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2009 Volume 26 Issue 5
2009, 26(5): 501-506
Abstract:
A novel type of molecular tweezers with different chiral center and cleft has been designed and synthesized with α-hyodeoxycholic acid as spacer and D/L-amino acid methyl ester as chiral arm attached at 3-position under microwave irradiation.Their structures were elucidated by 1H NMR,FTIR spectra and elemental analysis.Their molecular recognition properties for D/L-amino acid methyl esters were investigated by UV-Vis spectral titration,which showed that all these molecular clefts possessed a good recognition ability for D/L-amino acid methyl esters.The supramolecular complexes formed between the tweezers and various substrates consisted of a 1:1 type of host to guest of molecules.Based on the Hildebrand-Benesi equation,plotting 1/ΔA vs 1/[G]0 gave a straight line.From the line slopes and intercepts,the stability constants(Ka) of the complexes were calculated and thereafter the correspondent Gibbs free energies(-ΔG0) were also obtained.Preliminary results indicate that due to the structural micro-environmental changes,the synthesized chiral single-armed molecular tweezers exhibit different enantio-selectivity for D/L-amino acid methyl esters.
A novel type of molecular tweezers with different chiral center and cleft has been designed and synthesized with α-hyodeoxycholic acid as spacer and D/L-amino acid methyl ester as chiral arm attached at 3-position under microwave irradiation.Their structures were elucidated by 1H NMR,FTIR spectra and elemental analysis.Their molecular recognition properties for D/L-amino acid methyl esters were investigated by UV-Vis spectral titration,which showed that all these molecular clefts possessed a good recognition ability for D/L-amino acid methyl esters.The supramolecular complexes formed between the tweezers and various substrates consisted of a 1:1 type of host to guest of molecules.Based on the Hildebrand-Benesi equation,plotting 1/ΔA vs 1/[G]0 gave a straight line.From the line slopes and intercepts,the stability constants(Ka) of the complexes were calculated and thereafter the correspondent Gibbs free energies(-ΔG0) were also obtained.Preliminary results indicate that due to the structural micro-environmental changes,the synthesized chiral single-armed molecular tweezers exhibit different enantio-selectivity for D/L-amino acid methyl esters.
2009, 26(5): 507-510
Abstract:
Nine compounds of N-nitro urea were prepared by one pot method.The yields of products were in a range of 50.2%~76.8%.The structures of the compounds were identified by 1H NMR,IR and elemental analysis.Preliminary bacteriostatic activity tests show that all the compounds exhibited varying degrees of antibacterial activity on tested strains when the concentration was 50 mg/L;especially,the inhibitory rates of compounds 3d and 3e on Rhizoctonia Solani were over 50%.Quantum chemistry calculation results indicate that the urea-bridge in the compounds was the chemical active site for such bacteriostatic activity.
Nine compounds of N-nitro urea were prepared by one pot method.The yields of products were in a range of 50.2%~76.8%.The structures of the compounds were identified by 1H NMR,IR and elemental analysis.Preliminary bacteriostatic activity tests show that all the compounds exhibited varying degrees of antibacterial activity on tested strains when the concentration was 50 mg/L;especially,the inhibitory rates of compounds 3d and 3e on Rhizoctonia Solani were over 50%.Quantum chemistry calculation results indicate that the urea-bridge in the compounds was the chemical active site for such bacteriostatic activity.
2009, 26(5): 511-514
Abstract:
The synthetic method of 4-oxo-β-ionone from α-ionone reported by Kaiser was improved.Factors that influnences epoxidation,ring opening and oxidation were discussed,and the purification method for title compound was investigated.Epoxidation of α-ionone with 30% H2O2 catalyzed by tungstophosphoric acid,4,5-epoxy-α-ionone was obtained with a yield of 85% and a purity of 94% when the mole ratio of α-ionone to H2O2 was 2:3 and that of tungstophosphoric acid to H2O2 was 5:100.Then it was converted into 4-hydroxyl-β-ionone under alkaline condition with a yield of 94% and a purity of 85% when the mole ratio of sodium methoxide to ionone epoxidation was 1.5:1.After purification of 4-hydroxyl-β-ionone by succine anhydride,the yield was 83% and the purity was 96%.After oxidation by aluminum isopropoxide,the yield was 93% and the purity was 96%.The title compound was obtained by column chromatography with a total yield of 61.7% compared with a yield of 47.2% obtained by Kaiser method.The structure of the compound was characterized by MS,IR,1H NMR,13C NMR and elemental analysis.
The synthetic method of 4-oxo-β-ionone from α-ionone reported by Kaiser was improved.Factors that influnences epoxidation,ring opening and oxidation were discussed,and the purification method for title compound was investigated.Epoxidation of α-ionone with 30% H2O2 catalyzed by tungstophosphoric acid,4,5-epoxy-α-ionone was obtained with a yield of 85% and a purity of 94% when the mole ratio of α-ionone to H2O2 was 2:3 and that of tungstophosphoric acid to H2O2 was 5:100.Then it was converted into 4-hydroxyl-β-ionone under alkaline condition with a yield of 94% and a purity of 85% when the mole ratio of sodium methoxide to ionone epoxidation was 1.5:1.After purification of 4-hydroxyl-β-ionone by succine anhydride,the yield was 83% and the purity was 96%.After oxidation by aluminum isopropoxide,the yield was 93% and the purity was 96%.The title compound was obtained by column chromatography with a total yield of 61.7% compared with a yield of 47.2% obtained by Kaiser method.The structure of the compound was characterized by MS,IR,1H NMR,13C NMR and elemental analysis.
