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2011 Volume 28 Issue 2
2011, 28(2): 123-130
doi: 10.3724/SP.J.1095.2011.00194
Abstract:
Chitosan is a non-toxic,antibacterial,biocompatible and biodegradable biopolymer which is widely used for biomedical applications,separation membranes and others.In recent years,electrospinning has been found to be a novel technique to produce chitosan nanofibers.The nanofibers containing chitosan or its derivatives show wide applications due to their high surface area and porosity.This article summarizes the preparations and properties of the nanofibers produced by electrospinning of pure chitosan,hybrids of chitosan and synthetic polymers,hybrids of chitosan and proteins,chitosan derivatives,hybrids of chitosan and inorganic nanoparticles,respectively.The applications of some of the nanofibers are briefly described.
Chitosan is a non-toxic,antibacterial,biocompatible and biodegradable biopolymer which is widely used for biomedical applications,separation membranes and others.In recent years,electrospinning has been found to be a novel technique to produce chitosan nanofibers.The nanofibers containing chitosan or its derivatives show wide applications due to their high surface area and porosity.This article summarizes the preparations and properties of the nanofibers produced by electrospinning of pure chitosan,hybrids of chitosan and synthetic polymers,hybrids of chitosan and proteins,chitosan derivatives,hybrids of chitosan and inorganic nanoparticles,respectively.The applications of some of the nanofibers are briefly described.
2011, 28(2): 131-135
doi: 10.3724/SP.J.1095.2011.00302
Abstract:
Nanostructured egg-box was obtained through placing an air pressure on polystyrene(PS) nano film using an anodic aluminum oxide(AAO) membrane as the template.The surface morphology of PS film was studied by means of atomic force microscopy(AFM).The results showed that air pressure affected the morphology of PS film.There is an optimal pressure to achieve egg-box with a maximal density about 9 per μm2.The depth of the egg-box like nanostructure is about 15 nm.The density of egg-box decreases with the increase or decrease the pressure.
Nanostructured egg-box was obtained through placing an air pressure on polystyrene(PS) nano film using an anodic aluminum oxide(AAO) membrane as the template.The surface morphology of PS film was studied by means of atomic force microscopy(AFM).The results showed that air pressure affected the morphology of PS film.There is an optimal pressure to achieve egg-box with a maximal density about 9 per μm2.The depth of the egg-box like nanostructure is about 15 nm.The density of egg-box decreases with the increase or decrease the pressure.
2011, 28(2): 136-141
doi: 10.3724/SP.J.1095.2011.00318
Abstract:
Three novel ferrocene-based oligo(phenylene ethynylene)s molecular wires were prepared by the Sonogashira coupling reaction of 1,1'-diiodoferrocene with different acetylenic compounds.The structures of all the products were confirmed by 1H NMR,13C NMR and MS.The electronic structures of these molecular wires were forecasted by a quantum chemistry calculation,which indicated that they might contain favorable charge transport properties due to their abnormal LUMO energy level continuous attenuation.
Three novel ferrocene-based oligo(phenylene ethynylene)s molecular wires were prepared by the Sonogashira coupling reaction of 1,1'-diiodoferrocene with different acetylenic compounds.The structures of all the products were confirmed by 1H NMR,13C NMR and MS.The electronic structures of these molecular wires were forecasted by a quantum chemistry calculation,which indicated that they might contain favorable charge transport properties due to their abnormal LUMO energy level continuous attenuation.
2011, 28(2): 142-148
doi: 10.3724/SP.J.1095.2011.00240
Abstract:
Organic CdTe quantum dots with average size of about 4.5 nm were synthesized in organic solution using dodecanethiol as stabilizing reagent.Nanocomposites of CdTe/polymethyl methacrylate(PMMA) and CdTe/Eu/PMMA were prepared via the van der Waal force interaction or the ionic coordination respectively by mixing organic CdTe quantum dots or triisopropoxyeuropium and organic CdTe quantum dots with PMMA.The resultant nanocomposites were characterized by infrared spectra(IR),ultraviolet absorption spectra(UV-Vis),fluorescence spectroscopy(FS),scanning electron microscope(SEM) and transmission electron microscope(TEM).The results indicated that CdTe/PMMA emitted strong red light under UV-Vis excitation in solution or in film.However,the CdTe/Eu/PMMA also emitted red light,but with decreased relative intensity than that of CdTe/PMMA.The emission of europium and organic CdTe quantum dots in CdTe/Eu/PMMA quenched because of the interaction between the organic CdTe quantum dots and europium ion.
Organic CdTe quantum dots with average size of about 4.5 nm were synthesized in organic solution using dodecanethiol as stabilizing reagent.Nanocomposites of CdTe/polymethyl methacrylate(PMMA) and CdTe/Eu/PMMA were prepared via the van der Waal force interaction or the ionic coordination respectively by mixing organic CdTe quantum dots or triisopropoxyeuropium and organic CdTe quantum dots with PMMA.The resultant nanocomposites were characterized by infrared spectra(IR),ultraviolet absorption spectra(UV-Vis),fluorescence spectroscopy(FS),scanning electron microscope(SEM) and transmission electron microscope(TEM).The results indicated that CdTe/PMMA emitted strong red light under UV-Vis excitation in solution or in film.However,the CdTe/Eu/PMMA also emitted red light,but with decreased relative intensity than that of CdTe/PMMA.The emission of europium and organic CdTe quantum dots in CdTe/Eu/PMMA quenched because of the interaction between the organic CdTe quantum dots and europium ion.
