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2006 Volume 23 Issue 3
The Influence of Quaternary Ammonium Salt on the Dehydration Properties of Blend Polyimide Membranes
2006, 23(3): 233-237
Abstract:
The hydrophilicities of a series of blend modified polyimide membranes and the apparent viscosities of mixed solutions were investigated.The results show that both membrane hydrophilicities and solution viscosities were increased with increasing the quantity of quaternary ammonium salt(BAN) in the solution,and a viscosity enhancement phenomenon was observed.The dehydration properties of the blend hollow fiber membranes were tested,it was found that the increases of the pressure and the sweeping flux favored the dehydration performances of the blend membranes.Although the properties of membranes are not always improved with increasing the membrane hydrophilicity,when the quantity of quaternary ammonium salt(BAN) is appropriately increased,the dehydration properties of blend hollow fiber membranes would be improved effectively.
The hydrophilicities of a series of blend modified polyimide membranes and the apparent viscosities of mixed solutions were investigated.The results show that both membrane hydrophilicities and solution viscosities were increased with increasing the quantity of quaternary ammonium salt(BAN) in the solution,and a viscosity enhancement phenomenon was observed.The dehydration properties of the blend hollow fiber membranes were tested,it was found that the increases of the pressure and the sweeping flux favored the dehydration performances of the blend membranes.Although the properties of membranes are not always improved with increasing the membrane hydrophilicity,when the quantity of quaternary ammonium salt(BAN) is appropriately increased,the dehydration properties of blend hollow fiber membranes would be improved effectively.
2006, 23(3): 238-241
Abstract:
Two cyclotriphosphazenes containing carbazole chromophores were prepared via a post-azo-coupling reaction.These two molecules were characterized by using 1H NMR,31P NMR,IR,UV-Vis and DSC.The single resonance in the 31P NMR spectra of compounds 3~5 show that the chloro-groups on the cyclotriphos-phazene was completely substituted by the carbazolyl group.Results of 1H NMR,IR and UV-Vis demonstrate that the azo group was linked to the 3-position of the carbazole ring with different contents.DSC measurement results indicate that these molecules are amorphous in nature and the glass transition temperature increases with increasing the content of chromophores.
Two cyclotriphosphazenes containing carbazole chromophores were prepared via a post-azo-coupling reaction.These two molecules were characterized by using 1H NMR,31P NMR,IR,UV-Vis and DSC.The single resonance in the 31P NMR spectra of compounds 3~5 show that the chloro-groups on the cyclotriphos-phazene was completely substituted by the carbazolyl group.Results of 1H NMR,IR and UV-Vis demonstrate that the azo group was linked to the 3-position of the carbazole ring with different contents.DSC measurement results indicate that these molecules are amorphous in nature and the glass transition temperature increases with increasing the content of chromophores.
Synthesis and Bioactivity of β-(2-Methoxyl carbonyl-1-methyl)-ethyl-(β'-D-acetyl-pyranosyl)-Thiourea
2006, 23(3): 242-245
Abstract:
Five new N-glucosylated compounds were synthesized by condensation of acetyl glycosyl isothiocyanate with methyl β-aminobutyric acid ester in benzene under reflux.The structures were confirmed by element analysis and 1H NMR.The elicitation activities on the natural defense of plants were tested.
Five new N-glucosylated compounds were synthesized by condensation of acetyl glycosyl isothiocyanate with methyl β-aminobutyric acid ester in benzene under reflux.The structures were confirmed by element analysis and 1H NMR.The elicitation activities on the natural defense of plants were tested.
2006, 23(3): 246-250
Abstract:
Cobalt phthalocyanine/SnO2 nanocomposite was synthesized in-situ through the annulation of dicyanobenzene on the surface of SnO2 nanoparticles with Co(Ⅱ) as template.The prepared products were characterized by means of XRD,DTA,UV-Vis and FT-IR methods.The photocatalytic activity of materials under visible light was also discussed.The experimental results indicate that Cobalt phthalocyanine and SnO2 are indeed synthesized with the in-situ method.Under the visible light irradiation,CoPc molecules are excited first and then the excited electrons are injected into the conduction band of SnO2 through the Co-O chemical bond.Superoxide radicals are formed by reaction with O2,the degradative rate of Rodanming B is up to 87.1% within 150 min.The degradative rate is very stable during circulating degradation for 10 times.
Cobalt phthalocyanine/SnO2 nanocomposite was synthesized in-situ through the annulation of dicyanobenzene on the surface of SnO2 nanoparticles with Co(Ⅱ) as template.The prepared products were characterized by means of XRD,DTA,UV-Vis and FT-IR methods.The photocatalytic activity of materials under visible light was also discussed.The experimental results indicate that Cobalt phthalocyanine and SnO2 are indeed synthesized with the in-situ method.Under the visible light irradiation,CoPc molecules are excited first and then the excited electrons are injected into the conduction band of SnO2 through the Co-O chemical bond.Superoxide radicals are formed by reaction with O2,the degradative rate of Rodanming B is up to 87.1% within 150 min.The degradative rate is very stable during circulating degradation for 10 times.
