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2010 Volume 27 Issue 1
2010, 27(1): 1-11
Abstract:
Retro-cycloaddition reaction is one of the most important reactions of fullerene derivatives.Many kinds of organofullerenes are not stable under reductive,oxidative or thermal conditions,where the functional addends are removed from the fullerene sphere and lead to the formation of pristine fullerenes.Such addition-retro-addition reaction has shown promising application in the protection/deprotection strategy for the purification and functionalization of fullerenes.However,the retro-addition reactions may cause problems for the applications of organofullerenes due to the instability of the compounds.Recently the electrochemical stabilities of a series of fullerooxazoles have been studied.The results show that there is an intramolecular C-H····X(X=N,O) hydrogen bonding among the addends for one of the compounds,which attributes to the stability of the compound.Herein,the progress of the retro-cycloaddition reaction of organofullerenes and the factors that may affect the stability of organofullerenes is reviewed.
Retro-cycloaddition reaction is one of the most important reactions of fullerene derivatives.Many kinds of organofullerenes are not stable under reductive,oxidative or thermal conditions,where the functional addends are removed from the fullerene sphere and lead to the formation of pristine fullerenes.Such addition-retro-addition reaction has shown promising application in the protection/deprotection strategy for the purification and functionalization of fullerenes.However,the retro-addition reactions may cause problems for the applications of organofullerenes due to the instability of the compounds.Recently the electrochemical stabilities of a series of fullerooxazoles have been studied.The results show that there is an intramolecular C-H····X(X=N,O) hydrogen bonding among the addends for one of the compounds,which attributes to the stability of the compound.Herein,the progress of the retro-cycloaddition reaction of organofullerenes and the factors that may affect the stability of organofullerenes is reviewed.
2010, 27(1): 12-15
Abstract:
Twelve o-hydroxybenzyl-amino acids were synthesized.Salicylaldehyde and its two-derivatives were respectively condensed with each of 4 L-α-amino acids in the presence of sodium hydroxide to obtain amino acid Schiff bases,which were subsequently reduced by NaBH4 to produce o-hydroxy-benzyl-amino acids(3).The structures of the products were confirmed by IR,1H NMR and elemental analysis.The result of preliminary bioassay shows that these compounds are highly effective in S.aureus inhibition at 0.05%(mass concentration) with an inhibitory ratio of 100% and have antibacterial activities to M.albicans and E.coli to some extent.Structure of the substituent R has important effect on the antibacterial activity of o-hydroxy-benzyl-amino acids.The effects of different alkyl R on antibacterial activities to M.albicans and E.coli show the following order CH(CH3)2>CH3,CH2CH(CH3)2>H.The bromine atoms on the benzene ring of the title compounds have little effect on antibacterial activities to M.albicans and E.coli.
Twelve o-hydroxybenzyl-amino acids were synthesized.Salicylaldehyde and its two-derivatives were respectively condensed with each of 4 L-α-amino acids in the presence of sodium hydroxide to obtain amino acid Schiff bases,which were subsequently reduced by NaBH4 to produce o-hydroxy-benzyl-amino acids(3).The structures of the products were confirmed by IR,1H NMR and elemental analysis.The result of preliminary bioassay shows that these compounds are highly effective in S.aureus inhibition at 0.05%(mass concentration) with an inhibitory ratio of 100% and have antibacterial activities to M.albicans and E.coli to some extent.Structure of the substituent R has important effect on the antibacterial activity of o-hydroxy-benzyl-amino acids.The effects of different alkyl R on antibacterial activities to M.albicans and E.coli show the following order CH(CH3)2>CH3,CH2CH(CH3)2>H.The bromine atoms on the benzene ring of the title compounds have little effect on antibacterial activities to M.albicans and E.coli.
2010, 27(1): 16-20
Abstract:
A new macromolecular coupling agent,maleic anhydride(MAn)-butyl acrylate(BA)-styrene(St) tercopolymer,was synthesized via solution free radical polymerization and used to modify aluminum nitride(AIN).The molecular structure of the terpolymer was confirmed by FTIR,and its average molecular mass was determined by GPC.The structure,surface properties and thermal stability of the modified nano-AlN were systematically investigated by FTIR,contact angle,TGA,TEM and sedimentation experiment.The results show that the stability of nano-AlN modified by MAn-BA-St(molar ratio is 1:1:5) was the best in styrene solution;the chemistry and physics usage efficiencies of the macromolecular coupling agent were 52.5% and 25% respectively.The surface free energy of the modified nano-AlN decreased from 879 J/m2 to 221 J/m2 which has a good dispersibility in styrene.
A new macromolecular coupling agent,maleic anhydride(MAn)-butyl acrylate(BA)-styrene(St) tercopolymer,was synthesized via solution free radical polymerization and used to modify aluminum nitride(AIN).The molecular structure of the terpolymer was confirmed by FTIR,and its average molecular mass was determined by GPC.The structure,surface properties and thermal stability of the modified nano-AlN were systematically investigated by FTIR,contact angle,TGA,TEM and sedimentation experiment.The results show that the stability of nano-AlN modified by MAn-BA-St(molar ratio is 1:1:5) was the best in styrene solution;the chemistry and physics usage efficiencies of the macromolecular coupling agent were 52.5% and 25% respectively.The surface free energy of the modified nano-AlN decreased from 879 J/m2 to 221 J/m2 which has a good dispersibility in styrene.