2011, 28(2): 149-153
doi: 10.3724/SP.J.1095.2011.00224
Abstract:
Amphiphilic mixed-shell polymeric nanoparticles(MSNPs) were synthesized efficiently by non-covalently cross-linking of two diblock copolymers(1:1 mass ratio) of poly(ethylene oxide)-b-poly(acrylic acid)(PEO-b-PAA) and poly(2-vinylnaphthalene)-b-poly-(acrylic acid)(P2VN-b-PAA) with 1,2-propane diamine(PDA) in DMF.In such amphiphilic MSNPs,the shell consisted of poly(2-vinyl naphthalene)(P2VN)/polyethylene oxide(PEO) while the core was formed from non-covalently cross-linked poly(acrylic acid)(PAA).The MSNPs could disperse in water and DMF without coalescence due to their distinct amphiphilic nature.The flexible cores of MSNPs were confirmed by SEM and FTIR.Dynamic light scattering result showed that the diameter of the amphiphlic MSNP was about 300 nm.The shells of the MSNPs could collapse in solid state resulted in their flexible cores.The MSNPs could be used as template for preparing gold nanoclusters in water.
Amphiphilic mixed-shell polymeric nanoparticles(MSNPs) were synthesized efficiently by non-covalently cross-linking of two diblock copolymers(1:1 mass ratio) of poly(ethylene oxide)-b-poly(acrylic acid)(PEO-b-PAA) and poly(2-vinylnaphthalene)-b-poly-(acrylic acid)(P2VN-b-PAA) with 1,2-propane diamine(PDA) in DMF.In such amphiphilic MSNPs,the shell consisted of poly(2-vinyl naphthalene)(P2VN)/polyethylene oxide(PEO) while the core was formed from non-covalently cross-linked poly(acrylic acid)(PAA).The MSNPs could disperse in water and DMF without coalescence due to their distinct amphiphilic nature.The flexible cores of MSNPs were confirmed by SEM and FTIR.Dynamic light scattering result showed that the diameter of the amphiphlic MSNP was about 300 nm.The shells of the MSNPs could collapse in solid state resulted in their flexible cores.The MSNPs could be used as template for preparing gold nanoclusters in water.
2011, 28(2): 154-158
doi: 10.3724/SP.J.1095.2011.00167
Abstract:
Coupling agent γ-aminopropyltrimethoxysilane(AMPS) was firstly bond onto the surface of silica gel particles forming modified AMPS-SiO2 particles.With the presence of ammonium persulphate in the solution,a redox initiating system was then achieved and allowed the surface-initiated graft polymerization of methacrylic acid(MAA) on the silica gel particles with a high grafting degree(0.30 g/g).The effects of different factors on the whole process were investigated in depth.The experimental results show that an optimal temperature for the surface-initiated graft polymerization system is 40℃.At higher temperature,the graft degree will decline due to the heat decomposition of ammonium persulphate.In addition,the grafted polymer layer hinders further polymerization.The appropriate reaction conditions are:1.1% of the initiator and nearly 5% of the monomer concentration.
Coupling agent γ-aminopropyltrimethoxysilane(AMPS) was firstly bond onto the surface of silica gel particles forming modified AMPS-SiO2 particles.With the presence of ammonium persulphate in the solution,a redox initiating system was then achieved and allowed the surface-initiated graft polymerization of methacrylic acid(MAA) on the silica gel particles with a high grafting degree(0.30 g/g).The effects of different factors on the whole process were investigated in depth.The experimental results show that an optimal temperature for the surface-initiated graft polymerization system is 40℃.At higher temperature,the graft degree will decline due to the heat decomposition of ammonium persulphate.In addition,the grafted polymer layer hinders further polymerization.The appropriate reaction conditions are:1.1% of the initiator and nearly 5% of the monomer concentration.
2011, 28(2): 159-163
doi: 10.3724/SP.J.1095.2011.00189
Abstract:
Using o-fluorine hydroquinone and 1,4-di(4'-fluorobenzoyl)benzene as precursors,a fluorine-containing poly(ether ether ketone ketone) was prepared via a nucleophilic aromatic substitution polymerization.Fourier transform infrared spectra(FTIR),nuclear magnetric resonance(1H NMR) and X-ray diffraction(XRD) were used to determine the structure of the polymer.Differential scanning calorimetry(DSC),thermal gravimetric analysis(TGA) and near infrared spectra(NIR) were used to characterize the properties of the polymer.The solubility,water absorption,dielectric property and optical property of the polymer were investigated.The results show that FPEEKK is amorphous.The polymer shows high thermal stability(in nitrogen atmosphere,the degradation temperature for losing 5% mass is 505℃).The polymer is soluble in common organic solvents such as chloroform,tetrahydrofuran(THF) and N,N-dimethylacetamide(DMAC).The dielectric constant is 3.0 and the water absorption is 0.24%.The polymer exhibits low absorption at 1300 nm and 1550 nm wavelength.
