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2004 Volume 21 Issue 12
2004, 21(12): 1205-1210
Abstract:
A series of binuclear zinc Schiff base complexes were synthesized by the reaction of di-Schiff base dimers bridged with alkyloxy links of different length and zinc acetate. The complexes were characterized by elemental analysis, FT-IR, 1H NMR and UV-vis. The result shows that the complexes adopt stretched conformations in DMSO. The red shift of B10-Zn2 in CH2Cl2 can be explained in terms of metal-π interaction in the close conformation of the discrete di-Schiff base units. The conformation analysis was performed to explain the experimental results.
A series of binuclear zinc Schiff base complexes were synthesized by the reaction of di-Schiff base dimers bridged with alkyloxy links of different length and zinc acetate. The complexes were characterized by elemental analysis, FT-IR, 1H NMR and UV-vis. The result shows that the complexes adopt stretched conformations in DMSO. The red shift of B10-Zn2 in CH2Cl2 can be explained in terms of metal-π interaction in the close conformation of the discrete di-Schiff base units. The conformation analysis was performed to explain the experimental results.
2004, 21(12): 1211-1216
Abstract:
The ternary solid complex Er(Et2dtc)3(phen) was synthesized from sodium diethyldithiocarbamate (NaEt2dtc), 1,10-phenanthroline(o-phen) and hydrated terbium chloride in absolute ethanol. The general formula of the complex was determined by chemical and elemental analyses. The IR spectrum of the complex shows that the Er3+ is coordinated with the sulfur atoms of NaEt2dtc and the nitrogen atoms of o-phen. The enthalpy change in the liquid-phase formation reaction of the complex, ΔrHmθ(l), was determined by means of a microcalorimeter to be (-13.857±0.096) kJ/mol at 298.15 K. The enthalpy change in the solid-phase formation reaction, ΔrHmθ(s), was calculated to be (119.662±0.695) kJ/mol. The thermodynamic and kinetic parameters of the liquid-phase formation reaction of the complex were obtained. The constant-volumetric combustion energy of the complex ΔcU was determined to be (-18 436.62±9.11) kJ/mol at 298.15 K. Its standard enthalpy of combustion ΔcHmθ and standard enthalpy of formation ΔfHmθ were calculated to be (-18 455.83±9.11) kJ/mol and (-329.48±9.91) kJ/mol, respectively.
The ternary solid complex Er(Et2dtc)3(phen) was synthesized from sodium diethyldithiocarbamate (NaEt2dtc), 1,10-phenanthroline(o-phen) and hydrated terbium chloride in absolute ethanol. The general formula of the complex was determined by chemical and elemental analyses. The IR spectrum of the complex shows that the Er3+ is coordinated with the sulfur atoms of NaEt2dtc and the nitrogen atoms of o-phen. The enthalpy change in the liquid-phase formation reaction of the complex, ΔrHmθ(l), was determined by means of a microcalorimeter to be (-13.857±0.096) kJ/mol at 298.15 K. The enthalpy change in the solid-phase formation reaction, ΔrHmθ(s), was calculated to be (119.662±0.695) kJ/mol. The thermodynamic and kinetic parameters of the liquid-phase formation reaction of the complex were obtained. The constant-volumetric combustion energy of the complex ΔcU was determined to be (-18 436.62±9.11) kJ/mol at 298.15 K. Its standard enthalpy of combustion ΔcHmθ and standard enthalpy of formation ΔfHmθ were calculated to be (-18 455.83±9.11) kJ/mol and (-329.48±9.91) kJ/mol, respectively.
2004, 21(12): 1217-1220
Abstract:
The spectral characteristic of the system of I3--butyl rhodamine B(BRhB) in 0.08 mol/L HCl were investi-gated by resonance scattering spectroscopy combined with fluorescence, absorption spectroscopy and SEM. It is found that there is an absorption peak at 585 nm, a fluorescence peak at 580 nm and a synchronous fluorescence peak at 570 nm for BRhB. By mixing with I3-, the BRhB forms an ion association nano-particle in size of about 60 nm. The nanoparticles exhibit three resonance scattering peaks at 420 nm, 530 nm and 605 nm, and fluorescence quenching at 580 nm, and hypochromic effect at 585 nm. In the range of 2.0×10-7 to 4.0×-7 mol/L of iodine, it is found the concentration is proportional to the resonance scattering peak at 605 nm. The spectroscopy and scan electron microscopy results verified the formation of (BRhB-I3)n and that the fluorescence quenching, hypochromic and resonance scattering effects are mainly caused by the formation and interface of associated nanoparticles.
The spectral characteristic of the system of I3--butyl rhodamine B(BRhB) in 0.08 mol/L HCl were investi-gated by resonance scattering spectroscopy combined with fluorescence, absorption spectroscopy and SEM. It is found that there is an absorption peak at 585 nm, a fluorescence peak at 580 nm and a synchronous fluorescence peak at 570 nm for BRhB. By mixing with I3-, the BRhB forms an ion association nano-particle in size of about 60 nm. The nanoparticles exhibit three resonance scattering peaks at 420 nm, 530 nm and 605 nm, and fluorescence quenching at 580 nm, and hypochromic effect at 585 nm. In the range of 2.0×10-7 to 4.0×-7 mol/L of iodine, it is found the concentration is proportional to the resonance scattering peak at 605 nm. The spectroscopy and scan electron microscopy results verified the formation of (BRhB-I3)n and that the fluorescence quenching, hypochromic and resonance scattering effects are mainly caused by the formation and interface of associated nanoparticles.