2009, 26(5): 515-518
Abstract:
Four novel azo derivatives of indolizine were synthesized and fully characterized by 1H and 13C NMR,FTIR,elemental analysis,and thermal analysis.The behaviour of these diazo dyes in various solvents was evaluated.Substituent,acid and base effects on the visible absorption maxima of the dyes were also reported.The absorption maxima displayed a blue-shift when the compounds were present under ionic condition.DSC curves show that the decomposition temperature for the compound having alkyl substituent at the C-2 position is 180 ℃.2-Phenyl-substituted compounds are comparatively stable,with a decomposition temperatures above 200 ℃.
Four novel azo derivatives of indolizine were synthesized and fully characterized by 1H and 13C NMR,FTIR,elemental analysis,and thermal analysis.The behaviour of these diazo dyes in various solvents was evaluated.Substituent,acid and base effects on the visible absorption maxima of the dyes were also reported.The absorption maxima displayed a blue-shift when the compounds were present under ionic condition.DSC curves show that the decomposition temperature for the compound having alkyl substituent at the C-2 position is 180 ℃.2-Phenyl-substituted compounds are comparatively stable,with a decomposition temperatures above 200 ℃.
2009, 26(5): 519-522
Abstract:
Reaction of MoO2(acac)2 with 3-{6-[(1R,2R,4S)-2-hydroxy-1,3,3-trimethylbicycloheptan-2-yl]pyridine-2-yl}-2'-pivaloyloxy-(R)-BINOL(2),synthesized from 3-{6-[(1R,2R,4S)-2-hydroxy-1,3,3-trime-thylbicycloheptan-2-yl]pyridine-2-yl}-(R)-BINOL(1) and pivaloyl chloride,afforded the chiral molybdnum complex 2(Mo(Ⅵ)-2).The compound Mo(Ⅵ)-2 was charactierized by 1H NMR,IR,ESI-MS and X-ray single crystal diffraction.The crystatal belongs to monoclinic system with space group P21,a=1.179 34(10) nm,b=2.304 5(2) nm,c=1.518 88(13) nm,α=90°,β=112.84°,γ=90°,V=3.804 2(6) nm3,Z=4,μ=0.392 mm-1,Dc=1.298 Mg/m3,F(000)=1 544,R1=0.077 5,wR2=0.193 4,GOF=1.122.In this molecule,the Mo(Ⅵ) atom exists in a coordination environment with one water molecule and one tridentate ONO ligand in compound 2.This chiral molybdenum complex was found to catalyse the epoxidation of 2-vinylnaphthalene in 7%e.e..
Reaction of MoO2(acac)2 with 3-{6-[(1R,2R,4S)-2-hydroxy-1,3,3-trimethylbicycloheptan-2-yl]pyridine-2-yl}-2'-pivaloyloxy-(R)-BINOL(2),synthesized from 3-{6-[(1R,2R,4S)-2-hydroxy-1,3,3-trime-thylbicycloheptan-2-yl]pyridine-2-yl}-(R)-BINOL(1) and pivaloyl chloride,afforded the chiral molybdnum complex 2(Mo(Ⅵ)-2).The compound Mo(Ⅵ)-2 was charactierized by 1H NMR,IR,ESI-MS and X-ray single crystal diffraction.The crystatal belongs to monoclinic system with space group P21,a=1.179 34(10) nm,b=2.304 5(2) nm,c=1.518 88(13) nm,α=90°,β=112.84°,γ=90°,V=3.804 2(6) nm3,Z=4,μ=0.392 mm-1,Dc=1.298 Mg/m3,F(000)=1 544,R1=0.077 5,wR2=0.193 4,GOF=1.122.In this molecule,the Mo(Ⅵ) atom exists in a coordination environment with one water molecule and one tridentate ONO ligand in compound 2.This chiral molybdenum complex was found to catalyse the epoxidation of 2-vinylnaphthalene in 7%e.e..
2009, 26(5): 523-529
Abstract:
In order to find novel low toxic and high-efficiency fungicides,12 1-[6-alkoxy(benzloxy)-3,4-methylenedioxyphenyl]-2-(1H-1,2,4-triazole-1-yl)-enthone(ol) compounds were prepared from sesamol and 1-H-1,2,4-triazole.The structures of all the synthesized compounds were confirmed by IR,1H NMR,13C NMR and elemental analysis.Preliminary bioassay tests showed that at a concentration of 1×10-4 g/mL,the inhibitory rate of compounds Ⅴc to Fusarium graminearum was 81.3%;that of Ⅳe to Fusarium oxysporium was 83.4%;those of Ⅴe and Ⅴf to Cercospora sorghi were 79.7% and 72.4% respectively.
In order to find novel low toxic and high-efficiency fungicides,12 1-[6-alkoxy(benzloxy)-3,4-methylenedioxyphenyl]-2-(1H-1,2,4-triazole-1-yl)-enthone(ol) compounds were prepared from sesamol and 1-H-1,2,4-triazole.The structures of all the synthesized compounds were confirmed by IR,1H NMR,13C NMR and elemental analysis.Preliminary bioassay tests showed that at a concentration of 1×10-4 g/mL,the inhibitory rate of compounds Ⅴc to Fusarium graminearum was 81.3%;that of Ⅳe to Fusarium oxysporium was 83.4%;those of Ⅴe and Ⅴf to Cercospora sorghi were 79.7% and 72.4% respectively.
