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2007 Volume 24 Issue 9
2007, 24(9): 977-981
Abstract:
Silvery glaze is a kind of common disease covered on the surface of ancient lead glazed ceramics. Using analytical methods of SEM-EDS, XRD, FTIR, XPS, a piece of green glazed pottery of Song dynasty excavated from Huanggang area, Hubei province, was analyzed. The analysis indicates that the silvery glaze is in high content of calcium(Ca:5.1%~10.3%), phosphor(P:4.6%~9.2%) and lead(Pb:56.9%~70.5%), which was mainly in crystalline phase of Pb10-xCax(PO4)(OH)2(x<2.7). In addition, elements of iron(Fe:2.5%~3.8%) and chlorine (Cl:1.8%~2.1%) were detected in the area of brown and yellow of the silvery glaze. Due to the local burial circumstance of weak acid, the silvery glaze is the result from the chemical reaction between the lead ion in the glaze of pottery and all kinds of phosphate compound in the soil.
Silvery glaze is a kind of common disease covered on the surface of ancient lead glazed ceramics. Using analytical methods of SEM-EDS, XRD, FTIR, XPS, a piece of green glazed pottery of Song dynasty excavated from Huanggang area, Hubei province, was analyzed. The analysis indicates that the silvery glaze is in high content of calcium(Ca:5.1%~10.3%), phosphor(P:4.6%~9.2%) and lead(Pb:56.9%~70.5%), which was mainly in crystalline phase of Pb10-xCax(PO4)(OH)2(x<2.7). In addition, elements of iron(Fe:2.5%~3.8%) and chlorine (Cl:1.8%~2.1%) were detected in the area of brown and yellow of the silvery glaze. Due to the local burial circumstance of weak acid, the silvery glaze is the result from the chemical reaction between the lead ion in the glaze of pottery and all kinds of phosphate compound in the soil.
2007, 24(9): 982-985
Abstract:
The non-isothermal crystallization behavior of isotactic polypropylene(iPP) in mixed diluents was investigated by polarizing microscopy, and the structure of iPP microporous materials prepared via thermally induced phase separation was studied by scanning electron microscopy(SEM). The mixtures of DBP and soybean oil were used as the diluents, and the mass fraction of iPP in the solution was fixed at 30%. Both the growth rate of iPP spherulite and the structure of iPP microporous materials are significantly influenced by the composition of mixed diluents, which result from the changes of the viscosity of the system and the compatibility between iPP and diluents. At a cooling rate of 2 K/min, the radius and growth rate of iPP spherulites both increase exponentially with time. The growth rate of iPP spherulites decreases with the increase of the mass fraction of DBP in mixed diluents. When the mass fraction of DBP in mixed diluents increases from 0 to 60%, the growth rate.of iPP spherulites decreases from 41.9 μm/min to 10.3 μm/min. Cellular structure is obtained at the cooling rate of 2 K/min, while the pore size increases significantly with the decrease of soybean oil in the mixed diluents.
The non-isothermal crystallization behavior of isotactic polypropylene(iPP) in mixed diluents was investigated by polarizing microscopy, and the structure of iPP microporous materials prepared via thermally induced phase separation was studied by scanning electron microscopy(SEM). The mixtures of DBP and soybean oil were used as the diluents, and the mass fraction of iPP in the solution was fixed at 30%. Both the growth rate of iPP spherulite and the structure of iPP microporous materials are significantly influenced by the composition of mixed diluents, which result from the changes of the viscosity of the system and the compatibility between iPP and diluents. At a cooling rate of 2 K/min, the radius and growth rate of iPP spherulites both increase exponentially with time. The growth rate of iPP spherulites decreases with the increase of the mass fraction of DBP in mixed diluents. When the mass fraction of DBP in mixed diluents increases from 0 to 60%, the growth rate.of iPP spherulites decreases from 41.9 μm/min to 10.3 μm/min. Cellular structure is obtained at the cooling rate of 2 K/min, while the pore size increases significantly with the decrease of soybean oil in the mixed diluents.
2007, 24(9): 986-990
Abstract:
The coupling reaction of aryl bromide with phenylboronic acid was studied as probe reaction of Suzuki-Miyaura cross-coupling reaction with ferrocene derivatives of monophosphine or bidentate ligand coordinated palladium complex as catalyst. PPFOMe(1-[2-(diphenylphosphino)ferrocenyl]ethyl methyl ether) was most active for the Suzuki-Miyaura cross-coupling reaction when coordinated to palladium. K2CO3 was more effective than CsF, and Pd(OAc)2 was more active than PdCl2 for the Suzuki-Miyaura cross-coupling reaction between aryl bromides(or its derivatives) and phenylboronic acid. The catalyst made from PPFOMe and Pd(OAc)2(with a mole ratio of 2:1) was promoted by K2CO3, and the yield of 4-methyldiphenyl reached 94% at 110℃ when the reaction of 4-bromotoluene with phenylboronic acid was performed for 1 h. Under the same reaction conditions, all the aryl bromides tested, either electron-poor or electron-rich, led to yields higher than 90%, indicating that ferrocene derivatives of monophosphine coordinated palladium complex are better catalysts for the Suzuki-Miyaura cross-coupling reaction.
The coupling reaction of aryl bromide with phenylboronic acid was studied as probe reaction of Suzuki-Miyaura cross-coupling reaction with ferrocene derivatives of monophosphine or bidentate ligand coordinated palladium complex as catalyst. PPFOMe(1-[2-(diphenylphosphino)ferrocenyl]ethyl methyl ether) was most active for the Suzuki-Miyaura cross-coupling reaction when coordinated to palladium. K2CO3 was more effective than CsF, and Pd(OAc)2 was more active than PdCl2 for the Suzuki-Miyaura cross-coupling reaction between aryl bromides(or its derivatives) and phenylboronic acid. The catalyst made from PPFOMe and Pd(OAc)2(with a mole ratio of 2:1) was promoted by K2CO3, and the yield of 4-methyldiphenyl reached 94% at 110℃ when the reaction of 4-bromotoluene with phenylboronic acid was performed for 1 h. Under the same reaction conditions, all the aryl bromides tested, either electron-poor or electron-rich, led to yields higher than 90%, indicating that ferrocene derivatives of monophosphine coordinated palladium complex are better catalysts for the Suzuki-Miyaura cross-coupling reaction.
2007, 24(9): 991-995
Abstract:
Carbon supported Pt(Pt/C) catalyst was prepared via the improved organic sol method with methanol as the solvent and SnCl2 as reductant. This method has the advantages of simple procedure and low cost. The Pt particles in the Pt/C catalyst prepared with this method possess the high uniformity and good dispersity. The Pt/C catalysts with Pt loadings from 10% to 60% were prepared and the Pt particle sizes in the Pt/C catalysts are basically the same with adjusting the evaporating temperature of the solvent, particle size between 3.3~4.3 nm. The membrane electrode assemblies(MEA) with the different Pt/C catalysts were prepared with the coating and hot-press method, and the effect of Pt loading on the electrocatalytic activity of Pt/C catalysts was studied, too. The result shows that the Pt/C catalyst with 40% Pt loading shows an excellent electrocatalytic activity for the methanol oxidation.
Carbon supported Pt(Pt/C) catalyst was prepared via the improved organic sol method with methanol as the solvent and SnCl2 as reductant. This method has the advantages of simple procedure and low cost. The Pt particles in the Pt/C catalyst prepared with this method possess the high uniformity and good dispersity. The Pt/C catalysts with Pt loadings from 10% to 60% were prepared and the Pt particle sizes in the Pt/C catalysts are basically the same with adjusting the evaporating temperature of the solvent, particle size between 3.3~4.3 nm. The membrane electrode assemblies(MEA) with the different Pt/C catalysts were prepared with the coating and hot-press method, and the effect of Pt loading on the electrocatalytic activity of Pt/C catalysts was studied, too. The result shows that the Pt/C catalyst with 40% Pt loading shows an excellent electrocatalytic activity for the methanol oxidation.
