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2014 Volume 31 Issue 12
2014, 31(12): 1359-1367
doi: 10.3724/SP.J.1095.2014.30641
Abstract:
The progress of the synthesis and applications of nanosized bismuth oxides is reviewed in this paper.Synthetic methods including solid-phase synthesis,precipitation process,hydrolysis method,sol-gel,atomizing-combustion technique,microemulsion method are systematically introduced.Potential applications of nanosized bismuth oxide as functional electronic materials,burning rate catalysts,photocatalytic decomposition materials,optical materials,medical composite materials and anti-radiation materials are also introduced.
The progress of the synthesis and applications of nanosized bismuth oxides is reviewed in this paper.Synthetic methods including solid-phase synthesis,precipitation process,hydrolysis method,sol-gel,atomizing-combustion technique,microemulsion method are systematically introduced.Potential applications of nanosized bismuth oxide as functional electronic materials,burning rate catalysts,photocatalytic decomposition materials,optical materials,medical composite materials and anti-radiation materials are also introduced.
2014, 31(12): 1368-1377
doi: 10.3724/SP.J.1095.2014.40095
Abstract:
It is very important to take appropriate inhibiting scaling measurements in brackish water reverse osmosis(BWRO) desalination process,which depends on feed water characteristics and scaling formation mechanism on membrane surface.Managing scale formation relies on early scaling potential prediction,judicious system design,influent pretreatment and non-destructive detection.A range of conventional and emerging analytical techniques,including molar ratio,direct observation and spectroscopic methods have evolved to predict scale potential and detect scale formation in real time.This review considers the prediction of scaling tendency,scale control techniques and non-destructive scale monitoring techniques based scales that are encountered when reverse osmosis is used in brackish water desalination applications.These techniques can significantly inhibit membrane surface scaling and decrease membrane fouling.Moreover,the suggestions are also presented in this field.
It is very important to take appropriate inhibiting scaling measurements in brackish water reverse osmosis(BWRO) desalination process,which depends on feed water characteristics and scaling formation mechanism on membrane surface.Managing scale formation relies on early scaling potential prediction,judicious system design,influent pretreatment and non-destructive detection.A range of conventional and emerging analytical techniques,including molar ratio,direct observation and spectroscopic methods have evolved to predict scale potential and detect scale formation in real time.This review considers the prediction of scaling tendency,scale control techniques and non-destructive scale monitoring techniques based scales that are encountered when reverse osmosis is used in brackish water desalination applications.These techniques can significantly inhibit membrane surface scaling and decrease membrane fouling.Moreover,the suggestions are also presented in this field.
2014, 31(12): 1378-1383
doi: 10.3724/SP.J.1095.2014.40063
Abstract:
Under pseudo high dilution conditions,cyclic oligomers of phenolphthalein poly(ether ketone ketone) s(c-PEKK-C) were synthesized from phenolphthalein and 4,4'-difluorotribenzodiketone(DFTBDK) with a cyclization ratio of 78%.MALDI-TOF MS characterization indicates that c-PEKK-C has a broad size distribution(n=2~8) with cyclic dimers and trimers as main components(85%).The molecular structure of DFTBDK is prone to form cyclic structure that can be confirmed by Jacobson-Stockmayer theory.Melt ringopening polymerization(ROP)(300~350℃) of cyclic oligomers catalyzed by potassium 4,4'-biohenol gives the corresponding linear products with high relative molecular mass(Mw 1.2×105).
Under pseudo high dilution conditions,cyclic oligomers of phenolphthalein poly(ether ketone ketone) s(c-PEKK-C) were synthesized from phenolphthalein and 4,4'-difluorotribenzodiketone(DFTBDK) with a cyclization ratio of 78%.MALDI-TOF MS characterization indicates that c-PEKK-C has a broad size distribution(n=2~8) with cyclic dimers and trimers as main components(85%).The molecular structure of DFTBDK is prone to form cyclic structure that can be confirmed by Jacobson-Stockmayer theory.Melt ringopening polymerization(ROP)(300~350℃) of cyclic oligomers catalyzed by potassium 4,4'-biohenol gives the corresponding linear products with high relative molecular mass(Mw 1.2×105).
