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2014 Volume 31 Issue 2
2014, 31(2): 123-132
doi: 10.3724/SP.J.1095.2014.30131
Abstract:
Considering their peculiar properties,nanometer materials can be embedded into polymeric membrane to obtain nanocomposite membranes that could help to solve the "trade-off effect",which has restricted the development of membrane technology.In recent years,a variety of nanometer materials have been applied in the preparation of nanocomposite membranes.This review summarizes the researches of nanocomposite membranes involving nanomaterials such as carbon nanotubes,graphene,SiO2,TiO2,molecular sieve,ZrO2 and silver nanoparticles in the field of membrane separation.The nanometer materials can significantly improve the mechanical stability,hydrophilicity,selectivity,permeability and anti-pollution capacity of composite membranes.The perspectives of the development and application of nanocomposite membranes were proposed and the existing problems and solutions in this field were also presented.
Considering their peculiar properties,nanometer materials can be embedded into polymeric membrane to obtain nanocomposite membranes that could help to solve the "trade-off effect",which has restricted the development of membrane technology.In recent years,a variety of nanometer materials have been applied in the preparation of nanocomposite membranes.This review summarizes the researches of nanocomposite membranes involving nanomaterials such as carbon nanotubes,graphene,SiO2,TiO2,molecular sieve,ZrO2 and silver nanoparticles in the field of membrane separation.The nanometer materials can significantly improve the mechanical stability,hydrophilicity,selectivity,permeability and anti-pollution capacity of composite membranes.The perspectives of the development and application of nanocomposite membranes were proposed and the existing problems and solutions in this field were also presented.
2014, 31(2): 133-139
doi: 10.3724/SP.J.1095.2014.30186
Abstract:
The nucleophilic substitution reaction between the chloromethyl group of chloromethylated polystyrene(CMPS) and phenolic hydroxyl group of 3-nitro-4-hydroxy benzoic acid(NHBA) was conducted,and the nitro-benzoic acid(NBA) ligand was bonded on the side chains of polystyrene(PS) to yield nitro benzoic acid functionalization polystyrene PS-NBA.In this work,the nucleophilic substitution reaction between CMPS and NHBA was systematically investigated to optimize the reaction conditions.The coordination reaction between PS-NBA and Eu3+ ion was carried out to give polymer-rare earth complex,PS-(NBA)3-Eu(Ⅲ).The chemical structure of PS-NBA was characterized by FTIR and 1H NMR spectra and the florescence emission of PS-(NBA)3-Eu(Ⅲ) was preliminarily examined.The results show that the nitro substitute group in benzene ring can reduce the rate of the substitution reaction.The stronger polarity solvents and higher reaction temperature(70℃) favor the substitution reaction.The ligand NBA on the side chain of the functionalized polymer PS-NBA can strongly sensitize the fluorescence-emission of Eu3+ ion,and its sensibilization is much stronger than that of benzoic acid(BA) ligand.The polymer-rare earth complex PS-(NBA)3-Eu(Ⅲ) possesses much stronger fluorescence emission intensity than PS-(BA)3-Eu(Ⅲ).
The nucleophilic substitution reaction between the chloromethyl group of chloromethylated polystyrene(CMPS) and phenolic hydroxyl group of 3-nitro-4-hydroxy benzoic acid(NHBA) was conducted,and the nitro-benzoic acid(NBA) ligand was bonded on the side chains of polystyrene(PS) to yield nitro benzoic acid functionalization polystyrene PS-NBA.In this work,the nucleophilic substitution reaction between CMPS and NHBA was systematically investigated to optimize the reaction conditions.The coordination reaction between PS-NBA and Eu3+ ion was carried out to give polymer-rare earth complex,PS-(NBA)3-Eu(Ⅲ).The chemical structure of PS-NBA was characterized by FTIR and 1H NMR spectra and the florescence emission of PS-(NBA)3-Eu(Ⅲ) was preliminarily examined.The results show that the nitro substitute group in benzene ring can reduce the rate of the substitution reaction.The stronger polarity solvents and higher reaction temperature(70℃) favor the substitution reaction.The ligand NBA on the side chain of the functionalized polymer PS-NBA can strongly sensitize the fluorescence-emission of Eu3+ ion,and its sensibilization is much stronger than that of benzoic acid(BA) ligand.The polymer-rare earth complex PS-(NBA)3-Eu(Ⅲ) possesses much stronger fluorescence emission intensity than PS-(BA)3-Eu(Ⅲ).