2007, 24(9): 996-999
Abstract:
A fast and convenient analytical technique was suggested to detect naphthol isomers directly and simultaneously. In 0.1 mol/L sodium phosphate buffer solution(pH=8.0), the electrochemical behaviors of 1-naphthol and 2-naphthol were investigated with differential pulse voltammetry method at the glassy carbon electrode. Each of them exhibited an irreversible oxidation peak, and the two oxidation peaks overlapped partly in the base, meaning that the presence of 1-naphthol would interfere with the determination of 2-naphthol. Via semi-derivative technique, the two oxidation peaks were separated completely and did not overlap any more. Meanwhile, the surfactant of cetyl pyridinium chloride(CTAB) was used to enhance the detection sensitivity. The semi-derivative oxidation currents of 1-naphthol and 2-naphthol increased 2.2 and 1.9 times respectively in the presence of 1.2×10-4 mol/L of CTAB. The enhancement mechanism of surfactant was also studied, and both 1-naphthol and 2-naphthol were detected simultaneously. The linear calibration ranges were 9.2×10-7 to 2.0×10-4 mol/L for 1-naphthol and 1.3×10-6 to 2.0×10-4 mol/L for 2-naphthol, and with detection limits of 3.2×10-7 and 4.3×10-7 mol/L, respectively. The reproducibility and interference tests were performed. This method was also applied to the determination of naphthol isomers in simulated water samples, and the recovery was from 97.7% to 104.0%.
A fast and convenient analytical technique was suggested to detect naphthol isomers directly and simultaneously. In 0.1 mol/L sodium phosphate buffer solution(pH=8.0), the electrochemical behaviors of 1-naphthol and 2-naphthol were investigated with differential pulse voltammetry method at the glassy carbon electrode. Each of them exhibited an irreversible oxidation peak, and the two oxidation peaks overlapped partly in the base, meaning that the presence of 1-naphthol would interfere with the determination of 2-naphthol. Via semi-derivative technique, the two oxidation peaks were separated completely and did not overlap any more. Meanwhile, the surfactant of cetyl pyridinium chloride(CTAB) was used to enhance the detection sensitivity. The semi-derivative oxidation currents of 1-naphthol and 2-naphthol increased 2.2 and 1.9 times respectively in the presence of 1.2×10-4 mol/L of CTAB. The enhancement mechanism of surfactant was also studied, and both 1-naphthol and 2-naphthol were detected simultaneously. The linear calibration ranges were 9.2×10-7 to 2.0×10-4 mol/L for 1-naphthol and 1.3×10-6 to 2.0×10-4 mol/L for 2-naphthol, and with detection limits of 3.2×10-7 and 4.3×10-7 mol/L, respectively. The reproducibility and interference tests were performed. This method was also applied to the determination of naphthol isomers in simulated water samples, and the recovery was from 97.7% to 104.0%.
2007, 24(9): 1000-1004
Abstract:
The Ti(Ⅳ)-substituted tungstophosphate and tungstosilicate polyoxometalates(Bu4N+ salt or Me4N+ salt) were synthesized under the acid condition(pH=2) with Ti(O-iPr)4 as Ti source. The structures and cation contents of the samples were characterized by IR, 31P NMR, 1H NMR and TG-DTA. The states of the samples, i.e., dimer(anhydride form), monomer, protonated monomer, as well as the interconversion between the states were also investigated. The IR spectra of the samples show that both the tungstophosphate and tungstosilicate contain Ti-O-Ti linkages, indicating that the compounds are Ti(Ⅳ)-substituted polyoxometalate dimers or contain dimers. This has also been confirmed by the contents of Me4N+ measured by TG-DTA experiments. 31P NMR and 1H NMR further reveal that Ti(Ⅳ)-substituted tungstophosphate sample is a mixture of protonated monomer and dimer. It has also been found that acidic medium is necessary for the formation of protonated monomer and dimer. The stability of the dimer of the tungstophosphate is lower; a pure monomer can be obtained by treating the mixture with a base (Bu4NOH). However, the dimer of tungstosilicate is stable under the same condition.
The Ti(Ⅳ)-substituted tungstophosphate and tungstosilicate polyoxometalates(Bu4N+ salt or Me4N+ salt) were synthesized under the acid condition(pH=2) with Ti(O-iPr)4 as Ti source. The structures and cation contents of the samples were characterized by IR, 31P NMR, 1H NMR and TG-DTA. The states of the samples, i.e., dimer(anhydride form), monomer, protonated monomer, as well as the interconversion between the states were also investigated. The IR spectra of the samples show that both the tungstophosphate and tungstosilicate contain Ti-O-Ti linkages, indicating that the compounds are Ti(Ⅳ)-substituted polyoxometalate dimers or contain dimers. This has also been confirmed by the contents of Me4N+ measured by TG-DTA experiments. 31P NMR and 1H NMR further reveal that Ti(Ⅳ)-substituted tungstophosphate sample is a mixture of protonated monomer and dimer. It has also been found that acidic medium is necessary for the formation of protonated monomer and dimer. The stability of the dimer of the tungstophosphate is lower; a pure monomer can be obtained by treating the mixture with a base (Bu4NOH). However, the dimer of tungstosilicate is stable under the same condition.
2007, 24(9): 1005-1008
Abstract:
Eleven new schiff bases of 4-(4-methoxybenzylidene)-1-benzylimino-2-meth-ylthio-1H-imidazolin-5-ones(6) were synthesized by condensation reaction of aryl carbaldehyde and 4-(4-methoxybenzylidene)-1-am-ino-2-(meth-ylthio)-1H-imidazol-5-one(5), which was synthesized by S-alkylation of thioimidazol-inone(4). Thioimidazolinone 4 was obtained by a new tandem aza-Wittig reaction of vinyliminophosphorane, carbon disulfide and hydrazine hadrate. The structures of compounds 6 were confirmed by elemental analysis, 1H NMR, IR and MS. The preliminary bioassay shows that the compounds 6 exhibit good herbicidal and fungicidal activities. Compounds 6j and 6k exhibit 100% inhibition to the tested five fungus.
Eleven new schiff bases of 4-(4-methoxybenzylidene)-1-benzylimino-2-meth-ylthio-1H-imidazolin-5-ones(6) were synthesized by condensation reaction of aryl carbaldehyde and 4-(4-methoxybenzylidene)-1-am-ino-2-(meth-ylthio)-1H-imidazol-5-one(5), which was synthesized by S-alkylation of thioimidazol-inone(4). Thioimidazolinone 4 was obtained by a new tandem aza-Wittig reaction of vinyliminophosphorane, carbon disulfide and hydrazine hadrate. The structures of compounds 6 were confirmed by elemental analysis, 1H NMR, IR and MS. The preliminary bioassay shows that the compounds 6 exhibit good herbicidal and fungicidal activities. Compounds 6j and 6k exhibit 100% inhibition to the tested five fungus.
2007, 24(9): 1009-1012
Abstract:
Ammonia is usually added as a complex agent in preparation of high electrochemical and spherical nickel hydroxide by chemical precipitation. As the result, a lot of liquid waste with ammonia has to be disposed. Studies show that part of the mother liquor with crystal seeds can be reused in the preparation. SEM, charge-discharge, and cycle life test were used to analyze the influence on nickel electrode of the content of crystal seeds and the quantity of mother liquid. Studies showed that the mother liquid with crystal seeds was much better than the one without crystal seeds in the field of surface and sphericity. When mother liquor with 6~9 g/L crystal seeds reacting for about 8 hours, the tap density of the nickel hydroxide can reached 1.90 g/cm3, the diameter of 10 μm and the discharge capacity of 200 mA·h/g. When the cycle content of mother liquid was less than 20%, the content of SO42- could be less than 0.3%. Using 20% mother liquor with 6~9 g/L crystal seeds to react for about 10 hours, the discharge capacity of nickel electrode reached 215.06 mA·h/g. The discharge capacity of nickel electrode above 1.2 V is 153.33 mA·h/g, accounting for 71.3% of the discharge capacity. It not only improves the discharge capacity and reduces the dispose quantity of liquid waste with ammonia, but also improves the tap density and the spheroid degrees of nickel hydroxide. It also shortens the reaction time effectively.