2014, 31(12): 1384-1389
doi: 10.3724/SP.J.1095.2014.40243
Abstract:
The copolymerization reaction rate of cyclohexene oxide(CHO) and carbon dioxide is faster than that of propylene oxide(PO) and carbon dioxide,which leads to the difficulty in controlling the composition of the CHO-PO-CO2 terpolymer from one-pot synthesis.In this work,continuous feeding of CHO was used for the terpolymerization of CHO,PO and CO2 under a ternary rare earth metal coordination catalyst.Its catalytic activity can reach 575 g/(mol Zn h).Terpolymer PPCH100x(x is the molar farction of CHO in total oxides in comonomer feed) from the continuous process has only one glass transition temperature,while the terpolymer from one-pot synthesis has two glass transition temperatures.The glass transition temperature of PPCHx increases from 44.3℃ to 70.1℃ when the feed ratio of CHO increases from 0.19 to 0.59.It is encouraging to note that the composition of the terpolymer from continuous CHO feeding is similar to the feed ratio of comonomers,indicating that continuous feeding of comonomers is effective for controlling the composition of the terpolymer.
The copolymerization reaction rate of cyclohexene oxide(CHO) and carbon dioxide is faster than that of propylene oxide(PO) and carbon dioxide,which leads to the difficulty in controlling the composition of the CHO-PO-CO2 terpolymer from one-pot synthesis.In this work,continuous feeding of CHO was used for the terpolymerization of CHO,PO and CO2 under a ternary rare earth metal coordination catalyst.Its catalytic activity can reach 575 g/(mol Zn h).Terpolymer PPCH100x(x is the molar farction of CHO in total oxides in comonomer feed) from the continuous process has only one glass transition temperature,while the terpolymer from one-pot synthesis has two glass transition temperatures.The glass transition temperature of PPCHx increases from 44.3℃ to 70.1℃ when the feed ratio of CHO increases from 0.19 to 0.59.It is encouraging to note that the composition of the terpolymer from continuous CHO feeding is similar to the feed ratio of comonomers,indicating that continuous feeding of comonomers is effective for controlling the composition of the terpolymer.
2014, 31(12): 1390-1398
doi: 10.3724/SP.J.1095.2014.40070
Abstract:
The surface-initiated graft-polymerization of glycidyl methacrylate(GMA) on micron-sized silica gel particles was first conducted with a surface-initiating system of thiol group/azodiisobutyronitrile(AIBN) to obtain PGMA-grafted SiO2 particles.Sulfonate groups were bonded onto the side chains of PGMA by ringopening reaction between the epoxy groups of PGMA and sodium 2,4-diaminobenzene sulfonate(SAS),resulting in the formation of SAS-PGMA/SiO2 particles.The interaction between SAS-PGMA/SiO2 and matrine was examined.Surface-imprinting of the matrine molecule was performed with glutaraldehyde as the crosslinking agent to yield the matrine molecule surface-imprinted material MIP-SASP/SiO2.The experiment results show that in the nearly neutral solution,there is strong host-guest interaction between the functional grafted particles SAS-PGMA/SiO2 and matrine.The surface-imprinted MIP-SASP/SiO2 particles,have specific recognition selectivity and excellent binding affinity for matrine.Relative to the cytosine control,the coefficient of recognition selectivity of the imprinted material MIP-SASP/SiO2 for matrine reaches 10.7.