2009, 26(5): 530-533
Abstract:
Two amido azobenzene compounds were synthesized by diazo coupling reaction,which were purified and dried and reacted with salicylaldehyde at 60 ℃ for 4 hours to yield,two azo schiff bases respectively.All the compounds were characterized by elemental analysis,1H NMR and IR.The UV-Vis spectroscopy testing of the compounds showed that compounds A and B have good thermochromism behavior at a heating rate of 1.5 ℃/min;at 45 ℃ compound A's absorptions at 450 nm and 348 nm exhibited linear relationship with time,and compound B's absorptions at 425 nm and 356 nm exhibited linear relationship with time,respectively.The results showed they are good thermochromism materials.
Two amido azobenzene compounds were synthesized by diazo coupling reaction,which were purified and dried and reacted with salicylaldehyde at 60 ℃ for 4 hours to yield,two azo schiff bases respectively.All the compounds were characterized by elemental analysis,1H NMR and IR.The UV-Vis spectroscopy testing of the compounds showed that compounds A and B have good thermochromism behavior at a heating rate of 1.5 ℃/min;at 45 ℃ compound A's absorptions at 450 nm and 348 nm exhibited linear relationship with time,and compound B's absorptions at 425 nm and 356 nm exhibited linear relationship with time,respectively.The results showed they are good thermochromism materials.
2009, 26(5): 534-537
Abstract:
A binuclear Schiff base ligand was synthesized via the reaction of 3-carboxylsalicylaldehyde and dithiocarbohydrazon.The cobalt(Ⅱ),copper(Ⅱ),nickel(Ⅱ) and zinc(Ⅱ) complexes were also synthesized via the complexation of the resulting ligand to the corresponding metal ions with yields of 57%～78%,and characterized by elementalan alysis,1H NMR,IR,UV-Vis,molar conductance and MS.The antiba-cterial activities of the compounds were tested against seven kinds of bacteria.The results show that the compounds possess different inhibiting effects.
A binuclear Schiff base ligand was synthesized via the reaction of 3-carboxylsalicylaldehyde and dithiocarbohydrazon.The cobalt(Ⅱ),copper(Ⅱ),nickel(Ⅱ) and zinc(Ⅱ) complexes were also synthesized via the complexation of the resulting ligand to the corresponding metal ions with yields of 57%～78%,and characterized by elementalan alysis,1H NMR,IR,UV-Vis,molar conductance and MS.The antiba-cterial activities of the compounds were tested against seven kinds of bacteria.The results show that the compounds possess different inhibiting effects.
2009, 26(5): 538-542
Abstract:
PS-MAA copolymer particles were prepared by suspension polymerization,which was used to prepare metal cobalt coated PS-MAA composite particles by ultraviolet irradiation.The shapes of metal cobalt on the surface of composite particles could be changed from flaky,rod to spherical with the amount of surfactant used.The influencing factors on coating formation and composite reaction rate such as surfactant,concentration of Co2+,stirring,etc.were also studied.The study shows that the coating formation can be increased by using composite surfactant,decreasing the concentration of Co2+ from 0.01 mol/L to 0.005 mol/L,or increasing the number of stirring from once to 3 times a day.The composite reaction rate of the anion surfactant system is higher than that of the nonionic surfactant system.When the surfactant conce-ntration in the system is too high,the micelle will be associated with liquid crystal layer,resulting in amorphous metal cobalt coated on the surface of composite particles,while crystal cobalt coated composite particles can be prepared on decreasing the surfactant concentration.
PS-MAA copolymer particles were prepared by suspension polymerization,which was used to prepare metal cobalt coated PS-MAA composite particles by ultraviolet irradiation.The shapes of metal cobalt on the surface of composite particles could be changed from flaky,rod to spherical with the amount of surfactant used.The influencing factors on coating formation and composite reaction rate such as surfactant,concentration of Co2+,stirring,etc.were also studied.The study shows that the coating formation can be increased by using composite surfactant,decreasing the concentration of Co2+ from 0.01 mol/L to 0.005 mol/L,or increasing the number of stirring from once to 3 times a day.The composite reaction rate of the anion surfactant system is higher than that of the nonionic surfactant system.When the surfactant conce-ntration in the system is too high,the micelle will be associated with liquid crystal layer,resulting in amorphous metal cobalt coated on the surface of composite particles,while crystal cobalt coated composite particles can be prepared on decreasing the surfactant concentration.
2009, 26(5): 543-546
Abstract:
We chose three epiphytes,Saccharomyces cerevisiae,Endomyces decipiens,Rhizopus Nigricans,with two kinds of silicon sources tetraethyl orthosilicate(TEOS) and Na2SiO3,to carry out the biological nano-structured SiO2 deposition via biomineralization.The samples were investigated by SEM,TEM,EDX,and ED,and the results indicate that(1)Saccharomyces cerevisiae deposited a SiO2 nano-granule;(2)Endomyces decipiens deposited a nano-shell SiO2;(3)Rhizopus Nigricans deposited a SiO2 nano-tube;(4)the epiphyte can use not only TEOS but also Na2SiO3.The epiphyte mineralization depended on surface tension,template composition,spatial structure and silicon nutrition.
We chose three epiphytes,Saccharomyces cerevisiae,Endomyces decipiens,Rhizopus Nigricans,with two kinds of silicon sources tetraethyl orthosilicate(TEOS) and Na2SiO3,to carry out the biological nano-structured SiO2 deposition via biomineralization.The samples were investigated by SEM,TEM,EDX,and ED,and the results indicate that(1)Saccharomyces cerevisiae deposited a SiO2 nano-granule;(2)Endomyces decipiens deposited a nano-shell SiO2;(3)Rhizopus Nigricans deposited a SiO2 nano-tube;(4)the epiphyte can use not only TEOS but also Na2SiO3.The epiphyte mineralization depended on surface tension,template composition,spatial structure and silicon nutrition.