2004, 21(12): 1221-1224
Abstract:
V2O5/γ-Al2O3 and V2O5/SiO2 catalysts were prepared by the impregnation method and characte-rized by H2-TPR, NH3-TPD and ESR. Their catalytic activities were compared in the dehydrogenation of isobutane to isobutene at 580℃. The results show that V2O5/γ-Al2O3 exhibits higher activity than V2O5/SiO2, resulting in 35.4% conversion rate, which is correlated with that vanadium oxide is better dispersed and more easily reduced on γ-Al2O3(reduction temperature 542℃) than on SiO2, whereas V2O5/SiO2 exhibits higher selectivity of isobutene higher than V2O5/γ-Al2O3 due to weaker acidity of the SiO2 surface than that of the γ-Al2O3 surface.
V2O5/γ-Al2O3 and V2O5/SiO2 catalysts were prepared by the impregnation method and characte-rized by H2-TPR, NH3-TPD and ESR. Their catalytic activities were compared in the dehydrogenation of isobutane to isobutene at 580℃. The results show that V2O5/γ-Al2O3 exhibits higher activity than V2O5/SiO2, resulting in 35.4% conversion rate, which is correlated with that vanadium oxide is better dispersed and more easily reduced on γ-Al2O3(reduction temperature 542℃) than on SiO2, whereas V2O5/SiO2 exhibits higher selectivity of isobutene higher than V2O5/γ-Al2O3 due to weaker acidity of the SiO2 surface than that of the γ-Al2O3 surface.
Preparation and Resonance Light Scattering Property of Functional β-Diketone Polymeric Nanoparticles
2004, 21(12): 1225-1228
Abstract:
A kind of functional β-diketone polymeric nanoparticles(PVK) was prepared by an oxidation-degradation of PVK under ultrasonic radiation. The enol structures of PVK were characterized by IR spectroscopy. The nanoparticles are spherical with an average diameter of 20 nm. Studies on the resonance light scattering(RLS) properties of PVK show that the interaction of PVK with the proteins results in a great enhancement of RLS signals at 380 nm when pH=3.0. And the enhanced intensity of PLS at this wavelength is proportional to the concentration of the proteins. A protein determination method is thus proposed based on this property. Under optimal conditions, the linear ranges are o~15.0×10-6 g/mL and 0.2×10-6~8.5×10-6 g/mL for HSA and γ-G, respectively. The detection limits are 1.4×10-9 g/mL and 17.5×10-9 g/mL for HSA and γ-G, respectively. The method has been applied to the analysis of total proteins in human serum samples with satisfactory result.
A kind of functional β-diketone polymeric nanoparticles(PVK) was prepared by an oxidation-degradation of PVK under ultrasonic radiation. The enol structures of PVK were characterized by IR spectroscopy. The nanoparticles are spherical with an average diameter of 20 nm. Studies on the resonance light scattering(RLS) properties of PVK show that the interaction of PVK with the proteins results in a great enhancement of RLS signals at 380 nm when pH=3.0. And the enhanced intensity of PLS at this wavelength is proportional to the concentration of the proteins. A protein determination method is thus proposed based on this property. Under optimal conditions, the linear ranges are o~15.0×10-6 g/mL and 0.2×10-6~8.5×10-6 g/mL for HSA and γ-G, respectively. The detection limits are 1.4×10-9 g/mL and 17.5×10-9 g/mL for HSA and γ-G, respectively. The method has been applied to the analysis of total proteins in human serum samples with satisfactory result.
2004, 21(12): 1229-1232
Abstract:
The auxiliaries of gasoline antiknock additive TKC were analysed by means of gas chromatography/mass spectrometry. The main auxiliary components were found to be toluene, dichloroethane, tetrachloroethy-lene, and butyl acetate. The electrochemical properties of ferrocene in the auxiliary additive in the presence and the absence of hydrogen peroxide were investigated at a platinum electrode by cyclic voltammetry. The electrode processes and cooperative effect of the additive components were determined. All the electrode reactions in the various media followed the catalytic EC(electron transfer-chemical reaction) mechanism.
The auxiliaries of gasoline antiknock additive TKC were analysed by means of gas chromatography/mass spectrometry. The main auxiliary components were found to be toluene, dichloroethane, tetrachloroethy-lene, and butyl acetate. The electrochemical properties of ferrocene in the auxiliary additive in the presence and the absence of hydrogen peroxide were investigated at a platinum electrode by cyclic voltammetry. The electrode processes and cooperative effect of the additive components were determined. All the electrode reactions in the various media followed the catalytic EC(electron transfer-chemical reaction) mechanism.
2004, 21(12): 1233-1236
Abstract:
Two novel benzimidazole derivatives, 3-N-5,8,8-trimethylbicyclo[3.2.1]octan-2-one[3.4-a]-benzoimidazole and 3-N-1,8,8-trimethylbicyclo[3.2.1]octan-2-one[3.4-a]benzoimidazole, were synthesized by the condensation of camphorated acid with o-phenylenediamine under microwave irradiation. The structures of the compounds were confirmed by 1H NMR, IR, elemental analysis and X-ray crystal analysis.
Two novel benzimidazole derivatives, 3-N-5,8,8-trimethylbicyclo[3.2.1]octan-2-one[3.4-a]-benzoimidazole and 3-N-1,8,8-trimethylbicyclo[3.2.1]octan-2-one[3.4-a]benzoimidazole, were synthesized by the condensation of camphorated acid with o-phenylenediamine under microwave irradiation. The structures of the compounds were confirmed by 1H NMR, IR, elemental analysis and X-ray crystal analysis.