Using o-fluorine hydroquinone and 1,4-di(4'-fluorobenzoyl)benzene as precursors,a fluorine-containing poly(ether ether ketone ketone) was prepared via a nucleophilic aromatic substitution polymerization.Fourier transform infrared spectra(FTIR),nuclear magnetric resonance(1H NMR) and X-ray diffraction(XRD) were used to determine the structure of the polymer.Differential scanning calorimetry(DSC),thermal gravimetric analysis(TGA) and near infrared spectra(NIR) were used to characterize the properties of the polymer.The solubility,water absorption,dielectric property and optical property of the polymer were investigated.The results show that FPEEKK is amorphous.The polymer shows high thermal stability(in nitrogen atmosphere,the degradation temperature for losing 5% mass is 505℃).The polymer is soluble in common organic solvents such as chloroform,tetrahydrofuran(THF) and N,N-dimethylacetamide(DMAC).The dielectric constant is 3.0 and the water absorption is 0.24%.The polymer exhibits low absorption at 1300 nm and 1550 nm wavelength.
2011, 28(2): 164-167
doi: 10.3724/SP.J.1095.2011.00298
Abstract:
Well-aligned ZnO nanorod arrays were obtained at 90℃,using zinc foil as the substrate and zinc nitrate and ammonia as source materials,in the absence of any surfactants by hydrothermal method.As-synthesized ZnO nanorod arrays are from 500 to 800 nm in the length,and are about 100 nm in the diameter.The results show that the top of the nanorod is hexagonal and owns the wurtzite structure.Also,the effect of experimental parameters on the morphology and structure of as-products are studied systematically.
Well-aligned ZnO nanorod arrays were obtained at 90℃,using zinc foil as the substrate and zinc nitrate and ammonia as source materials,in the absence of any surfactants by hydrothermal method.As-synthesized ZnO nanorod arrays are from 500 to 800 nm in the length,and are about 100 nm in the diameter.The results show that the top of the nanorod is hexagonal and owns the wurtzite structure.Also,the effect of experimental parameters on the morphology and structure of as-products are studied systematically.
2011, 28(2): 168-176
doi: 10.3724/SP.J.1095.2011.00264
Abstract:
A uranyl-containing supramolecular compound [UO2Cl4][phenH]2(phen=1,10-phenanthroline) has been synthesized under hydrothermal condition and characterized by X-ray single-crystal analysis,IR,UV and fluorescence spectrum.Crystal structural analysis indicates that it consists of two [phenH]+ and one heteropolyanion of [UO2Cl4]2- in the asymmetric unit.The results of IR spectra and X-ray single crystal diffraction reveal that the title complex present a 3D framework built up by N——H…Cl,C——H…Cl and C——H…O weak hydrogen bonds interactions.The central uranium atom has a distorted octahedral environment and is coordinated by four Cl atoms and two O atoms.In addition,there are also uncoordinated protonated 1,10-phenanthroline bonded by hydrogen bonds and π…π stacking interactions,which is rarely observed in previous reports.Its polyvinyl alcohol(PVA) film was casted by a sol-gel process and characterized by IR,UV and fluorescence spectrum.Both the title compound and its film show strong fluorescence.CCDC:713149
A uranyl-containing supramolecular compound [UO2Cl4][phenH]2(phen=1,10-phenanthroline) has been synthesized under hydrothermal condition and characterized by X-ray single-crystal analysis,IR,UV and fluorescence spectrum.Crystal structural analysis indicates that it consists of two [phenH]+ and one heteropolyanion of [UO2Cl4]2- in the asymmetric unit.The results of IR spectra and X-ray single crystal diffraction reveal that the title complex present a 3D framework built up by N——H…Cl,C——H…Cl and C——H…O weak hydrogen bonds interactions.The central uranium atom has a distorted octahedral environment and is coordinated by four Cl atoms and two O atoms.In addition,there are also uncoordinated protonated 1,10-phenanthroline bonded by hydrogen bonds and π…π stacking interactions,which is rarely observed in previous reports.Its polyvinyl alcohol(PVA) film was casted by a sol-gel process and characterized by IR,UV and fluorescence spectrum.Both the title compound and its film show strong fluorescence.CCDC:713149
2011, 28(2): 177-181
doi: 10.3724/SP.J.1095.2011.00244
Abstract:
Perfluoroalkyoxy-substituted cyclohexene oxides(EFPO1 and EFPO2) were obtained by two-step reactions using the dimer and trimer of hexafluoropropylene oxide and 4-cyclohexene-1,2-dimethanol as main raw materials.The structures of as-synthesized products were confirmed by spectroscopy analyses including FT-IR and 1H NMR.These fluoro-epoxides are compatible with the prepolymers such as bisphenol-A diglycidyl ether and ethylene glycol diglycidyl ether,thereby endowing the coatings composed of them with improved hydrophobicity as evidenced by the photoinitiated curing experiments.The preliminary investigation of their UV-curing performance shows that the hydrophobicity increases linearly with increasing fluoro-epoxide content in the composition.As expected,the hydrophobic effect is more pronounced for EFPO2 than EFPO1 at the same conditions,because the former has a longer ferfluoroalkyoxy group.For example,upon addiing 1% mass fraction of EFPO2,the water contact angle of the UV-cured films was 99° and was higher 14° than that found for the films without the fluoro-component,whereas the value for EFPO1-modified films was 87°.When containing 5% EFPO2,high hydrophobic surface was achieved with a water contact angle of 113 for the UV-cured films.In addition,it should be pointed out that the hydrophobic surface can be further improved by heating the UV-cured films at 110℃ for 6 h.For the coatings containing 1%~5% EFPO2,the post-heating treatment resulted in a change of the water contact angles from the range 99°~113° to 113°~118°,while the changes were from 87°~100° to 99°~110° for EFPO1 analogs.The thermal migration of fluoro-chains and aggregation on the film surface seems to be responsible for the enhancement in hydrophobicity.Consequently,this new type of fluorine-containing epoxy monomers is expected as the surface modifier used in coatings,inks and release materials.
