Login In
2010 Volume 27 Issue 3
2010, 27(3): 249-256
doi: 10.3724/SP.J.1095.2010.90383
Abstract:
Research on the gas-phase radical/ion chemistry was briefly summarized.Emphasis was given to the application of mass spectrometric technique to ion-molecule reactions between halocarbocations and aromatic compounds which gave rise to chlorobenzenes as one of the targeted products.That chlorobenzenes were readily formed in the mass spectrometer implied that chlorobenzenes in the atmosphere should not exclude the possibility of ion/radical chemistry reactions.The environmental significance of such reactions was also explored.
Research on the gas-phase radical/ion chemistry was briefly summarized.Emphasis was given to the application of mass spectrometric technique to ion-molecule reactions between halocarbocations and aromatic compounds which gave rise to chlorobenzenes as one of the targeted products.That chlorobenzenes were readily formed in the mass spectrometer implied that chlorobenzenes in the atmosphere should not exclude the possibility of ion/radical chemistry reactions.The environmental significance of such reactions was also explored.
2010, 27(3): 257-261
doi: 10.3724/SP.J.1095.2010.90229
Abstract:
Friedel-Crafts acylation reaction of crosslinked polystyrene(CPS) microspheres was conducted in the precence of a Lewis acid catalyst at room temperature using two kinds of ω-chloroacyl chloride,chloroacetyl chloride and chlorobutyryl chloride,and chloroacylation crosslinked polystyrene(CACPS) microspheres were prepared.The chemical structure and composition of the resultant microspheres were characterized and determined by means of infrerad spectroscopy and Volhard methods.The effects of various factors on the chloroacylation reaction were investigated.The experimental results show that the chloroacylation process is always accompanied by Friedel-Crafts alkylation reaction,which is a side reaction leading to additional crosslinking.This side reaction not only decreases the content of the chloroacyl groups on CACPS microspheres,but also makes the property of the microspheres poor.An optimal equilibrium point,at which the chlorine content of CACPS microspheres is the highest,between acylation reaction and alkylation crosslinking reaction can be reached under the following conditions:room temperature,CHCl3 as the solvent,SnCl4 as the catalyst,a 1.2:1 molar ratio of catalyst to chain unit of polystyrene of CPS,10 mL used solvent per 1g CPS microspheres.The result still indicates that the chloroacylation via chlorobutyryl chloride is better than that via chloroacetyl chloride.
Friedel-Crafts acylation reaction of crosslinked polystyrene(CPS) microspheres was conducted in the precence of a Lewis acid catalyst at room temperature using two kinds of ω-chloroacyl chloride,chloroacetyl chloride and chlorobutyryl chloride,and chloroacylation crosslinked polystyrene(CACPS) microspheres were prepared.The chemical structure and composition of the resultant microspheres were characterized and determined by means of infrerad spectroscopy and Volhard methods.The effects of various factors on the chloroacylation reaction were investigated.The experimental results show that the chloroacylation process is always accompanied by Friedel-Crafts alkylation reaction,which is a side reaction leading to additional crosslinking.This side reaction not only decreases the content of the chloroacyl groups on CACPS microspheres,but also makes the property of the microspheres poor.An optimal equilibrium point,at which the chlorine content of CACPS microspheres is the highest,between acylation reaction and alkylation crosslinking reaction can be reached under the following conditions:room temperature,CHCl3 as the solvent,SnCl4 as the catalyst,a 1.2:1 molar ratio of catalyst to chain unit of polystyrene of CPS,10 mL used solvent per 1g CPS microspheres.The result still indicates that the chloroacylation via chlorobutyryl chloride is better than that via chloroacetyl chloride.
2010, 27(3): 262-266
doi: 10.3724/SP.J.1095.2010.90236
Abstract:
Novel hyperbranched poly(para-phenylene)s were synthesized by Suzuki polycondensation with Ir complex as core and poly(p-phenylene) as branch.The emission from the host was completely quenched when the content of Ir complex in the polymer was more than 0.5%,leading the EL spectra of the polymers to show only one main emission at 520 nm,which indicated that there was an efficient energy transfer between the host and the guest.The device based on the copolymer with 1% molar fraction of Ir complex in the polymer had a peak luminous efficiency(LE) of 2.89 cd/A,and the maximal luminance of 1689 cd/m2 with the configuration of ITO/PEDOT:PSS/emissive layer/Ba/Al (PEDOT:poly (3,4-ethytenedioxythiophene,PSS:poly(styenesulfonate)).
Novel hyperbranched poly(para-phenylene)s were synthesized by Suzuki polycondensation with Ir complex as core and poly(p-phenylene) as branch.The emission from the host was completely quenched when the content of Ir complex in the polymer was more than 0.5%,leading the EL spectra of the polymers to show only one main emission at 520 nm,which indicated that there was an efficient energy transfer between the host and the guest.The device based on the copolymer with 1% molar fraction of Ir complex in the polymer had a peak luminous efficiency(LE) of 2.89 cd/A,and the maximal luminance of 1689 cd/m2 with the configuration of ITO/PEDOT:PSS/emissive layer/Ba/Al (PEDOT:poly (3,4-ethytenedioxythiophene,PSS:poly(styenesulfonate)).