2004, 21(12): 1237-1240
Abstract:
The mechanism of the preparation of 0.5Pb(Mg1/2W1/2)O3-0.5PbTiO3(PMW-PT) powder by the semichemical method was studied. The precursors were prepared by addition of an aqueous Mg(Ac)2 solution into the alcohol slurry of PbO, WO3 and TiO2 instead of solid MgO commonly used. The TG-DTG-DSC analyses of the precursors and XRD analyses of the powders obtained at different calcination temperatures show that the mechanism of this method is different from that of the conventional mixed oxide method. The aqueous Mg(Ac)2 solution reacts with PbO to form Pb(Ac)2·Pb(OH)2·H2O, Pb(Ac)2·2PbO·H2O and Mg(OH)2, which decompose to form nascent PbO and MgO, significantly improving the reactivity and dispersion of PbO and MgO. The method requires much lower temperature for the formation of the perofskite PMW-PT phase. At a calcination temperature of 850℃, PMW-PT powder with 99% perofskite phase could be obtained.
The mechanism of the preparation of 0.5Pb(Mg1/2W1/2)O3-0.5PbTiO3(PMW-PT) powder by the semichemical method was studied. The precursors were prepared by addition of an aqueous Mg(Ac)2 solution into the alcohol slurry of PbO, WO3 and TiO2 instead of solid MgO commonly used. The TG-DTG-DSC analyses of the precursors and XRD analyses of the powders obtained at different calcination temperatures show that the mechanism of this method is different from that of the conventional mixed oxide method. The aqueous Mg(Ac)2 solution reacts with PbO to form Pb(Ac)2·Pb(OH)2·H2O, Pb(Ac)2·2PbO·H2O and Mg(OH)2, which decompose to form nascent PbO and MgO, significantly improving the reactivity and dispersion of PbO and MgO. The method requires much lower temperature for the formation of the perofskite PMW-PT phase. At a calcination temperature of 850℃, PMW-PT powder with 99% perofskite phase could be obtained.
2004, 21(12): 1241-1244
Abstract:
A gel is formed when a mixture of methyl methacrylate(MMA) and styrene(St) is added to tri-isopropoxyl-rare earth(Eu(OPri)3, Tb(OPri)3 or their mixture), and the rare earth-doped copolymers P(MMA-co-St) are obtained by in-situ polymerization. The copolymers were characterized by dynamic mechanical thermal analysis(DMTA), fluorescence spectro-photometry(FS) and environmental scanning electron microscopy(ESEM). The effects of co-doping of the mixture Eu(OPri)3/Tb(OPri)3 on the properties of the copolymers were studied with emphasis on their fluorescence property. The results show that, the storage moduli of the copolymers co-doped with the mixture Eu(OPri)3/Tb(OPri)3 are higher than that of the corresponding P(MMA-co-St), and the characteristic fluorescence strength of Eu3+ ions increases by about 100 times due to the energy transfer between Tb3+ as a donor and Eu3+ as an acceptor.
A gel is formed when a mixture of methyl methacrylate(MMA) and styrene(St) is added to tri-isopropoxyl-rare earth(Eu(OPri)3, Tb(OPri)3 or their mixture), and the rare earth-doped copolymers P(MMA-co-St) are obtained by in-situ polymerization. The copolymers were characterized by dynamic mechanical thermal analysis(DMTA), fluorescence spectro-photometry(FS) and environmental scanning electron microscopy(ESEM). The effects of co-doping of the mixture Eu(OPri)3/Tb(OPri)3 on the properties of the copolymers were studied with emphasis on their fluorescence property. The results show that, the storage moduli of the copolymers co-doped with the mixture Eu(OPri)3/Tb(OPri)3 are higher than that of the corresponding P(MMA-co-St), and the characteristic fluorescence strength of Eu3+ ions increases by about 100 times due to the energy transfer between Tb3+ as a donor and Eu3+ as an acceptor.
2004, 21(12): 1245-1248
Abstract:
A series of random polycondensates were synthesized by low temperature solution polycondensation of 2,2',6,6'-tetramethyl-diphenoxydiphenylsulfone(o-M2DPODPS), isophthaloyl chloride(IPC) and terephthaloyl chloride(TPC) in the presence of AlCl3 and NMP in 1,2-dicholroethane. The polycondensates were characterized by IR, WAXD, TGA and 1H NMR, and their ηinh and solubilities were determined. The polymers show high Tg due to the presence of bis(o-methyl) groups in the main chain, and the Tg increases with the increase of the ratio of TPC to IPC. The polymers are non-crystalline, and have excellent solubilities.
A series of random polycondensates were synthesized by low temperature solution polycondensation of 2,2',6,6'-tetramethyl-diphenoxydiphenylsulfone(o-M2DPODPS), isophthaloyl chloride(IPC) and terephthaloyl chloride(TPC) in the presence of AlCl3 and NMP in 1,2-dicholroethane. The polycondensates were characterized by IR, WAXD, TGA and 1H NMR, and their ηinh and solubilities were determined. The polymers show high Tg due to the presence of bis(o-methyl) groups in the main chain, and the Tg increases with the increase of the ratio of TPC to IPC. The polymers are non-crystalline, and have excellent solubilities.