Perfluoroalkyoxy-substituted cyclohexene oxides(EFPO1 and EFPO2) were obtained by two-step reactions using the dimer and trimer of hexafluoropropylene oxide and 4-cyclohexene-1,2-dimethanol as main raw materials.The structures of as-synthesized products were confirmed by spectroscopy analyses including FT-IR and 1H NMR.These fluoro-epoxides are compatible with the prepolymers such as bisphenol-A diglycidyl ether and ethylene glycol diglycidyl ether,thereby endowing the coatings composed of them with improved hydrophobicity as evidenced by the photoinitiated curing experiments.The preliminary investigation of their UV-curing performance shows that the hydrophobicity increases linearly with increasing fluoro-epoxide content in the composition.As expected,the hydrophobic effect is more pronounced for EFPO2 than EFPO1 at the same conditions,because the former has a longer ferfluoroalkyoxy group.For example,upon addiing 1% mass fraction of EFPO2,the water contact angle of the UV-cured films was 99° and was higher 14° than that found for the films without the fluoro-component,whereas the value for EFPO1-modified films was 87°.When containing 5% EFPO2,high hydrophobic surface was achieved with a water contact angle of 113 for the UV-cured films.In addition,it should be pointed out that the hydrophobic surface can be further improved by heating the UV-cured films at 110℃ for 6 h.For the coatings containing 1%~5% EFPO2,the post-heating treatment resulted in a change of the water contact angles from the range 99°~113° to 113°~118°,while the changes were from 87°~100° to 99°~110° for EFPO1 analogs.The thermal migration of fluoro-chains and aggregation on the film surface seems to be responsible for the enhancement in hydrophobicity.Consequently,this new type of fluorine-containing epoxy monomers is expected as the surface modifier used in coatings,inks and release materials.
2011, 28(2): 182-187
doi: 10.3724/SP.J.1095.2011.00314
Abstract:
Acetoxy-substituted triene(6) was synthesized from oleanolic acid(1) via methyl esterification of 17-carboxylic acid,benzoylation of 3-hydroxy,oxidation of 12-double bond by O3,dehydrogenation with Br2/HBr,enol acetylation of carbonyl group,and ring-C opening under UV light.Oxidations of compound 6 with different oxidants such as O3,meta-cholorperoxybenzoic acid(mCPBA),H2O2,t-BuOOH and Na2S2O8,yield decalin-type chiral synthons,epoxides,and/or lactone of oleanolic acid derivatives.
Acetoxy-substituted triene(6) was synthesized from oleanolic acid(1) via methyl esterification of 17-carboxylic acid,benzoylation of 3-hydroxy,oxidation of 12-double bond by O3,dehydrogenation with Br2/HBr,enol acetylation of carbonyl group,and ring-C opening under UV light.Oxidations of compound 6 with different oxidants such as O3,meta-cholorperoxybenzoic acid(mCPBA),H2O2,t-BuOOH and Na2S2O8,yield decalin-type chiral synthons,epoxides,and/or lactone of oleanolic acid derivatives.