2010, 27(3): 267-271
doi: 10.3724/SP.J.1095.2010.90235
Abstract:
A selective and mild PS-DIB(diacetoxyiodo polystyrene)/ionic-liquid immobilized 2,2,6,6-tetramethyl-piperidin-4-ol-N-oxyl(TeMPO) catalytic oxidation procedure of alcohols to the corresponding aldehydes and ketones in ionic liquid[bmim]BF4 at room temperature was developed.The oxidant PS-DIB was prepared via the iodation and acetylation of polystyrene resin.For the preparation of the ionic-liquid immobilized TeMPO(TeMPO-IL) catalyst,4-(2,2,6,6-Tetramethyl-1-oxyl-4-piperidoxyl)butyl bromide was first synthesized from TeMPO and 1,4-dibromobutane.The TeMPO-IL was then obtained via the quaternization of 1-methyl-1H-imidazole with TeMPO-IL followed by ion exchange with NaBF4.The PS-DIB/TeMPO-IL catalytic system was applied to the oxidation of a variety of alcohols to their corresponding aldehydes or ketones selectively.No carboxylic acid was detected under the experimental conditions.In the case of the oxidation of benzyl alcohol,the oxidant,catalyst and the solvent can be recovered and reused for 5 times without decreasing the benzyl alcohol conversions and yields.
A selective and mild PS-DIB(diacetoxyiodo polystyrene)/ionic-liquid immobilized 2,2,6,6-tetramethyl-piperidin-4-ol-N-oxyl(TeMPO) catalytic oxidation procedure of alcohols to the corresponding aldehydes and ketones in ionic liquid[bmim]BF4 at room temperature was developed.The oxidant PS-DIB was prepared via the iodation and acetylation of polystyrene resin.For the preparation of the ionic-liquid immobilized TeMPO(TeMPO-IL) catalyst,4-(2,2,6,6-Tetramethyl-1-oxyl-4-piperidoxyl)butyl bromide was first synthesized from TeMPO and 1,4-dibromobutane.The TeMPO-IL was then obtained via the quaternization of 1-methyl-1H-imidazole with TeMPO-IL followed by ion exchange with NaBF4.The PS-DIB/TeMPO-IL catalytic system was applied to the oxidation of a variety of alcohols to their corresponding aldehydes or ketones selectively.No carboxylic acid was detected under the experimental conditions.In the case of the oxidation of benzyl alcohol,the oxidant,catalyst and the solvent can be recovered and reused for 5 times without decreasing the benzyl alcohol conversions and yields.
2010, 27(3): 272-275
doi: 10.3724/SP.J.1095.2010.90217
Abstract:
Microporous polymer honeycomb films with hexagonal pores were prepared by self-organization under humid conditions.The amphiphilic polymer acted as a stabilizer of condensed water droplets and prevented water droplets from fusion.The honeycomb film was shrunk by a shrinkable film.Various shapes could be formed upon the mechanical shrink deformation of hexagonal micro polymer meshes.Shapes such as rectangle,shuttle,slot and dumbbell were found in the shrunk honeycomb films.The pore size of honeycomb structure film(4~8 μm) was also shrunk to 130 nm.The deformation mechanism of the film was discussed.
Microporous polymer honeycomb films with hexagonal pores were prepared by self-organization under humid conditions.The amphiphilic polymer acted as a stabilizer of condensed water droplets and prevented water droplets from fusion.The honeycomb film was shrunk by a shrinkable film.Various shapes could be formed upon the mechanical shrink deformation of hexagonal micro polymer meshes.Shapes such as rectangle,shuttle,slot and dumbbell were found in the shrunk honeycomb films.The pore size of honeycomb structure film(4~8 μm) was also shrunk to 130 nm.The deformation mechanism of the film was discussed.
2010, 27(3): 276-279
doi: 10.3724/SP.J.1095.2010.90241
Abstract:
Polymeric HAP/P(MMA-St) composite microspheres were synthesized via suspension polymerization with microporous hydroxyl apatite(HAP) nanomaterial as inorganic carrier,polymethyl methacrylate(MMA) and styrene(St) as monomers.The effects of main factors on the particle distribution and adsorption performance of polymeric HAP/P(MMA-St) composite microspheres were investigated.Experimental results show that a maximal yield of qualified microspheres of 86.4% could be achived when the mass fractions of surfactant,MMA and HAP were 10%,20% and 30% accordingly under a rotation speed of 300 r/min.The absorbability of polymeric microspheres for BSA was studied through a static adsorption process.When the mass fraction of HAP was 36.07%,adsorption quantity was Qe=18.70 mg/g,an increase of 4.65 mg/g could be observed compared to that without adding.
Polymeric HAP/P(MMA-St) composite microspheres were synthesized via suspension polymerization with microporous hydroxyl apatite(HAP) nanomaterial as inorganic carrier,polymethyl methacrylate(MMA) and styrene(St) as monomers.The effects of main factors on the particle distribution and adsorption performance of polymeric HAP/P(MMA-St) composite microspheres were investigated.Experimental results show that a maximal yield of qualified microspheres of 86.4% could be achived when the mass fractions of surfactant,MMA and HAP were 10%,20% and 30% accordingly under a rotation speed of 300 r/min.The absorbability of polymeric microspheres for BSA was studied through a static adsorption process.When the mass fraction of HAP was 36.07%,adsorption quantity was Qe=18.70 mg/g,an increase of 4.65 mg/g could be observed compared to that without adding.
2010, 27(3): 280-284
doi: 10.3724/SP.J.1095.2010.90202
Abstract:
The metal bis(perfluorooctanesulfonyl)imide complexes were prepared and used in Friedel-Crafts alkylation in fluorous biphasic system.The effects of Lewis acid catalysts,reaction time,temperature and dosage of catalysts,as well as the catalytic reaction of different alkylating agents with aromatic compounds in the presence of 0.2% molar fraction of Yb[N(SO2C8F17)2]3 were investigated.All the experimental results show that metal bis(perfluorooctanesulfonyl)imide complexes were more effective for Friedel-Crafts alkylation than conventional Lewis acid catalysts.Furthermore,by simple phase-separation,the fluorous phase containing only catalyst could be re-utilized up to four times with a slight decrease in activity.