2004, 21(12): 1249-1252
Abstract:
CoTiO3 nanoparticles were prepared by a sol-gel method and used for modification of K2FeO4 electrodes. The electrochemical tests showed that the modified electrode provided both the longest high discharge plateau and satisfactory discharge capacity with addition of 20%(mass fraction) CoTiO3. Co(Ⅱ) salt could be oxidized to Co(Ⅲ) by K2FeO4, which resulted in the loss of active material K2FeO4. However, the presence of Co(Ⅲ) could efficiently improve the discharge plateau of K2FeO4 electrodes.
CoTiO3 nanoparticles were prepared by a sol-gel method and used for modification of K2FeO4 electrodes. The electrochemical tests showed that the modified electrode provided both the longest high discharge plateau and satisfactory discharge capacity with addition of 20%(mass fraction) CoTiO3. Co(Ⅱ) salt could be oxidized to Co(Ⅲ) by K2FeO4, which resulted in the loss of active material K2FeO4. However, the presence of Co(Ⅲ) could efficiently improve the discharge plateau of K2FeO4 electrodes.
2004, 21(12): 1253-1256
Abstract:
A new strong cationic amphoteric polymeric flocculant was prepared from a starch-g-polyacrylamide through aminomethylation, sulfonation and quaterization. The effect of the ratio of reagents, temperature, pH and reaction time on the degrees of amination, anion and quaterization were examined. The optimum synthesis conditions were as follows:the mole ratio of n(starch-g-polyacrylamide):n(formaldehyde):n(sodium-bisulfite):n(epoxy chloropropane) equal to 1:1.2:0.7:0.4:0.4, the conditions of sulfomethylation t=65℃, pH=12, time=3.0 h, and the conditions of quaterization t=50℃, pH=11, time=3.5 h. The degrees of amination, anion and quaterization in the product were 5.55 mmol/g, 2.44 mmol/g, and 2.55 mmol/g, respectively.
A new strong cationic amphoteric polymeric flocculant was prepared from a starch-g-polyacrylamide through aminomethylation, sulfonation and quaterization. The effect of the ratio of reagents, temperature, pH and reaction time on the degrees of amination, anion and quaterization were examined. The optimum synthesis conditions were as follows:the mole ratio of n(starch-g-polyacrylamide):n(formaldehyde):n(sodium-bisulfite):n(epoxy chloropropane) equal to 1:1.2:0.7:0.4:0.4, the conditions of sulfomethylation t=65℃, pH=12, time=3.0 h, and the conditions of quaterization t=50℃, pH=11, time=3.5 h. The degrees of amination, anion and quaterization in the product were 5.55 mmol/g, 2.44 mmol/g, and 2.55 mmol/g, respectively.
2004, 21(12): 1257-1260
Abstract:
A nonsteroidal antiinflammatory drug, probenecid, was covalently linked with 2-hydroxyethyl methacrylate(HEMA) through esterification reaction. The drug-linked HEMA(abbreviated as HP) was copolymerized with polyoxyethylene macromers(PEO-MA) to obtain macromolecular prodrugs using azobisisobutyronitrile(AIBN) as an initiator. The polymer was characterized with IR, 1H NMR and GPC. The effect of initiator amount and the ratio of drug to monomer were discussed. Increasing the amount of AIBN decreased the molecular weight of the copolymer. Increasing HP content in monomers increased probenecid content in the copolymer.
A nonsteroidal antiinflammatory drug, probenecid, was covalently linked with 2-hydroxyethyl methacrylate(HEMA) through esterification reaction. The drug-linked HEMA(abbreviated as HP) was copolymerized with polyoxyethylene macromers(PEO-MA) to obtain macromolecular prodrugs using azobisisobutyronitrile(AIBN) as an initiator. The polymer was characterized with IR, 1H NMR and GPC. The effect of initiator amount and the ratio of drug to monomer were discussed. Increasing the amount of AIBN decreased the molecular weight of the copolymer. Increasing HP content in monomers increased probenecid content in the copolymer.
2004, 21(12): 1261-1264
Abstract:
The extraction of ferrous ions from natural wollastonite was carried out with a mixture of oxalic acid and O-phenanthroline. The leaching percentage of ferrous ions, concentration of extracting reagent, extracting time and temperature on the extraction were investigated in the extraction procedure. Under the optimum extracting conditions, the leaching percentage of ferrous ions is up to 98.35%. The luminescence material was synthesized by ceramics method with Eu3+-doped wollastonite.And the luminescence intensity of the material almost approached that of chemically synthesized CaSiO3:Eu3+.
The extraction of ferrous ions from natural wollastonite was carried out with a mixture of oxalic acid and O-phenanthroline. The leaching percentage of ferrous ions, concentration of extracting reagent, extracting time and temperature on the extraction were investigated in the extraction procedure. Under the optimum extracting conditions, the leaching percentage of ferrous ions is up to 98.35%. The luminescence material was synthesized by ceramics method with Eu3+-doped wollastonite.And the luminescence intensity of the material almost approached that of chemically synthesized CaSiO3:Eu3+.
2004, 21(12): 1265-1268
Abstract:
Twenty five thiazoline compounds were synthesized and characterized by elemental analysis and 1H NMR technique. The molecular structure of compound 4f was confirmed by XRD. The antibacterial activities of the compounds were tested in vitro. It was found that the substituted phenylaminothiazoline, e.g., compounds 3b, 3c and 3e exhibit excellent activity against Phoma asparagi in dosage of 50 mg/L(inhibitory ratio 100%), while 3b and 3c give the analogues results against Gibberella zeae at the same concentration.