2011, 28(2): 188-193
doi: 10.3724/SP.J.1095.2011.00260
Abstract:
Liquid phase oxidation of 4-methylpyridine(4-MP) was carried out under mild reaction conditions over mesoporous Co-MCM-41 catalysts using aqueous hydrogen peroxide(30%) as oxidant and acetic acid as solvent without adding any initiator.The catalysts exhibited high substrate conversion and good product isonicotinic acid(4-PCA) selectivity.Recycling of the catalyst indicates that the catalyst can be used for a number of times without losing its activity significantly.The effects of solvent,reaction time,catalyst concentration,and reaction temperature on the catalyst performance were examined in order to optimize the conversion of 4-methylpyridine and the selectivity of isonicotinic acid.A 91.4% selectivity to isonicotinic acid was obtained at 96.5% conversion of 4-methylpyridine under the optimum reaction conditions:m(4-methyl pyridine):m(catalyst)=10:1,V(4-methyl pyridine):V(acetic acid glacial)=1:10,reaction temperature=363 K,reaction time=6 h.The reaction mechanism is proposed based on the results.
Liquid phase oxidation of 4-methylpyridine(4-MP) was carried out under mild reaction conditions over mesoporous Co-MCM-41 catalysts using aqueous hydrogen peroxide(30%) as oxidant and acetic acid as solvent without adding any initiator.The catalysts exhibited high substrate conversion and good product isonicotinic acid(4-PCA) selectivity.Recycling of the catalyst indicates that the catalyst can be used for a number of times without losing its activity significantly.The effects of solvent,reaction time,catalyst concentration,and reaction temperature on the catalyst performance were examined in order to optimize the conversion of 4-methylpyridine and the selectivity of isonicotinic acid.A 91.4% selectivity to isonicotinic acid was obtained at 96.5% conversion of 4-methylpyridine under the optimum reaction conditions:m(4-methyl pyridine):m(catalyst)=10:1,V(4-methyl pyridine):V(acetic acid glacial)=1:10,reaction temperature=363 K,reaction time=6 h.The reaction mechanism is proposed based on the results.
2011, 28(2): 194-198
doi: 10.3724/SP.J.1095.2011.00367
Abstract:
Zeolite H-BEA modified by ethylene diamine tetraacetic acid(EDTA),citric acid,oxalic acid,and tartaric acid were prepared and characterized by XRD and NH3-TPD.The catalytic performance was evaluated in the synthesis of 1-tetralone by intramolecular Friedel-Crafts reaction of 4-phenylbutyric acids.Zeolites H-BEA modified by citric acid showed high catalytic activity.In addition,the reaction conditions such as catalyst amount,reaction temperature and reaction time were examined for the optimal process conditions.Under the optimal reaction conditions,the yield for 1-tetralone was 94.3%.
Zeolite H-BEA modified by ethylene diamine tetraacetic acid(EDTA),citric acid,oxalic acid,and tartaric acid were prepared and characterized by XRD and NH3-TPD.The catalytic performance was evaluated in the synthesis of 1-tetralone by intramolecular Friedel-Crafts reaction of 4-phenylbutyric acids.Zeolites H-BEA modified by citric acid showed high catalytic activity.In addition,the reaction conditions such as catalyst amount,reaction temperature and reaction time were examined for the optimal process conditions.Under the optimal reaction conditions,the yield for 1-tetralone was 94.3%.
2011, 28(2): 199-202
doi: 10.3724/SP.J.1095.2011.00322
Abstract:
Au/γ-Fe2O3,Au/α-Fe2O3 and Au/Fe3O4 catalysts were prepared via deposition-precipitation methods and characterized by X-ray diffraction.The catalytic performance of these catalysts was studied and compared for the hydrogenation of 3-nitrostyrene.In addition,the influences of temperature,support as well as the reaction medium were discussed.The results showed that the conversion of 3-nitrostyrene in H2O is much higher than that in ethanol and solvent-free system,and it increased with increasing of temperature,however,the selectivity to 3-aminostyrene did not change.The catalytic activity of Au/FeOx catalysts was in an order of Au/γ-Fe2O3 >Au/α-Fe2O3 >Au/Fe3O4.The different reducibility of the iron oxide supports may be the main reason for such a catalytic activity.
Au/γ-Fe2O3,Au/α-Fe2O3 and Au/Fe3O4 catalysts were prepared via deposition-precipitation methods and characterized by X-ray diffraction.The catalytic performance of these catalysts was studied and compared for the hydrogenation of 3-nitrostyrene.In addition,the influences of temperature,support as well as the reaction medium were discussed.The results showed that the conversion of 3-nitrostyrene in H2O is much higher than that in ethanol and solvent-free system,and it increased with increasing of temperature,however,the selectivity to 3-aminostyrene did not change.The catalytic activity of Au/FeOx catalysts was in an order of Au/γ-Fe2O3 >Au/α-Fe2O3 >Au/Fe3O4.The different reducibility of the iron oxide supports may be the main reason for such a catalytic activity.
2011, 28(2): 203-208
doi: 10.3724/SP.J.1095.2011.00299
Abstract:
HCl and KOH were used to modify bentonite(BEN).The Ni catalysts supported on acidified and alkalified bentonite had been prepared by aqueous impregnation.Methanation of carbon dioxide was used as a probe reaction to characterize the catalytic performance.The samples were characterized by BET,XRD,TPR and TPD.The results showed that a higher catalyst activity was achieved for Ni/alkali-BEN,although the alkali-BEN had lower surface area.CO2-TPD and H2-TPR study showed that Ni/alkali-BEN could absorb more carbon dioxide and be reduced easier.XRD and TPR analysis indicated that nickel oxide was the dominant species for both catalysts,which was easily reduced to metal nickel.The amount of nickel oxide presented in the Ni/alkali-BEN was higher than that of Ni/acid-BEN,which might account for the higher activity of Ni/alkali-BEN.