The metal bis(perfluorooctanesulfonyl)imide complexes were prepared and used in Friedel-Crafts alkylation in fluorous biphasic system.The effects of Lewis acid catalysts,reaction time,temperature and dosage of catalysts,as well as the catalytic reaction of different alkylating agents with aromatic compounds in the presence of 0.2% molar fraction of Yb[N(SO2C8F17)2]3 were investigated.All the experimental results show that metal bis(perfluorooctanesulfonyl)imide complexes were more effective for Friedel-Crafts alkylation than conventional Lewis acid catalysts.Furthermore,by simple phase-separation,the fluorous phase containing only catalyst could be re-utilized up to four times with a slight decrease in activity.
2010, 27(3): 285-289
doi: 10.3724/SP.J.1095.2010.90240
Abstract:
A screened lipase from Candida.sp.GXU08 strain was used to catalyze the synthesis reaction of cyclopentadecanolide from methyl 15-hydroxy-pentadecanate.The lipase solution was dispersed in cyclohexane by ultrasonication to form an aqueous/organic solvent emulsion system.Different effects of reaction conditions on the production of cyclopentadecanolide were studied.The maximal production of cyclopentadecanolide was 47.77×10-3 mg/U in the emulsion system under the reaction conditions:40℃,180 r/min,1 g lipase solution(pH=7.0),8 mmol/L substrate,72 h. The production in the emulsion system was 3.285 times of that 14.54×10-3 mg in cyclohexane organic system.It was also found that reusing the lipase once would greatly increase the production of cyclopentadecanolide.So the lipase powder could be replaced by lipase solution to catalyze the synthesis of cyclopentadecanolide,which could enhance the conversion of the reaction,save time and reduce the use of energy.
A screened lipase from Candida.sp.GXU08 strain was used to catalyze the synthesis reaction of cyclopentadecanolide from methyl 15-hydroxy-pentadecanate.The lipase solution was dispersed in cyclohexane by ultrasonication to form an aqueous/organic solvent emulsion system.Different effects of reaction conditions on the production of cyclopentadecanolide were studied.The maximal production of cyclopentadecanolide was 47.77×10-3 mg/U in the emulsion system under the reaction conditions:40℃,180 r/min,1 g lipase solution(pH=7.0),8 mmol/L substrate,72 h. The production in the emulsion system was 3.285 times of that 14.54×10-3 mg in cyclohexane organic system.It was also found that reusing the lipase once would greatly increase the production of cyclopentadecanolide.So the lipase powder could be replaced by lipase solution to catalyze the synthesis of cyclopentadecanolide,which could enhance the conversion of the reaction,save time and reduce the use of energy.
2010, 27(3): 290-294
doi: 10.3724/SP.J.1095.2010.90258
Abstract:
A series of amphiphilic graft copolymers P(SPEG)-g-P(HFMA) comprising poly(hexafluorobutyl methacrylate)(PHFMA) backbones and poly(ethylene glycol)(PEG) side chains was synthesized via a macromonomer method.The resultant macromonomer and amphiphilic graft copolymers were characterized by 1H NMR and GPC spectroscopy.The crystallization of P(SPEG)-g-P(HFMA) was studied by differential scanning calorimetry(DSC),X-ray diffraction(XRD) and polarized optical microscopy(POM).DSC and XRD measurements indicated that the crystallizing temperature(Tc) and crystallinity(Xc) of the copolymer all decreased with the increase of HFMA content in the graft copolymer.The melting temperature(Tm) of the amphiphilic graft copolymer first decreased appropriately and then increased with the increase of HFMA content in the graft copolymer.POM micrographs showed that the crystal rate of the graft copolymer decreased and the PEG phase had a decreasing tendency for spherical crystallization and less clear spherical structure as the HFMA content in the graft copolymer increased.When the HFMA content in the graft copolymer was 57%,no clear crystalline was found.
A series of amphiphilic graft copolymers P(SPEG)-g-P(HFMA) comprising poly(hexafluorobutyl methacrylate)(PHFMA) backbones and poly(ethylene glycol)(PEG) side chains was synthesized via a macromonomer method.The resultant macromonomer and amphiphilic graft copolymers were characterized by 1H NMR and GPC spectroscopy.The crystallization of P(SPEG)-g-P(HFMA) was studied by differential scanning calorimetry(DSC),X-ray diffraction(XRD) and polarized optical microscopy(POM).DSC and XRD measurements indicated that the crystallizing temperature(Tc) and crystallinity(Xc) of the copolymer all decreased with the increase of HFMA content in the graft copolymer.The melting temperature(Tm) of the amphiphilic graft copolymer first decreased appropriately and then increased with the increase of HFMA content in the graft copolymer.POM micrographs showed that the crystal rate of the graft copolymer decreased and the PEG phase had a decreasing tendency for spherical crystallization and less clear spherical structure as the HFMA content in the graft copolymer increased.When the HFMA content in the graft copolymer was 57%,no clear crystalline was found.