Ammonia is usually added as a complex agent in preparation of high electrochemical and spherical nickel hydroxide by chemical precipitation. As the result, a lot of liquid waste with ammonia has to be disposed. Studies show that part of the mother liquor with crystal seeds can be reused in the preparation. SEM, charge-discharge, and cycle life test were used to analyze the influence on nickel electrode of the content of crystal seeds and the quantity of mother liquid. Studies showed that the mother liquid with crystal seeds was much better than the one without crystal seeds in the field of surface and sphericity. When mother liquor with 6~9 g/L crystal seeds reacting for about 8 hours, the tap density of the nickel hydroxide can reached 1.90 g/cm3, the diameter of 10 μm and the discharge capacity of 200 mA·h/g. When the cycle content of mother liquid was less than 20%, the content of SO42- could be less than 0.3%. Using 20% mother liquor with 6~9 g/L crystal seeds to react for about 10 hours, the discharge capacity of nickel electrode reached 215.06 mA·h/g. The discharge capacity of nickel electrode above 1.2 V is 153.33 mA·h/g, accounting for 71.3% of the discharge capacity. It not only improves the discharge capacity and reduces the dispose quantity of liquid waste with ammonia, but also improves the tap density and the spheroid degrees of nickel hydroxide. It also shortens the reaction time effectively.
2007, 24(9): 1013-1017
Abstract:
We have discovered a novel three-component reaction yielding 6 chiral oxime ether 5-(S)-menthyloxy-4-oxime ether-3-bromo-2(5H)-furanone(12a~12f) in a one-pot procedure with chiral-5-menthyloxy-3,4-dibrome-2(5H)-furanone, aldehyde, hydroxylamine hydrochloride, and the yield is 50%~80%. Due to the special structure and the presence of nitrogen atom, those compounds can be used for many reaction and provide a kind of feasible approach for the synthesis and study of chiral chelate compound and chiral oxime ether. The target compounds were characterized by IR, 1H NMR, 13C NMR and HRMS.
We have discovered a novel three-component reaction yielding 6 chiral oxime ether 5-(S)-menthyloxy-4-oxime ether-3-bromo-2(5H)-furanone(12a~12f) in a one-pot procedure with chiral-5-menthyloxy-3,4-dibrome-2(5H)-furanone, aldehyde, hydroxylamine hydrochloride, and the yield is 50%~80%. Due to the special structure and the presence of nitrogen atom, those compounds can be used for many reaction and provide a kind of feasible approach for the synthesis and study of chiral chelate compound and chiral oxime ether. The target compounds were characterized by IR, 1H NMR, 13C NMR and HRMS.
2007, 24(9): 1018-1022
Abstract:
Six isomers of sodium dodecyl xylenesulfonate were synthesized from chloride and o-xylene via a five-step process involving Friedel-Crafts reaction, Grignard reaction, reduction, sulfonation. and neutralization. The structures of the intermediates and the final products were characterized by IR, ESI-MS and 1H NMR. The surface tensions of dilute aqueous solutions of product were measured at 25℃ by drop-volume method and then the critical micelle concentration(CMC) was determined. The values of CMC(mmol/L) and γCMC(mN/m) are Ⅰ.0.25, 30.00; Ⅱ.0.50, 28.21; Ⅲ.0.79, 28.10; Ⅳ.1.00, 27.01; Ⅴ.2.00, 26.41; Ⅵ.2.50, 26.40. These results indicate that the CMC increases but the γCMC decreases as the position of benzene ring is moved from the edge to the middle of the long chain alkyl.
Six isomers of sodium dodecyl xylenesulfonate were synthesized from chloride and o-xylene via a five-step process involving Friedel-Crafts reaction, Grignard reaction, reduction, sulfonation. and neutralization. The structures of the intermediates and the final products were characterized by IR, ESI-MS and 1H NMR. The surface tensions of dilute aqueous solutions of product were measured at 25℃ by drop-volume method and then the critical micelle concentration(CMC) was determined. The values of CMC(mmol/L) and γCMC(mN/m) are Ⅰ.0.25, 30.00; Ⅱ.0.50, 28.21; Ⅲ.0.79, 28.10; Ⅳ.1.00, 27.01; Ⅴ.2.00, 26.41; Ⅵ.2.50, 26.40. These results indicate that the CMC increases but the γCMC decreases as the position of benzene ring is moved from the edge to the middle of the long chain alkyl.
2007, 24(9): 1023-1026
Abstract:
Waterborne polyurethane(WPU) dispersion with a high solid content of about 38% and a volatile oganic compound content of about 60 g/L was prepared from isophorone diisocyanate(IPDI), dihydrooxypolydimethylsiloxane(DHPDMS), polyester-diol, dimethyloxypropionic acid(DMPA). Effects of the amount of DHPDMS, the molecular mass of DHPDMS on the appearance, viscosity, adhesion, water resistance, hardness, tensile strength, elongation of polyurethane modified by DHPDMS were discussed. IR spectrum indicates the silica-oxygen bond is introduced to the polymer and lots of hydrogen bonds are present in the polymer; DSC demonstrates two glass transition temperatures(Tg1=-28.1℃, Tg2=34.4℃) and microphase separation is present; SEM has verified the above results. The polymer was also compared with the non-modified polyurethane. The result shows that the modified resin has good performance(good mechanical properities, σ=14.48 MPa, ε=521%) when the amount of DHPDMS is 2% and molecular mass is 3 000.
Waterborne polyurethane(WPU) dispersion with a high solid content of about 38% and a volatile oganic compound content of about 60 g/L was prepared from isophorone diisocyanate(IPDI), dihydrooxypolydimethylsiloxane(DHPDMS), polyester-diol, dimethyloxypropionic acid(DMPA). Effects of the amount of DHPDMS, the molecular mass of DHPDMS on the appearance, viscosity, adhesion, water resistance, hardness, tensile strength, elongation of polyurethane modified by DHPDMS were discussed. IR spectrum indicates the silica-oxygen bond is introduced to the polymer and lots of hydrogen bonds are present in the polymer; DSC demonstrates two glass transition temperatures(Tg1=-28.1℃, Tg2=34.4℃) and microphase separation is present; SEM has verified the above results. The polymer was also compared with the non-modified polyurethane. The result shows that the modified resin has good performance(good mechanical properities, σ=14.48 MPa, ε=521%) when the amount of DHPDMS is 2% and molecular mass is 3 000.
2007, 24(9): 1027-1031
Abstract:
The method of precipitation polymerization was employed to synthesize styrene-co-maleic anhydride copolymers(SMA). The comb-like amphiphilic copolymers based on maleic anhydride copolymer backbone and PEG grafts(PEG-g-PS) were prepared at high conversion rate by utilizing thionyl chloride to convert acid anhydride groups into acyl chloride groups. When this amphiphilic copolymer was used as the surface modifying macromolecules, the chain segments of polyether on PEG-g-PS could preferentially aggregate on the surface of PEG-g-PS/PS blends to increase the surface polarity of PS. The surface polarity of the blends could reach to 11.6 mN/m, which is about three times higher than that of pure PS(3.5 mN/m). Because of the compatibility between PEG-g-PS and PS, the effective duration of surface modification by PEG-g-PS is greatly extended and the surface functionalization even becomes permanent for the material. Furthermore, more polyether chain segments on PEG-g-PS could selectively migrate to the surface by the inducement of polar solvent. The attenuated total reflectance Fourier transform infrared spectroscopy and contact angle measurement were used to detect the surface structure and surface properties.