2009, 26(5): 547-550
Abstract:
Silane coupling agent was used to introduce polymeric groups containing C=C onto the surface of nano-TiO2 particles by self-assembly technique.Then in-situ grafting polymerization was carried out between the functionalized particles and butyl methacrylate monomer to modify the surface of nano-TiO2.The effects of different reaction conditions on the grafting degree were studied,and the optimal conditions for the experiment were 5:6 the ratio of toluene to butyl methacrylate(BMA),0.5% initiator,0.125 mol/L of the modified nano-TiO2,3 h reaction time,and 90 ℃ reaction temperature,and the grafting degree was 13.9%.FTIR,TG and UV-Vis results showed that new organic chains were introduced onto the surface of nano-TiO2,and the dispersion stability of the nano-TiO2 in organic phase was obviously improved.
Silane coupling agent was used to introduce polymeric groups containing C=C onto the surface of nano-TiO2 particles by self-assembly technique.Then in-situ grafting polymerization was carried out between the functionalized particles and butyl methacrylate monomer to modify the surface of nano-TiO2.The effects of different reaction conditions on the grafting degree were studied,and the optimal conditions for the experiment were 5:6 the ratio of toluene to butyl methacrylate(BMA),0.5% initiator,0.125 mol/L of the modified nano-TiO2,3 h reaction time,and 90 ℃ reaction temperature,and the grafting degree was 13.9%.FTIR,TG and UV-Vis results showed that new organic chains were introduced onto the surface of nano-TiO2,and the dispersion stability of the nano-TiO2 in organic phase was obviously improved.
2009, 26(5): 551-556
Abstract:
A series of sodium humate/polyisopropylacrylamide/clay(SH/PNIPA/clay) hydrogels was synthesized by solution polymerization with acrylamide,clay and sodium humate(SH) as raw materials,ammonium persulfate(APS) as the initiator and N,N'-methylenebisacrylamide(MBA) as the crosslinker,respectively.Their swelling and decoloring properties were examined.Experimental results show that there exists hydrogen bonding between SH and PNIPA;the absorption and desorption of methylene blue(MB) by hydrogels were influenced by temperature,SH content,clay content and initial MB concentration.Low temperature and 2% clay content favor the absorption and desorption.Appropriate SH amount of the hydrogels is crucial for the adsorption and desorption of MB.High initial MB concentration favors the adsorption of MB and low initial concentration favors the desorption of MB.
A series of sodium humate/polyisopropylacrylamide/clay(SH/PNIPA/clay) hydrogels was synthesized by solution polymerization with acrylamide,clay and sodium humate(SH) as raw materials,ammonium persulfate(APS) as the initiator and N,N'-methylenebisacrylamide(MBA) as the crosslinker,respectively.Their swelling and decoloring properties were examined.Experimental results show that there exists hydrogen bonding between SH and PNIPA;the absorption and desorption of methylene blue(MB) by hydrogels were influenced by temperature,SH content,clay content and initial MB concentration.Low temperature and 2% clay content favor the absorption and desorption.Appropriate SH amount of the hydrogels is crucial for the adsorption and desorption of MB.High initial MB concentration favors the adsorption of MB and low initial concentration favors the desorption of MB.
2009, 26(5): 557-561
Abstract:
Magnetic polystyrene(PS) microspheres were prepared by layer-by-layer self-assembly technique.The core-shell microspheres were constructed by alternately depositing negative and positive polyelectrolytes onto sulfate-stabilized PS latex particles.And then,papain was immobilized on them.The best circumstance of enzyme immobilization was determined:pH=6.0,1.0 h,30 ℃,mass ratio(papain:microspheres) 37.98%.And the largest ratio of enzyme immobilization could reach 93.0%.The properties of the immobilized enzyme were also studied.The best application temperature and pH were 50 ℃ and 8.0,respectively.When used for 3 times or reserved for 1.5~2.0 h at 80 ℃,the activity of the immobilized papain would fall by nearly half.
Magnetic polystyrene(PS) microspheres were prepared by layer-by-layer self-assembly technique.The core-shell microspheres were constructed by alternately depositing negative and positive polyelectrolytes onto sulfate-stabilized PS latex particles.And then,papain was immobilized on them.The best circumstance of enzyme immobilization was determined:pH=6.0,1.0 h,30 ℃,mass ratio(papain:microspheres) 37.98%.And the largest ratio of enzyme immobilization could reach 93.0%.The properties of the immobilized enzyme were also studied.The best application temperature and pH were 50 ℃ and 8.0,respectively.When used for 3 times or reserved for 1.5~2.0 h at 80 ℃,the activity of the immobilized papain would fall by nearly half.
2009, 26(5): 562-565
Abstract:
Based on the principles of biomineralization,uniform large particles of spherial calcium carbonate were prepared using sodium citrate as the template and insoluble calcium sulphate as the raw material.The obtained calcium carbonate samples were characterized by X-ray diffraction(XRD),Fourier transform infrared spectrometry(FTIR),scanning electron microscopy(SEM),and tbermogravimetry analysis(TGA).The crystal morphology of the calcium carbonate was controlled by sodium citrate.When the concentration of the sodium citrate was 0.9%(mass fraction),product with uniform large particles of a mean size of 10~15 μm and narrow size distribution and good dispersivity was synthesized.The growth mechanism of CaCO3 was also discussed.