2010, 27(3): 295-299
doi: 10.3724/SP.J.1095.2010.90218
Abstract:
A new organic polyamine(1-(N,N-2-aminopropyl) aminoethyl-4-aminopropyl piperazine) was synthesized from 1-(2-aminoethyl)piperazine and acrylonitrile.Using this polyamine ligand purple needle single crystals of[Co(L)HCl](ClO4)2 was synthesized.The compound was characterized by elemental analysis,molar conductivity and X-ray single crystal analysis.X-ray data reveals that the title complex crystallized in the orthorhombic system,with space group I4/m,a=2.5006(3),b=2.5006(3),c=0.85615(11) nm,Mr=594.79,V=5.3534(10) nm3,Z=8,F(000)=2488,Dc=1.476 g/cm3,μ(MoKα)=0.989 mm-1,R1=0.0666,wR2=0.1852(I>2σ(I)).The complex showed a certain anti-bacteriostatic property to staphylococcus aureus,escherichia coli,bacillus subtilis and marine vibrio using an agar diffusion antimicrobial test.
A new organic polyamine(1-(N,N-2-aminopropyl) aminoethyl-4-aminopropyl piperazine) was synthesized from 1-(2-aminoethyl)piperazine and acrylonitrile.Using this polyamine ligand purple needle single crystals of[Co(L)HCl](ClO4)2 was synthesized.The compound was characterized by elemental analysis,molar conductivity and X-ray single crystal analysis.X-ray data reveals that the title complex crystallized in the orthorhombic system,with space group I4/m,a=2.5006(3),b=2.5006(3),c=0.85615(11) nm,Mr=594.79,V=5.3534(10) nm3,Z=8,F(000)=2488,Dc=1.476 g/cm3,μ(MoKα)=0.989 mm-1,R1=0.0666,wR2=0.1852(I>2σ(I)).The complex showed a certain anti-bacteriostatic property to staphylococcus aureus,escherichia coli,bacillus subtilis and marine vibrio using an agar diffusion antimicrobial test.
2010, 27(3): 300-303
doi: 10.3724/SP.J.1095.2010.90243
Abstract:
In order to find new anticonvulsant compounds,we designed and synthesized eleven target compounds of γ-aminobutyric acid isothiocyanate conjugated norcantharidin and substituted anilin.The structures were identified by IR,1H NMR and HR-MS.Preliminary test of anticonvulsant activity shows that compounds Ⅱ2,Ⅱ3 and Ⅱ8 have appreciable antiepileptic activity.
In order to find new anticonvulsant compounds,we designed and synthesized eleven target compounds of γ-aminobutyric acid isothiocyanate conjugated norcantharidin and substituted anilin.The structures were identified by IR,1H NMR and HR-MS.Preliminary test of anticonvulsant activity shows that compounds Ⅱ2,Ⅱ3 and Ⅱ8 have appreciable antiepileptic activity.
2010, 27(3): 304-307
doi: 10.3724/SP.J.1095.2010.90271
Abstract:
C-Benzylation of 4-chlorophenol(BCP) was selectively perpared via the catalysis of Zn(OTf)2 under mild conditions with an excellent yield.The optimum reaction conditions included that the molar ratio of the reactants(4-chlorophol:benzyl chloride) was 1.2:1,5% Zn(OTf)2(molar ratio),and 6 h agitation at 60℃ in nitromethane.The conversion of 4-chlorophenol and selectivity of BCP were >99% and 94%,respectively under the conditions.
C-Benzylation of 4-chlorophenol(BCP) was selectively perpared via the catalysis of Zn(OTf)2 under mild conditions with an excellent yield.The optimum reaction conditions included that the molar ratio of the reactants(4-chlorophol:benzyl chloride) was 1.2:1,5% Zn(OTf)2(molar ratio),and 6 h agitation at 60℃ in nitromethane.The conversion of 4-chlorophenol and selectivity of BCP were >99% and 94%,respectively under the conditions.
2010, 27(3): 308-312
doi: 10.3724/SP.J.1095.2010.90163
Abstract:
At B3LYP/6-31G* and MP2/6-31G* levels,the bond dissociation energies(BDEs) of O-NO2 bond in four nitrates such as n-propyl nitrate(NPN),isopropyl nitrate(IPN),2-ethylhexyl nitrate(EHN),and tri-ethylene glycol dinitrate(Tri-EGDN) were calculated.The thermal decomposition characteristics of NPN,IPN,EHN,and Tri-EGDN were investigated by means of ambient-pressure DSC and high-pressure DSC.Kinetic parameters of thermal decomposition were obtained.The results show that the thermal decomposition of four nitrates under ambient-pressure occurred in gas phase.When the pressure increased up to 2 MPa,their decomposition processes occurred in liquid phase.According to the fact that the calculated results of O-NO2 BDEs of the four nitrates are in good agreement with the experimental results of apparent activation energies obtained from DSC,we deduce that the thermolysis of the four nitrates is only unimolecular homolytic cleavage of the O-NO2 bonds.
At B3LYP/6-31G* and MP2/6-31G* levels,the bond dissociation energies(BDEs) of O-NO2 bond in four nitrates such as n-propyl nitrate(NPN),isopropyl nitrate(IPN),2-ethylhexyl nitrate(EHN),and tri-ethylene glycol dinitrate(Tri-EGDN) were calculated.The thermal decomposition characteristics of NPN,IPN,EHN,and Tri-EGDN were investigated by means of ambient-pressure DSC and high-pressure DSC.Kinetic parameters of thermal decomposition were obtained.The results show that the thermal decomposition of four nitrates under ambient-pressure occurred in gas phase.When the pressure increased up to 2 MPa,their decomposition processes occurred in liquid phase.According to the fact that the calculated results of O-NO2 BDEs of the four nitrates are in good agreement with the experimental results of apparent activation energies obtained from DSC,we deduce that the thermolysis of the four nitrates is only unimolecular homolytic cleavage of the O-NO2 bonds.