2014, 31(2): 140-146
doi: 10.3724/SP.J.1095.2014.30187
Abstract:
Hydrophobical monomer N,N-diallyl-N-hexadecylamine was synthesized by the reaction between diallyamine and 1-bromohexadecane.The monomer was characterized using FTIR,1H NMR and element analysis.A series of hydrophobically modified pH sensitive intelligent hydrogels poly(2-hydroxylethyl methacrylate/sodium acrylate/N,N-diallyl-N-hexadecylamine)[P(HEMA-NaAA-DiAC16)]was successfully prepared by radically micellar copolymerization with 2-hydroxylethyl methacrylate(HEMA),sodium acrylate(NaAA),and N,N-diallyl-N-hexadecylamine(DiAC16) as comonomers,sodium dodecyl sulfate(SDS) as the surfactant,N,N'-methylenebisacrylamide(BIS) as crosslinking agent,ammonium persulfate[(NH4)2S2O8]-N,N,N',N'-tetramethylethylenediamine(TMEDA) as initiating agent.The effects of hydrophobical monomer,NaAA,BIS contents and pH,ionic strength on swelling behaviors of P(HEMA-NaAA-DiAC16) had been studied.The results indicate that the equilibrium swelling ratio SR0 of the hydrogels decreases with increasing the amounts of DiAC 16 or BIS,with decreasing of NaAA,which are 78.9~163.91 in distilled water.The n values are 0.5~1.0 and increase with the increase of DiAC 16,NaAA or BIS.The diffusions of water into P(HEMA-NaAA-DiAC16) gels are found to be a non-Fickian mode and exothermic process.The ΔHm are -2.09~-3.64 kJ/mol,the modulus of ΔHm and affinity between the polymers and water increase with the increase of NaAA and BIS,and the decrease of DiAC16.The equilibrium swelling ratio decreases with the increase of ionic strength.
Hydrophobical monomer N,N-diallyl-N-hexadecylamine was synthesized by the reaction between diallyamine and 1-bromohexadecane.The monomer was characterized using FTIR,1H NMR and element analysis.A series of hydrophobically modified pH sensitive intelligent hydrogels poly(2-hydroxylethyl methacrylate/sodium acrylate/N,N-diallyl-N-hexadecylamine)[P(HEMA-NaAA-DiAC16)]was successfully prepared by radically micellar copolymerization with 2-hydroxylethyl methacrylate(HEMA),sodium acrylate(NaAA),and N,N-diallyl-N-hexadecylamine(DiAC16) as comonomers,sodium dodecyl sulfate(SDS) as the surfactant,N,N'-methylenebisacrylamide(BIS) as crosslinking agent,ammonium persulfate[(NH4)2S2O8]-N,N,N',N'-tetramethylethylenediamine(TMEDA) as initiating agent.The effects of hydrophobical monomer,NaAA,BIS contents and pH,ionic strength on swelling behaviors of P(HEMA-NaAA-DiAC16) had been studied.The results indicate that the equilibrium swelling ratio SR0 of the hydrogels decreases with increasing the amounts of DiAC 16 or BIS,with decreasing of NaAA,which are 78.9~163.91 in distilled water.The n values are 0.5~1.0 and increase with the increase of DiAC 16,NaAA or BIS.The diffusions of water into P(HEMA-NaAA-DiAC16) gels are found to be a non-Fickian mode and exothermic process.The ΔHm are -2.09~-3.64 kJ/mol,the modulus of ΔHm and affinity between the polymers and water increase with the increase of NaAA and BIS,and the decrease of DiAC16.The equilibrium swelling ratio decreases with the increase of ionic strength.
2014, 31(2): 147-152
doi: 10.3724/SP.J.1095.2014.30133
Abstract:
A series of cobalt(Ⅱ) complexes bearing 2-(1-aryliminomethylene) quinolines was synthesized and characterized.The structures of complexes 2a,3a and 4a were further analyzed by X-ray crystallography.Complexes 2a and 3a crystallize in the form of mononuclear four-coordination mode(two nitrogen and two chlorine atoms),whereas complex 4a crystallizes as a centrosymmetric binuclear mode due to the less steric hindrance of the substituent on the ligand.Upon activation with ethylaluminum sesquichloride(EASC),polybutadienes with cis-1,4 content up to 98% could be produced using these complex as catalyst.Catalytic activity increases with the electronic effect of the substituent enhancing,while it decreases with the increase of the steric hindrance.The polybutadienes obtained by using[2-(1-aryliminomethylene) quinolines]cobalt/EASC catalyst have relatively high molecular mass(Mn~2.0×105) and relatively narrow molecular mass distributions(Mw/Mn< 2.7).