The surface-initiated graft-polymerization of glycidyl methacrylate(GMA) on micron-sized silica gel particles was first conducted with a surface-initiating system of thiol group/azodiisobutyronitrile(AIBN) to obtain PGMA-grafted SiO2 particles.Sulfonate groups were bonded onto the side chains of PGMA by ringopening reaction between the epoxy groups of PGMA and sodium 2,4-diaminobenzene sulfonate(SAS),resulting in the formation of SAS-PGMA/SiO2 particles.The interaction between SAS-PGMA/SiO2 and matrine was examined.Surface-imprinting of the matrine molecule was performed with glutaraldehyde as the crosslinking agent to yield the matrine molecule surface-imprinted material MIP-SASP/SiO2.The experiment results show that in the nearly neutral solution,there is strong host-guest interaction between the functional grafted particles SAS-PGMA/SiO2 and matrine.The surface-imprinted MIP-SASP/SiO2 particles,have specific recognition selectivity and excellent binding affinity for matrine.Relative to the cytosine control,the coefficient of recognition selectivity of the imprinted material MIP-SASP/SiO2 for matrine reaches 10.7.
2014, 31(12): 1399-1404
doi: 10.3724/SP.J.1095.2014.40072
Abstract:
(2-Hydroxy-3-butoxy) propyl hydroxypropyl chitosan(2-H-3-B-P-HPCS) was synthesized to prepare 2-H-3-B-P-HPCS/polyethylene glycol(2-H-3-B-P-HPCS/PEG) interpenetrating polymer network(IPN) hydrogels.The factors that could influence swelling properties of 2-H-3-B-P-HPCS/PEG IPN hydrogels were studied,such as concentration of 2-H-3-B-P-HPCS,reaction temperature,amount of PEG and glutaral.The 2-H-3-B-P-HPCS/PEG IPN hydrogels were investigated by SEM and IR.Aciclovir as a model drug was used to study the release performance.The results show that 2-H-3-B-P-HPCS/PEG IPN hydrogels have good swelling property,pH sensibility and drug releasing ability and can be used for a new drug carrier.
(2-Hydroxy-3-butoxy) propyl hydroxypropyl chitosan(2-H-3-B-P-HPCS) was synthesized to prepare 2-H-3-B-P-HPCS/polyethylene glycol(2-H-3-B-P-HPCS/PEG) interpenetrating polymer network(IPN) hydrogels.The factors that could influence swelling properties of 2-H-3-B-P-HPCS/PEG IPN hydrogels were studied,such as concentration of 2-H-3-B-P-HPCS,reaction temperature,amount of PEG and glutaral.The 2-H-3-B-P-HPCS/PEG IPN hydrogels were investigated by SEM and IR.Aciclovir as a model drug was used to study the release performance.The results show that 2-H-3-B-P-HPCS/PEG IPN hydrogels have good swelling property,pH sensibility and drug releasing ability and can be used for a new drug carrier.
2014, 31(12): 1405-1412
doi: 10.3724/SP.J.1095.2014.30591
Abstract:
2-Ethoxycarbonyl-3,4-tetramethylenepyrrole prepared from cyclohexene through an improved twostep procedure was treated with excess lithium aluminum hydride at high temperature to give 2-methyl-3,4-tetramethylenepyrrole.Further condensation with protected 4-formylphenylboronic acid in the presence of trifluoroacetic acid as catalyst,followed by oxidation with 2,3-dichloro-5,6-dicyanobenzoquinone(DDQ) and treatment with triethylamine and boron trifluoride etherate,gives a novel exocyclic ring-fused borondipyrromethene(BDP) dye derivative substituted with phenylboronic ester subunit at the meso-position.The UV-Vis absorption titration and fluorescence titration measurements for BDP dye derivative were carried out to examine its responsibility to D-fructose,D-galactose,and D-glucose at specific pH.The influence of covalent interactions of BDP dye derivative with monosaccharides on its spectroscopic properties can be selectively recognized by both absorption and fluorescence spectra.By the nonlinear curve-fitting analysis of the fluorescence titration data,the association constants Ks of BDP derivative 1 with monosaccharide such as Dfructose,D-galactose,and D-glucose are 1045,445 and 130 L/mol,respectively.Thus BDP derivative 1 can be used as a sensitive and selective fluorescent probe for monosaccharides.Moreover,the sensing mechanism of the fluorescent probe was also preliminarily discussed.