The method of precipitation polymerization was employed to synthesize styrene-co-maleic anhydride copolymers(SMA). The comb-like amphiphilic copolymers based on maleic anhydride copolymer backbone and PEG grafts(PEG-g-PS) were prepared at high conversion rate by utilizing thionyl chloride to convert acid anhydride groups into acyl chloride groups. When this amphiphilic copolymer was used as the surface modifying macromolecules, the chain segments of polyether on PEG-g-PS could preferentially aggregate on the surface of PEG-g-PS/PS blends to increase the surface polarity of PS. The surface polarity of the blends could reach to 11.6 mN/m, which is about three times higher than that of pure PS(3.5 mN/m). Because of the compatibility between PEG-g-PS and PS, the effective duration of surface modification by PEG-g-PS is greatly extended and the surface functionalization even becomes permanent for the material. Furthermore, more polyether chain segments on PEG-g-PS could selectively migrate to the surface by the inducement of polar solvent. The attenuated total reflectance Fourier transform infrared spectroscopy and contact angle measurement were used to detect the surface structure and surface properties.
2007, 24(9): 1032-1035
Abstract:
In this paper, two alkene substituted viologen derivatives were synthesized; NMR, IR and UV were used to confirm their structures; the CV showed that the these compounds have 2 reversible redox peaks. With PEO-gel polyelectrolyte as ionic conduction layer, electrochromic devices based on these compounds were assembled. Their thickness was about 2.35 mm. The completely solidification of the devices could improve the properties of colorization-decolonization and the maintenance of colorization after cutting off electricity compared with the liquid electrochromic device. The technics of the solidification device is much easier and has a good potential for large scale production. When charged voltage is in a range of 1.1 V to 3 V, the solidification device shows a color of blue or violet. After optimization, the response time is less than 50 ms, the number of redox circulation is over million times and the color of colorization could be kept for 3 days. The main indexes of this kind of device can meet the requirement of electronic ink.
In this paper, two alkene substituted viologen derivatives were synthesized; NMR, IR and UV were used to confirm their structures; the CV showed that the these compounds have 2 reversible redox peaks. With PEO-gel polyelectrolyte as ionic conduction layer, electrochromic devices based on these compounds were assembled. Their thickness was about 2.35 mm. The completely solidification of the devices could improve the properties of colorization-decolonization and the maintenance of colorization after cutting off electricity compared with the liquid electrochromic device. The technics of the solidification device is much easier and has a good potential for large scale production. When charged voltage is in a range of 1.1 V to 3 V, the solidification device shows a color of blue or violet. After optimization, the response time is less than 50 ms, the number of redox circulation is over million times and the color of colorization could be kept for 3 days. The main indexes of this kind of device can meet the requirement of electronic ink.
2007, 24(9): 1036-1040
Abstract:
The paper presents a novel method for the separation and preconcentration of vanadium with microcrystalline phenolphthalein as the sorbent. Experiments indicated that vanadium existed in the main form of V3O93- at pH 3.7~7.0, and vanadium reacted with Ethyl Violet(EV+) to form an ion-association complex (V3O93-)·(EV+)3 which was quantificationally adsorbed on the surface of microcrystalline phenolphthalein. At the same time, vanadium(V) was completely separated from Co(Ⅱ), Ni(Ⅱ), Zn(Ⅱ), Cd(Ⅱ), Al(Ⅲ), Cu(Ⅱ), Hg(Ⅱ), Pb(Ⅱ), Mn(Ⅱ), Fe(Ⅲ), Cr(Ⅲ) and hardly affected by SO42-, NO3-, Br-, Cl-, I-, ClO4-. After 5.00 mL of 1.0×10-3 mol/L EV+, 1.00 mL of 0.10 mol/L HCl(the pH of the solution was adjusted to about 4.0) and 5.00 mL of 15.8% phenolphthalein solution were added in 1.0 L environmental water sample, the mixture was stirred for 50 min, and trace vanadium(Ⅴ) can be completely enriched in the process of stirring. The preconcentration factor can reach 100~200. The recovery of V(Ⅴ) is beyond 98.0%. The relative standard deviation RSD is 1.1%~2.3%. The method is simple and the result of determination of trace vanadium is satisfactory.
The paper presents a novel method for the separation and preconcentration of vanadium with microcrystalline phenolphthalein as the sorbent. Experiments indicated that vanadium existed in the main form of V3O93- at pH 3.7~7.0, and vanadium reacted with Ethyl Violet(EV+) to form an ion-association complex (V3O93-)·(EV+)3 which was quantificationally adsorbed on the surface of microcrystalline phenolphthalein. At the same time, vanadium(V) was completely separated from Co(Ⅱ), Ni(Ⅱ), Zn(Ⅱ), Cd(Ⅱ), Al(Ⅲ), Cu(Ⅱ), Hg(Ⅱ), Pb(Ⅱ), Mn(Ⅱ), Fe(Ⅲ), Cr(Ⅲ) and hardly affected by SO42-, NO3-, Br-, Cl-, I-, ClO4-. After 5.00 mL of 1.0×10-3 mol/L EV+, 1.00 mL of 0.10 mol/L HCl(the pH of the solution was adjusted to about 4.0) and 5.00 mL of 15.8% phenolphthalein solution were added in 1.0 L environmental water sample, the mixture was stirred for 50 min, and trace vanadium(Ⅴ) can be completely enriched in the process of stirring. The preconcentration factor can reach 100~200. The recovery of V(Ⅴ) is beyond 98.0%. The relative standard deviation RSD is 1.1%~2.3%. The method is simple and the result of determination of trace vanadium is satisfactory.
2007, 24(9): 1041-1044
Abstract:
Rate constants of photo-generating singlet oxygen(1O2) by 28 new metallophthal-ocyanines with center metal Zn(Ⅱ), Cu(Ⅱ), Ni(Ⅱ) or Co(Ⅱ) and with 4 kinds of substituted aromaticoxyl groups containing nitrogen were determined in the presence of 2,5-dimethylfuran(DMFU) as the 1O2 quencher by GC. The influence of the electron structure of the center metal, the type of the substituent group, and substitution position on the photo-generation of 1O2 by the metallophthalocyanines were discussed. The results show that (1)for different metallophthalocyanies with the same subsituent group and the same substitution position, photo-generation of singlet oxygen(1O2) by the phthalocyaninatozinc, was more than that of the phthalocyaninatocopper, phthalocyaninatocobalt and phthalocyaninatonickel. (2)the rate constants of photo-generating 1O2 by the phthalocyaninatozinc substituted with azoaromaticoxy group were obviously higher than that for the phthalocyaninatozinc substituted with aromaticoxy containning amine group. (3)the rate constant of photo-generating 1O2 by the phthalocyaninatozinc substituted with azoaromaticoxy group at the α position was higher than that with β position substitution.
Rate constants of photo-generating singlet oxygen(1O2) by 28 new metallophthal-ocyanines with center metal Zn(Ⅱ), Cu(Ⅱ), Ni(Ⅱ) or Co(Ⅱ) and with 4 kinds of substituted aromaticoxyl groups containing nitrogen were determined in the presence of 2,5-dimethylfuran(DMFU) as the 1O2 quencher by GC. The influence of the electron structure of the center metal, the type of the substituent group, and substitution position on the photo-generation of 1O2 by the metallophthalocyanines were discussed. The results show that (1)for different metallophthalocyanies with the same subsituent group and the same substitution position, photo-generation of singlet oxygen(1O2) by the phthalocyaninatozinc, was more than that of the phthalocyaninatocopper, phthalocyaninatocobalt and phthalocyaninatonickel. (2)the rate constants of photo-generating 1O2 by the phthalocyaninatozinc substituted with azoaromaticoxy group were obviously higher than that for the phthalocyaninatozinc substituted with aromaticoxy containning amine group. (3)the rate constant of photo-generating 1O2 by the phthalocyaninatozinc substituted with azoaromaticoxy group at the α position was higher than that with β position substitution.