Twenty five thiazoline compounds were synthesized and characterized by elemental analysis and 1H NMR technique. The molecular structure of compound 4f was confirmed by XRD. The antibacterial activities of the compounds were tested in vitro. It was found that the substituted phenylaminothiazoline, e.g., compounds 3b, 3c and 3e exhibit excellent activity against Phoma asparagi in dosage of 50 mg/L(inhibitory ratio 100%), while 3b and 3c give the analogues results against Gibberella zeae at the same concentration.
2004, 21(12): 1269-1272
Abstract:
PCL/SiO2 hybrid materials with non-covalently bonding between polymeric and inorganic components were synthesized from high molecular weight poly(ε-caprolactone)(PCL) by a sol-gel process. The FTIR and 13C NMR results confirm that the linkage between the polymeric and inorganic components occur mainly as a result of strongly intermolecular hydrogen bonding in the hybrid system. The transparency of the hybrid materials is good and the geling time is short when the volume ratio of THF to EtOH in the co-solvent is 100:16. DSC and TGA results show that the enthalpy of fusion and melting temperature of PCL for the hybrid materials decrease with increasing the content of the inorganic component and that the onset and the end points of thermal degradation temperature of PCL in the hybrid materials are up to 358℃ and 562℃, respectively.
PCL/SiO2 hybrid materials with non-covalently bonding between polymeric and inorganic components were synthesized from high molecular weight poly(ε-caprolactone)(PCL) by a sol-gel process. The FTIR and 13C NMR results confirm that the linkage between the polymeric and inorganic components occur mainly as a result of strongly intermolecular hydrogen bonding in the hybrid system. The transparency of the hybrid materials is good and the geling time is short when the volume ratio of THF to EtOH in the co-solvent is 100:16. DSC and TGA results show that the enthalpy of fusion and melting temperature of PCL for the hybrid materials decrease with increasing the content of the inorganic component and that the onset and the end points of thermal degradation temperature of PCL in the hybrid materials are up to 358℃ and 562℃, respectively.
2004, 21(12): 1273-1276
Abstract:
A 5 mL disposable separator syringe, a connector and a micro-column is fabricated for the separation and concentration of Pb2+ for its subsquent FAAS determination. The flow rates of samples could be controlled manually by a disposable syringe. A 5 mL of sample solution(pH=3.30) is injected through the micro-column filled with SDG in about 30 seconds and the adsorbed Pb2+ is eluted by 5 mL of 2 mol/L HCl in the same flow rate. The average recovery of Pb2+ is up to 96.95%, RSD is 3.33%(n=22)and pre-concentration factor is 200 for Pb. It can be applied to the separation and concentration of a large volume of sample solution containing trace amounts of Pb2+.
A 5 mL disposable separator syringe, a connector and a micro-column is fabricated for the separation and concentration of Pb2+ for its subsquent FAAS determination. The flow rates of samples could be controlled manually by a disposable syringe. A 5 mL of sample solution(pH=3.30) is injected through the micro-column filled with SDG in about 30 seconds and the adsorbed Pb2+ is eluted by 5 mL of 2 mol/L HCl in the same flow rate. The average recovery of Pb2+ is up to 96.95%, RSD is 3.33%(n=22)and pre-concentration factor is 200 for Pb. It can be applied to the separation and concentration of a large volume of sample solution containing trace amounts of Pb2+.
2004, 21(12): 1277-1280
Abstract:
The relationship between the permeating amount and time of three vinyl silanes(vinyl trimethoxy silane:A171, vinyl tri-2-methoxyethoxysilane:A172, vinyl triethoxysilane:A151) in three different polyethylenes(LDPE, LLDPE, HDPE) was obtained by using a soak-weighing method. The diffusion coefficients at different temperatures were calculated according to Fick's law. Meanwhile, computer simulation of the diffusion behavior in above systems was carried out by using the finite differences method. The diffusion coefficients were also calculated. According to the Arrhenius equation, the activation energies of the diffusion of A171 in HDPE, LDPE, LLDPE were calculated to be 38.2, 24.0 and 22.0 kJ, respectively. This provides a convenient method for the evaluation of the soaking time in the grafting process of polyethylene with silanes.
The relationship between the permeating amount and time of three vinyl silanes(vinyl trimethoxy silane:A171, vinyl tri-2-methoxyethoxysilane:A172, vinyl triethoxysilane:A151) in three different polyethylenes(LDPE, LLDPE, HDPE) was obtained by using a soak-weighing method. The diffusion coefficients at different temperatures were calculated according to Fick's law. Meanwhile, computer simulation of the diffusion behavior in above systems was carried out by using the finite differences method. The diffusion coefficients were also calculated. According to the Arrhenius equation, the activation energies of the diffusion of A171 in HDPE, LDPE, LLDPE were calculated to be 38.2, 24.0 and 22.0 kJ, respectively. This provides a convenient method for the evaluation of the soaking time in the grafting process of polyethylene with silanes.
2004, 21(12): 1281-1284
Abstract:
2-Thio-3-amino-5-arylmethylene-4-imidazolidinones(3) were prepared via the tandem aza-Wittig reaction of vinyliminophosphoranes(1) with carbon disulfide and hydrazines. Then 2-alkylthio-3-amino-5-arylmethylene-4H-imidazolin-4-ones(4) were synthesized by S-alkylation of compound 3. The reaction conditions were discussed, the spectral properties of the synthesized compounds were elucidated, and their structures were confirmed by elemental analysis, IR, 1H NMR and MS. At room temperature or 60~80℃ the compounds 3a~3d and 4a~4f were obtained in yields of 63%~97% and 53%~76% respectively.