2010, 27(1): 21-26
Abstract:
Chitosan/polyvinyl alcohol/sodium tripolyphosphate complex microparticles were prepared from chitosan(CS),polyvinyl alcohol(PVA) and sodium tripolyphosphate(TPP).The effects of CS content on complex microparticles and different ions,pH on the degree of equilibrium swelling were investigated.The component,structure and morphology of the complex microparticles were characterized by means of X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM).The results indicate that the CS-PVA is a compatible system;the crystallization of PVA declines with the increase of CS content;the particle size is about 400~950 μm with rough surfaces.The equilibrium swelling tests show that with the increase of CS content,the equilibrium swelling ratio increases firstly then decreases.The CS/PVA/TPP complex microparticles show highest equilibrium swelling ratio in a pH 3~8 solution and tend to decrease with the increase of ion content in the same aqueous solution.The microparticles have swelling-shrinking reversibility,implying that CS/PVA/TPP complex microparticles are pH/ion-sensitive and could provide experimental and theoretical basis for drug delivery system.
Chitosan/polyvinyl alcohol/sodium tripolyphosphate complex microparticles were prepared from chitosan(CS),polyvinyl alcohol(PVA) and sodium tripolyphosphate(TPP).The effects of CS content on complex microparticles and different ions,pH on the degree of equilibrium swelling were investigated.The component,structure and morphology of the complex microparticles were characterized by means of X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM).The results indicate that the CS-PVA is a compatible system;the crystallization of PVA declines with the increase of CS content;the particle size is about 400~950 μm with rough surfaces.The equilibrium swelling tests show that with the increase of CS content,the equilibrium swelling ratio increases firstly then decreases.The CS/PVA/TPP complex microparticles show highest equilibrium swelling ratio in a pH 3~8 solution and tend to decrease with the increase of ion content in the same aqueous solution.The microparticles have swelling-shrinking reversibility,implying that CS/PVA/TPP complex microparticles are pH/ion-sensitive and could provide experimental and theoretical basis for drug delivery system.
2010, 27(1): 27-31
Abstract:
Influences of the reaction conditions including the reaction temperature,reaction time and the quantity of the catalyst added on the epoxidation of castor oil were investigated using acidic alumina as the catalyst,in order to optimize the reaction conditions.The structure and properties of epoxidized castor oil were characterized by FT-IR and TG.The epoxy value of product ECO was measured by hydrochloric acid-acetone method.The utilization of H2O2 could be improved and the epoxy value of castor oil could be as high as 2.094×10-3 mol/g under optimized synthetic conditions,where acidic alumina was used as catalyst,thiourea was added as stabilizer,the temperature of added H2O2 solution was 50~55℃,the reaction temperature were kept at 65℃ for 11.5 h.The viscosity of ECO increases with the increas of epoxy value and lower with temperature increase.ECO remains stable up to 250℃ then started to decompose.There were three obvious thermal decomposition stages:250~390℃,390~470℃,470~580℃,which showed ECO had a good thermal stability.
Influences of the reaction conditions including the reaction temperature,reaction time and the quantity of the catalyst added on the epoxidation of castor oil were investigated using acidic alumina as the catalyst,in order to optimize the reaction conditions.The structure and properties of epoxidized castor oil were characterized by FT-IR and TG.The epoxy value of product ECO was measured by hydrochloric acid-acetone method.The utilization of H2O2 could be improved and the epoxy value of castor oil could be as high as 2.094×10-3 mol/g under optimized synthetic conditions,where acidic alumina was used as catalyst,thiourea was added as stabilizer,the temperature of added H2O2 solution was 50~55℃,the reaction temperature were kept at 65℃ for 11.5 h.The viscosity of ECO increases with the increas of epoxy value and lower with temperature increase.ECO remains stable up to 250℃ then started to decompose.There were three obvious thermal decomposition stages:250~390℃,390~470℃,470~580℃,which showed ECO had a good thermal stability.
2010, 27(1): 32-37
Abstract:
The azobenzene-containing metal complexes with different length carbon chains have ben synthesized.The compounds have been characterized by spectrophotometric methods as well as thermal,and X-ray diffractometric analysis.It is found that the carbon chain length between azobenzene moiety and diamine metal complex has a great influence on the thermal and fluorescent behavior of the bi-functional compounds.The advantage of combining azobenzene chromophore with metal complex is evidenced by the remarkable high efficiency of azobenzene isomerization behavior and two fluorescent emission bands centered at 290 and 560 nm respectively,induced by metal complex part of the compounds.The holographic image inscription and readout experiment by one of the metal complexes in PMMA matrices is successful.
The azobenzene-containing metal complexes with different length carbon chains have ben synthesized.The compounds have been characterized by spectrophotometric methods as well as thermal,and X-ray diffractometric analysis.It is found that the carbon chain length between azobenzene moiety and diamine metal complex has a great influence on the thermal and fluorescent behavior of the bi-functional compounds.The advantage of combining azobenzene chromophore with metal complex is evidenced by the remarkable high efficiency of azobenzene isomerization behavior and two fluorescent emission bands centered at 290 and 560 nm respectively,induced by metal complex part of the compounds.The holographic image inscription and readout experiment by one of the metal complexes in PMMA matrices is successful.