A series of cobalt(Ⅱ) complexes bearing 2-(1-aryliminomethylene) quinolines was synthesized and characterized.The structures of complexes 2a,3a and 4a were further analyzed by X-ray crystallography.Complexes 2a and 3a crystallize in the form of mononuclear four-coordination mode(two nitrogen and two chlorine atoms),whereas complex 4a crystallizes as a centrosymmetric binuclear mode due to the less steric hindrance of the substituent on the ligand.Upon activation with ethylaluminum sesquichloride(EASC),polybutadienes with cis-1,4 content up to 98% could be produced using these complex as catalyst.Catalytic activity increases with the electronic effect of the substituent enhancing,while it decreases with the increase of the steric hindrance.The polybutadienes obtained by using[2-(1-aryliminomethylene) quinolines]cobalt/EASC catalyst have relatively high molecular mass(Mn~2.0×105) and relatively narrow molecular mass distributions(Mw/Mn< 2.7).
2014, 31(2): 153-158
doi: 10.3724/SP.J.1095.2014.30235
Abstract:
Cetyltrimethylammonium bromide(CTAB) and tetraethylorthosilicate(TEOS) were selected as raw materials for the synthesis of pure silicon MCM-41.Using Al(NO3)3·9H2O as aluminum source to modify pure silicon MCM-41 by grafting method.The AlMCM-41 was characterized by NH3-TPD.The results show that AlMCM-41 produced mild acid after grafting.The synthesis of bisphenol F was catalyzed by AlMCM-41 with different silicon/aluminium.The optimized reaction conditions are:n(phenol)/n(formaldehyde)=30,reaction time of 5 h,reaction temperature of 90℃,m(formaldehyde)/m(AlMCM-41)=7.In a certain range,the yield of bisphenol F increases with the increase of Al.When the n(Si)/n(Al) is less than 50,the yield of bisphenol F tends to decrease.While n(Si)/n(Al)=50,the yield of bisphenol F can reach its highest value of 42.28%.
Cetyltrimethylammonium bromide(CTAB) and tetraethylorthosilicate(TEOS) were selected as raw materials for the synthesis of pure silicon MCM-41.Using Al(NO3)3·9H2O as aluminum source to modify pure silicon MCM-41 by grafting method.The AlMCM-41 was characterized by NH3-TPD.The results show that AlMCM-41 produced mild acid after grafting.The synthesis of bisphenol F was catalyzed by AlMCM-41 with different silicon/aluminium.The optimized reaction conditions are:n(phenol)/n(formaldehyde)=30,reaction time of 5 h,reaction temperature of 90℃,m(formaldehyde)/m(AlMCM-41)=7.In a certain range,the yield of bisphenol F increases with the increase of Al.When the n(Si)/n(Al) is less than 50,the yield of bisphenol F tends to decrease.While n(Si)/n(Al)=50,the yield of bisphenol F can reach its highest value of 42.28%.
2014, 31(2): 159-164
doi: 10.3724/SP.J.1095.2014.30126
Abstract:
With the Schiff base of L-aspartic acid and salicylaldehyde as the ligands,the composite resin of chitosan/attapulgite(CS/ATP) produced by NaOH curing method as the carrier,the Schiff base metal complexes and the load-type Schiff base metal complexes of Co,Mn,Cu,Fe,Ni were synthesized.Their structural characterizations were determined by FT-IR.The catalytic performance of each catalyst for epoxidation of styrene was studied.Experiments show that the catalytic performance of Co-Schiff base is better in small molecule ligand Schiff base metal complexes.Therefore,Co-Schiff base was loaded in CS/ATP composite resin and the effects of the amount of Co-Schiff base-CS/ATP catalyst,reaction temperature and reaction time on the catalytic epoxidation of styrene were investigated.Finally the results show that the best reaction conditions are as follows:the temperature is 80℃ and the reaction time is 8 h,which results in a conversion rate of 93.1% for epoxidation of styrene.
With the Schiff base of L-aspartic acid and salicylaldehyde as the ligands,the composite resin of chitosan/attapulgite(CS/ATP) produced by NaOH curing method as the carrier,the Schiff base metal complexes and the load-type Schiff base metal complexes of Co,Mn,Cu,Fe,Ni were synthesized.Their structural characterizations were determined by FT-IR.The catalytic performance of each catalyst for epoxidation of styrene was studied.Experiments show that the catalytic performance of Co-Schiff base is better in small molecule ligand Schiff base metal complexes.Therefore,Co-Schiff base was loaded in CS/ATP composite resin and the effects of the amount of Co-Schiff base-CS/ATP catalyst,reaction temperature and reaction time on the catalytic epoxidation of styrene were investigated.Finally the results show that the best reaction conditions are as follows:the temperature is 80℃ and the reaction time is 8 h,which results in a conversion rate of 93.1% for epoxidation of styrene.