2007, 24(9): 1045-1049
Abstract:
Adsorbent for flue gas desulfurization was prepared from surplus sludge of sewage by modifation method of loading metal oxides, and its properties were studied by means of pore characteristics, SEM and elemental analysis. The adsorption mechanism of system of the adsorbent for SO2-O2-H2O(g)-N2 was studied by FTIR and thermal analysis. The results show that the performance of the adsorbent with loaded(mass fraction) both 5% MnO2 and 5% MgO is the best. The pore structure mainly consists of intermediate and large pores, the corresponding specific surface area is lower. Under the adsorption conditions of inlet concentration of SO2 2 021.38 mg/m3, mass fractions of O2 12% and H2O(g) 12%, flue gas velocity 2.13 m/min, temperature 60℃, the desulfurization efficiency and adsorption capacity of sludge-derived adsorbent are 93.7% and 99.3 mg/g respectively, and those decrease to 93% and 84.4 mg/g after renovation by washing twice with ammonia, indicating that the renovation effect is better. In the presence of water vapour, the synergistic action of the complex oxides accelerates the chemical adsorption of sludge-derived adsorbent for SO2. The isothermal adsorption process can be described by Freundlich Model, and the adsorption heat value is 78.4 kJ/mol. Predictable values via stationary adsorption bed model are in agreement with experimental values.
Adsorbent for flue gas desulfurization was prepared from surplus sludge of sewage by modifation method of loading metal oxides, and its properties were studied by means of pore characteristics, SEM and elemental analysis. The adsorption mechanism of system of the adsorbent for SO2-O2-H2O(g)-N2 was studied by FTIR and thermal analysis. The results show that the performance of the adsorbent with loaded(mass fraction) both 5% MnO2 and 5% MgO is the best. The pore structure mainly consists of intermediate and large pores, the corresponding specific surface area is lower. Under the adsorption conditions of inlet concentration of SO2 2 021.38 mg/m3, mass fractions of O2 12% and H2O(g) 12%, flue gas velocity 2.13 m/min, temperature 60℃, the desulfurization efficiency and adsorption capacity of sludge-derived adsorbent are 93.7% and 99.3 mg/g respectively, and those decrease to 93% and 84.4 mg/g after renovation by washing twice with ammonia, indicating that the renovation effect is better. In the presence of water vapour, the synergistic action of the complex oxides accelerates the chemical adsorption of sludge-derived adsorbent for SO2. The isothermal adsorption process can be described by Freundlich Model, and the adsorption heat value is 78.4 kJ/mol. Predictable values via stationary adsorption bed model are in agreement with experimental values.
2007, 24(9): 1050-1053
Abstract:
Poly(acrylic acid)(Mn 2 400~9 000) was prepared by reversible addition-fragmentation chain transfer(RAFT) polymerization with water as the solvent. GPC analysis indicats that the polymer possesses narrow molecular distribution(the polydispersity index PDI was ~1.2). Scale inhibition test indicates that the poly(acrylic acid) prepared by RAFT has better scale inhibition performance than a commercial poly(acrylic acid) scale inhibitor, which was prepared by traditional radical polymerization. For example, when the concentration of poly(acrylic acid) with a molecular mass of ~2 400 was 2 mg/L or 10 mg/L, the scale inhibition against CaCO3 was 83.8% or 97.5%, respectively, while the scale inhibition against CaCO3 of the commercial poly(acrylic acid) scale inhibitor was 21.3% or 42.9%, respectively, at the same concentration. The scale inhibition performance decreases with temperature raising(50~90℃). However, the decreased extent for poly(acrylic acid) prepared by RAFT was markedly less than that for the commercial poly(acrylic acid) scale inhibitor. The difference between scale inhibition performances of the two inhibitors is maximal at 80℃, which is usually the maximal temperature in the practical cooling systems. The smaller the molecular mass of the poly(acrylic acid) in the range studied, the better the scale inhibition performance.
Poly(acrylic acid)(Mn 2 400~9 000) was prepared by reversible addition-fragmentation chain transfer(RAFT) polymerization with water as the solvent. GPC analysis indicats that the polymer possesses narrow molecular distribution(the polydispersity index PDI was ~1.2). Scale inhibition test indicates that the poly(acrylic acid) prepared by RAFT has better scale inhibition performance than a commercial poly(acrylic acid) scale inhibitor, which was prepared by traditional radical polymerization. For example, when the concentration of poly(acrylic acid) with a molecular mass of ~2 400 was 2 mg/L or 10 mg/L, the scale inhibition against CaCO3 was 83.8% or 97.5%, respectively, while the scale inhibition against CaCO3 of the commercial poly(acrylic acid) scale inhibitor was 21.3% or 42.9%, respectively, at the same concentration. The scale inhibition performance decreases with temperature raising(50~90℃). However, the decreased extent for poly(acrylic acid) prepared by RAFT was markedly less than that for the commercial poly(acrylic acid) scale inhibitor. The difference between scale inhibition performances of the two inhibitors is maximal at 80℃, which is usually the maximal temperature in the practical cooling systems. The smaller the molecular mass of the poly(acrylic acid) in the range studied, the better the scale inhibition performance.
2007, 24(9): 1054-1057
Abstract:
The coprecipitation method was used to prepare the active material of nickel hydroxide with Mn doped at a certain temperature, pH and stirring rate. XRD and electrochemical methods were applied to analyze the product. The XRD shows that α and β phases co-exist on mixing Mn with nickel ion to prepare the active material. The capability of nickel electrode is greatly improved by doping a certain amount of Mn, and when the molar amount of Mn is 10%, the oxygen evolution potential is increased, the charge potential of nickel electrode is decreased, the discharge potential of nickel electrode is increased, and the specific capacity is 243.21 mA·h/g. Because α nickel hydroxide is partially formed during the process of mixing Mn, the transition amount of electrons per mol nickel hydroxide is increased(approaching to 1). The cycle charge and discharge test results show that doping Mn into the nickel electrode could improve the cycle performance and level off the capacity at the same time.
The coprecipitation method was used to prepare the active material of nickel hydroxide with Mn doped at a certain temperature, pH and stirring rate. XRD and electrochemical methods were applied to analyze the product. The XRD shows that α and β phases co-exist on mixing Mn with nickel ion to prepare the active material. The capability of nickel electrode is greatly improved by doping a certain amount of Mn, and when the molar amount of Mn is 10%, the oxygen evolution potential is increased, the charge potential of nickel electrode is decreased, the discharge potential of nickel electrode is increased, and the specific capacity is 243.21 mA·h/g. Because α nickel hydroxide is partially formed during the process of mixing Mn, the transition amount of electrons per mol nickel hydroxide is increased(approaching to 1). The cycle charge and discharge test results show that doping Mn into the nickel electrode could improve the cycle performance and level off the capacity at the same time.
2007, 24(9): 1058-1061
Abstract:
By reaction with Me4NOH, a series of fluorine-containing polysiloxanes(PTFMS) were synthesized from D4, D3F and MDM with different contents [x(DF)/%] of SiCH3(CF3CH2CH2)O chain of PTFMS. Parameters such as refractive index n25℃D, viscosity η25℃ and surface free energy D25℃ were tested. The performance of breaking and inhibiting foam of single PTFMS and the mixture of PTFMS and silica in water- and oil-based systems were studied, respectively. Results show that with the increase of x(DF), the value of ηD25℃ decreases from 1.404 0 to 1.378 5, and the value of viscosity in both water- and oil-based systems increases from 58.13 mPa·s to 214.3 mPa·s, and value of surface free energy increases from 18.96 mN/m to 21.37 mN/m. In an oil-based system, the performance of breaking foam of single PTFMS and the mixture of PTFMS and silica is better than that of MD0FD20M, and doesn't change obviously with the increase of x(DF). The performance of foam inhibition for the compounds improve with the increase of x(DF). Silica is not helpful for antifoaming function of PTFMS in the oil-based system, which lays a foundation for choosing antifoam in an oil-based system. In a water-based system, the performance of breaking and inhibiting foam of single PTFMS is poor. With the aid of silica, the breaking foam ability of PTFMS increases significantly, and the inhibiting foam ability becomes better at first, but then worse, so silica is helpful for antifoaming function of PTFMS in a water-based system.