2010, 27(1): 38-42
Abstract:
Two series of schiff-base type liquid crystalline crown ether potassium complexes containing dibenzo-18-crown-6 were synthesized from cis-and trans-4,4'-bis[(4'-alkoxylbiphenyl-4-carboxy) benzylideneamino] dibenzo-18-crown-6 in yields of 85.5%~92.1% and 88.7%~90.7% respectively.Their structures and properties were characterized by elemental analysis,IR,UV-Vis,AAS,DSC,XRD and polarizing optical microscopy(POM) with a heating stage.Results show that the complexes changed into liquid crystal phase upon heated to temperatures higher than their melting points,and the melting points Tm and isotropization temperature Ti of the complexes changed regularly with the increase of the carbon number in the terminal alkoxyl groups.There is a gradual increase in smectic phase length and a gradual decrease in nemetic phase length.The liquid crystalline phase temperature range became broader after complexation.
Two series of schiff-base type liquid crystalline crown ether potassium complexes containing dibenzo-18-crown-6 were synthesized from cis-and trans-4,4'-bis[(4'-alkoxylbiphenyl-4-carboxy) benzylideneamino] dibenzo-18-crown-6 in yields of 85.5%~92.1% and 88.7%~90.7% respectively.Their structures and properties were characterized by elemental analysis,IR,UV-Vis,AAS,DSC,XRD and polarizing optical microscopy(POM) with a heating stage.Results show that the complexes changed into liquid crystal phase upon heated to temperatures higher than their melting points,and the melting points Tm and isotropization temperature Ti of the complexes changed regularly with the increase of the carbon number in the terminal alkoxyl groups.There is a gradual increase in smectic phase length and a gradual decrease in nemetic phase length.The liquid crystalline phase temperature range became broader after complexation.
2010, 27(1): 43-47
Abstract:
Several resistive-type humidity sensors were prepared from copolymer of [2-(methacryloyloxy) ethyl]dimethyl butyl ammonium bromide(MEBA) and γ-methacryloxypropyl trimethoxy silane(KH570) and used as humidity-sensitive material,which were respectively doped with inorganic salt LiCl,CaCl2 or CaCl3.The effects of concentrations of polymer,type of doped inorganic salt,doping concentration of salt on humidity-sensitive properties of the humidity sensors were examined.The experimental results show that these humidity sensors exhibited high sensitivities(b=-0.043 8~-0.038 8) and good linearities(R=-0.994 8~-0.981 6) in a humidity range of 33%~95%RH.Increasing the concentration of polymer resulted in impedance,decrease but slower response.In addition,doping LiCl and CaCl2 caused the impedance decreases,while CaCl3 doping exhibited a different behavior.At an optimal doping concentration(1×10-2 mol/L) of LiCl,the sensor exhibits the best sensitivity(b=-0.044 6) and the shortest desorption time(20 s).
Several resistive-type humidity sensors were prepared from copolymer of [2-(methacryloyloxy) ethyl]dimethyl butyl ammonium bromide(MEBA) and γ-methacryloxypropyl trimethoxy silane(KH570) and used as humidity-sensitive material,which were respectively doped with inorganic salt LiCl,CaCl2 or CaCl3.The effects of concentrations of polymer,type of doped inorganic salt,doping concentration of salt on humidity-sensitive properties of the humidity sensors were examined.The experimental results show that these humidity sensors exhibited high sensitivities(b=-0.043 8~-0.038 8) and good linearities(R=-0.994 8~-0.981 6) in a humidity range of 33%~95%RH.Increasing the concentration of polymer resulted in impedance,decrease but slower response.In addition,doping LiCl and CaCl2 caused the impedance decreases,while CaCl3 doping exhibited a different behavior.At an optimal doping concentration(1×10-2 mol/L) of LiCl,the sensor exhibits the best sensitivity(b=-0.044 6) and the shortest desorption time(20 s).
2010, 27(1): 48-52
Abstract:
2,4-Dimethyl-3-(3-methoxy-3-oxopropyl)-5-benzylcarboxylate-1H-pyrrole(2) and 2,4-dimethyl-3-methoxymethyl-5-benzylcarboxylate-1H-pyrrole(3) were synthesized from benzyl ethylacetate(4) via the Knorr condensation reaction.In the ether solution of bromine,pyrrole(2) was converted to the corresponding dipyrromethane(7) through self-condensation,while no reaction happened to pyrrole(3).Under the 2 mol/L Pb(OAC)4 oxidative condition,when it was twice the concentration of pyrrole(3),at 80℃,pyrrole(3) was completely consumed.After the subsequent refluxing in the methanol solution of hydrochloride acid,a novel 2-methoxymethyl-3-methylcarboxylate-4-methyl-5-benzylcarboxylate-1H-pyrrole(1) was synthesized in a yield of 82%.Pyrrole(1),pyrrole(2),pyrrole(3) and dipyrrolemethane(7) were characterized through NMR,elemental analysis,MS and IR.The construction of pyrrole(1) will be helpful for the further study of the structure-functionality relationship of pyrrole derivatives.
2,4-Dimethyl-3-(3-methoxy-3-oxopropyl)-5-benzylcarboxylate-1H-pyrrole(2) and 2,4-dimethyl-3-methoxymethyl-5-benzylcarboxylate-1H-pyrrole(3) were synthesized from benzyl ethylacetate(4) via the Knorr condensation reaction.In the ether solution of bromine,pyrrole(2) was converted to the corresponding dipyrromethane(7) through self-condensation,while no reaction happened to pyrrole(3).Under the 2 mol/L Pb(OAC)4 oxidative condition,when it was twice the concentration of pyrrole(3),at 80℃,pyrrole(3) was completely consumed.After the subsequent refluxing in the methanol solution of hydrochloride acid,a novel 2-methoxymethyl-3-methylcarboxylate-4-methyl-5-benzylcarboxylate-1H-pyrrole(1) was synthesized in a yield of 82%.Pyrrole(1),pyrrole(2),pyrrole(3) and dipyrrolemethane(7) were characterized through NMR,elemental analysis,MS and IR.The construction of pyrrole(1) will be helpful for the further study of the structure-functionality relationship of pyrrole derivatives.