HCl and KOH were used to modify bentonite(BEN).The Ni catalysts supported on acidified and alkalified bentonite had been prepared by aqueous impregnation.Methanation of carbon dioxide was used as a probe reaction to characterize the catalytic performance.The samples were characterized by BET,XRD,TPR and TPD.The results showed that a higher catalyst activity was achieved for Ni/alkali-BEN,although the alkali-BEN had lower surface area.CO2-TPD and H2-TPR study showed that Ni/alkali-BEN could absorb more carbon dioxide and be reduced easier.XRD and TPR analysis indicated that nickel oxide was the dominant species for both catalysts,which was easily reduced to metal nickel.The amount of nickel oxide presented in the Ni/alkali-BEN was higher than that of Ni/acid-BEN,which might account for the higher activity of Ni/alkali-BEN.
2011, 28(2): 209-213
doi: 10.3724/SP.J.1095.2011.00248
Abstract:
Five kinds of 4,6-diaryl-2-aminopyrimidine derivatives were synthesized and characterized by IR,MS and 1H NMR.The Escherichia coli methionine aminopeptidase(EcMetAP) inhibit-activities and the CXCR4 receptor antogonists activities of the five compounds were determined.The results show that all the five compounds have the EcMetAP inhibit-activities,and they also have CXCR4 receptor antogonists activities except the compound 2.The structure-activity relationships were studied by the FieldTemplater and FieldAlign software through molecular field analysis.The results show that the pharmacophore could be 3-N atom and 4,6-bencycles used as the EcMetAP inhibitor,and the EcMetAP inhibit-activities could be increased by addition of electron-donating groups at 6-benzyl.It also shows that the pharmacophore could be 2-C atom and 4,6-bencycles used as the CXCR4 receptor antogonists.The CXCR4 receptor antogonists could be increased by addition of electron-donating substituent at 2-C.
Five kinds of 4,6-diaryl-2-aminopyrimidine derivatives were synthesized and characterized by IR,MS and 1H NMR.The Escherichia coli methionine aminopeptidase(EcMetAP) inhibit-activities and the CXCR4 receptor antogonists activities of the five compounds were determined.The results show that all the five compounds have the EcMetAP inhibit-activities,and they also have CXCR4 receptor antogonists activities except the compound 2.The structure-activity relationships were studied by the FieldTemplater and FieldAlign software through molecular field analysis.The results show that the pharmacophore could be 3-N atom and 4,6-bencycles used as the EcMetAP inhibitor,and the EcMetAP inhibit-activities could be increased by addition of electron-donating groups at 6-benzyl.It also shows that the pharmacophore could be 2-C atom and 4,6-bencycles used as the CXCR4 receptor antogonists.The CXCR4 receptor antogonists could be increased by addition of electron-donating substituent at 2-C.
2011, 28(2): 214-218
doi: 10.3724/SP.J.1095.2011.00220
Abstract:
The porous carbon-fiber/poly(lactic acid)/chitosan(CF/PLA/CS) composites scaffold was preparated by using solution blending and freeze-drying technique,and the biocompatibility between the composites and bone marrow stromal cells(BMSCs) was estimated by using inverted phase contrast microscope and scanning electron microscope(SEM).The curve of cell growth was obtained by using MTT assay,and the cell cytotoxicity were also assessed.The results showed that the cultured cells did not appear the deformation or death in the leach liquor and grew densely after 8 days.The SEM images showed that the cell morphology was normal,and the cell started to grow along the deep pore on the composites after 4 days.The MTT curve of cell growth indicated that cell proliferation rate of the experimental group was 30% higher than the blank test group after 4 days.According to the morphological observation and cell proliferation evaluation,it indicated the three-dimensional porous CF/PLA/CS composites do not have cell toxicity,and have excellent adhesion and proliferation of bone cells,suggesting that they may be promising bone repairing materials.
The porous carbon-fiber/poly(lactic acid)/chitosan(CF/PLA/CS) composites scaffold was preparated by using solution blending and freeze-drying technique,and the biocompatibility between the composites and bone marrow stromal cells(BMSCs) was estimated by using inverted phase contrast microscope and scanning electron microscope(SEM).The curve of cell growth was obtained by using MTT assay,and the cell cytotoxicity were also assessed.The results showed that the cultured cells did not appear the deformation or death in the leach liquor and grew densely after 8 days.The SEM images showed that the cell morphology was normal,and the cell started to grow along the deep pore on the composites after 4 days.The MTT curve of cell growth indicated that cell proliferation rate of the experimental group was 30% higher than the blank test group after 4 days.According to the morphological observation and cell proliferation evaluation,it indicated the three-dimensional porous CF/PLA/CS composites do not have cell toxicity,and have excellent adhesion and proliferation of bone cells,suggesting that they may be promising bone repairing materials.