2006, 23(3): 251-255
Abstract:
The electrochemical behavior of Ti/nano-TiO2 film electrode was investigated by means of Electrochemical Impedance Spectra(EIS) in two different solutions,relevant equivalent circuit and electro- chemical kinetic parameters were also presented.The results indicate that the electrode impedance is consisted of film resistance Rf,electrochemical polarization impedance Rct and Warburg impedance Zw in the potential range of film reaction.The Rf values are 125 Ω·cm2 and 7 450 Ω·cm2 respectively in 1 mol/L H2SO4 and 0.5 mol/L HOAc-NaOAc buffer electrolyte containing ethanol.There is dispersion effect due to the roughness and inhomogeneity of nano-TiO2 film surface.
The electrochemical behavior of Ti/nano-TiO2 film electrode was investigated by means of Electrochemical Impedance Spectra(EIS) in two different solutions,relevant equivalent circuit and electro- chemical kinetic parameters were also presented.The results indicate that the electrode impedance is consisted of film resistance Rf,electrochemical polarization impedance Rct and Warburg impedance Zw in the potential range of film reaction.The Rf values are 125 Ω·cm2 and 7 450 Ω·cm2 respectively in 1 mol/L H2SO4 and 0.5 mol/L HOAc-NaOAc buffer electrolyte containing ethanol.There is dispersion effect due to the roughness and inhomogeneity of nano-TiO2 film surface.
2006, 23(3): 256-259
Abstract:
A series of 1-aryloxy-4-chloro phthalazines(3) was prepared in DMF with a high yield from the condensation reaction of substituted phenols with 1,4-dichloro phthalazine,which was obtained from the chlorination of 1,4-phthalazin-dione by PCl5/POCl3.These novel compounds were characterized by means of 1H NMR and elemental analyses and some of them were confirmed by IR.Preliminary bioassay indicates that some of above compounds show a certain herbicidal activity against Brassica napus and Echinochloa Crusgalli at 0.01 g/L.
A series of 1-aryloxy-4-chloro phthalazines(3) was prepared in DMF with a high yield from the condensation reaction of substituted phenols with 1,4-dichloro phthalazine,which was obtained from the chlorination of 1,4-phthalazin-dione by PCl5/POCl3.These novel compounds were characterized by means of 1H NMR and elemental analyses and some of them were confirmed by IR.Preliminary bioassay indicates that some of above compounds show a certain herbicidal activity against Brassica napus and Echinochloa Crusgalli at 0.01 g/L.
2006, 23(3): 260-263
Abstract:
To understand the reaction of tetrakis hydroxymethyl phosphonium chloride(THPC) with collagen protein,the interactions of THPC with polycaprolactam,poly vinyl alcohol or ethylenediamine which were used as the model substances of amido,hydroxy and amino groups of collagen protein were examed.It was found that tetrakis hydroxymethyl phosphonium mainly linked with amino groups of collagen,while less with hydroxy groups or amido groups at a mole ratio of n(P):n(N)=1:2.2.The combination capacities of tetrakis hydroxymethyl phosphonium chloride with hydroxy groups and amido groups changed with pH,it reached the maximum at pH=8.0.The 31P NMR spectra indicate that trihydroxymethyl phosphonium hydroxide(THPOH) or trihydroxymethyl phosphine(THP) was an effective crosslinking agent and THPO was not reactive to collagen protein.
To understand the reaction of tetrakis hydroxymethyl phosphonium chloride(THPC) with collagen protein,the interactions of THPC with polycaprolactam,poly vinyl alcohol or ethylenediamine which were used as the model substances of amido,hydroxy and amino groups of collagen protein were examed.It was found that tetrakis hydroxymethyl phosphonium mainly linked with amino groups of collagen,while less with hydroxy groups or amido groups at a mole ratio of n(P):n(N)=1:2.2.The combination capacities of tetrakis hydroxymethyl phosphonium chloride with hydroxy groups and amido groups changed with pH,it reached the maximum at pH=8.0.The 31P NMR spectra indicate that trihydroxymethyl phosphonium hydroxide(THPOH) or trihydroxymethyl phosphine(THP) was an effective crosslinking agent and THPO was not reactive to collagen protein.
2006, 23(3): 264-267
Abstract:
This paper focuses studies on the characteristics of electroless composite coating of Ni-P-TiO2 nanoparticles.The results of the experiment reveal that electroless composite coating consisting of nanoparticles not only has good mechanical property,but also possesses good cautery-resistant property.And photocatalytic property of the composite coating is as good as that of TiO2 nanometer powders.So the application of the coating consisting of TiO2 nanoparticles in environment technology would be promising.