2010, 27(3): 313-317
doi: 10.3724/SP.J.1095.2010.90269
Abstract:
Micron-sized silicon particles were chemically surface-modified with coupling agent KH570,and the grafted particles PAN/SiO2 were obtained.The graft polymerization of acrylonitrile(AN) on the surfaces of particles PAN/SiO2 was performed in a solution polymerization system.The transformation reaction of nitrile groups of the grafted PAN to amidoxime groups(AO) was conducted with hydroxylamine hydrochloride as reagent in the presence of Na2CO3,resulting in functional composite particles of PAO/SiO2,on which poly(amidoxime) macromolecules were chemically anchored.The two kinds of particles were characterized with FTIR,TGA and SEM methods.The effects of the main factors on the graft polymerization of AN and on the amidoxime transformation reaction of the grafted PAN were examined.The experimental results show that in the graft polymerization process,the suitable amount of initiator used is 1.5% of monomer mass,and the appropriate reaction temperature is 75℃.As the graft polymerization is carried out for 5 h under the proper conditions,the grafted particles PAN/SiO2 with a grafting degree of 0.14 g/g can be obtained.The amidoxime transformation reaction can not be carried out completely due to the steric hindrance of amidoxime groups.The optimal reaction conditions for the amidoxime transformation reaction of the grafted PAN are as follows:pH value in a range of 6~7,reaction temperature 70℃ and reaction time 4 h.Under the appropriate conditions,the functional particles of PAO/SiO2 with a nitrile group conversion ratio of 78% can be obtained.
Micron-sized silicon particles were chemically surface-modified with coupling agent KH570,and the grafted particles PAN/SiO2 were obtained.The graft polymerization of acrylonitrile(AN) on the surfaces of particles PAN/SiO2 was performed in a solution polymerization system.The transformation reaction of nitrile groups of the grafted PAN to amidoxime groups(AO) was conducted with hydroxylamine hydrochloride as reagent in the presence of Na2CO3,resulting in functional composite particles of PAO/SiO2,on which poly(amidoxime) macromolecules were chemically anchored.The two kinds of particles were characterized with FTIR,TGA and SEM methods.The effects of the main factors on the graft polymerization of AN and on the amidoxime transformation reaction of the grafted PAN were examined.The experimental results show that in the graft polymerization process,the suitable amount of initiator used is 1.5% of monomer mass,and the appropriate reaction temperature is 75℃.As the graft polymerization is carried out for 5 h under the proper conditions,the grafted particles PAN/SiO2 with a grafting degree of 0.14 g/g can be obtained.The amidoxime transformation reaction can not be carried out completely due to the steric hindrance of amidoxime groups.The optimal reaction conditions for the amidoxime transformation reaction of the grafted PAN are as follows:pH value in a range of 6~7,reaction temperature 70℃ and reaction time 4 h.Under the appropriate conditions,the functional particles of PAO/SiO2 with a nitrile group conversion ratio of 78% can be obtained.
2010, 27(3): 318-322
doi: 10.3724/SP.J.1095.2010.90186
Abstract:
The effects of NaBr on the properties of heterogemini surfactant CmOhpNC8 (m:10,14,16) in aqueous solution were investigated by means of surface tension and fluorescence probe techniques.The results show that NaBr strongly promoted the adsorption and the aggregation of CmOhpNC8 at the air/water interface in aqueous bulk solution.The c20 was reduced to extremely low order of magnitude of micromole per liter at c(NaBr) ≥ 10 mmol/L,showing quite a high efficiency in surface tension reduction.Upon NaBr addition,CmOhpNC8 exhibited strong premicellization in aqueous bulk solution.So low c20 and evident premicellization could not be observed in the equal-mole mixture of the corresponding conventional surfactants,exhibiting the surface-active advantage as well as the salt-sensitivity of heterogemini-type surfactant,in which a short spacer was introduced to link the two different headgroups.
The effects of NaBr on the properties of heterogemini surfactant CmOhpNC8 (m:10,14,16) in aqueous solution were investigated by means of surface tension and fluorescence probe techniques.The results show that NaBr strongly promoted the adsorption and the aggregation of CmOhpNC8 at the air/water interface in aqueous bulk solution.The c20 was reduced to extremely low order of magnitude of micromole per liter at c(NaBr) ≥ 10 mmol/L,showing quite a high efficiency in surface tension reduction.Upon NaBr addition,CmOhpNC8 exhibited strong premicellization in aqueous bulk solution.So low c20 and evident premicellization could not be observed in the equal-mole mixture of the corresponding conventional surfactants,exhibiting the surface-active advantage as well as the salt-sensitivity of heterogemini-type surfactant,in which a short spacer was introduced to link the two different headgroups.
2010, 27(3): 323-327
doi: 10.3724/SP.J.1095.2010.90206
Abstract:
A method using a microcolumn packed with nanometer TiO2 as solid-phase extractant has been developed for the preconcentration of trace amounts of Se(Ⅳ) prior to the measurement by ultraviolet spectrophotometry.Effects of pH,sample flow rate and volume,elution solution and interfering ions on the recovery of the analytes have been investigated.The sorption was optimized with respect to the pH,maximum sorption was achieved from the solutions of pH 1~6.The optimum sample flow rate to adsorb Se(Ⅳ) ions was 0.5 mL/min,and the adsorption percentage was 98.3%.Sorbed Se(Ⅳ) was desorbed with 1.0 mL of 0.1 mol/L NaOH,with an enirchment of 40.The detection limit(3 σ) of the method for Se(Ⅳ) was 0.13 mg/L(n=13);and the relative standard deviation was 1.56% (n=13,c=10 mg/L).At room temperature,dynamic saturated adsorption capacity was 7.92 mg/g.The proposed method was applied to the determination of trace amounts of Se(Ⅳ) in GBW07280,the determined value was in good agreement with the certified value.