Based on the principles of biomineralization,uniform large particles of spherial calcium carbonate were prepared using sodium citrate as the template and insoluble calcium sulphate as the raw material.The obtained calcium carbonate samples were characterized by X-ray diffraction(XRD),Fourier transform infrared spectrometry(FTIR),scanning electron microscopy(SEM),and tbermogravimetry analysis(TGA).The crystal morphology of the calcium carbonate was controlled by sodium citrate.When the concentration of the sodium citrate was 0.9%(mass fraction),product with uniform large particles of a mean size of 10~15 μm and narrow size distribution and good dispersivity was synthesized.The growth mechanism of CaCO3 was also discussed.
2009, 26(5): 566-570
Abstract:
Polystyrene(PS) mesh was prepared with water drops as template.Water drops formed regular patterns under the refrigeration of solvent evaporation.After solvent evaporation,the regular patterns of polymer form mesh structures.An amphiphilic copolymer was added to stabilize the water drops to form a regular mesh.Water solution of polyvinyl alcohol(PVA) was filled into the mesh,and PVA spherical microlens arrays were obtained after drying and washing with chloroform.Peeling off the surface of PS mesh gave a PS pincushion structure,which had semi-spherical structure interspaces.PVA semi-spherical microlenses were prepared by PS pincushion structures as templates.Both the spherical and semispherical microlenses have a function of imaging.The result shows that semi-spherical has better imaging effect.
Polystyrene(PS) mesh was prepared with water drops as template.Water drops formed regular patterns under the refrigeration of solvent evaporation.After solvent evaporation,the regular patterns of polymer form mesh structures.An amphiphilic copolymer was added to stabilize the water drops to form a regular mesh.Water solution of polyvinyl alcohol(PVA) was filled into the mesh,and PVA spherical microlens arrays were obtained after drying and washing with chloroform.Peeling off the surface of PS mesh gave a PS pincushion structure,which had semi-spherical structure interspaces.PVA semi-spherical microlenses were prepared by PS pincushion structures as templates.Both the spherical and semispherical microlenses have a function of imaging.The result shows that semi-spherical has better imaging effect.
2009, 26(5): 571-575
Abstract:
Bisphenol A(BPA) was determined by on-line preconcentration on self-assembly adsorption column filled with fibres from cigarette filter tips coupled with high-performance liquid chromatography(HPLC).The mobile phase was methanol-deionized water(90:10 in volume ratio).The thermodynamics properties and the possible mechanism of adsorption process for Bisphenol A on carbon nanotubes(CNTs) in aqueous solution were studied and the isotherm adsorptions at different temperstures were determined.The results show that the adsorption of BPA on CNTs is a quick adsorption.The adsorption amount of BPA on CNTs in aqueous solution at 20 ℃ reached to 24.65 mg/g when the concentration was 70 mg/L. At ambient temperature,the adsorption amount was increased with increasing of initial concentration or dropping of temperature.The correlation coefficients were larger than 0.99 when both Langmuir equation and Freundlich equation were used to fit data.Thermodynamic parameters such as ΔG,ΔH and ΔS are-39.48~-43.51 kJ/mol,-18.06 kJ/mol and 71.73 J/(mol·K),respectively.The adsorption proved to be a spontaneous process having a characteristic of physical adsorption.In addition,lower temperature is beneficial to accelerating the adsorption.
Bisphenol A(BPA) was determined by on-line preconcentration on self-assembly adsorption column filled with fibres from cigarette filter tips coupled with high-performance liquid chromatography(HPLC).The mobile phase was methanol-deionized water(90:10 in volume ratio).The thermodynamics properties and the possible mechanism of adsorption process for Bisphenol A on carbon nanotubes(CNTs) in aqueous solution were studied and the isotherm adsorptions at different temperstures were determined.The results show that the adsorption of BPA on CNTs is a quick adsorption.The adsorption amount of BPA on CNTs in aqueous solution at 20 ℃ reached to 24.65 mg/g when the concentration was 70 mg/L. At ambient temperature,the adsorption amount was increased with increasing of initial concentration or dropping of temperature.The correlation coefficients were larger than 0.99 when both Langmuir equation and Freundlich equation were used to fit data.Thermodynamic parameters such as ΔG,ΔH and ΔS are-39.48~-43.51 kJ/mol,-18.06 kJ/mol and 71.73 J/(mol·K),respectively.The adsorption proved to be a spontaneous process having a characteristic of physical adsorption.In addition,lower temperature is beneficial to accelerating the adsorption.
2009, 26(5): 576-581
Abstract:
Rare earth solid superacid catalyst SO2-4/ZrO2-SnO2-Nd2O3 is prepared by precipitation-co-impre-gnation method. The obtained catalyst if characterized by IR,TG-DTA and XRD,and used to the synthesis of terpinyl acetate.The results show that catalyst SO42-/ZrO2-SnO2-Nd2O3 has an excellent reactivity and reusability.Factors influencing the esterification are investigated,and the optimum reaction conditions have been found: the molar ratio between terpineol and acetic anhydride is 1.0:1.5,the reaction temperature is 50 ℃ and the reaction time is 5 h,the amount of catalyst is 2% of the mass of terpineol.Under the optimum conditions,the conversion of terpineol is about 93%,the content of terpinyl acetate in the product is 88%.The main reason of the catalyst deactivation is that the active sites are covered by organic materials coming from reacting solution.The catalyst can be regenerated by alcohol washing and drying at 110 ℃ for 12 h.