This paper focuses studies on the characteristics of electroless composite coating of Ni-P-TiO2 nanoparticles.The results of the experiment reveal that electroless composite coating consisting of nanoparticles not only has good mechanical property,but also possesses good cautery-resistant property.And photocatalytic property of the composite coating is as good as that of TiO2 nanometer powders.So the application of the coating consisting of TiO2 nanoparticles in environment technology would be promising.
2006, 23(3): 268-272
Abstract:
The supported NiB/MgO amorphous alloy catalyst was prepared by powder electroless plating and applied in the catalytic hydrogenation of sulfolene to sulfolane.The XRD,ICP,HRTEM were used to characterize the as-prepared samples,the Ag loading and amount of KBH4 in the plating solution were changed to optimize the preparation of NiB/MgO catalyst.The characterizations of XRD and SAED revealed the amorphous structure of the sample,and the results of ICP showed that the load of Ag could improve the Ni loading,resulting in enhancing the catalytic activity.Moreover,the different amounts of KBH4 in the plating solution could not change the composition of NiB/MgO but has an affect on the load of NiB.
The supported NiB/MgO amorphous alloy catalyst was prepared by powder electroless plating and applied in the catalytic hydrogenation of sulfolene to sulfolane.The XRD,ICP,HRTEM were used to characterize the as-prepared samples,the Ag loading and amount of KBH4 in the plating solution were changed to optimize the preparation of NiB/MgO catalyst.The characterizations of XRD and SAED revealed the amorphous structure of the sample,and the results of ICP showed that the load of Ag could improve the Ni loading,resulting in enhancing the catalytic activity.Moreover,the different amounts of KBH4 in the plating solution could not change the composition of NiB/MgO but has an affect on the load of NiB.
2006, 23(3): 273-277
Abstract:
Bis(amino-triazole sulfurethers)(2a~2n) and the corresponding piperonal schiff's base derivatives(3a~3n) were synthesized via the condensation of amino-triazole thiols(1a~1n) with 1,2-dibromoenthane to obtain 2a~2n followed by the condensation of compounds 2a~2n with piperonal in acetic acid,respectively.The compounds were confirmed by IR,1H NMR,MS and elemental analysis.Among the new compounds synthesized,the sulfurether compounds(2c),(2m) exhibit strong inhibiting activity against Staphylococcus aureus,and compound 2g does against Proteus vulgaris in dosage of 1.0×10-4(mass fraction);the schiff's base compounds 3a~3j exhibit stronger inhibiting activity to Escherichia.coli,while they exhibit medium inhibiting activity to Staphylococcus aureus.
Bis(amino-triazole sulfurethers)(2a~2n) and the corresponding piperonal schiff's base derivatives(3a~3n) were synthesized via the condensation of amino-triazole thiols(1a~1n) with 1,2-dibromoenthane to obtain 2a~2n followed by the condensation of compounds 2a~2n with piperonal in acetic acid,respectively.The compounds were confirmed by IR,1H NMR,MS and elemental analysis.Among the new compounds synthesized,the sulfurether compounds(2c),(2m) exhibit strong inhibiting activity against Staphylococcus aureus,and compound 2g does against Proteus vulgaris in dosage of 1.0×10-4(mass fraction);the schiff's base compounds 3a~3j exhibit stronger inhibiting activity to Escherichia.coli,while they exhibit medium inhibiting activity to Staphylococcus aureus.
2006, 23(3): 278-282
Abstract:
Dendritic p-t-butylcalix[n] arene amide derivatives with terminal amino groups of the first and second generations were synthesized from the ammonolysis of ethyl calixylacetate with 1,6-diaminohexane and Michael addition of methyl acrylate.Their structures were confirmed by IR,1H NMR.The recognition properties of these amide derivatives for several kinds of metal ions were studied with UV-Vis spectroscopy.In the processes of recognition they showed a great affinity for soft Ag+ and UO22+ ions and formed 1:2 or 1:3 stoichiometric complexes.
Dendritic p-t-butylcalix[n] arene amide derivatives with terminal amino groups of the first and second generations were synthesized from the ammonolysis of ethyl calixylacetate with 1,6-diaminohexane and Michael addition of methyl acrylate.Their structures were confirmed by IR,1H NMR.The recognition properties of these amide derivatives for several kinds of metal ions were studied with UV-Vis spectroscopy.In the processes of recognition they showed a great affinity for soft Ag+ and UO22+ ions and formed 1:2 or 1:3 stoichiometric complexes.