2011, 28(2): 219-223
doi: 10.3724/SP.J.1095.2011.00211
Abstract:
The effects of pH value and eluent of phosphate buffer solution on the regeneration of immobilized metal affinity capture arrays-Cu(IMAC-Cu) proteinchip was studied by scanning electron microscope(SEM) and SELDI-TOF-MS proteinchip system.The results show that the adsorbed proteins can be easily removed.However,the negative influence on chemical structure of the proteinchip is getting worse with decreasing the pH value of the phosphate buffer solution.Adding eluent of EDTA or Gly in the phosphate buffer solution can obviously improve the protein desorption.The best regeneration results of IMAC-Cu proteinchip by phosphate solution are gained at pH=6.5 with using 0.02 mol/L EDTA as eluent for 72 h.
The effects of pH value and eluent of phosphate buffer solution on the regeneration of immobilized metal affinity capture arrays-Cu(IMAC-Cu) proteinchip was studied by scanning electron microscope(SEM) and SELDI-TOF-MS proteinchip system.The results show that the adsorbed proteins can be easily removed.However,the negative influence on chemical structure of the proteinchip is getting worse with decreasing the pH value of the phosphate buffer solution.Adding eluent of EDTA or Gly in the phosphate buffer solution can obviously improve the protein desorption.The best regeneration results of IMAC-Cu proteinchip by phosphate solution are gained at pH=6.5 with using 0.02 mol/L EDTA as eluent for 72 h.
2011, 28(2): 224-228
doi: 10.3724/SP.J.1095.2011.00169
Abstract:
The electrocatalytic performance for the oxygen reduction and the methanol tolerance ability of the Pd-Pt/C catalysts with different atom ratios of Pd and Pt was investigated.It is found that when the atom ratio of Pd and Pt is increased from 20:0 to 17:3,the electrocatalytic performance of the Pd-Pt/C catalyst for the oxygen reduction is increased.Furthermore,all the Pd-Pt/C catalysts with the atom ratios in the range of 20:0~17:3 have no electrocatalytic activity for the methanol oxidation and thus possess the excellent methanol tolerance ability.When the atom ratio is increased to 16:4,the electrocatalytic performance of the Pd-Pt/C catalyst for the oxygen reduction is still increased,but the methanol tolerance ability is decreased.Thus,the Pd-Pt/C catalyst with 17:3 atom ratio possesses an excellent electrocatalytic activity for oxygen reduction and methanol tolerance ability.Therefore,it can be used as the cathodic catalyst in direct methanol fuel cell(DMFC).
The electrocatalytic performance for the oxygen reduction and the methanol tolerance ability of the Pd-Pt/C catalysts with different atom ratios of Pd and Pt was investigated.It is found that when the atom ratio of Pd and Pt is increased from 20:0 to 17:3,the electrocatalytic performance of the Pd-Pt/C catalyst for the oxygen reduction is increased.Furthermore,all the Pd-Pt/C catalysts with the atom ratios in the range of 20:0~17:3 have no electrocatalytic activity for the methanol oxidation and thus possess the excellent methanol tolerance ability.When the atom ratio is increased to 16:4,the electrocatalytic performance of the Pd-Pt/C catalyst for the oxygen reduction is still increased,but the methanol tolerance ability is decreased.Thus,the Pd-Pt/C catalyst with 17:3 atom ratio possesses an excellent electrocatalytic activity for oxygen reduction and methanol tolerance ability.Therefore,it can be used as the cathodic catalyst in direct methanol fuel cell(DMFC).
2011, 28(2): 229-233
doi: 10.3724/SP.J.1095.2011.00159
Abstract:
Eight xanthones and one anthraquinone were isolated by chromatographic separation of 85% ethanol extract of Pericarpium Garciniae Mangostanae.The obtained compounds were identified as α-mangostin-3,6-diyl diacetate(Ⅰ),8-hydroxycudraxanthone G(Ⅱ),cowaxanthone B(Ⅲ),cowaxanthone A(Ⅳ),trapezifolixanthone(Ⅴ),brasilixanthone B(Ⅵ),allanxanthone A(Ⅶ),2,4-di-(3-methylbut-2-enyl)-1,3,8-trihydroxy-5-methoxyxanthone(Ⅷ),and 1,4,8-trihydroxy-6-methyl-3-methoxy-9,10-anthraquinone(Ⅸ) by physico-chemical properties,NMR and MS spectral data,compounds Ⅰ,Ⅴ,Ⅵ,Ⅶ and Ⅸ were isolated from plants of Garcinia for the first time,and compounds Ⅱ,Ⅲ,Ⅳ and Ⅷ were isolated from Pericarpium Garciniae Mangostanae for the first time.