2-Ethoxycarbonyl-3,4-tetramethylenepyrrole prepared from cyclohexene through an improved twostep procedure was treated with excess lithium aluminum hydride at high temperature to give 2-methyl-3,4-tetramethylenepyrrole.Further condensation with protected 4-formylphenylboronic acid in the presence of trifluoroacetic acid as catalyst,followed by oxidation with 2,3-dichloro-5,6-dicyanobenzoquinone(DDQ) and treatment with triethylamine and boron trifluoride etherate,gives a novel exocyclic ring-fused borondipyrromethene(BDP) dye derivative substituted with phenylboronic ester subunit at the meso-position.The UV-Vis absorption titration and fluorescence titration measurements for BDP dye derivative were carried out to examine its responsibility to D-fructose,D-galactose,and D-glucose at specific pH.The influence of covalent interactions of BDP dye derivative with monosaccharides on its spectroscopic properties can be selectively recognized by both absorption and fluorescence spectra.By the nonlinear curve-fitting analysis of the fluorescence titration data,the association constants Ks of BDP derivative 1 with monosaccharide such as Dfructose,D-galactose,and D-glucose are 1045,445 and 130 L/mol,respectively.Thus BDP derivative 1 can be used as a sensitive and selective fluorescent probe for monosaccharides.Moreover,the sensing mechanism of the fluorescent probe was also preliminarily discussed.
2014, 31(12): 1413-1418
doi: 10.3724/SP.J.1095.2014.40090
Abstract:
Sirtuin is a type of nicotinamide adenine dinucleotide(NAD) dependent histone deacetylase,which has seven members.It is a potential therapeutic target for many diseases.However,the present fluorescent screening method is limited to SIRT1~SIRT3.Therefore,based on the discovery of SIRT5's novel enzymatic activity,we designed and synthesized the fluorescence labeled peptide for SIRT5,ISGASE(SuK)-AMC;and by the validations of LC-MS and fluorescence detection,the fluorescence labeled peptide can be used as a tool to perform the screening based on the enzymatic activity of SIRT5.
Sirtuin is a type of nicotinamide adenine dinucleotide(NAD) dependent histone deacetylase,which has seven members.It is a potential therapeutic target for many diseases.However,the present fluorescent screening method is limited to SIRT1~SIRT3.Therefore,based on the discovery of SIRT5's novel enzymatic activity,we designed and synthesized the fluorescence labeled peptide for SIRT5,ISGASE(SuK)-AMC;and by the validations of LC-MS and fluorescence detection,the fluorescence labeled peptide can be used as a tool to perform the screening based on the enzymatic activity of SIRT5.
2014, 31(12): 1419-1427
doi: 10.3724/SP.J.1095.2014.40096
Abstract:
3-Aliphatic-1,2,4-triazole derivatives 1a~1f were synthesized through the reaction of six kinds of fatty acids with diaminothiourea,in which compounds 1e and 1f were first synthesized.In the presence of phosphorus oxychloride,compounds 1a~1f reacted with 4-pyridine carboxylic acid and 2,6-pyridine dicarboxylic acid,respectively.The 12 kinds of aliphatic triazoles,thiadiazoles 2a~2f and 3a~3f were synthesized in high yields for the first time.In order to study the influence of 3-aliphatic group and pyridine,compounds 5,6,7a~7c and 8a~8c without pyridine units were also synthesized.The target compounds were well characterized by IR,1H NMR and HRMS.In the biotic screening test,the inhibitory properties of Cdc25B and PTP1B were explored.The results show that compounds 3b,3d,3e and 3f have good inhibition activity against Cdc25B with IC50 values of(1.12±0.27),(2.72±1.07),(0.72±0.05) and(4.97±0.93) mg/L,respectively;compounds 2b,3d,and 5 exhibit higher inhibition activity against PTP1B with IC50 values of(0.98±0.13),(1.33±0.11),(2.18±0.20) mg/L,respectively.