Rare earth solid superacid catalyst SO2-4/ZrO2-SnO2-Nd2O3 is prepared by precipitation-co-impre-gnation method. The obtained catalyst if characterized by IR,TG-DTA and XRD,and used to the synthesis of terpinyl acetate.The results show that catalyst SO42-/ZrO2-SnO2-Nd2O3 has an excellent reactivity and reusability.Factors influencing the esterification are investigated,and the optimum reaction conditions have been found: the molar ratio between terpineol and acetic anhydride is 1.0:1.5,the reaction temperature is 50 ℃ and the reaction time is 5 h,the amount of catalyst is 2% of the mass of terpineol.Under the optimum conditions,the conversion of terpineol is about 93%,the content of terpinyl acetate in the product is 88%.The main reason of the catalyst deactivation is that the active sites are covered by organic materials coming from reacting solution.The catalyst can be regenerated by alcohol washing and drying at 110 ℃ for 12 h.
2009, 26(5): 582-587
Abstract:
The chitosan(CTS) microspheres grafted with pyromellitic dianhydride(PMDA) were prepared for the adsorption of lead and cadmium metal ions in aqueous solution.The structure of the modified microspheres was characterized by FT-IR and XPS.The adsorption behavior of the modified microspheres for Pb2+ and Cd2+ and other factors were tested.The equilibrium process conforms to the Langmuir isotherm.At an initial pH of 5.0,the maximum adsorption capacities for Pb2+ and Cd2+ are 296.7 mg/g and 149.9 mg/g,respectively.The kinetic processes show good correlation coefficients for a pseudo-second-order kinetic model,confirming that the sorption rate is controlled by chemical adsorption.The regeneration of the adsorbent can be carried out by treating the loaded microspheres with 0.2 mol/L EDTA.The regeneration rate for Pb2+ and Cd2+ can be achieved to 92.4% and 85.3%,respectively.
The chitosan(CTS) microspheres grafted with pyromellitic dianhydride(PMDA) were prepared for the adsorption of lead and cadmium metal ions in aqueous solution.The structure of the modified microspheres was characterized by FT-IR and XPS.The adsorption behavior of the modified microspheres for Pb2+ and Cd2+ and other factors were tested.The equilibrium process conforms to the Langmuir isotherm.At an initial pH of 5.0,the maximum adsorption capacities for Pb2+ and Cd2+ are 296.7 mg/g and 149.9 mg/g,respectively.The kinetic processes show good correlation coefficients for a pseudo-second-order kinetic model,confirming that the sorption rate is controlled by chemical adsorption.The regeneration of the adsorbent can be carried out by treating the loaded microspheres with 0.2 mol/L EDTA.The regeneration rate for Pb2+ and Cd2+ can be achieved to 92.4% and 85.3%,respectively.
2009, 26(5): 588-592
Abstract:
In a pH 0.65 ～ 1.10 HCl-NaAc buffer solution, isopoly tungstic acid(IPT) was reacted with amikacin(AMK) to form an ion-association complex, which resulted in great enhancement of resonance Rayleigh scattering(RRS) and the appearance of a new RRS spectrum.The maximum scattering peak was located at 340 nm.The scattering in tensity was proportional to the concentration of AMK in a range of 0.001 ×10 -6～0.08 ×10-6 g/mL, based on which a new RRS method for the determination of AMK was established.Th emethod exhibited a high sensitivity and the detection limit(3σ) was 0.4 ×10-9 g/mL.The RRS and absorption spectral characteristics and optimum reaction conditions of the system were discussed. Effects of coexisting substances were tested, and the results demonstrated that this method had a good selectivity.It was applied to the determination of AMK in human serum samples with satisfactory results.The reactionm echanism and reasons for RRS enhancement were discussed.
In a pH 0.65 ～ 1.10 HCl-NaAc buffer solution, isopoly tungstic acid(IPT) was reacted with amikacin(AMK) to form an ion-association complex, which resulted in great enhancement of resonance Rayleigh scattering(RRS) and the appearance of a new RRS spectrum.The maximum scattering peak was located at 340 nm.The scattering in tensity was proportional to the concentration of AMK in a range of 0.001 ×10 -6～0.08 ×10-6 g/mL, based on which a new RRS method for the determination of AMK was established.Th emethod exhibited a high sensitivity and the detection limit(3σ) was 0.4 ×10-9 g/mL.The RRS and absorption spectral characteristics and optimum reaction conditions of the system were discussed. Effects of coexisting substances were tested, and the results demonstrated that this method had a good selectivity.It was applied to the determination of AMK in human serum samples with satisfactory results.The reactionm echanism and reasons for RRS enhancement were discussed.
Chromatographic Separation of Camptothecine and Vincoside-Lactam by Resins with Nanometer Micropores
2009, 26(5): 593-596
Abstract:
The performance of adsorption and chromatographic separation of camptothecine and vincoside-lactam by polymeric resins with different nanometer pores were studied.The static adsorption results show the adsorption capacity of vincoside-lactam is related to the specific area of the resin.The adsorption capacity of gel post-crosslinked resin with a specific area of 1 100 m2/g is larger than that of other two adsorbents.The adsorption discrepancy of Rf8 for camptothecine and vincoside-lactam was the most and the separation factor reached to 2.01.The dynamic desorption results show that macroporous post-crosslinked resin Rf8 with micropore and macropore structures and carbonyl group can separate camptothecine and vincoside-lactam effectively via chromatography,but macroporous resin ADS-5 and gel post-crosslinked resin X1 can not.Such effective chromatographic separation of camptothecine and vincoside-lactam with resin Rf8 is ascribed to the surface character and hole structure of the resin.