By reaction with Me4NOH, a series of fluorine-containing polysiloxanes(PTFMS) were synthesized from D4, D3F and MDM with different contents [x(DF)/%] of SiCH3(CF3CH2CH2)O chain of PTFMS. Parameters such as refractive index n25℃D, viscosity η25℃ and surface free energy D25℃ were tested. The performance of breaking and inhibiting foam of single PTFMS and the mixture of PTFMS and silica in water- and oil-based systems were studied, respectively. Results show that with the increase of x(DF), the value of ηD25℃ decreases from 1.404 0 to 1.378 5, and the value of viscosity in both water- and oil-based systems increases from 58.13 mPa·s to 214.3 mPa·s, and value of surface free energy increases from 18.96 mN/m to 21.37 mN/m. In an oil-based system, the performance of breaking foam of single PTFMS and the mixture of PTFMS and silica is better than that of MD0FD20M, and doesn't change obviously with the increase of x(DF). The performance of foam inhibition for the compounds improve with the increase of x(DF). Silica is not helpful for antifoaming function of PTFMS in the oil-based system, which lays a foundation for choosing antifoam in an oil-based system. In a water-based system, the performance of breaking and inhibiting foam of single PTFMS is poor. With the aid of silica, the breaking foam ability of PTFMS increases significantly, and the inhibiting foam ability becomes better at first, but then worse, so silica is helpful for antifoaming function of PTFMS in a water-based system.
2007, 24(9): 1062-1065
Abstract:
With sodium tripolyphosphate as ionic crosslinking reagent, levodopa-chitosan microspheres were prepared by means of emulsion-dispersion and ionic cross-linking. The physicochemical properties and the drug-release performance of the microspheres were investigated. The polarized optical microscopy showed that the particles prepared were basically spheric. The average diameter of the microspheres detected by a laser particle analyzer was about 3.5 μm. FT-IR analysis indicated that the protonated amino groups in chitosan combined with tripolyphosphate via electrostatic interactions, and levodopa was enwrapped in chitosan microspheres. DSC and XRD analyses indicated that levodopa crystals existed in the microspheres, while chitosan was amorphous. TG analysis showed that the crystallinity of chitosan was lower when chitosan combined with tripolyphosphate. The drug-release performance of the microspheres was affected by the pH value of the media. In acid media, the release of levodopa slowed down when the concentration of chitosan was higher or when the mass ratio of levodopa to chitosan increased. In basic media, the drug-releasing rate was, on the whole, higher than that in acid media.
With sodium tripolyphosphate as ionic crosslinking reagent, levodopa-chitosan microspheres were prepared by means of emulsion-dispersion and ionic cross-linking. The physicochemical properties and the drug-release performance of the microspheres were investigated. The polarized optical microscopy showed that the particles prepared were basically spheric. The average diameter of the microspheres detected by a laser particle analyzer was about 3.5 μm. FT-IR analysis indicated that the protonated amino groups in chitosan combined with tripolyphosphate via electrostatic interactions, and levodopa was enwrapped in chitosan microspheres. DSC and XRD analyses indicated that levodopa crystals existed in the microspheres, while chitosan was amorphous. TG analysis showed that the crystallinity of chitosan was lower when chitosan combined with tripolyphosphate. The drug-release performance of the microspheres was affected by the pH value of the media. In acid media, the release of levodopa slowed down when the concentration of chitosan was higher or when the mass ratio of levodopa to chitosan increased. In basic media, the drug-releasing rate was, on the whole, higher than that in acid media.
2007, 24(9): 1066-1070
Abstract:
The metal ions of different oxidation states doped LiMn1.95M0.05O4(M:Li,Mg,Co,Ti,V) samples were synthesized with CH3COOLi·2H2O、(CH3CO22)2Mn·4H2O, oxide and citric acid as the starting material by rheolegical phase reaction method. The XRD results show that the samples exhibit the same phase as pure spinel. The data of the lattice parameter of LiMn1.95M0.05O4 were calculated by winplotr.exe and the lattice parameter was smaller than that of the undoped one, which was decreased to some extent due to the doped-ion. The studies of the cyclic voltammetry showed two reversible processes, which are corresponding to the typical response of spinel LiMn2O4 and revealed that the insertion-extraction reaction occurred at two stages in the 4 V region. The doped ions had impact on the position and the area of the peaks. The lower the content of Mn(Ⅲ), the smaller the area of the peak. The higher the bond energy of the metal ion with oxygen, the higher the voltage of the peak. The electrochemical performances of the samples after 50 cycles of charge-discharge were studied and the results show that LiMn1.95M0.05O4 displays a better capacity and cyclability at the same content of the doped ions.
The metal ions of different oxidation states doped LiMn1.95M0.05O4(M:Li,Mg,Co,Ti,V) samples were synthesized with CH3COOLi·2H2O、(CH3CO22)2Mn·4H2O, oxide and citric acid as the starting material by rheolegical phase reaction method. The XRD results show that the samples exhibit the same phase as pure spinel. The data of the lattice parameter of LiMn1.95M0.05O4 were calculated by winplotr.exe and the lattice parameter was smaller than that of the undoped one, which was decreased to some extent due to the doped-ion. The studies of the cyclic voltammetry showed two reversible processes, which are corresponding to the typical response of spinel LiMn2O4 and revealed that the insertion-extraction reaction occurred at two stages in the 4 V region. The doped ions had impact on the position and the area of the peaks. The lower the content of Mn(Ⅲ), the smaller the area of the peak. The higher the bond energy of the metal ion with oxygen, the higher the voltage of the peak. The electrochemical performances of the samples after 50 cycles of charge-discharge were studied and the results show that LiMn1.95M0.05O4 displays a better capacity and cyclability at the same content of the doped ions.
2007, 24(9): 1071-1073
Abstract:
Cyclic voltammetry of CO2 in MeCN solution containing 0.1 mol/L TEABF4 and DMF solution containing 0.1 mol/L TEABF4 were studied at Cu electrode and it was shown that CO2 will be reduced irreversibly at E=-2.3 V(vs.Ag/AgI). Dimethyl carbonate(DMC) was electrosynthesized from CO2 and CH3OH in the relevant solvent-supporting electrolyte systems in a one-compartment cell with Mg as consuming anode and Cu as cathode, followed by addition of MeI as an alkylating agent. The procedure was safe, clean and carried out under very mild conditions. The effect of solvent, supporting electrolyte, electrodes and temperature was investigated to optimize the electrolytic conditions. The highest yield of 14.92% was obtained when the reaction was carried out at E=-2.3 V(vs.Ag/AgI) in MeCN solution containing 0.1 mol/L TEABF4 at temperature of 25℃ with 1 F/mol passed charge. It is a new electrochemical procedure for the synthesis of DMC from CO2 and CH3OH under mild conditions(PCO2=1.0 atm, T=25℃).
Cyclic voltammetry of CO2 in MeCN solution containing 0.1 mol/L TEABF4 and DMF solution containing 0.1 mol/L TEABF4 were studied at Cu electrode and it was shown that CO2 will be reduced irreversibly at E=-2.3 V(vs.Ag/AgI). Dimethyl carbonate(DMC) was electrosynthesized from CO2 and CH3OH in the relevant solvent-supporting electrolyte systems in a one-compartment cell with Mg as consuming anode and Cu as cathode, followed by addition of MeI as an alkylating agent. The procedure was safe, clean and carried out under very mild conditions. The effect of solvent, supporting electrolyte, electrodes and temperature was investigated to optimize the electrolytic conditions. The highest yield of 14.92% was obtained when the reaction was carried out at E=-2.3 V(vs.Ag/AgI) in MeCN solution containing 0.1 mol/L TEABF4 at temperature of 25℃ with 1 F/mol passed charge. It is a new electrochemical procedure for the synthesis of DMC from CO2 and CH3OH under mild conditions(PCO2=1.0 atm, T=25℃).