2-Thio-3-amino-5-arylmethylene-4-imidazolidinones(3) were prepared via the tandem aza-Wittig reaction of vinyliminophosphoranes(1) with carbon disulfide and hydrazines. Then 2-alkylthio-3-amino-5-arylmethylene-4H-imidazolin-4-ones(4) were synthesized by S-alkylation of compound 3. The reaction conditions were discussed, the spectral properties of the synthesized compounds were elucidated, and their structures were confirmed by elemental analysis, IR, 1H NMR and MS. At room temperature or 60~80℃ the compounds 3a~3d and 4a~4f were obtained in yields of 63%~97% and 53%~76% respectively.
2004, 21(12): 1285-1289
Abstract:
Aniline was polymerized on a nanocrystalline titanium dioxide film electrode(Nano-TiO2) in 1.0 mol/L sulfuric acid by the potentiostatic method. The structure of the composite film was characterized by TEM, XRD and FTIR. Nano-TiO2/polyaniline was used as a positive electrode active material for Zn|Nano-TiO2-PANI rechargeable battery. The charge-discharge behavior of the rechargeable battery and the coulomb efficiency were investigated. The result shows that the initial chargeable capacity and reversible efficiency of the rechargeable battery are 98.04 mA·h/g and 91.67% respectively, charge-discharge curves are observeved stable.
Aniline was polymerized on a nanocrystalline titanium dioxide film electrode(Nano-TiO2) in 1.0 mol/L sulfuric acid by the potentiostatic method. The structure of the composite film was characterized by TEM, XRD and FTIR. Nano-TiO2/polyaniline was used as a positive electrode active material for Zn|Nano-TiO2-PANI rechargeable battery. The charge-discharge behavior of the rechargeable battery and the coulomb efficiency were investigated. The result shows that the initial chargeable capacity and reversible efficiency of the rechargeable battery are 98.04 mA·h/g and 91.67% respectively, charge-discharge curves are observeved stable.
2004, 21(12): 1290-1294
Abstract:
Manganese(Ⅱ)-tetrasulfophthalocyanine(b) was synthesized from the reaction of manganous chloride with tetrachlorosulfonylphthalocyanine(a) obtained from phthalocyanine(H2Pc) by chlorosulfonation with chlorosulfonic acid. Products (a) and (b) were characterized by UV-Vis, 1H NMR, FT-IR, elemental analysis and TGA. The catalytic property of (b) was studied as hydrogen peroxide enzyme-mimic in aqueous solution by catalytical spectrophotometry. The result shows that the maximum absorption wavelength of (b) for the system of (b)+phenol+4-aminoantipyrene(4-AAP)+H2O2 is at 508 nm, well close to that of the system catalyzed by horse radish peroxydase(HRP), and the absorption intensity increases with the increase of the concentration of hydrogen peroxide. Indicating compound (b) has similar catalytic activity as HRP.The linear regression equation for hydrogen peroxide determination was A=(0.489 97±0.055 27)+(0.021 98±0.002 02)×103[H2O2], with correlation coefficient R=0.991 7, and linear range of 1~50 mmol/L. The linear regression equation for glucose determination(coupled with GOD catalytic system) was A=(0.091 55±0.014 93)+(0.022 64±0.001 77)×103[glucose], with correlation coefficient R=0.990 9, and linear range of 1~14 mmol/L.
Manganese(Ⅱ)-tetrasulfophthalocyanine(b) was synthesized from the reaction of manganous chloride with tetrachlorosulfonylphthalocyanine(a) obtained from phthalocyanine(H2Pc) by chlorosulfonation with chlorosulfonic acid. Products (a) and (b) were characterized by UV-Vis, 1H NMR, FT-IR, elemental analysis and TGA. The catalytic property of (b) was studied as hydrogen peroxide enzyme-mimic in aqueous solution by catalytical spectrophotometry. The result shows that the maximum absorption wavelength of (b) for the system of (b)+phenol+4-aminoantipyrene(4-AAP)+H2O2 is at 508 nm, well close to that of the system catalyzed by horse radish peroxydase(HRP), and the absorption intensity increases with the increase of the concentration of hydrogen peroxide. Indicating compound (b) has similar catalytic activity as HRP.The linear regression equation for hydrogen peroxide determination was A=(0.489 97±0.055 27)+(0.021 98±0.002 02)×103[H2O2], with correlation coefficient R=0.991 7, and linear range of 1~50 mmol/L. The linear regression equation for glucose determination(coupled with GOD catalytic system) was A=(0.091 55±0.014 93)+(0.022 64±0.001 77)×103[glucose], with correlation coefficient R=0.990 9, and linear range of 1~14 mmol/L.
2004, 21(12): 1295-1299
Abstract:
Lead(Ⅱ) can form precipitate with dibromo-p-methylcarboxysulfonazo and polyglycol. This precipitate can be floated quantitatively. The experimental results show that in a HAc-NaAc medium(pH=4.0) with (NH4)2SO4 present, lead(Ⅱ) can be completely separated by floatation from Fe(Ⅲ), Cr(Ⅲ), Al(Ⅲ), Co(Ⅱ), Ni(Ⅱ), Cu(Ⅱ), Zn(Ⅱ), Mn(Ⅱ), Cd(Ⅱ) and Hg(Ⅱ) within 5 min at room temperature. The great features of this method are simple, rapid and selective for lead(Ⅱ). It has been applied to the floatation of lead(Ⅱ) in synthetic water sample with satisfactory results.