2010, 27(1): 53-57
Abstract:
A series of pyrimido[1,2-a] benzimidazoles derivatives were synthesized by the reaction of 2-aminobenzimidazole with an aldehyde in the presence of malononitrile under microwave irradiation or classical heating conditions in water without any catalyst.The results show the optimal conditions of the reaction are as follows: the molar ratio of three components(malononitrile/aldehyde/2-aminobenzimidazole) is 1.1 and the microwave irradiation time is 6~8 min with the power of 400 W.The total yield of 1,4-dihydropyrimido[1,2-a]benzimidazole was above 85%.The reaction rate was increased by 70 times against ordinary heating.Their optical characteristics were tested by fluorescence spectroscopy.Peaks ranging from 480 nm to 550 nm are observed in their fluorescence emission spectra.
A series of pyrimido[1,2-a] benzimidazoles derivatives were synthesized by the reaction of 2-aminobenzimidazole with an aldehyde in the presence of malononitrile under microwave irradiation or classical heating conditions in water without any catalyst.The results show the optimal conditions of the reaction are as follows: the molar ratio of three components(malononitrile/aldehyde/2-aminobenzimidazole) is 1.1 and the microwave irradiation time is 6~8 min with the power of 400 W.The total yield of 1,4-dihydropyrimido[1,2-a]benzimidazole was above 85%.The reaction rate was increased by 70 times against ordinary heating.Their optical characteristics were tested by fluorescence spectroscopy.Peaks ranging from 480 nm to 550 nm are observed in their fluorescence emission spectra.
2010, 27(1): 58-62
Abstract:
A novel substituent styryl pyridinium tetraphenylborate,4-N,N-dimethylamino-4'-N'-9-methano-anthracene-stilbazolium tetraphenylborate,was synthesized and characterized by means of IR,1H NMR,13C NMR,MS-EI and X-ray single-crystal diffraction.The compound crystallized in the monoclinic space group P21/c with a=1.255 7(1) nm,b=1.539(1) nm,c=2.220 2(8)nm,β=101.099(1)°,and V=4.210 5(4)nm3,Z=4,Dc=1.159 g/cm3.The nonlinear optical properties of the compound were investigated by virtue of 1 064 nm nanosecond laser beam,and the results show that the novel pyridinium salt has a two photon absorption(TPA) coefficient of β=0.028 cm/GW,a TPA cross-section of σ=8.68×10-48 cm4·s·photon-1.
A novel substituent styryl pyridinium tetraphenylborate,4-N,N-dimethylamino-4'-N'-9-methano-anthracene-stilbazolium tetraphenylborate,was synthesized and characterized by means of IR,1H NMR,13C NMR,MS-EI and X-ray single-crystal diffraction.The compound crystallized in the monoclinic space group P21/c with a=1.255 7(1) nm,b=1.539(1) nm,c=2.220 2(8)nm,β=101.099(1)°,and V=4.210 5(4)nm3,Z=4,Dc=1.159 g/cm3.The nonlinear optical properties of the compound were investigated by virtue of 1 064 nm nanosecond laser beam,and the results show that the novel pyridinium salt has a two photon absorption(TPA) coefficient of β=0.028 cm/GW,a TPA cross-section of σ=8.68×10-48 cm4·s·photon-1.
2010, 27(1): 63-68
Abstract:
Attapulgite（Att） was used as the matrix of SnO2-TiO2 hybrid oxide to synthesize a novel kind of composite photocatalyst（Att-SnO2-TiO2） by depositing SnO2-TiO2 hybrid oxides on the surface of Att via an in stiu sol-gel technique.The obtained products were characterized by means of X-ray diffraction（XRD）,BET surface area and transmission electron microscope（TEM）.Experimental results show that the surface of attapulgite was evenly covered by SnO2-TiO2 nanocomposites with particle size around 10 nm.The modification of attapulgite by loading these composites resulted an improvement of its surface morphology while retaining its high surface area.Photocatalytic removal of methyl orange under ultraviolet radiation was studied in the presence of Att composites.Results show that the Att composite photocatalysts presented preferable photocatalytic property,and the photoactivity of the composite photocatalyst decreased in a sequence of Att-SnO2-TiO2 >Att-SnO2 >Att-TiO2.The Att-SnO2-TiO2 exhibited excellent activity and the decomposition rate of methyl orange was up to 99% within 30 min when the Att-SnO2-TiO2 powder was used as the photocatalyst.The repeated use of the composite photocatalyst was also confirmed.
