
Abstract:
Nanometer-sized SnO2 powders were prepa red by a chemical coprecipitation method using SnCl4·5H2O and SbCl3 as precursors. The characteristics of the powders were investigated by DSC-TG, XRD and TEM. The influences of coprecipitation temperature and pH value on the particle size and powder resistance have been investig ated. The results indicate that the powders with a homogenous particle-size distribution and a good dispersivity are tetragonal rutile-type antimony-doped tin oxide polycrystalline particles. The particle size and powder resistance are insensitive to the coprecipitation temperature. The proper coprecipitation temperature is about 45~70℃. The particle size reaches a maximum at pH=4~6 whereas the corresponding resistance of the sample is smaller. The optimal range of pH value is 3~5, when both particle size and electrical property are in consideration.
Nanometer-sized SnO2 powders were prepa red by a chemical coprecipitation method using SnCl4·5H2O and SbCl3 as precursors. The characteristics of the powders were investigated by DSC-TG, XRD and TEM. The influences of coprecipitation temperature and pH value on the particle size and powder resistance have been investig ated. The results indicate that the powders with a homogenous particle-size distribution and a good dispersivity are tetragonal rutile-type antimony-doped tin oxide polycrystalline particles. The particle size and powder resistance are insensitive to the coprecipitation temperature. The proper coprecipitation temperature is about 45~70℃. The particle size reaches a maximum at pH=4~6 whereas the corresponding resistance of the sample is smaller. The optimal range of pH value is 3~5, when both particle size and electrical property are in consideration.
2002, 19(2): 168-172
Abstract:
The Mo-Bi-Fe-P/sepiolite catalysts were prepared by a coprecipitation method and characterized by XRD and BET techniques. Their catalytic activities were investigated in a selfe made fixed bed reactor as function of temperature, pore size distribution of the catalysts and space velocity(GHSV) of the feed gas. The results showed that at the conditions of V(propylene):V(ammonia):V (air)=1:1.05:11, GHSV=580 h-1, reaction temperature ca. 530℃, the catalyst had pore size ranged in 40~100 nm, acrylonitrile in yield being of 81.4% and propylene conversion of 98.5% could be achieved.
The Mo-Bi-Fe-P/sepiolite catalysts were prepared by a coprecipitation method and characterized by XRD and BET techniques. Their catalytic activities were investigated in a selfe made fixed bed reactor as function of temperature, pore size distribution of the catalysts and space velocity(GHSV) of the feed gas. The results showed that at the conditions of V(propylene):V(ammonia):V (air)=1:1.05:11, GHSV=580 h-1, reaction temperature ca. 530℃, the catalyst had pore size ranged in 40~100 nm, acrylonitrile in yield being of 81.4% and propylene conversion of 98.5% could be achieved.
2002, 19(2): 173-175
Abstract:
The catalytic activity of complex[(ButC5H4)2NdMe]2(1) for MMA polymerization has been investigated. It was found that (1) shows high catalytic activity at-78℃, however, the catalytic activity decreases with the increase of polymerization temperature dramatically. The conversion is as high as 100% at 40℃ in the case of n(catalyst):n(monomer)=3:1000, while the conversion is 0 at 40℃. The stoichiometric reaction between (1) and MMA in 1:2 mole ratio at 40℃ gave complex[(ButC5H4)2NdMe]2(2), which was formed by the nucleophilic substitution reaction of (1) to ester group of MMA. The result is explained in terms of deactivation of (1) for MMA polymerization above room temperature. The structure of (2) was confirmed by elemental analysis, IR, MS and X-ray diffraction measurements.
The catalytic activity of complex[(ButC5H4)2NdMe]2(1) for MMA polymerization has been investigated. It was found that (1) shows high catalytic activity at-78℃, however, the catalytic activity decreases with the increase of polymerization temperature dramatically. The conversion is as high as 100% at 40℃ in the case of n(catalyst):n(monomer)=3:1000, while the conversion is 0 at 40℃. The stoichiometric reaction between (1) and MMA in 1:2 mole ratio at 40℃ gave complex[(ButC5H4)2NdMe]2(2), which was formed by the nucleophilic substitution reaction of (1) to ester group of MMA. The result is explained in terms of deactivation of (1) for MMA polymerization above room temperature. The structure of (2) was confirmed by elemental analysis, IR, MS and X-ray diffraction measurements.