3-Aliphatic-1,2,4-triazole derivatives 1a~1f were synthesized through the reaction of six kinds of fatty acids with diaminothiourea,in which compounds 1e and 1f were first synthesized.In the presence of phosphorus oxychloride,compounds 1a~1f reacted with 4-pyridine carboxylic acid and 2,6-pyridine dicarboxylic acid,respectively.The 12 kinds of aliphatic triazoles,thiadiazoles 2a~2f and 3a~3f were synthesized in high yields for the first time.In order to study the influence of 3-aliphatic group and pyridine,compounds 5,6,7a~7c and 8a~8c without pyridine units were also synthesized.The target compounds were well characterized by IR,1H NMR and HRMS.In the biotic screening test,the inhibitory properties of Cdc25B and PTP1B were explored.The results show that compounds 3b,3d,3e and 3f have good inhibition activity against Cdc25B with IC50 values of(1.12±0.27),(2.72±1.07),(0.72±0.05) and(4.97±0.93) mg/L,respectively;compounds 2b,3d,and 5 exhibit higher inhibition activity against PTP1B with IC50 values of(0.98±0.13),(1.33±0.11),(2.18±0.20) mg/L,respectively.
2014, 31(12): 1428-1433
doi: 10.3724/SP.J.1095.2014.40052
Abstract:
Electrophilic aromatic imines synthesized by the condensation of aromatic amines with cinnamyl aldehyde were allowed to react with diethyl phosphite or triethyl phosphite as nucleophile in the presence of 10% molar fraction of phosphoric acid(Brønsted acid).The α-aminophosphonate derivatives were obtained through binary or single hydrogen bonding interaction of catalyst with nucleophiles and electrophiles in up to 79%~85% yields.
Electrophilic aromatic imines synthesized by the condensation of aromatic amines with cinnamyl aldehyde were allowed to react with diethyl phosphite or triethyl phosphite as nucleophile in the presence of 10% molar fraction of phosphoric acid(Brønsted acid).The α-aminophosphonate derivatives were obtained through binary or single hydrogen bonding interaction of catalyst with nucleophiles and electrophiles in up to 79%~85% yields.
2014, 31(12): 1434-1440
doi: 10.3724/SP.J.1095.2014.40080
Abstract:
Two ionic liquids with phosphoryl group,1-butyl-3-(3-diphenylphosphoryl) propyl imidazolium hexafluorophophate([BIMC3P(O)Ph2]PF6,IL-1) and(3-diphenylphosphoryl)-triethylamonium hexafluorophophate([TEAC3P(O)Ph2]PF6,IL-2),were synthesized and characterized by NMR and IR.Their Eu3+ complexes,Eu(IL-1)3(NO3)3 and Eu(IL-2)3(NO3)3 were also synthesized.Thermal analysis shows that both ionic liquids have excellent thermal stability than their Eu3+ complexes.Upon coordination,the IR absorption of P=O group in ionic liquid complexes moves to a lower wavenumber and the intensities of UV absorption spectra of their complexes are also increased.These results clearly demonstrate that ionic liquids with phosphoryl groups are coordinated to Eu3+ ions.The fluorescence study indicates that there is a sharp and strong emission of characteristic red light of Eu3+ ion.The results show that these Eu3+ complexes are promising photoluminescent materials.
Two ionic liquids with phosphoryl group,1-butyl-3-(3-diphenylphosphoryl) propyl imidazolium hexafluorophophate([BIMC3P(O)Ph2]PF6,IL-1) and(3-diphenylphosphoryl)-triethylamonium hexafluorophophate([TEAC3P(O)Ph2]PF6,IL-2),were synthesized and characterized by NMR and IR.Their Eu3+ complexes,Eu(IL-1)3(NO3)3 and Eu(IL-2)3(NO3)3 were also synthesized.Thermal analysis shows that both ionic liquids have excellent thermal stability than their Eu3+ complexes.Upon coordination,the IR absorption of P=O group in ionic liquid complexes moves to a lower wavenumber and the intensities of UV absorption spectra of their complexes are also increased.These results clearly demonstrate that ionic liquids with phosphoryl groups are coordinated to Eu3+ ions.The fluorescence study indicates that there is a sharp and strong emission of characteristic red light of Eu3+ ion.The results show that these Eu3+ complexes are promising photoluminescent materials.