Lead(Ⅱ) can form precipitate with dibromo-p-methylcarboxysulfonazo and polyglycol. This precipitate can be floated quantitatively. The experimental results show that in a HAc-NaAc medium(pH=4.0) with (NH4)2SO4 present, lead(Ⅱ) can be completely separated by floatation from Fe(Ⅲ), Cr(Ⅲ), Al(Ⅲ), Co(Ⅱ), Ni(Ⅱ), Cu(Ⅱ), Zn(Ⅱ), Mn(Ⅱ), Cd(Ⅱ) and Hg(Ⅱ) within 5 min at room temperature. The great features of this method are simple, rapid and selective for lead(Ⅱ). It has been applied to the floatation of lead(Ⅱ) in synthetic water sample with satisfactory results.
2004, 21(12): 1300-1304
Abstract:
A novel β-diketone compound, 1-(p-chloro-phenyl)-3-phenyl-4-(α-furoyl)pyrazolone-5(HL) and its Pb(Ⅱ), Cu(Ⅱ), Cr(Ⅲ) and Fe(Ⅲ) complexes were synthesized. The general formula of the complexes were [ML2] and [ML3], based on the elemental analysis, chemical methods and molar conduc-tance results. The coordinational structure, property and electrochemical behaviour of the complexes were studied by IR, UV-visible, 1H NMR, 13C NMR,TG-DTA, and polarography. The results show that the ligand in a keto-form structure is changed into an enol form structure after coordination and bonded to the central ions by the O atom of the carbonyl group and enolic hydroxyl group; polarographic analysis illustrated that the complex of Pb(Ⅱ) has a coordination adsorption wave at -0.50 V and the electrode reaction is a reversible two-electron reduction process.
A novel β-diketone compound, 1-(p-chloro-phenyl)-3-phenyl-4-(α-furoyl)pyrazolone-5(HL) and its Pb(Ⅱ), Cu(Ⅱ), Cr(Ⅲ) and Fe(Ⅲ) complexes were synthesized. The general formula of the complexes were [ML2] and [ML3], based on the elemental analysis, chemical methods and molar conduc-tance results. The coordinational structure, property and electrochemical behaviour of the complexes were studied by IR, UV-visible, 1H NMR, 13C NMR,TG-DTA, and polarography. The results show that the ligand in a keto-form structure is changed into an enol form structure after coordination and bonded to the central ions by the O atom of the carbonyl group and enolic hydroxyl group; polarographic analysis illustrated that the complex of Pb(Ⅱ) has a coordination adsorption wave at -0.50 V and the electrode reaction is a reversible two-electron reduction process.
2004, 21(12): 1305-1309
Abstract:
The synthesis and structure of a Mo/S complex containing citrate ligands are reported. The complex was characterized by means of elemental analysis, IR, UV-Vis, EPR, NMR and TG-DTA. The electronic structure of the complex anion is discussed using the EHMO method. A corelation between the bonding order and the IR band of the C=O group was established, that is, the bonding orders 0.914, 0.869 and 0.809 correspond to vibration adsorption peaks of the carboxyl group at 1 606,1 587 and 1 550 cm-1, respectively, which helped explain why the IR band for the carboxyl groups are wide and split.
The synthesis and structure of a Mo/S complex containing citrate ligands are reported. The complex was characterized by means of elemental analysis, IR, UV-Vis, EPR, NMR and TG-DTA. The electronic structure of the complex anion is discussed using the EHMO method. A corelation between the bonding order and the IR band of the C=O group was established, that is, the bonding orders 0.914, 0.869 and 0.809 correspond to vibration adsorption peaks of the carboxyl group at 1 606,1 587 and 1 550 cm-1, respectively, which helped explain why the IR band for the carboxyl groups are wide and split.
2004, 21(12): 1310-1314
Abstract:
Morphological structures of PC/UHMWPE blends were observed by SEM and their dynamic rheology was studied with a dynamic rheometer. The relationship between the morphological structure and the dynamic rheology behavior of the blends is discussed. The size distribution of the dispersion domains of compatibilized blends(PC content was maintained at 100 g) was uniform when the mass ratio of UHMWPE to compatibilizer HDPE-g-GMA was 1:1.5 and UHMWPE content was less than 4 g. However, the size of the dispersion domains increased when the UHMWPE content was greater than 4 g. The complex moduli of the blends decreased with the increase of shear frequency, and their tan δ first increased, then decreased. The blend containing 4 g UHMWPE and 6 g compatibilizer had the maximal modulus, uniform distribution of dispersion domains and the loss peak shifted to 2 Hz.
Morphological structures of PC/UHMWPE blends were observed by SEM and their dynamic rheology was studied with a dynamic rheometer. The relationship between the morphological structure and the dynamic rheology behavior of the blends is discussed. The size distribution of the dispersion domains of compatibilized blends(PC content was maintained at 100 g) was uniform when the mass ratio of UHMWPE to compatibilizer HDPE-g-GMA was 1:1.5 and UHMWPE content was less than 4 g. However, the size of the dispersion domains increased when the UHMWPE content was greater than 4 g. The complex moduli of the blends decreased with the increase of shear frequency, and their tan δ first increased, then decreased. The blend containing 4 g UHMWPE and 6 g compatibilizer had the maximal modulus, uniform distribution of dispersion domains and the loss peak shifted to 2 Hz.