Attapulgite（Att） was used as the matrix of SnO2-TiO2 hybrid oxide to synthesize a novel kind of composite photocatalyst（Att-SnO2-TiO2） by depositing SnO2-TiO2 hybrid oxides on the surface of Att via an in stiu sol-gel technique.The obtained products were characterized by means of X-ray diffraction（XRD）,BET surface area and transmission electron microscope（TEM）.Experimental results show that the surface of attapulgite was evenly covered by SnO2-TiO2 nanocomposites with particle size around 10 nm.The modification of attapulgite by loading these composites resulted an improvement of its surface morphology while retaining its high surface area.Photocatalytic removal of methyl orange under ultraviolet radiation was studied in the presence of Att composites.Results show that the Att composite photocatalysts presented preferable photocatalytic property,and the photoactivity of the composite photocatalyst decreased in a sequence of Att-SnO2-TiO2 >Att-SnO2 >Att-TiO2.The Att-SnO2-TiO2 exhibited excellent activity and the decomposition rate of methyl orange was up to 99% within 30 min when the Att-SnO2-TiO2 powder was used as the photocatalyst.The repeated use of the composite photocatalyst was also confirmed.
2010, 27(1): 69-73
Abstract:
The conversions and selectivities of the oxidation of tetralin to α-tetralone in acetic acid with H2O2 as oxidant over transition metals(Fe,Co,Ni,Ce,Cu,La,Zr and Cr) loaded MCM-41 were compared.An excellent conversion of tetralin and high selectivity of α-tetralone were also obtained when Co/MCM-41 was used.The effects of reaction temperature,reaction time and catalyst concentration on the catalyst performance were examined in order to optimize the conversion of tetralin and selectivity of α-tetralone.A selectivity of 70.3% of tetralin to α-tetralone was obtained at 94.7% conversion of tetralin under the optimum reaction condition:m(tetralin):m(catalyst) =12.5:1;reaction temperature=383 K,reaction time=8 h.Co/MCM-41 act as a solid heterogeneous catalyst in the reaction system and it can be recycled three times without losing its activity to a great extent.
The conversions and selectivities of the oxidation of tetralin to α-tetralone in acetic acid with H2O2 as oxidant over transition metals(Fe,Co,Ni,Ce,Cu,La,Zr and Cr) loaded MCM-41 were compared.An excellent conversion of tetralin and high selectivity of α-tetralone were also obtained when Co/MCM-41 was used.The effects of reaction temperature,reaction time and catalyst concentration on the catalyst performance were examined in order to optimize the conversion of tetralin and selectivity of α-tetralone.A selectivity of 70.3% of tetralin to α-tetralone was obtained at 94.7% conversion of tetralin under the optimum reaction condition:m(tetralin):m(catalyst) =12.5:1;reaction temperature=383 K,reaction time=8 h.Co/MCM-41 act as a solid heterogeneous catalyst in the reaction system and it can be recycled three times without losing its activity to a great extent.
2010, 27(1): 74-77
Abstract:
SrO-TiO2 films on glass slides were prepared via sol-gel process and dip-coating technique using tetrabutyl titanate as a precursor.The structure of SrO-TiO2 powder was characterized by XRD and IR.The transmission rates of the films were measured by UV-Vis spectroscopy.The water contact angles of the films were also measured.The results obtained are as follows:the grain size of TiO2 in the SrO-TiO2 powder became smaller when a proper amount of Sr2+ was introduced.The hydroxyl content on the surface of the thin film and its stability have been increased,which are beneficial to the super-hydrophilicity of the film.Under the irradiation of either ultraviolet light for an hour or natural light for five hours,the contact angles of SrO-TiO2 thin films with 1.0%(molar percentage) Sr2+ doping amount were close to 0°,and water can easily spread over the surfaces of the films suggesting good hydrophilicities of the as-prepared films.
SrO-TiO2 films on glass slides were prepared via sol-gel process and dip-coating technique using tetrabutyl titanate as a precursor.The structure of SrO-TiO2 powder was characterized by XRD and IR.The transmission rates of the films were measured by UV-Vis spectroscopy.The water contact angles of the films were also measured.The results obtained are as follows:the grain size of TiO2 in the SrO-TiO2 powder became smaller when a proper amount of Sr2+ was introduced.The hydroxyl content on the surface of the thin film and its stability have been increased,which are beneficial to the super-hydrophilicity of the film.Under the irradiation of either ultraviolet light for an hour or natural light for five hours,the contact angles of SrO-TiO2 thin films with 1.0%(molar percentage) Sr2+ doping amount were close to 0°,and water can easily spread over the surfaces of the films suggesting good hydrophilicities of the as-prepared films.
2010, 27(1): 78-81
Abstract:
CoFe2O4 nanocrystals were prepared by means of a low temperature refluxing method with CTAB as templet,Fe(NO3)3·9H2O and Co(NO3)2·6H2O as precursors,NaOH as precipitator.The as-prepared products were characterized by X-ray diffraction,transmission electron microscopy,infrared and Raman spectroscopies.The room temperature magnetic properties were determined by means of vibrating sample magnetometer.The results show that CoFe2O4 has a single-phase spinel structure.The average particle size was in a range of 15~20 nm.CoFe2O4 exhibited a clearly magnetic hysteretic behavior under applied magnetic field at room temperature.The values of variation of saturation magnetization(MS) and coercivity(HC) were 36.5 A·m2/kg and 5.89×104 A/m,respectively.
CoFe2O4 nanocrystals were prepared by means of a low temperature refluxing method with CTAB as templet,Fe(NO3)3·9H2O and Co(NO3)2·6H2O as precursors,NaOH as precipitator.The as-prepared products were characterized by X-ray diffraction,transmission electron microscopy,infrared and Raman spectroscopies.The room temperature magnetic properties were determined by means of vibrating sample magnetometer.The results show that CoFe2O4 has a single-phase spinel structure.The average particle size was in a range of 15~20 nm.CoFe2O4 exhibited a clearly magnetic hysteretic behavior under applied magnetic field at room temperature.The values of variation of saturation magnetization(MS) and coercivity(HC) were 36.5 A·m2/kg and 5.89×104 A/m,respectively.