2006, 23(3): 283-288
Abstract:
12 Benzisoquinolinone analogues were synthesized,which contained two chirality compounds with[α]57925=-59°(c=0.2,DMF)(3b) and[α]57925=-96°(c=0.1,THF)(8b);2(5)-nitro and 3(4)-chloro isomers were separated.Meanwhile,the mechanisms for nucleophilic substitution(SN2Ar) reaction on the aromatic rings were explored.The ultraviolet spectra and fluorescence emission spectra of the synthesized compounds were determined;the relative fluorescence quantum yield(Φf) was studied.The results show that the fluorescence efficiency,the Strokes shift and the molar absorption coefficient of the compounds are affected by conjugation and substituting groups.
12 Benzisoquinolinone analogues were synthesized,which contained two chirality compounds with[α]57925=-59°(c=0.2,DMF)(3b) and[α]57925=-96°(c=0.1,THF)(8b);2(5)-nitro and 3(4)-chloro isomers were separated.Meanwhile,the mechanisms for nucleophilic substitution(SN2Ar) reaction on the aromatic rings were explored.The ultraviolet spectra and fluorescence emission spectra of the synthesized compounds were determined;the relative fluorescence quantum yield(Φf) was studied.The results show that the fluorescence efficiency,the Strokes shift and the molar absorption coefficient of the compounds are affected by conjugation and substituting groups.
2006, 23(3): 289-293
Abstract:
A B-Anderson-type polyoxometalate[Co(2,2-'bipy)3]H-[Al(OH)6(Mo6O18)]·5H2O has been synthesized from AlCl3·H2O,Na2MoO4·2H2O,CoCl2·6H2O and 2,2'-bipydine and characterized by means of IR,UV spectra,thermogravimetric analysis and Xray diffraction.The X-ray crystallography indicates that the title compound crystallizes in a triclinic lattice,P1 space group,with a=1.216 0(2),b=1.221 5(2),c=1.780 0(4) nm,α=86.83(3)°,β=88.76(3)°, γ=89.82(3)°,V=2.639 4(9) nm3,Z=2,R1=0.079 4,wR2=0.176 6.Structural analysis reveals that the molecule of the title compound is composed of one[Co(2,2'-bipy)3]2+coordination cation,one H+ ion,two crystallographically independent "one-half" polyoxoanions[Al(OH)6(Mo6O18)]3- and five hydration water molecules.Under the participation of water and coordinated metal ions,the[Al(OH)6(Mo6O18)]3- polyoxoanions form a two-dimensional network structure by means of supramolecular interaction.The adjacent network structures interact with each other,generating a three-dimensional structure infinitely extended via supramolecular interaction.Thermogravimetric analysis elucidates that the process of weight loss of the title compound is divided into two stages and also reveals that the backbone of heteropolyoxoanion decomposes at 547.5℃.
A B-Anderson-type polyoxometalate[Co(2,2-'bipy)3]H-[Al(OH)6(Mo6O18)]·5H2O has been synthesized from AlCl3·H2O,Na2MoO4·2H2O,CoCl2·6H2O and 2,2'-bipydine and characterized by means of IR,UV spectra,thermogravimetric analysis and Xray diffraction.The X-ray crystallography indicates that the title compound crystallizes in a triclinic lattice,P1 space group,with a=1.216 0(2),b=1.221 5(2),c=1.780 0(4) nm,α=86.83(3)°,β=88.76(3)°, γ=89.82(3)°,V=2.639 4(9) nm3,Z=2,R1=0.079 4,wR2=0.176 6.Structural analysis reveals that the molecule of the title compound is composed of one[Co(2,2'-bipy)3]2+coordination cation,one H+ ion,two crystallographically independent "one-half" polyoxoanions[Al(OH)6(Mo6O18)]3- and five hydration water molecules.Under the participation of water and coordinated metal ions,the[Al(OH)6(Mo6O18)]3- polyoxoanions form a two-dimensional network structure by means of supramolecular interaction.The adjacent network structures interact with each other,generating a three-dimensional structure infinitely extended via supramolecular interaction.Thermogravimetric analysis elucidates that the process of weight loss of the title compound is divided into two stages and also reveals that the backbone of heteropolyoxoanion decomposes at 547.5℃.
2006, 23(3): 294-298
Abstract:
The cassawa starch phosphate monoesters with a high degree of substitution(CSP-HDS) were prepared via the dry process with sodium tripolyphosphate(STP) as esterifying agent.The physicochemical properties of CSP-HDS were investigated and the structures were characterized.CSP-HDS with a DS of 0.073 had a maximum apparent viscosity of 2.656 Pa·s,CSP-HDS with a DS of 0.055 had the highest transparency of 85.6%,and CSP-HDS with a DS of 0.073 had the best stability of freeze-thaw and no water was separated from the gel after freeze-thaw for 5 times.Compared with native starch,CSP-HDS shows higher viscosity,its gelation temperature is lower and gelation time is shorter.CSP-HDS with DS>0.064 dissolves in water at room temperature,its paste transparency and freeze-thaw stability are improved.The FTIR results show that the peak at 1 016 cm-1 is enhanced,indicating the group of phosphate has been induced in starch molecule.The XRD results indicate that the esterification of starch mainly occurs in the amorphous region and less in the crystalline region.The absorbency of the starch-iodine composite is decreased,indicating that the helix structure of cassawa starch has been partly destroyed.