2004, 21(12): 1315-1319
Abstract:
Polyaniline(PANI) nanoparticles were prepared in reversed micell systems consisted of sodium di(2-ethylhexyl)sulfosuccinate, p-octyl polyethylene glycol phenylether and cetyltrimethyl ammo-nium bromide, respectively. UV-Vis, IR and X-ray diffractometry were used to characterize the structure of the PANI nano-particles. The influences of size of "water pool" of reversed micelle, aniline concentration and the kind of the surfactant on the size and morphology of the products were investigated. The self-assembly of PANI nano-particles in reversed micelle is discussed briefly. The results show that the size of PANI nanoparticles became bigger with increase the size of "water pool", and ellipsoidal PANI could be formed from the small round nanoparticles by self-assembly at a high concentration. Increasing the aniline concentration from 0.05 mol/L to 0.2 mol/L and using ionic surfactant such as AOT or CTAB, would make the assembly products more compact.
Polyaniline(PANI) nanoparticles were prepared in reversed micell systems consisted of sodium di(2-ethylhexyl)sulfosuccinate, p-octyl polyethylene glycol phenylether and cetyltrimethyl ammo-nium bromide, respectively. UV-Vis, IR and X-ray diffractometry were used to characterize the structure of the PANI nano-particles. The influences of size of "water pool" of reversed micelle, aniline concentration and the kind of the surfactant on the size and morphology of the products were investigated. The self-assembly of PANI nano-particles in reversed micelle is discussed briefly. The results show that the size of PANI nanoparticles became bigger with increase the size of "water pool", and ellipsoidal PANI could be formed from the small round nanoparticles by self-assembly at a high concentration. Increasing the aniline concentration from 0.05 mol/L to 0.2 mol/L and using ionic surfactant such as AOT or CTAB, would make the assembly products more compact.
2004, 21(12): 1320-1322
Abstract:
Six novel bis-benzoylphenylurea compounds have been synthesized from available compound chlorothalonil 1(2,4,5,6-tetrachloroisophthalonitrile) in yield of 30%~50%. The synthetic route has advantages of mild reaction conditions and higher yields. All of the bis-benzoylphenylurea compounds were investigated by IR, 1H NMR, FAB-MS and HRMS. Preliminary insecticidal activities of the title compounds have been tested. The results showed the compounds had only weak activity against Mythimna Separata Walker and Culex Pipiens Pallens.
Six novel bis-benzoylphenylurea compounds have been synthesized from available compound chlorothalonil 1(2,4,5,6-tetrachloroisophthalonitrile) in yield of 30%~50%. The synthetic route has advantages of mild reaction conditions and higher yields. All of the bis-benzoylphenylurea compounds were investigated by IR, 1H NMR, FAB-MS and HRMS. Preliminary insecticidal activities of the title compounds have been tested. The results showed the compounds had only weak activity against Mythimna Separata Walker and Culex Pipiens Pallens.
2004, 21(12): 1323-1325
Abstract:
Three ternary complexes were synthesized from terbium with aromatic carboxylic acids(benzoic acid, salicylic acid, p-hydroxylbenzoic acid) and acrylonitrile and characterized by means of elemental analysis, FT-IR and UV-Vis. Fluorescence spectra show the three ternary complexes exhibit good luminescence.
Three ternary complexes were synthesized from terbium with aromatic carboxylic acids(benzoic acid, salicylic acid, p-hydroxylbenzoic acid) and acrylonitrile and characterized by means of elemental analysis, FT-IR and UV-Vis. Fluorescence spectra show the three ternary complexes exhibit good luminescence.
2004, 21(12): 1326-1328
Abstract:
A catalytical spectrophotometry method for the quantitative analysis of trace sodium sulfoxylate formaldehyde in foods is proposed based on the catalytical activity of sodium sulfoxylate formaldehyde in the oxidation reaction of Brilliant cresyl blue by BrO3- in H2SO4. The concentration range where the response in linear is from 5×10-9 to 1.52×10-5 g/mL, with a detection limit of 2×10-9 g/mL. The suggested method was satisfactorily used to determine trace sodium sulfoxylate formaldehyde in foods.
A catalytical spectrophotometry method for the quantitative analysis of trace sodium sulfoxylate formaldehyde in foods is proposed based on the catalytical activity of sodium sulfoxylate formaldehyde in the oxidation reaction of Brilliant cresyl blue by BrO3- in H2SO4. The concentration range where the response in linear is from 5×10-9 to 1.52×10-5 g/mL, with a detection limit of 2×10-9 g/mL. The suggested method was satisfactorily used to determine trace sodium sulfoxylate formaldehyde in foods.
2004, 21(12): 1329-1330
Abstract:
Four 2-(α-hydroxyalkyl)-2-oxazolines and a 2-(α-hydroxy-α, α-diphenyl)-2-benzooxazolewere synthesized from β-amimoalcohols and α-hydroxy carboxylic acids under microwave irradiation in the absence of a solvent.
Four 2-(α-hydroxyalkyl)-2-oxazolines and a 2-(α-hydroxy-α, α-diphenyl)-2-benzooxazolewere synthesized from β-amimoalcohols and α-hydroxy carboxylic acids under microwave irradiation in the absence of a solvent.