2010, 27(1): 82-86
Abstract:
The inclusion complex of 1-methylcyclopropene(1-MCP) encapsulated by α-cyclodextrin(α-CD) was synthesized by inletting 1-MCP gas into the α-cyclodextrin saturated solution.Raman spectroscopy,X-ray powder diffraction(XRD),gas chromatography/mass spectrometry(GC-MS) and nuclear magnetic resonance spectrometry(NMR) methods were used to verify the existence of 1-MCP/α-CD inclusion complex.A rapid determination method was proposed for measuring the content of 1-MCP in the inclusion complex,which was about 3.6%.Moreover,the formation mechanism of the inclusion complex was also discussed.The inclusion ratio was suggested to be a 1:1 ratio of 1-MCP and α-CD complexation.
The inclusion complex of 1-methylcyclopropene(1-MCP) encapsulated by α-cyclodextrin(α-CD) was synthesized by inletting 1-MCP gas into the α-cyclodextrin saturated solution.Raman spectroscopy,X-ray powder diffraction(XRD),gas chromatography/mass spectrometry(GC-MS) and nuclear magnetic resonance spectrometry(NMR) methods were used to verify the existence of 1-MCP/α-CD inclusion complex.A rapid determination method was proposed for measuring the content of 1-MCP in the inclusion complex,which was about 3.6%.Moreover,the formation mechanism of the inclusion complex was also discussed.The inclusion ratio was suggested to be a 1:1 ratio of 1-MCP and α-CD complexation.
2010, 27(1): 87-91
Abstract:
Carboxymethyl chitosan magnetic nanoparticles(CMCS-OA-Fe3O4 NPs) were prepared by a two-step method,which involved,synthesizing nanosized Fe3O4 in the presence of oleic acid(OA-Fe3O4 NPs) and directly coating the OA-Fe3O4 NPs with carboxymethyl chitosan in aqueous solution.The prepared CMCS-OA-Fe3O4 NPs were characterized with transmission electron microscopy(TEM),vibrating sample magnetometer(VSM),Fourier transform infrared spectrometry(FT-IR) and simultaneous thermal analyzer(STA),respectively.The CMCS-OA-Fe3O4 NPs were found to be regularly spherical with carboxyl on their surface,with a diameter of roughly 10 nm.The CMCS-OA-Fe3O4 NPs exhibited good paramagnetism and stability.The drug loading and the sustained-release property of the CMCS-OA-Fe3O4 NPs for adriamycin(ADM) in phosphate buffer solution(PBS,pH=7.4) were studied.High drug loading(91.8 mg/g) of CMCS-OA-Fe3O4 NPs and obvious sustained-release effect in vitro for ADM were reached.The results indicate that CMCS-OA-Fe3O4 NPs may be used as a magnetic-targeted nano drug carrier for the treatment of tumour.
Carboxymethyl chitosan magnetic nanoparticles(CMCS-OA-Fe3O4 NPs) were prepared by a two-step method,which involved,synthesizing nanosized Fe3O4 in the presence of oleic acid(OA-Fe3O4 NPs) and directly coating the OA-Fe3O4 NPs with carboxymethyl chitosan in aqueous solution.The prepared CMCS-OA-Fe3O4 NPs were characterized with transmission electron microscopy(TEM),vibrating sample magnetometer(VSM),Fourier transform infrared spectrometry(FT-IR) and simultaneous thermal analyzer(STA),respectively.The CMCS-OA-Fe3O4 NPs were found to be regularly spherical with carboxyl on their surface,with a diameter of roughly 10 nm.The CMCS-OA-Fe3O4 NPs exhibited good paramagnetism and stability.The drug loading and the sustained-release property of the CMCS-OA-Fe3O4 NPs for adriamycin(ADM) in phosphate buffer solution(PBS,pH=7.4) were studied.High drug loading(91.8 mg/g) of CMCS-OA-Fe3O4 NPs and obvious sustained-release effect in vitro for ADM were reached.The results indicate that CMCS-OA-Fe3O4 NPs may be used as a magnetic-targeted nano drug carrier for the treatment of tumour.
2010, 27(1): 92-95
Abstract:
Sheet-like ZnFe2O4 was prepared by means of a modified citrate precursor method with Fe(NO3)3·9H2O and Zn(NO3)2·6H2O as starting materials.Polyaniline(PANI)/ZnFe2O4 nanocomposite was obtained by the in-situ polymerization of aniline in the presence of ZnFe2O4.The as-prepared samples were characterized by means of X-ray diffraction,scanning electron microscopy,transmission electron microscopy,infrared and fluorescence spectroscopies.The results show that PANI was deposited on the surface of sheet-like ZnFe2O4.X-ray diffraction and infrared spectra further confirmed the formation of PANI/ZnFe2O4 nanocomposite.Introducing ZnFe2O4 into polymer matrix enhanced the fluorescent emission intensity and thermal stability.