Eight xanthones and one anthraquinone were isolated by chromatographic separation of 85% ethanol extract of Pericarpium Garciniae Mangostanae.The obtained compounds were identified as α-mangostin-3,6-diyl diacetate(Ⅰ),8-hydroxycudraxanthone G(Ⅱ),cowaxanthone B(Ⅲ),cowaxanthone A(Ⅳ),trapezifolixanthone(Ⅴ),brasilixanthone B(Ⅵ),allanxanthone A(Ⅶ),2,4-di-(3-methylbut-2-enyl)-1,3,8-trihydroxy-5-methoxyxanthone(Ⅷ),and 1,4,8-trihydroxy-6-methyl-3-methoxy-9,10-anthraquinone(Ⅸ) by physico-chemical properties,NMR and MS spectral data,compounds Ⅰ,Ⅴ,Ⅵ,Ⅶ and Ⅸ were isolated from plants of Garcinia for the first time,and compounds Ⅱ,Ⅲ,Ⅳ and Ⅷ were isolated from Pericarpium Garciniae Mangostanae for the first time.
2011, 28(2): 234-239
doi: 10.3724/SP.J.1095.2011.00233
Abstract:
Supported liquid membrane separation processes have recently received considerable attention due to characteristics such as fast mass transfer,high selectivity and separation efficiency,lower operation costs and no secondary pollution.They are particularly suitable for the separation and enrichment of heavy metal ions.However,supported liquid membrane separation processes are limited in large-scale industrial applications due to membrane instability and short membrane life.The transportation and separation of Pb(Ⅱ) through a PC-88A-kerosene-HCl dispersion supported liquid membrane(DSLM),based on the theoretical study of the existing supported liquid membrane(SLM) separation technology,is reported.The effects of pH value in the feed phase,volume ratio of liquid membrane phase and hydrochloric acid,concentrations of HCl in the strip phase and initial concentration of Pb(Ⅱ) in the feed phase are also studied.The results show that lead ion can be transported effectively when pH=5.25 in the feed phase,the volume ratio is 160:40,concentrations of HCl in the strip phase is 5.00 mol/L.The transport rate of Pb(Ⅱ) can reach to 88.9% through DSLM,and 72.3% through traditional SLM,respectively,under the optimum condition,and the transport time is 190 min for initial concentration of 3.00×10-4 mol/L Pb(Ⅱ).It shows that DSLM has a high transmission efficiency in comparison with conventional SLM.At the same time,the system can improve the stability of the membrane and extend the life of the membrane.
Supported liquid membrane separation processes have recently received considerable attention due to characteristics such as fast mass transfer,high selectivity and separation efficiency,lower operation costs and no secondary pollution.They are particularly suitable for the separation and enrichment of heavy metal ions.However,supported liquid membrane separation processes are limited in large-scale industrial applications due to membrane instability and short membrane life.The transportation and separation of Pb(Ⅱ) through a PC-88A-kerosene-HCl dispersion supported liquid membrane(DSLM),based on the theoretical study of the existing supported liquid membrane(SLM) separation technology,is reported.The effects of pH value in the feed phase,volume ratio of liquid membrane phase and hydrochloric acid,concentrations of HCl in the strip phase and initial concentration of Pb(Ⅱ) in the feed phase are also studied.The results show that lead ion can be transported effectively when pH=5.25 in the feed phase,the volume ratio is 160:40,concentrations of HCl in the strip phase is 5.00 mol/L.The transport rate of Pb(Ⅱ) can reach to 88.9% through DSLM,and 72.3% through traditional SLM,respectively,under the optimum condition,and the transport time is 190 min for initial concentration of 3.00×10-4 mol/L Pb(Ⅱ).It shows that DSLM has a high transmission efficiency in comparison with conventional SLM.At the same time,the system can improve the stability of the membrane and extend the life of the membrane.
2011, 28(2): 240-244
doi: 10.3724/SP.J.1095.2011.00219
Abstract:
A gold nanoparticle-doped titanium dioxide nanoneedle modified glass carbon(Au-TiO2/GC) electrode was used for the electrochemical detection of the concentration of chloramphenicol(CAP).The results indicated that the Au-TiO2/GC electrode shows good electrochemical response for CAP in 0.1 mol/L PBS at pH=7.0.A linear relationship between the peak current and the concentration of CAP lies in the range of 8.0×10-7~1.0×10-4 mol/L with a detection limit of 7.8×10-8 mol/L.This method was applied to the detection of CAP concentration of CAP in eyedrop.It was found that this method has the high detection sensitivity,good reproducibility and ante-interference.
A gold nanoparticle-doped titanium dioxide nanoneedle modified glass carbon(Au-TiO2/GC) electrode was used for the electrochemical detection of the concentration of chloramphenicol(CAP).The results indicated that the Au-TiO2/GC electrode shows good electrochemical response for CAP in 0.1 mol/L PBS at pH=7.0.A linear relationship between the peak current and the concentration of CAP lies in the range of 8.0×10-7~1.0×10-4 mol/L with a detection limit of 7.8×10-8 mol/L.This method was applied to the detection of CAP concentration of CAP in eyedrop.It was found that this method has the high detection sensitivity,good reproducibility and ante-interference.