2002, 19(2): 176-178
Abstract:
Fourteen novel 4-dimethylaminobenzaldoxime of substituted carboxylates were synthesized. The bioassays indicated that compounds g, h, and m possessed good insecticidal activity, compound n showed significant fungicidal activity.
Fourteen novel 4-dimethylaminobenzaldoxime of substituted carboxylates were synthesized. The bioassays indicated that compounds g, h, and m possessed good insecticidal activity, compound n showed significant fungicidal activity.
2002, 19(2): 179-180
Abstract:
Four-1-methoxy-1-alkylthiopropanes(3a,3b,3c,3d) were synthesized by the reaction of 1-methoxy-1-alkylthiolpropane with n-propyl mercaptan, n-butyl mercaptan, fufuyl mercaptan or benzyl mercaptan, respectively, at 20℃ for 20 min in yield of 40%~64%. The structures of the products were identified by sulfur elemental analysis, IR, MS and 1HNMR.
Four-1-methoxy-1-alkylthiopropanes(3a,3b,3c,3d) were synthesized by the reaction of 1-methoxy-1-alkylthiolpropane with n-propyl mercaptan, n-butyl mercaptan, fufuyl mercaptan or benzyl mercaptan, respectively, at 20℃ for 20 min in yield of 40%~64%. The structures of the products were identified by sulfur elemental analysis, IR, MS and 1HNMR.
2002, 19(2): 181-183
Abstract:
Ozone-mediated nitration of chlorobenzene with nitrogen dioxide over solid acid catalysts is expected to be a green process. The reaction was carried out at ca. 0℃. It was found that the solid acid catalysts of SO42-/TiO2 and SO42-/ZrO2 and a series of SO42-/TiO2-ZrO2 catalysts exhibited a fairly good activity for the nitration reaction, whereas SO42-/TiO2-ZrO2(atomic ratio 1:1) gives yield of 62.4% and SO42-/TiO2-ZrO2(molar ratio 3:1) shows a good para selectivity in CH2Cl2 solvent. The ortho para isomer ratios(ortho/para) of the nitration products were varied in range from 1.11 to 0.36. This phenomenon is interpreted in terms of acid amount and acid strength of solid acid catalysts.
Ozone-mediated nitration of chlorobenzene with nitrogen dioxide over solid acid catalysts is expected to be a green process. The reaction was carried out at ca. 0℃. It was found that the solid acid catalysts of SO42-/TiO2 and SO42-/ZrO2 and a series of SO42-/TiO2-ZrO2 catalysts exhibited a fairly good activity for the nitration reaction, whereas SO42-/TiO2-ZrO2(atomic ratio 1:1) gives yield of 62.4% and SO42-/TiO2-ZrO2(molar ratio 3:1) shows a good para selectivity in CH2Cl2 solvent. The ortho para isomer ratios(ortho/para) of the nitration products were varied in range from 1.11 to 0.36. This phenomenon is interpreted in terms of acid amount and acid strength of solid acid catalysts.
2002, 19(2): 184-186
Abstract:
Three complexes of tetrachlorophenylporphyrinatomanganese acetates have been synthesized and characterized by IR and UV spectra. The asymmetric epoxdation of styrene has been investigated by using these three complexes as catalysts, chiral quaternary ammonium salts as phase transfer catalysts, and quinine as chiral auxiliary, sodium hypochlorite as oxidant. The results showed that the structure of manganese porphyrins, the chiral auxiliaries and temperature of reaction affected the asymmetric induction. The best enantiomer excess reached 12.8%.
Three complexes of tetrachlorophenylporphyrinatomanganese acetates have been synthesized and characterized by IR and UV spectra. The asymmetric epoxdation of styrene has been investigated by using these three complexes as catalysts, chiral quaternary ammonium salts as phase transfer catalysts, and quinine as chiral auxiliary, sodium hypochlorite as oxidant. The results showed that the structure of manganese porphyrins, the chiral auxiliaries and temperature of reaction affected the asymmetric induction. The best enantiomer excess reached 12.8%.
2002, 19(2): 187-189
Abstract:
The adsorption and separation of β-nephthalenesulfonic acid(NSA) from synthetic waste water by microporous resins have been investigated as function of temperature, acidity and co existed acids. The thermodynamic parameters have been preliminary calculated. The kinetic study for the adsorption process indicated resin Indion 860 appeared an effective adsorbent for NSA.
The adsorption and separation of β-nephthalenesulfonic acid(NSA) from synthetic waste water by microporous resins have been investigated as function of temperature, acidity and co existed acids. The thermodynamic parameters have been preliminary calculated. The kinetic study for the adsorption process indicated resin Indion 860 appeared an effective adsorbent for NSA.