Sheet-like ZnFe2O4 was prepared by means of a modified citrate precursor method with Fe(NO3)3·9H2O and Zn(NO3)2·6H2O as starting materials.Polyaniline(PANI)/ZnFe2O4 nanocomposite was obtained by the in-situ polymerization of aniline in the presence of ZnFe2O4.The as-prepared samples were characterized by means of X-ray diffraction,scanning electron microscopy,transmission electron microscopy,infrared and fluorescence spectroscopies.The results show that PANI was deposited on the surface of sheet-like ZnFe2O4.X-ray diffraction and infrared spectra further confirmed the formation of PANI/ZnFe2O4 nanocomposite.Introducing ZnFe2O4 into polymer matrix enhanced the fluorescent emission intensity and thermal stability.
2010, 27(1): 96-101
Abstract:
Polyvinyl alcohol(PEG) and polyethylenamine(PEI) have been widely applied in the techno-logical fields related to biochemistry.In this work,the interactions of amylase with PEG and tetraethylene pentamine(TEPA) were investigatied by fluorescence and UV absorption spectra.The results show both the inner fluorescence of amylase and the hydrophobicity of the microenvironment of tyrosine residues are enhanced in the presence of PEG.The quenching mechanism of inner fluorescence of amylase by TEPA is dynamic,but also exhibits a feature of static quenching.The polarity of microenvironment of tryptophan residues of increases amylase due to interaction with TEPA.In the range of this investigation,the binding constant of interaction of PEG with amylase reaches the highest value at 40℃,the value of quenching constant of binding between TEPA and amylase becomes the maximum at 30℃.The interaction of amylse with PEG or TEPA involves hydrophobic and electrostatic interactions.
Polyvinyl alcohol(PEG) and polyethylenamine(PEI) have been widely applied in the techno-logical fields related to biochemistry.In this work,the interactions of amylase with PEG and tetraethylene pentamine(TEPA) were investigatied by fluorescence and UV absorption spectra.The results show both the inner fluorescence of amylase and the hydrophobicity of the microenvironment of tyrosine residues are enhanced in the presence of PEG.The quenching mechanism of inner fluorescence of amylase by TEPA is dynamic,but also exhibits a feature of static quenching.The polarity of microenvironment of tryptophan residues of increases amylase due to interaction with TEPA.In the range of this investigation,the binding constant of interaction of PEG with amylase reaches the highest value at 40℃,the value of quenching constant of binding between TEPA and amylase becomes the maximum at 30℃.The interaction of amylse with PEG or TEPA involves hydrophobic and electrostatic interactions.
2010, 27(1): 102-106
Abstract:
This paper describes the use of surface initiated reversible addition-fragmentation chain transfer(RAFT) polymerization to graft thin molecularly imprinted polymer(MIP) films on silica gel particles(MIP-Silica).The grafted imprinted polymer film was characterized by elemental analysis and nitrogen adsorption analysis.The MIP-silica prepared in this study improved mass-transfer properties compared with MIPs prepared by conventional bulk polymerization.In addition,the MIP-Silica can be used as the sorbent in solid-phase extraction to determine the theophylline in blood serum with satisfactory recovery.Furthermore,the MIP-silica can also be applied in HPLC and capillary electrochromatography.
This paper describes the use of surface initiated reversible addition-fragmentation chain transfer(RAFT) polymerization to graft thin molecularly imprinted polymer(MIP) films on silica gel particles(MIP-Silica).The grafted imprinted polymer film was characterized by elemental analysis and nitrogen adsorption analysis.The MIP-silica prepared in this study improved mass-transfer properties compared with MIPs prepared by conventional bulk polymerization.In addition,the MIP-Silica can be used as the sorbent in solid-phase extraction to determine the theophylline in blood serum with satisfactory recovery.Furthermore,the MIP-silica can also be applied in HPLC and capillary electrochromatography.
2010, 27(1): 107-111
Abstract:
Molecularly imprinted membranes were prepared with malachite green as template molecule,acrylamide as functional monomer and N,N'-methylenebisacrylamide as cross-linker by means of surface molecularly imprinted technique(MIT) in the presence of 0.45 μm hydrophilic cellulose ester filter membranes,and the selective permeation characterization of the template molecule and its analogues through the membranes was studied via the competitive permeation experiment.Molecularly imprinted membranes showed a permeation amount of 0.118 mg/cm2 for malachite green after permeation for 13 h,and corresponding permeation amounts of only 0.064,0.057 and 0.044 mg/cm2 for methyl violet,cresol red and bromothymol in single permeation experiments.The permeation amount for malachite green didn not show significant reduction in the competitive permeation experiment,while that for its analogues methyl violet obviously decreased.The experiment results show that the molecularly imprinted membrane exhibited the higher permeation selectivity for the template malachite green,and the preferential permeation properties for malachite green in the presence of its analogues methyl violet.
Molecularly imprinted membranes were prepared with malachite green as template molecule,acrylamide as functional monomer and N,N'-methylenebisacrylamide as cross-linker by means of surface molecularly imprinted technique(MIT) in the presence of 0.45 μm hydrophilic cellulose ester filter membranes,and the selective permeation characterization of the template molecule and its analogues through the membranes was studied via the competitive permeation experiment.Molecularly imprinted membranes showed a permeation amount of 0.118 mg/cm2 for malachite green after permeation for 13 h,and corresponding permeation amounts of only 0.064,0.057 and 0.044 mg/cm2 for methyl violet,cresol red and bromothymol in single permeation experiments.The permeation amount for malachite green didn not show significant reduction in the competitive permeation experiment,while that for its analogues methyl violet obviously decreased.The experiment results show that the molecularly imprinted membrane exhibited the higher permeation selectivity for the template malachite green,and the preferential permeation properties for malachite green in the presence of its analogues methyl violet.