2014, 31(12): 1441-1446
doi: 10.3724/SP.J.1095.2014.40048
Abstract:
The three-dimensional ordered macroporous titanium dioxide(3DOM TiO2) was rapidly fabricated via a sandwich-vacuum method.In this method,tetrabutyl titanate in ethanol solution was filled in the voids between the acrylic acid-modified polystyrene(PS) colloidal crystals that served as the templates and calcified to form 3DOM TiO2.The template was removed during calcination.3DOM TiO2 has a typical inverse opal structure,and the macropores are arranged in a face-centered cubic(fcc) structure and interconnect with each other by small windows.The average diameter of macroporores is about 230 nm with a shrinkage of about 14%.The XRD result shows that the structure of macropores calcined at 500℃ is anatase.
The three-dimensional ordered macroporous titanium dioxide(3DOM TiO2) was rapidly fabricated via a sandwich-vacuum method.In this method,tetrabutyl titanate in ethanol solution was filled in the voids between the acrylic acid-modified polystyrene(PS) colloidal crystals that served as the templates and calcified to form 3DOM TiO2.The template was removed during calcination.3DOM TiO2 has a typical inverse opal structure,and the macropores are arranged in a face-centered cubic(fcc) structure and interconnect with each other by small windows.The average diameter of macroporores is about 230 nm with a shrinkage of about 14%.The XRD result shows that the structure of macropores calcined at 500℃ is anatase.
2014, 31(12): 1447-1452
doi: 10.3724/SP.J.1095.2014.40101
Abstract:
Binary transition metal oxide CoFe2O4 as a high capacity anode material for lithium-ion batteries with the microflower/nanosheet hierarchical structure was synthesized by layered double hydrotalcite-like precursors.The CoFe2O4 and reduced graphene oxide(rGO) coated CoFe2O4(CoFe2O4/rGO) materials were characterized by powder X-ray diffraction(XRD),scanning electron microscope(SEM),transmission electron microscope(TEM) techniques.The electrochemical performances of the CoFe2O4 and CoFe2O4/rGO electrodes were examined in terms of cyclic voltammetry and discharge/charge profiles.The electrodes exhibit high capacity and rate capacity.Furthermore,the cyclic performance of CoFe2O4/rGO electrode is better than that of the CoFe2O4 electrode.
Binary transition metal oxide CoFe2O4 as a high capacity anode material for lithium-ion batteries with the microflower/nanosheet hierarchical structure was synthesized by layered double hydrotalcite-like precursors.The CoFe2O4 and reduced graphene oxide(rGO) coated CoFe2O4(CoFe2O4/rGO) materials were characterized by powder X-ray diffraction(XRD),scanning electron microscope(SEM),transmission electron microscope(TEM) techniques.The electrochemical performances of the CoFe2O4 and CoFe2O4/rGO electrodes were examined in terms of cyclic voltammetry and discharge/charge profiles.The electrodes exhibit high capacity and rate capacity.Furthermore,the cyclic performance of CoFe2O4/rGO electrode is better than that of the CoFe2O4 electrode.
2014, 31(12): 1453-1457
doi: 10.3724/SP.J.1095.2014.40241
Abstract:
A simple approach to the synthesis of highly dispersed nano-Mn3O4 by mild aqueous synthesis method at low temperatures(90℃) is reported.The structure,composition and morphology of the material were investigated by X-ray diffraction,X-ray photoelectron spectroscopy and transmission electron microscope.The capacitance performance of the composites was explained by cyclic voltammetry and charge-discharge tests.The results show that the sample is tetragonal γ-Mn3O4 with 40~60 nm in diameter.The nano-Mn3O4 material has a good capacitance performance.The specific capacitance value of the material is 270 F/g.Furthermore,the specific capacitance value remains 85% of its initial value after 1000 charge-discharge circles.