The cassawa starch phosphate monoesters with a high degree of substitution(CSP-HDS) were prepared via the dry process with sodium tripolyphosphate(STP) as esterifying agent.The physicochemical properties of CSP-HDS were investigated and the structures were characterized.CSP-HDS with a DS of 0.073 had a maximum apparent viscosity of 2.656 Pa·s,CSP-HDS with a DS of 0.055 had the highest transparency of 85.6%,and CSP-HDS with a DS of 0.073 had the best stability of freeze-thaw and no water was separated from the gel after freeze-thaw for 5 times.Compared with native starch,CSP-HDS shows higher viscosity,its gelation temperature is lower and gelation time is shorter.CSP-HDS with DS>0.064 dissolves in water at room temperature,its paste transparency and freeze-thaw stability are improved.The FTIR results show that the peak at 1 016 cm-1 is enhanced,indicating the group of phosphate has been induced in starch molecule.The XRD results indicate that the esterification of starch mainly occurs in the amorphous region and less in the crystalline region.The absorbency of the starch-iodine composite is decreased,indicating that the helix structure of cassawa starch has been partly destroyed.
2006, 23(3): 299-304
Abstract:
The adsorption ability of manganese-oxide-coated-sand(MOCS) for copper and lead cations in mono-(non-competitive) and binary-(competitive) component aqueous solutions was studied on a fixed-bed column.The influences of influent flow rate and influent metal concentration on breakthrough time during the removal of copper and lead cations from aqueous solutions on a MOCS column were quantitively determined.The results show that the breakthrough time increased when metal concentration or/and the flow rate were decreased.For mono-component metal solutions,the saturation adsorption capacities of MOCS for copper and lead cations were decreased from 17.0 μmol/g and 19.0 μmol/g to 11.3 μmol/g and 16.0 μmol/g in a flow rate range of 3.33 mL/min to 7.69 mL/min,respectively.The Thomas model was applied to predicting the adsorption breakthrough curves of copper and lead cations at different flow rates and different initial concentrations and to calculate the characteristic process parameters of the column adsorption.MOCS can be regenerated with a nitrate acid solution to ten times in keeping its adsorption capacity.The removal efficiency of metal ions would be decreased due to the presence of other heavy metal ions,but the total saturation adsorption capacities of MOCS for copper and lead cations were slightly increased.This competitive adsorption also showed that adsorption of lead cations was decreased insignificantly in the presence of copper cations,whereas the adsorption of copper cations was obviously decreased in the presence of lead cations. The removal ability of copper and lead ions from aqueous solution with MOCS columns is:Pb2+>Cu2+.The adsorbed copper and lead cations could be easily desorbed from MOCS with a 0.50 mol/L nitrate acid solution.The elution rates were affected by the flow rates and concentration of nitrate acid.
The adsorption ability of manganese-oxide-coated-sand(MOCS) for copper and lead cations in mono-(non-competitive) and binary-(competitive) component aqueous solutions was studied on a fixed-bed column.The influences of influent flow rate and influent metal concentration on breakthrough time during the removal of copper and lead cations from aqueous solutions on a MOCS column were quantitively determined.The results show that the breakthrough time increased when metal concentration or/and the flow rate were decreased.For mono-component metal solutions,the saturation adsorption capacities of MOCS for copper and lead cations were decreased from 17.0 μmol/g and 19.0 μmol/g to 11.3 μmol/g and 16.0 μmol/g in a flow rate range of 3.33 mL/min to 7.69 mL/min,respectively.The Thomas model was applied to predicting the adsorption breakthrough curves of copper and lead cations at different flow rates and different initial concentrations and to calculate the characteristic process parameters of the column adsorption.MOCS can be regenerated with a nitrate acid solution to ten times in keeping its adsorption capacity.The removal efficiency of metal ions would be decreased due to the presence of other heavy metal ions,but the total saturation adsorption capacities of MOCS for copper and lead cations were slightly increased.This competitive adsorption also showed that adsorption of lead cations was decreased insignificantly in the presence of copper cations,whereas the adsorption of copper cations was obviously decreased in the presence of lead cations. The removal ability of copper and lead ions from aqueous solution with MOCS columns is:Pb2+>Cu2+.The adsorbed copper and lead cations could be easily desorbed from MOCS with a 0.50 mol/L nitrate acid solution.The elution rates were affected by the flow rates and concentration of nitrate acid.