2010, 27(1): 112-116
Abstract:
Adsorption/desorption characteristics of methyl parathion and carbaryl on the surfaces of montmorillonite,kaolinite and goethite were investigated.The results show that the isotherm adsorption of methyl parathion or carbaryl on clay minerals fitted Langmuir equation very well.Montmorillonite had a greater adsorption capacity for the two pesticides than goethite and kaolinite.Kinetics of methyl parathion or carbaryl adsorption could be described by first-order equation,Elovich equation and two-constant equation.Elovich equation was the optimum model for its adsorption kinetics,the coefficients(R2) of which ranged between 0.93 and 0.98,indicating that the adsorption was a non-homogeneous diffusion process.The binding strength of methyl parathion and carbaryl on the minerals followed the sequence of montmorillonite >kaolinite >goethite.
Adsorption/desorption characteristics of methyl parathion and carbaryl on the surfaces of montmorillonite,kaolinite and goethite were investigated.The results show that the isotherm adsorption of methyl parathion or carbaryl on clay minerals fitted Langmuir equation very well.Montmorillonite had a greater adsorption capacity for the two pesticides than goethite and kaolinite.Kinetics of methyl parathion or carbaryl adsorption could be described by first-order equation,Elovich equation and two-constant equation.Elovich equation was the optimum model for its adsorption kinetics,the coefficients(R2) of which ranged between 0.93 and 0.98,indicating that the adsorption was a non-homogeneous diffusion process.The binding strength of methyl parathion and carbaryl on the minerals followed the sequence of montmorillonite >kaolinite >goethite.
2010, 27(1): 117-121
Abstract:
The physicochemical properties of Rhizoma Pinelliae starches from four different regions were investigated.The contents of amylose in different Rhizoma Pinelliae starches ranged from 18.60% to 23.91%.The shapes of Rhizoma Pinelliae starch granules varied from round to oval or hemisphere with the sizes between 2~20 μm.All Rhizoma Pinelliae starches show the typical C-type crystal form but with crystallinity in the range of 15.0% to 37.9%.The transition temperatures(TO,TP and TC) and enthalpies of gelatinization were determined via differential scanning calorimetry(DSC).TO,TP and TC varied from 71.58 to 77.75,83.03 to 83.84,and 89.41 to 90.99℃,respectively.The enthalpy of gelatinization ranged from 4.316 J/g to 5.809 J/g.According to the viscosity measurements with a rapid visco analyser(RVA),the peak visc,hot visc,cold visc,breakdown and setbake of these Rhizoma Pinelliae starches varied from 149.5 to 226.2,97.7 to 127.2,141.8 to 194.3,50.4 to 99.0,and 44.2 to 67.2 RVU,respectively.The pasting temperature and peak time for these starches were 77.8 to 79.9℃ and 8.3 to 8.7 min,respectively.
The physicochemical properties of Rhizoma Pinelliae starches from four different regions were investigated.The contents of amylose in different Rhizoma Pinelliae starches ranged from 18.60% to 23.91%.The shapes of Rhizoma Pinelliae starch granules varied from round to oval or hemisphere with the sizes between 2~20 μm.All Rhizoma Pinelliae starches show the typical C-type crystal form but with crystallinity in the range of 15.0% to 37.9%.The transition temperatures(TO,TP and TC) and enthalpies of gelatinization were determined via differential scanning calorimetry(DSC).TO,TP and TC varied from 71.58 to 77.75,83.03 to 83.84,and 89.41 to 90.99℃,respectively.The enthalpy of gelatinization ranged from 4.316 J/g to 5.809 J/g.According to the viscosity measurements with a rapid visco analyser(RVA),the peak visc,hot visc,cold visc,breakdown and setbake of these Rhizoma Pinelliae starches varied from 149.5 to 226.2,97.7 to 127.2,141.8 to 194.3,50.4 to 99.0,and 44.2 to 67.2 RVU,respectively.The pasting temperature and peak time for these starches were 77.8 to 79.9℃ and 8.3 to 8.7 min,respectively.
2010, 27(1): 122-124
Abstract:
2-Mercapto-5-methoxyimidazo[4,5-b]pyridine was obtained with 2,6-dichloropyridine as the starting material in five steps,including methoxylation,nitration,amination,reduction and cyclization.The overall yield of 2-mercapto-5-methoxyimidazo[4,5-b]pyridine was up to 45.7%.The differences between reaction conditions and yields of nitration of 2-chloro-6-methoxypyridine and 2,6-dichloropyridine were discussed,the effects of the amounts of hydrazine hydrate and the amounts of sodium hydroxide on the yield of the target product were also discussed.The structure of the target product was identified by 1H NMR,MS and IR.
2-Mercapto-5-methoxyimidazo[4,5-b]pyridine was obtained with 2,6-dichloropyridine as the starting material in five steps,including methoxylation,nitration,amination,reduction and cyclization.The overall yield of 2-mercapto-5-methoxyimidazo[4,5-b]pyridine was up to 45.7%.The differences between reaction conditions and yields of nitration of 2-chloro-6-methoxypyridine and 2,6-dichloropyridine were discussed,the effects of the amounts of hydrazine hydrate and the amounts of sodium hydroxide on the yield of the target product were also discussed.The structure of the target product was identified by 1H NMR,MS and IR.