2014, 31(2): 165-170
doi: 10.3724/SP.J.1095.2014.30110
Abstract:
Using air as the ultimate oxidant,a facile method for the oxidative esterification of para-nitrobenzaldehyde has been developed.The results demonstrate that the catalyst precursors,catalyst loadings and solvents have considerably effects on both the yields and reaction rates.A variety of para-nitrobenzonates were conveniently prepared with the yields of 36%~64% under the optimal reaction conditions,where the corresponding alcohols were used as the solvents,and the 3-ethyl-4-methyl-5-hydroxyethyl thiazole bromide salt as the catalyst precursor,with 10% molar fraction catalyst loading.Modest yields of 9%~29% were obtained if only stoichiometric amount alcohol was used.
Using air as the ultimate oxidant,a facile method for the oxidative esterification of para-nitrobenzaldehyde has been developed.The results demonstrate that the catalyst precursors,catalyst loadings and solvents have considerably effects on both the yields and reaction rates.A variety of para-nitrobenzonates were conveniently prepared with the yields of 36%~64% under the optimal reaction conditions,where the corresponding alcohols were used as the solvents,and the 3-ethyl-4-methyl-5-hydroxyethyl thiazole bromide salt as the catalyst precursor,with 10% molar fraction catalyst loading.Modest yields of 9%~29% were obtained if only stoichiometric amount alcohol was used.
2014, 31(2): 171-176
doi: 10.3724/SP.J.1095.2014.30102
Abstract:
The methyl acrylate was synthesized from acrylic acid and methanol by using strong-acid cation exchange resin,Amberlyst-15,as catalyst and the hydroquinone as polymerization inhibitor.Effects of molar ratio of methanol to acrylic acid,amounts of catalyst and reaction temperature on esterification rate of acrylic acid were investigated.It was found that the reaction rate and the fractional conversion of acrylic acid increased with increasing the temperature or the catalyst's amounts,while the reaction rate increased first and then decreased with the increase of the molar ratio of methanol to acrylic acid.In the meanwhile,the kinetics of the esterification of acrylic acid with methanol was established on the basis of ideal and non-ideal state of Pseudo-Homogeneous(PH) and Langmuir-Hinshelwood(LH),with the identification of relevant parameters to obtain the equation of reaction rate.By comparison,the LH model,which uses activity instead of concentration,has the lowest multireference single-and double-excitation(MRD) of 1.446%,and is therefore best fit for the reaction.
The methyl acrylate was synthesized from acrylic acid and methanol by using strong-acid cation exchange resin,Amberlyst-15,as catalyst and the hydroquinone as polymerization inhibitor.Effects of molar ratio of methanol to acrylic acid,amounts of catalyst and reaction temperature on esterification rate of acrylic acid were investigated.It was found that the reaction rate and the fractional conversion of acrylic acid increased with increasing the temperature or the catalyst's amounts,while the reaction rate increased first and then decreased with the increase of the molar ratio of methanol to acrylic acid.In the meanwhile,the kinetics of the esterification of acrylic acid with methanol was established on the basis of ideal and non-ideal state of Pseudo-Homogeneous(PH) and Langmuir-Hinshelwood(LH),with the identification of relevant parameters to obtain the equation of reaction rate.By comparison,the LH model,which uses activity instead of concentration,has the lowest multireference single-and double-excitation(MRD) of 1.446%,and is therefore best fit for the reaction.
2014, 31(2): 177-181
doi: 10.3724/SP.J.1095.2014.30150
Abstract:
Pd/ZrO2 attracts more attention for methane combustion at low temperature.ZrO2 support plays an important role in stabilization of PdO.In this article,pure M-ZrO2 and T-ZrO2 were synthesized by solvothermal method,and then Pd/M-ZrO2 and Pd/T-ZrO2 were prepared by incipient wetness method in order to investigate the support structure effect on the methane combustion at low temperature.It has been demonstrated that the methane combustion activity and stability of Pd/M-ZrO2 is much better than that of Pd/T-ZrO2.Combined XRD,TEM,TPO with catalytic performance,it shows that the better activity and stability of Pd/M-ZrO2 is related to the greater dispersion of PdO and the type of interaction between PdO and ZrO2,respectively.
Pd/ZrO2 attracts more attention for methane combustion at low temperature.ZrO2 support plays an important role in stabilization of PdO.In this article,pure M-ZrO2 and T-ZrO2 were synthesized by solvothermal method,and then Pd/M-ZrO2 and Pd/T-ZrO2 were prepared by incipient wetness method in order to investigate the support structure effect on the methane combustion at low temperature.It has been demonstrated that the methane combustion activity and stability of Pd/M-ZrO2 is much better than that of Pd/T-ZrO2.Combined XRD,TEM,TPO with catalytic performance,it shows that the better activity and stability of Pd/M-ZrO2 is related to the greater dispersion of PdO and the type of interaction between PdO and ZrO2,respectively.