A simple approach to the synthesis of highly dispersed nano-Mn3O4 by mild aqueous synthesis method at low temperatures(90℃) is reported.The structure,composition and morphology of the material were investigated by X-ray diffraction,X-ray photoelectron spectroscopy and transmission electron microscope.The capacitance performance of the composites was explained by cyclic voltammetry and charge-discharge tests.The results show that the sample is tetragonal γ-Mn3O4 with 40~60 nm in diameter.The nano-Mn3O4 material has a good capacitance performance.The specific capacitance value of the material is 270 F/g.Furthermore,the specific capacitance value remains 85% of its initial value after 1000 charge-discharge circles.
2014, 31(12): 1458-1464
doi: 10.3724/SP.J.1095.2014.40065
Abstract:
Reduced graphene oxide(RGO) was prepared by reducing graphene oxide(GO) with ethylenediamine(EDA).The adsorption kinetics and thermodynamics of Zn(Ⅱ) onto RGO were investigated with a batch method.The Lagergren pseudo-first-order and pseudo-second-order kinetic model,Langmuir and Freundlich isotherm models were applied to simulate the experimental data.The results show that the experimental data are well described with the Lagergren pseudo-second-order model,indicating that the adsorption process is chemisorption mainly.The adsorption isothermal process fits well with the Langmuir model.The enthalpy change is -21.60 kJ/mol and the Gibbs free energy is positive,which indicates that the adsorption of Zn(Ⅱ) is exothermic and non-spontaneous,respectively.
Reduced graphene oxide(RGO) was prepared by reducing graphene oxide(GO) with ethylenediamine(EDA).The adsorption kinetics and thermodynamics of Zn(Ⅱ) onto RGO were investigated with a batch method.The Lagergren pseudo-first-order and pseudo-second-order kinetic model,Langmuir and Freundlich isotherm models were applied to simulate the experimental data.The results show that the experimental data are well described with the Lagergren pseudo-second-order model,indicating that the adsorption process is chemisorption mainly.The adsorption isothermal process fits well with the Langmuir model.The enthalpy change is -21.60 kJ/mol and the Gibbs free energy is positive,which indicates that the adsorption of Zn(Ⅱ) is exothermic and non-spontaneous,respectively.
2014, 31(12): 1465-1471
doi: 10.3724/SP.J.1095.2014.30612
Abstract:
Graphene/platinum nanoparticles hybrid membrane modified electrode was prepared by cyclic voltammetry(CV).The electrochemical behaviors of epinephrine(EP) were studied on this modified electrode,and an electrochemical method for determination of EP was developed.The morphology and the electrochemical properties of the modified electrode were characterized by scan electron microscopy(SEM) and cyclic voltammetry,respectively.The conditions that influence the electrochemical properties of the modified electrode during the preparation processes and the conditions for determination of EP were optimized.Experimental results show that the modified electrode has excellent catalytic properties for the redox of EP.In the Na2HPO4-citric acid buffer solution(pH=5.0),the oxidative peak current of EP is linear with its concentration in the range of 4.4×10-8~2.2×10-6 mol/L.The linear regressive equation is ipa(10 A)=0.0753c(mol/L)+3.7653×10-5 with r=0.9989,and the detection limit of 2.0×10-9 mol/L(S/N=3).The modified electrode shows good reproducibility,high sensitivity and selectivity.It could be used for determination of the content of EP in real samples.
Graphene/platinum nanoparticles hybrid membrane modified electrode was prepared by cyclic voltammetry(CV).The electrochemical behaviors of epinephrine(EP) were studied on this modified electrode,and an electrochemical method for determination of EP was developed.The morphology and the electrochemical properties of the modified electrode were characterized by scan electron microscopy(SEM) and cyclic voltammetry,respectively.The conditions that influence the electrochemical properties of the modified electrode during the preparation processes and the conditions for determination of EP were optimized.Experimental results show that the modified electrode has excellent catalytic properties for the redox of EP.In the Na2HPO4-citric acid buffer solution(pH=5.0),the oxidative peak current of EP is linear with its concentration in the range of 4.4×10-8~2.2×10-6 mol/L.The linear regressive equation is ipa(10 A)=0.0753c(mol/L)+3.7653×10-5 with r=0.9989,and the detection limit of 2.0×10-9 mol/L(S/N=3).The modified electrode shows good reproducibility,high sensitivity and selectivity.It could be used for determination of the content of EP in real samples.