2002, 19(2): 190-192
Abstract:
Notable features of EIMS cleavage for eight N,N'-diacyl adipyl dihydra zides are summarized. The sources and chemical structures of the main fragments are interpreted. All of the eight compounds give the base peak of m/z 143. The main fragments are from the T-cleavage and its rearranging ones at the carbonyl gronp.
Notable features of EIMS cleavage for eight N,N'-diacyl adipyl dihydra zides are summarized. The sources and chemical structures of the main fragments are interpreted. All of the eight compounds give the base peak of m/z 143. The main fragments are from the T-cleavage and its rearranging ones at the carbonyl gronp.
2002, 19(2): 193-195
Abstract:
The PbO2 was used as an electrode material with Pt flake as substrate. The optimum plating conditions for electrode preparation are described. The prepared PbO2 electrode is consisted of T-PbO2 and U-PbO2. XRD, XPS and SEM are used to approve the electrode performance. The results showed that the prepared PbO2 electrode has advantages of longer life, better stability and higher oxidation efficiency for organic compounds.
The PbO2 was used as an electrode material with Pt flake as substrate. The optimum plating conditions for electrode preparation are described. The prepared PbO2 electrode is consisted of T-PbO2 and U-PbO2. XRD, XPS and SEM are used to approve the electrode performance. The results showed that the prepared PbO2 electrode has advantages of longer life, better stability and higher oxidation efficiency for organic compounds.
2002, 19(2): 196-198
Abstract:
Following six compounds have been at first time isolated from the stems and leaves of Ginseng Panax ginseng C.A.Meyer by TLC technique and identified by IR, LC-MS and NMR as:(Ⅰ)hexadecanoic acid, (Ⅱ)1,7,7-trimethyl bicyclo-2,3-hexandione, (Ⅲ)(2E,4E) decadienal, (Ⅳ) Δ4(8)-d-menthene-3-one, (Ⅴ)2,6-di-tert-butyl-4-methylphenol and (Ⅵ)2-methylmethahexadecanoate.
Following six compounds have been at first time isolated from the stems and leaves of Ginseng Panax ginseng C.A.Meyer by TLC technique and identified by IR, LC-MS and NMR as:(Ⅰ)hexadecanoic acid, (Ⅱ)1,7,7-trimethyl bicyclo-2,3-hexandione, (Ⅲ)(2E,4E) decadienal, (Ⅳ) Δ4(8)-d-menthene-3-one, (Ⅴ)2,6-di-tert-butyl-4-methylphenol and (Ⅵ)2-methylmethahexadecanoate.
2002, 19(2): 199-201
Abstract:
A discoloring reaction has been developed that calcon-sodium carboxylate could be oxidized by hydrogen peroxide in the presence of catalase. The optimum conditions, kinetic parameters and reaction mechanism have been investigated. The maximum initial velocity of reaction is 1.4×10-6 mol/(L·s), and Michaelis constant Km is 2.9×10-5 mol/L. The linear range of determination for hydrogen peroxide is 0~2.6×10-5 mol/L. The method has been applied to the determination of trace amount of hydrogen peroxide in rainwater.
A discoloring reaction has been developed that calcon-sodium carboxylate could be oxidized by hydrogen peroxide in the presence of catalase. The optimum conditions, kinetic parameters and reaction mechanism have been investigated. The maximum initial velocity of reaction is 1.4×10-6 mol/(L·s), and Michaelis constant Km is 2.9×10-5 mol/L. The linear range of determination for hydrogen peroxide is 0~2.6×10-5 mol/L. The method has been applied to the determination of trace amount of hydrogen peroxide in rainwater.
2002, 19(2): 202-204
Abstract:
The nanosized Co3O4 was selected as pH-sensitive material, from which the solid pH electrode was fabricated by screen printed technique. Such an electrode showed linear response in the range of pH2~12 with response sensitivity of-56.4 mV/pH. The reproducibility and selectivity of the electrode have been discussed. The electrode exhibited satisfactory pH-response performance for the corrosion system containing HF.
The nanosized Co3O4 was selected as pH-sensitive material, from which the solid pH electrode was fabricated by screen printed technique. Such an electrode showed linear response in the range of pH2~12 with response sensitivity of-56.4 mV/pH. The reproducibility and selectivity of the electrode have been discussed. The electrode exhibited satisfactory pH-response performance for the corrosion system containing HF.