2007, 24(9): 1074-1076
Abstract:
Carbazole was nitrosylated and reduced to aminocarbazole by the action of zinc in acetic acid. Nine novel carbazole schiff bases(1~9) were synthesized by the reaction of 9-aminocarbazole and substituted aromatic aldehydes with yields of 63%~87%. Their structures were characterized by IR, 1H NMR, MS and elemental analysis. The preliminary test of bioactivity showed they displayed notable antibacterial activities. The bacterial inhibition of compounds 3 and 7 was more than 85%.
Carbazole was nitrosylated and reduced to aminocarbazole by the action of zinc in acetic acid. Nine novel carbazole schiff bases(1~9) were synthesized by the reaction of 9-aminocarbazole and substituted aromatic aldehydes with yields of 63%~87%. Their structures were characterized by IR, 1H NMR, MS and elemental analysis. The preliminary test of bioactivity showed they displayed notable antibacterial activities. The bacterial inhibition of compounds 3 and 7 was more than 85%.
2007, 24(9): 1077-1079
Abstract:
2-Cyclopropylbenzimidazole was synthesized from o-phenylenediamine and cyclopropanecarboxylic acid with polyphosphoric acid as the catalyst under microwave. An unreported compound 2-cyclopropylbenzimidazolium salt was obtained from 2-cyclopropyl benzimidazole and iodomethane. 1-Cyclopropylethanone was prepared via the addition-hydrolysis reaction of the 2-cyclopropyl benzimidazolium salt with a Grignard reagent. It was characterized by means of elemental analysis, IR, MS and 1H NMR. The title compound is colorless oil. The yield was 67%.This synthetic method for preparation of 1-cyclopropylethanone has not been reported.
2-Cyclopropylbenzimidazole was synthesized from o-phenylenediamine and cyclopropanecarboxylic acid with polyphosphoric acid as the catalyst under microwave. An unreported compound 2-cyclopropylbenzimidazolium salt was obtained from 2-cyclopropyl benzimidazole and iodomethane. 1-Cyclopropylethanone was prepared via the addition-hydrolysis reaction of the 2-cyclopropyl benzimidazolium salt with a Grignard reagent. It was characterized by means of elemental analysis, IR, MS and 1H NMR. The title compound is colorless oil. The yield was 67%.This synthetic method for preparation of 1-cyclopropylethanone has not been reported.
2007, 24(9): 1080-1082
Abstract:
Brønsted acid ionic liquids [Hmim]BF4, [bmim]HSO4 or [bmim]H2PO4 was used as substituted catalyst of oil of vitirol in the acylation of salicylic acid for the synthesis of Aspirin. The effects of reaction temperature, reaction time, amount of catalyst and molar ratio of salicylic acid to acetic anhydride on the acylation reaction and the reuseful ability of the ionic liquid were examined. The optimum reaction conditions were:the amount of [bmim]H2PO4 was 0.28 g(1.18×10-3 mol), salicylic acid 2.762 g(0.02 mol), acetic anhydride 4.083 g(0.04 mol), molar ratio of anhydride to salicylic acid 2:1; the reaction time 30 min; the reaction temperature 70℃. The yield was 63.43%. After filtration and evaporation, [bmim]H2PO4 could be reused three times, no obvious change was observed in the yield.
Brønsted acid ionic liquids [Hmim]BF4, [bmim]HSO4 or [bmim]H2PO4 was used as substituted catalyst of oil of vitirol in the acylation of salicylic acid for the synthesis of Aspirin. The effects of reaction temperature, reaction time, amount of catalyst and molar ratio of salicylic acid to acetic anhydride on the acylation reaction and the reuseful ability of the ionic liquid were examined. The optimum reaction conditions were:the amount of [bmim]H2PO4 was 0.28 g(1.18×10-3 mol), salicylic acid 2.762 g(0.02 mol), acetic anhydride 4.083 g(0.04 mol), molar ratio of anhydride to salicylic acid 2:1; the reaction time 30 min; the reaction temperature 70℃. The yield was 63.43%. After filtration and evaporation, [bmim]H2PO4 could be reused three times, no obvious change was observed in the yield.
2007, 24(9): 1083-1085
Abstract:
12-Tungstophosphoric acid reacted with diphenhydramine hydrochloride(DP·HCl) in an acidic medium pH 0~1.5 to form complexes, which resulted in great enhancement of resonance Rayleigh scattering(RRS). The maximum RRS peak is at 305 nm, and the RRS intensity is proportional to the concentration of DP·HCl in the range of 8.0×10-9~1.6×10-6 g/mL. Therefore, a RRS method of determining DP·HCl was developed. This method has high sensitivity and good selectivity, and the detection limit(3σ) is 0.8×10-9 g/mL. The method was applied to determine the content of DP·HCl in urine samples, the recovery was between 96.0% and 104.2%. The reaction mechanism was discussed by means of AM1 of quantum chemistry.
12-Tungstophosphoric acid reacted with diphenhydramine hydrochloride(DP·HCl) in an acidic medium pH 0~1.5 to form complexes, which resulted in great enhancement of resonance Rayleigh scattering(RRS). The maximum RRS peak is at 305 nm, and the RRS intensity is proportional to the concentration of DP·HCl in the range of 8.0×10-9~1.6×10-6 g/mL. Therefore, a RRS method of determining DP·HCl was developed. This method has high sensitivity and good selectivity, and the detection limit(3σ) is 0.8×10-9 g/mL. The method was applied to determine the content of DP·HCl in urine samples, the recovery was between 96.0% and 104.2%. The reaction mechanism was discussed by means of AM1 of quantum chemistry.
2007, 24(9): 1086-1088
Abstract:
In a cell without a septum, Ti alkoxide complex was synthesized by electrochemical dissolution of titanium. A CH3COOH solution of 0.20 mol/L (CH3COO)2Ba was added into the above solution at pH 8.5. The xerogel was obtained by drying in vacuum for 24 h and hydrolysis of the mixed solution. The xerogel was heated at 350℃ for 2 h to obtain the nano-BaTiO3 powder. IR, H NMR, TG-DTA, XRD and TEM were used to investigate the structure of the nano-BaTiO3. The results show that the complex is Ti(OCH2-CH3)(4-y)(acac)y, and the precursor contains acac- and Ac- groups, which can prevent it from aggregation in the course of hydrolysis and drying. The xerogel has an average particle size of 15~20 nm, and the nano-sized particle BaTiO3 is 15~40 nm in diameter. This method can reduce the temperature of synthesizing nano-BaTiO3 effectively compared with the current sol-gel method.
In a cell without a septum, Ti alkoxide complex was synthesized by electrochemical dissolution of titanium. A CH3COOH solution of 0.20 mol/L (CH3COO)2Ba was added into the above solution at pH 8.5. The xerogel was obtained by drying in vacuum for 24 h and hydrolysis of the mixed solution. The xerogel was heated at 350℃ for 2 h to obtain the nano-BaTiO3 powder. IR, H NMR, TG-DTA, XRD and TEM were used to investigate the structure of the nano-BaTiO3. The results show that the complex is Ti(OCH2-CH3)(4-y)(acac)y, and the precursor contains acac- and Ac- groups, which can prevent it from aggregation in the course of hydrolysis and drying. The xerogel has an average particle size of 15~20 nm, and the nano-sized particle BaTiO3 is 15~40 nm in diameter. This method can reduce the temperature of synthesizing nano-BaTiO3 effectively compared with the current sol-gel method.