2014, 31(2): 182-187
doi: 10.3724/SP.J.1095.2014.30140
Abstract:
ZnO hollow microspheres were synthesized by a facile solvothermal treatment of zinc nitrate and NaAc in the presence of polyethylene glycol 10000.The products were characterized by XRD,SEM,TG-DSC,BET techniques.The effects of the amount of zinc nitrate,the amount of PEG-10000,the reaction time and the reaction temperature on the morphology and size of products were investigated.The catalytic role of ZnO hollow microspheres in ammonium perchlorate decomposition was investigated.The result shows that ammonium perchlorate decomposition temperature decreases from 442℃ to 280℃ with the addition of ZnO hollow microspheres.
ZnO hollow microspheres were synthesized by a facile solvothermal treatment of zinc nitrate and NaAc in the presence of polyethylene glycol 10000.The products were characterized by XRD,SEM,TG-DSC,BET techniques.The effects of the amount of zinc nitrate,the amount of PEG-10000,the reaction time and the reaction temperature on the morphology and size of products were investigated.The catalytic role of ZnO hollow microspheres in ammonium perchlorate decomposition was investigated.The result shows that ammonium perchlorate decomposition temperature decreases from 442℃ to 280℃ with the addition of ZnO hollow microspheres.
2014, 31(2): 188-192
doi: 10.3724/SP.J.1095.2014.30055
Abstract:
ZnO powder was obtained by conventional precipitation method using ammonium oxalate and zinc acetate as raw materials.The effects of calcination temperature on the crystallization and fluorescent properties of the product were investigated.The powders were characterized and analyzed by TGA-DTA,XRD,UV-Vis,FS and SEM,respectively.The results show that the precursor is C2O4Zn·2H2O and its minimum calcination temperature is 400℃.With the increase of the calcination temperature,the crystallinity of the product is enhanced and the primary particle size tends to grow.The powder is consisted of 200 nm lamellar particles and has a strong ultraviolet luminescence peak after 600℃ calcination.When the calcination temperature was increased to 900℃,the product became highly agglomerated with particle size larger than 500 nm.In addition,the ZnO powder shows a strong ultraviolet absorption with a blue shift of absorption peak.
ZnO powder was obtained by conventional precipitation method using ammonium oxalate and zinc acetate as raw materials.The effects of calcination temperature on the crystallization and fluorescent properties of the product were investigated.The powders were characterized and analyzed by TGA-DTA,XRD,UV-Vis,FS and SEM,respectively.The results show that the precursor is C2O4Zn·2H2O and its minimum calcination temperature is 400℃.With the increase of the calcination temperature,the crystallinity of the product is enhanced and the primary particle size tends to grow.The powder is consisted of 200 nm lamellar particles and has a strong ultraviolet luminescence peak after 600℃ calcination.When the calcination temperature was increased to 900℃,the product became highly agglomerated with particle size larger than 500 nm.In addition,the ZnO powder shows a strong ultraviolet absorption with a blue shift of absorption peak.
2014, 31(2): 193-199
doi: 10.3724/SP.J.1095.2014.30093
Abstract:
A uranium(Ⅵ) hybrid supramolecules containing 2,9-dimethyl-1,10-phenanthroline,namely[UO2Cl4]2[dmphenH2]2·3H2O(1),has been synthesized and characterized by IR,UV,XPS and X-ray single-crystal diffraction methods and so on.The crystal of uranium hybrid material belongs to monoclinic system,space group Cc with:a=1.7043(2) nm,b=0.8809(13) nm,c=2.7492(10) nm,α=90°,β=94.493(2)°,γ=90°,Z=4,V=4.1149(8) nm3,with a hexa-coordinated distorted octahedral geometry.Because of the extensive hydrogen bonding interactions and π…π interactions,the structural stability of the compound has been greatly increased.The UV-Vis and fluorescence spectra at room temperature reveal that the maximal emission of the compound is red shifted as a result of coordination with the metal ion.The compound emits green luminescence at 506.6 nm(λex=407 nm).Cycling voltammetric study reveals that the compound exhibits an irreversible reduction peak and a pair of reversible redox peaks.The crystal shows high photocatalytic activity under UV light.CCDC:780721.