The performance of adsorption and chromatographic separation of camptothecine and vincoside-lactam by polymeric resins with different nanometer pores were studied.The static adsorption results show the adsorption capacity of vincoside-lactam is related to the specific area of the resin.The adsorption capacity of gel post-crosslinked resin with a specific area of 1 100 m2/g is larger than that of other two adsorbents.The adsorption discrepancy of Rf8 for camptothecine and vincoside-lactam was the most and the separation factor reached to 2.01.The dynamic desorption results show that macroporous post-crosslinked resin Rf8 with micropore and macropore structures and carbonyl group can separate camptothecine and vincoside-lactam effectively via chromatography,but macroporous resin ADS-5 and gel post-crosslinked resin X1 can not.Such effective chromatographic separation of camptothecine and vincoside-lactam with resin Rf8 is ascribed to the surface character and hole structure of the resin.
2009, 26(5): 597-601
Abstract:
Different substances were researched to modify glassy carbon electrode to make pH sensors.By means of potential titration,it was found that the electrode first modified with polyaniline and then with cobalt-cobalt oxide could had a good pH response.And it could be applied to the titration of real samples in place of glass electrode.Moreover,the best polymerization conditions were cyclic voltammetry scan 10 cycles at a concentration of 0.1 mol/L polyaniline in hydrochloride solution(1 mol/L) under the potential between-0.2 V to 1.0 V and cyclic voltammetry scan 5 cycles at a concentration of 2.0×10-4 mol/L cobalt in PBS solution(pH=7.5) under the potential between-1.2 V to 1.2 V.This electrode could have a response slope of-61.60 mV/pH,and the pH response range was from 0.5 to 13.
Different substances were researched to modify glassy carbon electrode to make pH sensors.By means of potential titration,it was found that the electrode first modified with polyaniline and then with cobalt-cobalt oxide could had a good pH response.And it could be applied to the titration of real samples in place of glass electrode.Moreover,the best polymerization conditions were cyclic voltammetry scan 10 cycles at a concentration of 0.1 mol/L polyaniline in hydrochloride solution(1 mol/L) under the potential between-0.2 V to 1.0 V and cyclic voltammetry scan 5 cycles at a concentration of 2.0×10-4 mol/L cobalt in PBS solution(pH=7.5) under the potential between-1.2 V to 1.2 V.This electrode could have a response slope of-61.60 mV/pH,and the pH response range was from 0.5 to 13.
2009, 26(5): 602-606
Abstract:
Daunorubicin(DNR) is a potent anti-leukemia agent.However,it also has cardiac,genic and genital toxicities.Thus,the study on the dosage of DNR and determination methods of DNR is very important to its clinical application.This paper is focused on the electrochemical performance of DNR at the β-cyclodextrin(β-CD) modified electrode.It was found that DNR can be complexed with β-CD on the electrode.The complexing constant was 6.1×104 L/mol.Furthermore,only the DNR complexed with β-CD can undergo irreversible electrochemical reaction.Its rate constant was 28.03/s.The cathodic peak current of DNR was proportional to the concentration of DNR in the 3~30 μmol/L concentration range.Therefore,the β-CD modified electrode can be applied to the quantitative determination of DNR.When the pH of the electrolyte was 7.0 and the temperature was close to 40 ℃,the electrochemical activity of DNR at the β-CD modified electrode was the best.Under these conditions,the detection limit of DNR at the β-CD modified electrode was low.
Daunorubicin(DNR) is a potent anti-leukemia agent.However,it also has cardiac,genic and genital toxicities.Thus,the study on the dosage of DNR and determination methods of DNR is very important to its clinical application.This paper is focused on the electrochemical performance of DNR at the β-cyclodextrin(β-CD) modified electrode.It was found that DNR can be complexed with β-CD on the electrode.The complexing constant was 6.1×104 L/mol.Furthermore,only the DNR complexed with β-CD can undergo irreversible electrochemical reaction.Its rate constant was 28.03/s.The cathodic peak current of DNR was proportional to the concentration of DNR in the 3~30 μmol/L concentration range.Therefore,the β-CD modified electrode can be applied to the quantitative determination of DNR.When the pH of the electrolyte was 7.0 and the temperature was close to 40 ℃,the electrochemical activity of DNR at the β-CD modified electrode was the best.Under these conditions,the detection limit of DNR at the β-CD modified electrode was low.
2009, 26(5): 607-612
Abstract:
Bis-Schiff-base-5-fluorosalicylaldehyde-o-phenylenediamine was prepared.The crystal and molecular structure was investigated by X-ray analysis.The crystal is in the monoclinic space group P2(1)/c with a=0.609 38(8),b=1.634 7(2),c=9.447 4(2),V=165.19(4) nm3,Z=4,Dc=1.417,μ(MoKα)=0.11 mm,F(000)=728,T=293 K,R=0.032.The Zn(Ⅱ) complex(C20H12F2N2O2Zn) was prepared and characterized by the analytical and spectroscopic methods and its fluorescence properties were also studied in the solution and in the solid state.
Bis-Schiff-base-5-fluorosalicylaldehyde-o-phenylenediamine was prepared.The crystal and molecular structure was investigated by X-ray analysis.The crystal is in the monoclinic space group P2(1)/c with a=0.609 38(8),b=1.634 7(2),c=9.447 4(2),V=165.19(4) nm3,Z=4,Dc=1.417,μ(MoKα)=0.11 mm,F(000)=728,T=293 K,R=0.032.The Zn(Ⅱ) complex(C20H12F2N2O2Zn) was prepared and characterized by the analytical and spectroscopic methods and its fluorescence properties were also studied in the solution and in the solid state.