2007, 24(9): 1089-1091
Abstract:
The basic functionalized ionic liquid, 1-butyl-3-methylimidazolium hydroxide([BMIM]OH), was prepared and used to catalyze the Knoevenagel condensation of aromatic aldehydes with malononitrile or ethyl cyanoacetate. The results show that the Knoevenagel condensation proceeds smoothly in the presence of 5% basic functionalized ionic liquid to afford the desired alkenes in good purity and 81%~97% yields under relatively mild conditions without solvent or any added catalyst. In this catalyst system, the Knoevenagel condensations of a series of aromatic aldehydes with malononitrile or ethyl cyanoacetate were programmed and a mechanism was postulated as well. When aromatic aldehydes reacted with ethyl cyanoacetate, the corresponding alkenes proved to be E-isomers by 1H NMR. The procedure is simple and the ionic liquid could be recycled efficiently. With the condensation of benzaldehyde and malononitrile as an example, the ionic liquid was recycled three times with a slight decrease in catalytic activity and a yield of 86% was gained.
The basic functionalized ionic liquid, 1-butyl-3-methylimidazolium hydroxide([BMIM]OH), was prepared and used to catalyze the Knoevenagel condensation of aromatic aldehydes with malononitrile or ethyl cyanoacetate. The results show that the Knoevenagel condensation proceeds smoothly in the presence of 5% basic functionalized ionic liquid to afford the desired alkenes in good purity and 81%~97% yields under relatively mild conditions without solvent or any added catalyst. In this catalyst system, the Knoevenagel condensations of a series of aromatic aldehydes with malononitrile or ethyl cyanoacetate were programmed and a mechanism was postulated as well. When aromatic aldehydes reacted with ethyl cyanoacetate, the corresponding alkenes proved to be E-isomers by 1H NMR. The procedure is simple and the ionic liquid could be recycled efficiently. With the condensation of benzaldehyde and malononitrile as an example, the ionic liquid was recycled three times with a slight decrease in catalytic activity and a yield of 86% was gained.
2007, 24(9): 1092-1094
Abstract:
The flotation separation of platinum, palladium, rhodium and gold was studied in aqueous solution containing SnCl2 and cetyltrimetheyl ammonium chloride in the presence of NaCl and HCl medium. After heating a solution of 0.10 mol/L SnCl2, 1.0×10-3 mol/L cetyltrimetyl ammonium chloride, 0.1 g/mL NaCl and 0.24 mol/L HCl with water bath at 60℃ for 10 min the percent separation of platinum, palladium, rhodium and gold was 95.2%~98.0%、97.3%~97.6%、93.4%~97.1%和96.6%~99.1%, respectively with flotation separation. The separation results of the synthetic samples show that the method can separate platinum, palladium, rhodium and gold from a great amount of base metals such as Fe(Ⅲ), Pb(Ⅱ), Al(Ⅲ), Cu(Ⅱ), Zn(Ⅱ), Ca(Ⅱ), and this method has been also used for the separation platinum, palladium, rhodium and gold from real samples with satisfactory results.
The flotation separation of platinum, palladium, rhodium and gold was studied in aqueous solution containing SnCl2 and cetyltrimetheyl ammonium chloride in the presence of NaCl and HCl medium. After heating a solution of 0.10 mol/L SnCl2, 1.0×10-3 mol/L cetyltrimetyl ammonium chloride, 0.1 g/mL NaCl and 0.24 mol/L HCl with water bath at 60℃ for 10 min the percent separation of platinum, palladium, rhodium and gold was 95.2%~98.0%、97.3%~97.6%、93.4%~97.1%和96.6%~99.1%, respectively with flotation separation. The separation results of the synthetic samples show that the method can separate platinum, palladium, rhodium and gold from a great amount of base metals such as Fe(Ⅲ), Pb(Ⅱ), Al(Ⅲ), Cu(Ⅱ), Zn(Ⅱ), Ca(Ⅱ), and this method has been also used for the separation platinum, palladium, rhodium and gold from real samples with satisfactory results.
2007, 24(9): 1095-1097
Abstract:
Two novel bi-dodecyl bi-phosphate compounds, DGDP and PDP were synthesized from phosphorous oxychloride, diethylene glycol (hydroquinone) and dodecanol via the esterification of two steps and the hydrolization of one step, and were purified by recrystallization in absolute ethyl alcohol. Their structures were characterized by IR, 1H NMR, MS and potentiometric titration. The results of potentiometric titration show that the acid strength of the two hydroxyls in bi-dodecyl bi-phosphate(DGDP,PDP) was nearly identitcal. Their ionization constants at 25℃ are 3.940×10-4 mol/L(DGDP) and 4.255×10-3 mol/L(PDP) respectively. The critical micelle concentrations of their aqueous solutions at 20℃ are 9.0×10-4 mol/L(DGDP) and 1.3×10-3 mol/L(PDP) respectively. Their coefficients of surface tension at 20℃ are 34.49 mN/m(DGDP) and 36.14 mN/m(PDP)at CMC respectively.
Two novel bi-dodecyl bi-phosphate compounds, DGDP and PDP were synthesized from phosphorous oxychloride, diethylene glycol (hydroquinone) and dodecanol via the esterification of two steps and the hydrolization of one step, and were purified by recrystallization in absolute ethyl alcohol. Their structures were characterized by IR, 1H NMR, MS and potentiometric titration. The results of potentiometric titration show that the acid strength of the two hydroxyls in bi-dodecyl bi-phosphate(DGDP,PDP) was nearly identitcal. Their ionization constants at 25℃ are 3.940×10-4 mol/L(DGDP) and 4.255×10-3 mol/L(PDP) respectively. The critical micelle concentrations of their aqueous solutions at 20℃ are 9.0×10-4 mol/L(DGDP) and 1.3×10-3 mol/L(PDP) respectively. Their coefficients of surface tension at 20℃ are 34.49 mN/m(DGDP) and 36.14 mN/m(PDP)at CMC respectively.
2007, 24(9): 1098-1100
Abstract:
The synthesis of a new aryl amide-based ligand:2,2'-(1,2-phenylenebis(oxy))bis-(N-plenylacetamide)(L) and its rare earth complexes(RE=La, Eu, Tb, Dy, Sm, Gd) is reported. All the compounds were characterized by 1H NMR, elemental analysis, molar conductivity, IR and TG-DTA. The formular of these complexes may be REL(NO3)3·H2O(RE=La3+,Sm3+,Eu3+,Gd3+,Tb3+,Dy3+), and the yields were about 78%. In these complexes, the NO3- groups which act as the counter anions are in bidentate coordination with the RE ions, and the coordination number may be 10. The fluorescent properties of [EuL(NO3)3]·H2O and [TbL(NO3)3]·H2O in solid state were determined at 298 K. The complexes exhibit the characteristic emissions of Eu3+ and Tb3+, respectively. In addition, the fluorescent intensity of [TbL(NO3)3]·H2O is stronger than that of [EuL(NO3)3]·H2O. This also shows that the luminescence sensitizing effect of the aryl amide-based ligand to Tb3+ is better than that to Eu3+.
The synthesis of a new aryl amide-based ligand:2,2'-(1,2-phenylenebis(oxy))bis-(N-plenylacetamide)(L) and its rare earth complexes(RE=La, Eu, Tb, Dy, Sm, Gd) is reported. All the compounds were characterized by 1H NMR, elemental analysis, molar conductivity, IR and TG-DTA. The formular of these complexes may be REL(NO3)3·H2O(RE=La3+,Sm3+,Eu3+,Gd3+,Tb3+,Dy3+), and the yields were about 78%. In these complexes, the NO3- groups which act as the counter anions are in bidentate coordination with the RE ions, and the coordination number may be 10. The fluorescent properties of [EuL(NO3)3]·H2O and [TbL(NO3)3]·H2O in solid state were determined at 298 K. The complexes exhibit the characteristic emissions of Eu3+ and Tb3+, respectively. In addition, the fluorescent intensity of [TbL(NO3)3]·H2O is stronger than that of [EuL(NO3)3]·H2O. This also shows that the luminescence sensitizing effect of the aryl amide-based ligand to Tb3+ is better than that to Eu3+.