A uranium(Ⅵ) hybrid supramolecules containing 2,9-dimethyl-1,10-phenanthroline,namely[UO2Cl4]2[dmphenH2]2·3H2O(1),has been synthesized and characterized by IR,UV,XPS and X-ray single-crystal diffraction methods and so on.The crystal of uranium hybrid material belongs to monoclinic system,space group Cc with:a=1.7043(2) nm,b=0.8809(13) nm,c=2.7492(10) nm,α=90°,β=94.493(2)°,γ=90°,Z=4,V=4.1149(8) nm3,with a hexa-coordinated distorted octahedral geometry.Because of the extensive hydrogen bonding interactions and π…π interactions,the structural stability of the compound has been greatly increased.The UV-Vis and fluorescence spectra at room temperature reveal that the maximal emission of the compound is red shifted as a result of coordination with the metal ion.The compound emits green luminescence at 506.6 nm(λex=407 nm).Cycling voltammetric study reveals that the compound exhibits an irreversible reduction peak and a pair of reversible redox peaks.The crystal shows high photocatalytic activity under UV light.CCDC:780721.
2014, 31(2): 200-205
doi: 10.3724/SP.J.1095.2014.30179
Abstract:
The electrochemical behavior of 8-hydroxydeoxyguanosine(8-OHdG) at the chitosan(Chi)/graphene(GR) modified glassy carbon electrode(GCE) was investigated by cyclic voltammetry,linear sweep voltammetry and differential pulse voltammetry.A linear relationship between the oxidative peak current and concentrations of 8-OHdG at the modified electrode was established in the range of 3.5×10-7~1.4×10-4 mol/L with a detection limit of 6.4×10-8 mol/L(S/N=3).Chi/GR/GCE was used for the detection of DNA oxidative damage,it showed that the oxidative peak current of 8-OHdG at the modified electrode was linear with concentration of damaged DNA in the range of 10~300 mg/L with a detection limit of 0.026 mg/L(S/N=3).
The electrochemical behavior of 8-hydroxydeoxyguanosine(8-OHdG) at the chitosan(Chi)/graphene(GR) modified glassy carbon electrode(GCE) was investigated by cyclic voltammetry,linear sweep voltammetry and differential pulse voltammetry.A linear relationship between the oxidative peak current and concentrations of 8-OHdG at the modified electrode was established in the range of 3.5×10-7~1.4×10-4 mol/L with a detection limit of 6.4×10-8 mol/L(S/N=3).Chi/GR/GCE was used for the detection of DNA oxidative damage,it showed that the oxidative peak current of 8-OHdG at the modified electrode was linear with concentration of damaged DNA in the range of 10~300 mg/L with a detection limit of 0.026 mg/L(S/N=3).
2014, 31(2): 206-211
doi: 10.3724/SP.J.1095.2014.30106
Abstract:
Melamine-formaldehyde-thiourea chelating resin coated multi-walled carbon nanotube(MFT/MWCNTs) composite was prepared by ultrasonic method,and characterized by field emission scanning electron microscope and electrochemical techniques.The composite modified waxed graphite electrode(MFT/MWCNTs/WGE) was successfully applied to Pb(Ⅱ),Cd(Ⅱ) simultaneously screening.The striping peak current shows a good linear relationship in the concentration range of 3×10-8~9×10-7 mol/L for Pb(Ⅱ) and 5×10-8~7×10-7 mol/L for Cd(Ⅱ),with a detection limit of 2×10-9 and 3×10-9 mol/L(3σ) for Pb(Ⅱ) and Cd(Ⅱ),respectively.
Melamine-formaldehyde-thiourea chelating resin coated multi-walled carbon nanotube(MFT/MWCNTs) composite was prepared by ultrasonic method,and characterized by field emission scanning electron microscope and electrochemical techniques.The composite modified waxed graphite electrode(MFT/MWCNTs/WGE) was successfully applied to Pb(Ⅱ),Cd(Ⅱ) simultaneously screening.The striping peak current shows a good linear relationship in the concentration range of 3×10-8~9×10-7 mol/L for Pb(Ⅱ) and 5×10-8~7×10-7 mol/L for Cd(Ⅱ),with a detection limit of 2×10-9 and 3×10-9 mol/L(3σ) for Pb(Ⅱ) and Cd(Ⅱ),respectively.