A method using a microcolumn packed with nanometer TiO2 as solid-phase extractant has been developed for the preconcentration of trace amounts of Se(Ⅳ) prior to the measurement by ultraviolet spectrophotometry.Effects of pH,sample flow rate and volume,elution solution and interfering ions on the recovery of the analytes have been investigated.The sorption was optimized with respect to the pH,maximum sorption was achieved from the solutions of pH 1~6.The optimum sample flow rate to adsorb Se(Ⅳ) ions was 0.5 mL/min,and the adsorption percentage was 98.3%.Sorbed Se(Ⅳ) was desorbed with 1.0 mL of 0.1 mol/L NaOH,with an enirchment of 40.The detection limit(3 σ) of the method for Se(Ⅳ) was 0.13 mg/L(n=13);and the relative standard deviation was 1.56% (n=13,c=10 mg/L).At room temperature,dynamic saturated adsorption capacity was 7.92 mg/g.The proposed method was applied to the determination of trace amounts of Se(Ⅳ) in GBW07280,the determined value was in good agreement with the certified value.
2010, 27(3): 328-332
doi: 10.3724/SP.J.1095.2010.90205
Abstract:
The interactions of Fe3+,Cr3+,Cu2+ with propyl gallate(PG) in water were studied.The solid complexes of PG-Fe,PG-Cr,PG-Cu were characterized by UV-Vis,1H NMR,IR,MS,elemental analysis,molar conductance and cyclic voltammetry.The results support the formation of the complexes with the formulae[C10H10O5]2Fe·H2O,[C10H10O5]3 Cr·2H2O and[C10H10O5]10 Cu·2H2O for investigated metal cations.The IR spectra show that the phenol hydroxyl group was coordinated to the metal center to form the Ph-O-M bond.The electrochemical data suggest that the metal complexes were more effective antioxidants than PG ligand,and the antioxidative property follows the order:PG-Cu>PG-Cr>PG-Fe.The superoxide dismutase(SOD) like activity of the metal complexes was measured by means of a reduction of NBT by VB2.The results indicate that the three metal complexes could catalyze the disproportionation of the superoxide anion free radical(O2-·),and could be used as the active center model complexes of SOD.
The interactions of Fe3+,Cr3+,Cu2+ with propyl gallate(PG) in water were studied.The solid complexes of PG-Fe,PG-Cr,PG-Cu were characterized by UV-Vis,1H NMR,IR,MS,elemental analysis,molar conductance and cyclic voltammetry.The results support the formation of the complexes with the formulae[C10H10O5]2Fe·H2O,[C10H10O5]3 Cr·2H2O and[C10H10O5]10 Cu·2H2O for investigated metal cations.The IR spectra show that the phenol hydroxyl group was coordinated to the metal center to form the Ph-O-M bond.The electrochemical data suggest that the metal complexes were more effective antioxidants than PG ligand,and the antioxidative property follows the order:PG-Cu>PG-Cr>PG-Fe.The superoxide dismutase(SOD) like activity of the metal complexes was measured by means of a reduction of NBT by VB2.The results indicate that the three metal complexes could catalyze the disproportionation of the superoxide anion free radical(O2-·),and could be used as the active center model complexes of SOD.
2010, 27(3): 333-337
doi: 10.3724/SP.J.1095.2010.90200
Abstract:
CuC2O4 porous spheres were prepared on a large scale by a mild aqueous solution method at 100℃ for 10 h with CuCl2 and H2 C2 O4 as raw materials.Structures and morphologies of as-products were characterized by X-ray powder diffraction(XRD) and scanning electron microscopy(SEM).The influences of experimental conditions such as the concentration of reactants,reactive temperature and the size of anions on the structures and morphologies of as-products were investigated.The results show that as-products were monoclinic structural CuC2O4 porous spheres with a diameter of 400~540 nm.Each porous sphere was made of many nanoparticles with a size of 50~80 nm.Reaction temperature had more effect on the size of CuC2O4 porous spheres.The concentrations of reactants and the volume of anions affect the size of the aggregates of particles.So through tuning the experimental conditions,CuC2O4 porous spheres could be controlled-synthesized.The formation mechanism of CuC2O4 porous spheres based on an etching effect was discussed.
CuC2O4 porous spheres were prepared on a large scale by a mild aqueous solution method at 100℃ for 10 h with CuCl2 and H2 C2 O4 as raw materials.Structures and morphologies of as-products were characterized by X-ray powder diffraction(XRD) and scanning electron microscopy(SEM).The influences of experimental conditions such as the concentration of reactants,reactive temperature and the size of anions on the structures and morphologies of as-products were investigated.The results show that as-products were monoclinic structural CuC2O4 porous spheres with a diameter of 400~540 nm.Each porous sphere was made of many nanoparticles with a size of 50~80 nm.Reaction temperature had more effect on the size of CuC2O4 porous spheres.The concentrations of reactants and the volume of anions affect the size of the aggregates of particles.So through tuning the experimental conditions,CuC2O4 porous spheres could be controlled-synthesized.The formation mechanism of CuC2O4 porous spheres based on an etching effect was discussed.