2006, 23(3): 305-308
Abstract:
TiO2 pillared bentonite and yttrium doped TiO2 pillared bentonite were prepared respectively by the sol-gel method from bentonite with TiO2 gelation and yttrium doped TiO2 gelation.They were characterized by XRD and the interlayer distance of them obviously increased to 1.9 nm or more and remained at 1.8 nm or more after 500℃ calcinations.The adsorptions of alizarin red on four TiO2 pillared bentonite samples were also studied.The results show that the speed and adsorbability of alizarin red dye on four TiO2 pillared bentonites are much higher.The adsorption dynamics follows the laws of Bangham and Langmuir.The relationship between adsorbing capacity(qe) and equilibrium mass concentration(ρe) is in accordance with the isothermal adsorption equations of Freundlich and Langmuir.The adsorptions are all endothermic process.The adsorption heat values range from 20 kJ/mol to 23 kJ/mol.The absorption exhibits both surface physical adsorption and ion-exchange mechanism.
TiO2 pillared bentonite and yttrium doped TiO2 pillared bentonite were prepared respectively by the sol-gel method from bentonite with TiO2 gelation and yttrium doped TiO2 gelation.They were characterized by XRD and the interlayer distance of them obviously increased to 1.9 nm or more and remained at 1.8 nm or more after 500℃ calcinations.The adsorptions of alizarin red on four TiO2 pillared bentonite samples were also studied.The results show that the speed and adsorbability of alizarin red dye on four TiO2 pillared bentonites are much higher.The adsorption dynamics follows the laws of Bangham and Langmuir.The relationship between adsorbing capacity(qe) and equilibrium mass concentration(ρe) is in accordance with the isothermal adsorption equations of Freundlich and Langmuir.The adsorptions are all endothermic process.The adsorption heat values range from 20 kJ/mol to 23 kJ/mol.The absorption exhibits both surface physical adsorption and ion-exchange mechanism.
2006, 23(3): 309-312
Abstract:
In pH=4.0 HCl-NaAc,the diphenhydramine hydrochloride (DPH)-silicontungstic acid(SiW) association particle system exhibits a maxmum absorption peak at 295 nm.The A295 nm is linear with the DPH concentration in range of 0.5×10-6~8.0×10-6 g/mL.The detection limit is 0.10×10-6 g/mL DPH.A new spectrophotometric method is used for the determination of DPH in commercial samples,with some advantages including high sensitivity,simplicity, rapidity and accuracy.The recovery is in the range of 98.0%~102%.The RSD is 0.9%~2.2%.The results of the resonance scattering spectra show that there are(DPH-SiW)n association particles in this system.
In pH=4.0 HCl-NaAc,the diphenhydramine hydrochloride (DPH)-silicontungstic acid(SiW) association particle system exhibits a maxmum absorption peak at 295 nm.The A295 nm is linear with the DPH concentration in range of 0.5×10-6~8.0×10-6 g/mL.The detection limit is 0.10×10-6 g/mL DPH.A new spectrophotometric method is used for the determination of DPH in commercial samples,with some advantages including high sensitivity,simplicity, rapidity and accuracy.The recovery is in the range of 98.0%~102%.The RSD is 0.9%~2.2%.The results of the resonance scattering spectra show that there are(DPH-SiW)n association particles in this system.
2006, 23(3): 313-318
Abstract:
Silica films were prepared on titanium substrate by a sol-gel method.The influence of different factors on the quality of silica films is discussed in this paper.The surface composition,microstructure and surface morphology of the films were characterized by X-ray diffraction(XRD),fourier transform infrared spectrometry(FTIR) and scanning electron microscopy(SEM),respectively.The results show that the sol prepared at pH 3 and a n(TEOS):n(H2O):n(EtOH) ratio of 1:4:11 and aged for 10 h at 70℃ was suitable for plating silica flims on titanium substrate.The silica films were crackfree,uniform and porous.The pore size distributions was between 2 and 3 μm.After immersing the silica films in simulated body fluid(1.5SBF) for 10 d,the rapid depositon of spherical carbonated hydroxyapatite(CHA) on the surface of the films showed that the bioactivity of silica films was very good.
Silica films were prepared on titanium substrate by a sol-gel method.The influence of different factors on the quality of silica films is discussed in this paper.The surface composition,microstructure and surface morphology of the films were characterized by X-ray diffraction(XRD),fourier transform infrared spectrometry(FTIR) and scanning electron microscopy(SEM),respectively.The results show that the sol prepared at pH 3 and a n(TEOS):n(H2O):n(EtOH) ratio of 1:4:11 and aged for 10 h at 70℃ was suitable for plating silica flims on titanium substrate.The silica films were crackfree,uniform and porous.The pore size distributions was between 2 and 3 μm.After immersing the silica films in simulated body fluid(1.5SBF) for 10 d,the rapid depositon of spherical carbonated hydroxyapatite(CHA) on the surface of the films showed that the bioactivity of silica films was very good.