2009, 26(5): 613-615
Abstract:
In the study of direct methanol fuel cell(DMFC),issues on catalysts with high electrocatalytic performance for oxygen reduction and without electrocatalytic performance for methanol oxidation ars important.In this work,the carbon supported Pd-Fe(Pd-Fe/C) catalyst was prepared in a mixed solution of water and tetrahydrofuran.It was found that in the Pd-Fe/C catalyst,Fe existed as the alloying state and amorphous non-alloying state.The amorphous non-alloying Fe can dissolve in the acid,while the alloying Fe cannot dissolve after acid treatment.In addition,electrochemical study indicates that the Pd-Fe/C catalyst treated with acid possesses the high electrocatalytic activity for oxygen reduction and has no electrocatalytic activity for methanol oxidation.These results indicate that the alloying Fe could effectively increase the electrocatalytic activity of Pd for oxygen reduction,while non-alloying Fe has no such function.Pd-Fe/C catalyst treated with acid is therefore an excellent cathodic catalyst in DMFC.
In the study of direct methanol fuel cell(DMFC),issues on catalysts with high electrocatalytic performance for oxygen reduction and without electrocatalytic performance for methanol oxidation ars important.In this work,the carbon supported Pd-Fe(Pd-Fe/C) catalyst was prepared in a mixed solution of water and tetrahydrofuran.It was found that in the Pd-Fe/C catalyst,Fe existed as the alloying state and amorphous non-alloying state.The amorphous non-alloying Fe can dissolve in the acid,while the alloying Fe cannot dissolve after acid treatment.In addition,electrochemical study indicates that the Pd-Fe/C catalyst treated with acid possesses the high electrocatalytic activity for oxygen reduction and has no electrocatalytic activity for methanol oxidation.These results indicate that the alloying Fe could effectively increase the electrocatalytic activity of Pd for oxygen reduction,while non-alloying Fe has no such function.Pd-Fe/C catalyst treated with acid is therefore an excellent cathodic catalyst in DMFC.
2009, 26(5): 616-618
Abstract:
The soap-free copolymer emulsion of silica sol and styrene-acrylate was synthesized by per-emulsified technology from silica sol,styrene and acrylate monomers with ammonium persulfate(APS) as initiator,and allylic oxygen nonylphenol ethoxylates ammonium sulfate(DNS-86) as emulsifier.The structure of the latex particles of the emulsion was characterized by IR.The influential factors including the content and the addition procedure of the reactive emulsifier were discussed.It was found that the performance of the emulsion was good when the reactive emulsifier used was 3%,silica sol amount used 1.5% at a polymerization tempe-rature of 80 ℃.In this way,the rate of monomer conversion was 95.1% and the water-absorption of the emulsion film was 8%.
The soap-free copolymer emulsion of silica sol and styrene-acrylate was synthesized by per-emulsified technology from silica sol,styrene and acrylate monomers with ammonium persulfate(APS) as initiator,and allylic oxygen nonylphenol ethoxylates ammonium sulfate(DNS-86) as emulsifier.The structure of the latex particles of the emulsion was characterized by IR.The influential factors including the content and the addition procedure of the reactive emulsifier were discussed.It was found that the performance of the emulsion was good when the reactive emulsifier used was 3%,silica sol amount used 1.5% at a polymerization tempe-rature of 80 ℃.In this way,the rate of monomer conversion was 95.1% and the water-absorption of the emulsion film was 8%.
2009, 26(5): 619-621
Abstract:
Conductive polyethylene composite was prepared by mixing HDPE,SEBS,conductive carbon black and carbon fiber etc,and prilling and injection molding.Methods to test the permeabilty and electrochemical corrosion resistance of the conductive plastic were designed.The bulk resistivity of the conductive polyethylene composite was 0.2 Ω·cm.The tensile strength was 47.6 MPa and the percent elongation at break was 1.6%.The conductive composite was solution impermeable and corrosion resistant.The SEM micrograph indicates that it could form the integrated conductive network,which can satisfy current collector requirements of vanadium redox flow battery.
Conductive polyethylene composite was prepared by mixing HDPE,SEBS,conductive carbon black and carbon fiber etc,and prilling and injection molding.Methods to test the permeabilty and electrochemical corrosion resistance of the conductive plastic were designed.The bulk resistivity of the conductive polyethylene composite was 0.2 Ω·cm.The tensile strength was 47.6 MPa and the percent elongation at break was 1.6%.The conductive composite was solution impermeable and corrosion resistant.The SEM micrograph indicates that it could form the integrated conductive network,which can satisfy current collector requirements of vanadium redox flow battery.
2009, 26(5): 622-624
Abstract:
Ball-flower-like and leaf-like Y2O3 materials were prepared by means of a template synthesis.XRD pattern shows the Y2O3 is cubic.Scanning electron microscopy(SEM) image of leaf-like material reveals that there are slots in the lateral leaves.Wettability studies reveal the film surface shows the super-hydrophilic property of ball-flower-like Y2O3 and the super-hydrophobic property of leaf-like Y2O3,respectively.
Ball-flower-like and leaf-like Y2O3 materials were prepared by means of a template synthesis.XRD pattern shows the Y2O3 is cubic.Scanning electron microscopy(SEM) image of leaf-like material reveals that there are slots in the lateral leaves.Wettability studies reveal the film surface shows the super-hydrophilic property of ball-flower-like Y2O3 and the super-hydrophobic property of leaf-like Y2O3,respectively.