2010, 27(3): 338-341
doi: 10.3724/SP.J.1095.2010.90242
Abstract:
A series of hydrotalcite samples with varied Mg/Al ratios were synthesized by coprecipitation route.Quantitative analysis on the basic sites of hydrotalcite samples was carried out by CO2-TPD(temperature programmed desorption) technique which was calibrated by calcium carbonate internal standard,and the effects of various experimental factors on the precision of testing results were evaluated.The relative standard deviation(RSD) of the experiments shows that the precision of test is obviously improved under the condition that the internal standard calibration is applied.Moreover,combined with the internal standard quantitative CO2-TPD-MS technique,the investigation on the catalytic performance of hydrotalcites in transesterification demonstrates that the solid base with the stronger alkalinity and the higher density of basic sites presents the higher catalytic activity.
A series of hydrotalcite samples with varied Mg/Al ratios were synthesized by coprecipitation route.Quantitative analysis on the basic sites of hydrotalcite samples was carried out by CO2-TPD(temperature programmed desorption) technique which was calibrated by calcium carbonate internal standard,and the effects of various experimental factors on the precision of testing results were evaluated.The relative standard deviation(RSD) of the experiments shows that the precision of test is obviously improved under the condition that the internal standard calibration is applied.Moreover,combined with the internal standard quantitative CO2-TPD-MS technique,the investigation on the catalytic performance of hydrotalcites in transesterification demonstrates that the solid base with the stronger alkalinity and the higher density of basic sites presents the higher catalytic activity.
2010, 27(3): 342-346
doi: 10.3724/SP.J.1095.2010.90183
Abstract:
Spectrophotometric determination of carboxylic acids in aqueous solutions has been developed based on the formation of hydroximic acid from carboxylic acid in the presence of hydroxylamine perchlorate(HAP) and dlcyclohexylcarbodiimide(DCC) as well as the formation of purple ferric hydroxamate from hydroximic acid in the presence of acidic ferric perchlorate solution.We have investigated the effects of acidity,concentration and addition volume of ferric perchlorate,concentration and addition volume of DCC and HAP,and reaction temperature and reaction time on the absorbance.The results illustrate that this reaction has the largest absorbance under the follow conditions:conditions of reaction:1.0 mL of 0.0687 mol/L HAP,0.5 mL of 0.6 mol/L DCC,after shaken,incubation of reaction mixture for 15 min at room temperature;conditions of pigmentation:0.02 mol/L acidic ferric perchlorate solution(0.3 mol/L perchloric acid). Working curves of n-butyric,n-valeric and benzoic acid have also been investigated,which indicate that this method is simple,easy to use,precise,and has a wide linear range.It can be applied to those carboxylic acids which are difficult to extract from aqueous solutions,and the application of this method for the determination of various kinds of acids in the eluate after chromatographic separation are expected to be advantageous.
Spectrophotometric determination of carboxylic acids in aqueous solutions has been developed based on the formation of hydroximic acid from carboxylic acid in the presence of hydroxylamine perchlorate(HAP) and dlcyclohexylcarbodiimide(DCC) as well as the formation of purple ferric hydroxamate from hydroximic acid in the presence of acidic ferric perchlorate solution.We have investigated the effects of acidity,concentration and addition volume of ferric perchlorate,concentration and addition volume of DCC and HAP,and reaction temperature and reaction time on the absorbance.The results illustrate that this reaction has the largest absorbance under the follow conditions:conditions of reaction:1.0 mL of 0.0687 mol/L HAP,0.5 mL of 0.6 mol/L DCC,after shaken,incubation of reaction mixture for 15 min at room temperature;conditions of pigmentation:0.02 mol/L acidic ferric perchlorate solution(0.3 mol/L perchloric acid). Working curves of n-butyric,n-valeric and benzoic acid have also been investigated,which indicate that this method is simple,easy to use,precise,and has a wide linear range.It can be applied to those carboxylic acids which are difficult to extract from aqueous solutions,and the application of this method for the determination of various kinds of acids in the eluate after chromatographic separation are expected to be advantageous.
2010, 27(3): 347-352
doi: 10.3724/SP.J.1095.2010.90299
Abstract:
Two carbonyl triruthenium metal clusters were separated with cellulose tris(3,5-dimethylphenyl-carbamate)(CDMPC) as chiral stationary phase.The effects of the optimal conditions were determined according to the effects of the mobile phase composition,the flow rate of the mobile phase and the solvents of the samples etc on the chiral separation of the metal clusters.The results show that good chiral separations of cluster 1 and cluster 2 were obtained,respectively,using the mobile phase with ethanol(V(hexane):V(ethanol)=95:5) and 2-propanol(V(hexane):V(2-propanol)=90:10).The solvents of the samples with similar composition to that of the mobile phase were beneficial to the chiral separation of the clusters.The structures of the metal-chelated ligand exerted an important influence on the retention and chiral separation of the metal clusters. The Rs of the clusters were above 1.5 under the optimal conditions.
Two carbonyl triruthenium metal clusters were separated with cellulose tris(3,5-dimethylphenyl-carbamate)(CDMPC) as chiral stationary phase.The effects of the optimal conditions were determined according to the effects of the mobile phase composition,the flow rate of the mobile phase and the solvents of the samples etc on the chiral separation of the metal clusters.The results show that good chiral separations of cluster 1 and cluster 2 were obtained,respectively,using the mobile phase with ethanol(V(hexane):V(ethanol)=95:5) and 2-propanol(V(hexane):V(2-propanol)=90:10).The solvents of the samples with similar composition to that of the mobile phase were beneficial to the chiral separation of the clusters.The structures of the metal-chelated ligand exerted an important influence on the retention and chiral separation of the metal clusters. The Rs of the clusters were above 1.5 under the optimal conditions.