2014, 31(2): 212-219
doi: 10.3724/SP.J.1095.2014.30129
Abstract:
The electrodeposition of metallic copper in the solution of ethylene glycol(EG) and 1-butyl-3-methylimidazolium chloride(BMIC) containing CuCl2 was studied.The effect of EG on the viscosity and the effect of BMIC on the conductivity are investigated.Cyclic voltammetry was performed to study the electrodeposition of Cu(Ⅱ) in BMIC-CuCl2-EG.The electrodeposition of Cu(Ⅱ) was affected by the scanning rate,temperature and the content of EG.The reduction of Cu(Ⅱ) consists of two processes.Both the redox processes of Cu(Ⅱ)/Cu(Ⅰ) and Cu(Ⅰ)/Cu are irreversible,in which Cu(Ⅱ)/Cu(Ⅰ) is under the control of diffusion.The diffusion coefficient of Cu(Ⅱ)/Cu(Ⅰ) is calculated to be 7.0×10-7 cm2/s and the transfer coefficient to be 0.24 at the temperature of 343 K.The metallic copper grains were electrodeposited on the copper film.Based on the scanning electron microscope micrographs,these grains demonstrate the dense location after the electrodeposition for 30 minutes at 343 K.These grains turn into globular morphology after the electrodeposition for 2 h.
The electrodeposition of metallic copper in the solution of ethylene glycol(EG) and 1-butyl-3-methylimidazolium chloride(BMIC) containing CuCl2 was studied.The effect of EG on the viscosity and the effect of BMIC on the conductivity are investigated.Cyclic voltammetry was performed to study the electrodeposition of Cu(Ⅱ) in BMIC-CuCl2-EG.The electrodeposition of Cu(Ⅱ) was affected by the scanning rate,temperature and the content of EG.The reduction of Cu(Ⅱ) consists of two processes.Both the redox processes of Cu(Ⅱ)/Cu(Ⅰ) and Cu(Ⅰ)/Cu are irreversible,in which Cu(Ⅱ)/Cu(Ⅰ) is under the control of diffusion.The diffusion coefficient of Cu(Ⅱ)/Cu(Ⅰ) is calculated to be 7.0×10-7 cm2/s and the transfer coefficient to be 0.24 at the temperature of 343 K.The metallic copper grains were electrodeposited on the copper film.Based on the scanning electron microscope micrographs,these grains demonstrate the dense location after the electrodeposition for 30 minutes at 343 K.These grains turn into globular morphology after the electrodeposition for 2 h.
2014, 31(2): 220-224
doi: 10.3724/SP.J.1095.2014.30114
Abstract:
Fluorescein isothiocyanate(FITC)-labeled vancomycin(FITC-Vanco,FV) was synthesized.After purified by preparative HPLC,the structure of the target compound was indentified by MS.Its combination amount toward bacteria with different concentration was evaluated by the fluorescence intensity of the bacterial suspension.FV synthesized in this study shows specific binding with different bacteria.It shows promising application value in studying bacterial resistance mechanism and bacterial susceptibility to vancomycin.
Fluorescein isothiocyanate(FITC)-labeled vancomycin(FITC-Vanco,FV) was synthesized.After purified by preparative HPLC,the structure of the target compound was indentified by MS.Its combination amount toward bacteria with different concentration was evaluated by the fluorescence intensity of the bacterial suspension.FV synthesized in this study shows specific binding with different bacteria.It shows promising application value in studying bacterial resistance mechanism and bacterial susceptibility to vancomycin.
2014, 31(2): 225-230
doi: 10.3724/SP.J.1095.2014.30156
Abstract:
A binuclear gadolinium(Ⅲ) complex,[Gd2(TP(DTTA)2)(H2O)4]2-,containing two DTTAGd paramagnetic units(DTTA=diethylenetriamine-N,N,N",N"-tetraacetate) bridged by a terephthaloyl(TP) core has been synthesized and evaluated as a potential magnetic resonance imaging(MRI) contrast agent.The relaxation measurements indicate that the dinuclear gadolinium(Ⅲ) complex has a much higher relaxivity than that of the previously reported dinuclear DTTA-based agent(21.7 L/(mmol·s) per Gd3+ vs 12.8 L/(mmol·s) at 20 MHz,37℃ and pH=7).Moreover,the luminescence lifetime measurements on the analogue terbium Tb2(TP(DTTA)2) give the inner-sphere hydration number of q=1.4.The results show that a more rigid linker in dinuclear MRI contrast agents is helpful for relaxivity improvement.
A binuclear gadolinium(Ⅲ) complex,[Gd2(TP(DTTA)2)(H2O)4]2-,containing two DTTAGd paramagnetic units(DTTA=diethylenetriamine-N,N,N",N"-tetraacetate) bridged by a terephthaloyl(TP) core has been synthesized and evaluated as a potential magnetic resonance imaging(MRI) contrast agent.The relaxation measurements indicate that the dinuclear gadolinium(Ⅲ) complex has a much higher relaxivity than that of the previously reported dinuclear DTTA-based agent(21.7 L/(mmol·s) per Gd3+ vs 12.8 L/(mmol·s) at 20 MHz,37℃ and pH=7).Moreover,the luminescence lifetime measurements on the analogue terbium Tb2(TP(DTTA)2) give the inner-sphere hydration number of q=1.4.The results show that a more rigid linker in dinuclear MRI contrast agents is helpful for relaxivity improvement.