2006, 23(3): 319-322
Abstract:
This paper reports the degradation of o-phenylene diamine in aqueous solution by glow discharge plasma combined with activated carbon and/or hydrogen peroxide.Some conditions such as pH and ferrous ions were also examined.The results show that the combined technology can increase the degradation of o-phenylene diamine effectively and has some advantages in operation and cost.Thus,it may be used for wastewater treatment.
This paper reports the degradation of o-phenylene diamine in aqueous solution by glow discharge plasma combined with activated carbon and/or hydrogen peroxide.Some conditions such as pH and ferrous ions were also examined.The results show that the combined technology can increase the degradation of o-phenylene diamine effectively and has some advantages in operation and cost.Thus,it may be used for wastewater treatment.
2006, 23(3): 323-327
Abstract:
The sensitizing effect of β-cyclodextrin(β-CD) and β-CD-CTAB on the determination of Bi(Ⅲ) by spectrofluorimetry was studied.The results show that β-CD has no sensitizing effect on Bi(Ⅲ)-8-hydroxy quinoline (HQ),while β-CD-CTAB microemulsion shows the highest sensitizing effect on the determination of Bismuth(Ⅲ)-HQ.The proposed method was applied to the determination of Bismuth(Ⅲ) in standard and real samples with satisfactory results.Under the optimized conditions,Lambert-Beer's law is obeyed in the range of 0.2~1.4 mg/L of Bi(Ⅲ) and the detection limit(3σ) is 13.8 μg/L.
The sensitizing effect of β-cyclodextrin(β-CD) and β-CD-CTAB on the determination of Bi(Ⅲ) by spectrofluorimetry was studied.The results show that β-CD has no sensitizing effect on Bi(Ⅲ)-8-hydroxy quinoline (HQ),while β-CD-CTAB microemulsion shows the highest sensitizing effect on the determination of Bismuth(Ⅲ)-HQ.The proposed method was applied to the determination of Bismuth(Ⅲ) in standard and real samples with satisfactory results.Under the optimized conditions,Lambert-Beer's law is obeyed in the range of 0.2~1.4 mg/L of Bi(Ⅲ) and the detection limit(3σ) is 13.8 μg/L.
2006, 23(3): 328-331
Abstract:
The adsorption of water in ethyl acetate on zeolite 3A was carried out in a batch system.The equilibrium behaviour was shown to fit a Langmuir isotherm.A surface diffusion model,coupled with the observed Langmuir isotherm equations,was used to interpret the observed experimental adsorption kinetic curves at different initial concentrations,temperatures and particle sizes.Surface diffusivity Ds can be calculated.The surface diffusivity increased as temperature and initial concentration increased,but it was independent of particles size.The pre-exponential factor Dso and the activation energy E was also calculated.
The adsorption of water in ethyl acetate on zeolite 3A was carried out in a batch system.The equilibrium behaviour was shown to fit a Langmuir isotherm.A surface diffusion model,coupled with the observed Langmuir isotherm equations,was used to interpret the observed experimental adsorption kinetic curves at different initial concentrations,temperatures and particle sizes.Surface diffusivity Ds can be calculated.The surface diffusivity increased as temperature and initial concentration increased,but it was independent of particles size.The pre-exponential factor Dso and the activation energy E was also calculated.
2006, 23(3): 332-336
Abstract:
Dichlorophenylphosphine(DCPP) was synthesized from benzene and phosphorus trichloride with aluminum chloride anhydrous as catalyst.The reactor was irradiated in the 40 kHz ultrasound field at an acoustic pressure of 159 kPa.After the reaction,0.076~0.09 mm NaCl powder was added to the reactor as a complexant to remove the catalyst.Petroleum ether was used to extract DCPP from the solid above- mentioned.Petroleum ether was distilled by an atmospheric distillation process,then DCPP was distilled at a reduced pressure of 1.33×103 Pa(absolute pressure),the boiling point of which is 90℃.The yield(92.3%) was increased by 6.6% with ultrasound over that(85%) without ultrasound for the same reaction time and the purity was 99.7%.
Dichlorophenylphosphine(DCPP) was synthesized from benzene and phosphorus trichloride with aluminum chloride anhydrous as catalyst.The reactor was irradiated in the 40 kHz ultrasound field at an acoustic pressure of 159 kPa.After the reaction,0.076~0.09 mm NaCl powder was added to the reactor as a complexant to remove the catalyst.Petroleum ether was used to extract DCPP from the solid above- mentioned.Petroleum ether was distilled by an atmospheric distillation process,then DCPP was distilled at a reduced pressure of 1.33×103 Pa(absolute pressure),the boiling point of which is 90℃.The yield(92.3%) was increased by 6.6% with ultrasound over that(85%) without ultrasound for the same reaction time and the purity was 99.7%.