2014, 31(12): 1472-1480
doi: 10.3724/SP.J.1095.2014.40059
Abstract:
The separation and determination methods of calcium antagonists manidipine hydrochloride and nicardipine hydrochloride enantiomers were developed by open-tubular capillary electrochromatography(CEC),respectively.A new capillary column with p-nitrophenylcarbamation β-cyclodextrin was prepared by sol-gel method.The sol-gel modified with cyclodextrin derivative was characterized by infrared spectroscopy(IR) and scanning electron microscopy(SEM).In polar organic mode,the effect of the volume fraction and concentration of added triethylamine and glacial acetic acid,the content of organic solvents,the operating voltage,and temperature on the resolution(RS) were investigated.The optimized conditions were at 20℃,detection wavelength at 236 nm,and injection pressure at 3.448 kPa×3 s.The compositions of mobile phases were V(MeOH):V(ACN):V(TEA):V(HOAc)=57:43:0.05:0.07 for manidipine hydrochloride and V(MeOH):V(ACN):V(TEA):V(HOAc)=55:45:0.05:0.08 for nicardipine hydrochloride.The resolution(Rs) of manidipine hydrochloride was 1.39 at 25 kV.The resolution(Rs) of nicardipine hydrochloride was 1.30 at 20 kV.The RSDs of retention time and peak area were less than 1.2% and 5.6%(n=5) for the drugs,respectively.It was indicated that new column has stable electrochromatography performance.The single run time were less than 5 min for manidipine hydrochloride and less than 7 min for nicardipine hydrochloride.Good linearity were observed in the concentration range of 5.2~125.0 mg/L with correlation coefficients 0.9969 or more for both drug enantiomers.The limit of detection values were 1.8 mg/L for manidipine and 2.3 mg/L for nicardipine,respectively.The nitrophenyl carbamated β-cyclodextrin phase(NCDP) column were preliminarily used for determinations of manidipine hydrochloride and nicardipine hydrochloride tablet and capsule.
The separation and determination methods of calcium antagonists manidipine hydrochloride and nicardipine hydrochloride enantiomers were developed by open-tubular capillary electrochromatography(CEC),respectively.A new capillary column with p-nitrophenylcarbamation β-cyclodextrin was prepared by sol-gel method.The sol-gel modified with cyclodextrin derivative was characterized by infrared spectroscopy(IR) and scanning electron microscopy(SEM).In polar organic mode,the effect of the volume fraction and concentration of added triethylamine and glacial acetic acid,the content of organic solvents,the operating voltage,and temperature on the resolution(RS) were investigated.The optimized conditions were at 20℃,detection wavelength at 236 nm,and injection pressure at 3.448 kPa×3 s.The compositions of mobile phases were V(MeOH):V(ACN):V(TEA):V(HOAc)=57:43:0.05:0.07 for manidipine hydrochloride and V(MeOH):V(ACN):V(TEA):V(HOAc)=55:45:0.05:0.08 for nicardipine hydrochloride.The resolution(Rs) of manidipine hydrochloride was 1.39 at 25 kV.The resolution(Rs) of nicardipine hydrochloride was 1.30 at 20 kV.The RSDs of retention time and peak area were less than 1.2% and 5.6%(n=5) for the drugs,respectively.It was indicated that new column has stable electrochromatography performance.The single run time were less than 5 min for manidipine hydrochloride and less than 7 min for nicardipine hydrochloride.Good linearity were observed in the concentration range of 5.2~125.0 mg/L with correlation coefficients 0.9969 or more for both drug enantiomers.The limit of detection values were 1.8 mg/L for manidipine and 2.3 mg/L for nicardipine,respectively.The nitrophenyl carbamated β-cyclodextrin phase(NCDP) column were preliminarily used for determinations of manidipine hydrochloride and nicardipine hydrochloride tablet and capsule.