2014, 31(2): 231-236
doi: 10.3724/SP.J.1095.2014.30125
Abstract:
After geniposide in the acetonitrile aqueous extract solution of Gardenia was separated into two phases by inductors,the partition characteristics of it in two phases were studied.A new method was established for the separation and purification of geniposide.The types of inductors inducing phase separation of acetonitrile aqueous solution were researched in detail.The effects on partition characteristics of geniposide were analyzed via investigation of the composition proportion of inductors,the additive amount of inductors,the volume fraction of acetonitrile,the additive amount of sample and temperature.The results show that when inductors were added into the acetonitrile/aqueous(volume ratio 1:1) extract at 25℃,the preliminary purification of geniposide could be finished by one step.The extraction yield of geniposide reaches 81.63% and the purity is increased from 3.05% primitively to 13.54%.The best inductors are composed of KCl and MgSO4(mass ratio 2:1).
After geniposide in the acetonitrile aqueous extract solution of Gardenia was separated into two phases by inductors,the partition characteristics of it in two phases were studied.A new method was established for the separation and purification of geniposide.The types of inductors inducing phase separation of acetonitrile aqueous solution were researched in detail.The effects on partition characteristics of geniposide were analyzed via investigation of the composition proportion of inductors,the additive amount of inductors,the volume fraction of acetonitrile,the additive amount of sample and temperature.The results show that when inductors were added into the acetonitrile/aqueous(volume ratio 1:1) extract at 25℃,the preliminary purification of geniposide could be finished by one step.The extraction yield of geniposide reaches 81.63% and the purity is increased from 3.05% primitively to 13.54%.The best inductors are composed of KCl and MgSO4(mass ratio 2:1).
2014, 31(2): 237-241
doi: 10.3724/SP.J.1095.2014.30135
Abstract:
To determine the chemical constituents from Sibiraea angustata(Rehd.) Hand-Mazz,its 80% ethanol extract was isolated and purified by chromatograph over silica gel,Sephadex LH-20 and HPLC,etc.Nine compounds were isolated and identified as hyperoside(Ⅰ),quercetin(Ⅱ),rutin(Ⅲ),quercetin-3-O-β-D-glucopyranoside(Ⅳ),catechin(Ⅴ),vanillic acid(Ⅵ),arbutin(Ⅶ),isoferulic acid(Ⅷ),daucosterol(Ⅸ).Their chemical structures were determined by chemical methods,NMR spectral data.Compounds Ⅰ~Ⅲ and Ⅴ~Ⅶ were isolated from the leaves of Sibiraea angustata(Rehd.) Hand-Mazz.for the first time.
To determine the chemical constituents from Sibiraea angustata(Rehd.) Hand-Mazz,its 80% ethanol extract was isolated and purified by chromatograph over silica gel,Sephadex LH-20 and HPLC,etc.Nine compounds were isolated and identified as hyperoside(Ⅰ),quercetin(Ⅱ),rutin(Ⅲ),quercetin-3-O-β-D-glucopyranoside(Ⅳ),catechin(Ⅴ),vanillic acid(Ⅵ),arbutin(Ⅶ),isoferulic acid(Ⅷ),daucosterol(Ⅸ).Their chemical structures were determined by chemical methods,NMR spectral data.Compounds Ⅰ~Ⅲ and Ⅴ~Ⅶ were isolated from the leaves of Sibiraea angustata(Rehd.) Hand-Mazz.for the first time.
2014, 31(2): 242-244
doi: 10.3724/SP.J.1095.2014.30194
Abstract:
An enantioselective synthesis of chiral alkylphosphonates bearing a β-stereogenic center,based on the Rh-catalyzed asymmetric hydrogenation of corresponding β-substituted β,γ-unsaturated phosphonates with(Rc,Sp)-WalPhos ligand under the mild hydrogenation conditions(1.0 MPa hydrogen pressure and room temperature),was developed.The full conversions can be achieved and an ee value of up to 87% is obtained.
An enantioselective synthesis of chiral alkylphosphonates bearing a β-stereogenic center,based on the Rh-catalyzed asymmetric hydrogenation of corresponding β-substituted β,γ-unsaturated phosphonates with(Rc,Sp)-WalPhos ligand under the mild hydrogenation conditions(1.0 MPa hydrogen pressure and room temperature),was developed.The full conversions can be achieved and an ee value of up to 87% is obtained.