2006, 23(3): 337-339
Abstract:
Excellent enantioselectives of up to 98% e.e.were achieved in the presence of benzyl N-chlorocarbamate as oxidant and nitrogen source when a free recoverable cinchona ligand was used for homogeneous asymmetric aminohydroxylation(AA) of five olefins.In the AA reaction of styrene,this ligand can be easily recovered and reused for five times without any significant loss in its catalytic efficiency.
Excellent enantioselectives of up to 98% e.e.were achieved in the presence of benzyl N-chlorocarbamate as oxidant and nitrogen source when a free recoverable cinchona ligand was used for homogeneous asymmetric aminohydroxylation(AA) of five olefins.In the AA reaction of styrene,this ligand can be easily recovered and reused for five times without any significant loss in its catalytic efficiency.
2006, 23(3): 340-342
Abstract:
A new heterogeneity racemization technology of valine in an ethanol solution of dibenzoyl-L-tartaric acid was described.Racemization kinetics of this process was studied.Racemization ratio of valine could be gradually increased when the amount of dibenzoyl-L-tartaric acid and the time of racemization were increased.For L-Valine,the relationship between the rate constant of racemization and its reaction temperature was roposed,i.e.:k=0.015 5e-13 200/RT,Ea of the heterogeneity racemization is much less than Ea of the racemization in the basic solution.The heterogeneity racemization technology would be suitable for large-scale industrial manufacture.
A new heterogeneity racemization technology of valine in an ethanol solution of dibenzoyl-L-tartaric acid was described.Racemization kinetics of this process was studied.Racemization ratio of valine could be gradually increased when the amount of dibenzoyl-L-tartaric acid and the time of racemization were increased.For L-Valine,the relationship between the rate constant of racemization and its reaction temperature was roposed,i.e.:k=0.015 5e-13 200/RT,Ea of the heterogeneity racemization is much less than Ea of the racemization in the basic solution.The heterogeneity racemization technology would be suitable for large-scale industrial manufacture.
2006, 23(3): 343-345
Abstract:
A new enviromental-freiendly catalyst,PAn-FeCl3 was prepared.Benzaldehyde 1,2-propylene acetalization was carried out with benzaldehyde and 1,2-propylene alcohol in the presence of polyaniline doped with ferric chloride.Factors influencing the product yield were discussed and optimum conditions were found.Experimental result shows that polyaniline doped with ferric chloride is an excellent catalyst.Under the conditions where a ratio of n(benzaldehyde):n(1,2-propylene)=1:1.4,ω(polyaniline doped with ferric chloride)=0.98%,cyclohexane 14 mL and reaction time 2.0 h,the yield of benzaldehyde 1,2-propylene acetal can reach 93%.
A new enviromental-freiendly catalyst,PAn-FeCl3 was prepared.Benzaldehyde 1,2-propylene acetalization was carried out with benzaldehyde and 1,2-propylene alcohol in the presence of polyaniline doped with ferric chloride.Factors influencing the product yield were discussed and optimum conditions were found.Experimental result shows that polyaniline doped with ferric chloride is an excellent catalyst.Under the conditions where a ratio of n(benzaldehyde):n(1,2-propylene)=1:1.4,ω(polyaniline doped with ferric chloride)=0.98%,cyclohexane 14 mL and reaction time 2.0 h,the yield of benzaldehyde 1,2-propylene acetal can reach 93%.
2006, 23(3): 346-348
Abstract:
Cellulose diacetate(CDA) was grafted with polyethylene glycol(PEG) by using 1,6-hexamethylene diisocyanate(HDI).The effects of molecular weight of PEG,the ratio of PEG to CDA,HDI amount,catalyst amount and reaction time on the grafting reaction were studied.The optimal condition were determined by means of orthogonal experiments,that is,n(NCO):n(OH) was 4:4;m(PEG):m(CDA) was 5.0:3.0;the mass fraction of catalyst was 0.10%,reaction time was 1.5 h and molecular weight of PEG was 200.The graft rate of CDA-g-PEG prepared under the optimal conditions was 253.3%.The graft copolymer was characterized by means of FT-IR,1H NMR,and 13C NMR techniques.
Cellulose diacetate(CDA) was grafted with polyethylene glycol(PEG) by using 1,6-hexamethylene diisocyanate(HDI).The effects of molecular weight of PEG,the ratio of PEG to CDA,HDI amount,catalyst amount and reaction time on the grafting reaction were studied.The optimal condition were determined by means of orthogonal experiments,that is,n(NCO):n(OH) was 4:4;m(PEG):m(CDA) was 5.0:3.0;the mass fraction of catalyst was 0.10%,reaction time was 1.5 h and molecular weight of PEG was 200.The graft rate of CDA-g-PEG prepared under the optimal conditions was 253.3%.The graft copolymer was characterized by means of FT-IR,1H NMR,and 13C NMR techniques.