2010, 27(3): 353-357
doi: 10.3724/SP.J.1095.2010.90208
Abstract:
A silver doped poly(L-aspartic acid) modified electrode(Ag-PLA/GCE) was prepared by electrochemical immobilization of silver and L-aspartic acid on a glassy carbon electrode surface.The polymerization conditions and the electrochemical behavior of epinephrine were studied.A novel cyclic voltammetric method was proposed for the determination of epinephrine.In a pH=3.5 phosphate buffer solution,a pair of redox peaks were observed at peak potential Epa=0.447 V and Epc=0.387 V(vs.Ag/AgCl) at a scan rate of 50 mV/s.By cyclic voltammetry,the oxidation peak current of epinephrine was proportional to the concentration in a range of 8.00×10-8~1.00×10-5 mol/L and that of 1.00×10-5~1.00×10-4 mol/L.The detection limit was 8.0×10-9 mol/L.
A silver doped poly(L-aspartic acid) modified electrode(Ag-PLA/GCE) was prepared by electrochemical immobilization of silver and L-aspartic acid on a glassy carbon electrode surface.The polymerization conditions and the electrochemical behavior of epinephrine were studied.A novel cyclic voltammetric method was proposed for the determination of epinephrine.In a pH=3.5 phosphate buffer solution,a pair of redox peaks were observed at peak potential Epa=0.447 V and Epc=0.387 V(vs.Ag/AgCl) at a scan rate of 50 mV/s.By cyclic voltammetry,the oxidation peak current of epinephrine was proportional to the concentration in a range of 8.00×10-8~1.00×10-5 mol/L and that of 1.00×10-5~1.00×10-4 mol/L.The detection limit was 8.0×10-9 mol/L.
2010, 27(3): 358-362
doi: 10.3724/SP.J.1095.2010.90239
Abstract:
The effects of aluminum substrate treatment,sintering temperature and film thickness on solar absorptance of the Ni-Al2O3 composite films were investigated.The optimal coating on aluminum substrates treated by a H3PO4-CrO3 solution after mechanical polishing had a nickel mole fraction of 80%,a sol concentration of 0.8 mol/L.The suitable sitering temperature is 600℃.Such prepared film has a good solar absorptance.
The effects of aluminum substrate treatment,sintering temperature and film thickness on solar absorptance of the Ni-Al2O3 composite films were investigated.The optimal coating on aluminum substrates treated by a H3PO4-CrO3 solution after mechanical polishing had a nickel mole fraction of 80%,a sol concentration of 0.8 mol/L.The suitable sitering temperature is 600℃.Such prepared film has a good solar absorptance.
2010, 27(3): 363-366
doi: 10.3724/SP.J.1095.2010.90180
Abstract:
A method for fabrication of glucose electrochemical biosensor based on simultaneously embedding gold nanoparticles and glucose oxidase in silica sol-gel network on gold electrode surface was investigated.The preparation conditions were optimized.The enzyme electrode displayed an excellent electrocatalytic response to glucose.The glucose sensor had a linear range from 0.02 to 2.0 mmol/L and a detection limit of 0.005 mmol/L.It was found that the response current to glucose was decreased by about 8% after storage for 100 days at 4℃.The biosensor exhibited high sensitivity,rapid response and good long-term stability.
A method for fabrication of glucose electrochemical biosensor based on simultaneously embedding gold nanoparticles and glucose oxidase in silica sol-gel network on gold electrode surface was investigated.The preparation conditions were optimized.The enzyme electrode displayed an excellent electrocatalytic response to glucose.The glucose sensor had a linear range from 0.02 to 2.0 mmol/L and a detection limit of 0.005 mmol/L.It was found that the response current to glucose was decreased by about 8% after storage for 100 days at 4℃.The biosensor exhibited high sensitivity,rapid response and good long-term stability.
2010, 27(3): 367-369
doi: 10.3724/SP.J.1095.2010.90283
Abstract:
With substituted azoaromatic diacid and thionyl chloride as starting materials,eight substituted azobenzene diacyl chlorides were first synthesized under ultrasonic irradiation.Compared with that of conventional heating method,the reaction time was shortened from 12 to 4 h,and the yields were in the range of 80%~95%.The structures of all as-prepared products were characterized by 1H NMR,IR spectra and elemental analysis.
With substituted azoaromatic diacid and thionyl chloride as starting materials,eight substituted azobenzene diacyl chlorides were first synthesized under ultrasonic irradiation.Compared with that of conventional heating method,the reaction time was shortened from 12 to 4 h,and the yields were in the range of 80%~95%.The structures of all as-prepared products were characterized by 1H NMR,IR spectra and elemental analysis.
2010, 27(3): 370-372
doi: 10.3724/SP.J.1095.2010.90361
Abstract:
A new process for the Brominations of aromatic amines and phenols was reported.The reactions were carried out at room temperature with CHCl3, EtOH or EtOH/CHCl3 as solvent,selective monobromination of some aromatic amines and phenols occurred(five substrates were investigated) at a ratio of N-bromosuccinimide to substrate 1:1,the yields were 92%~98%.Dibromination of some aromatic amines and phenols occur smoothly(five substrates were investigated),at a ratio of N-bromosuccinimide to substrate 2:1,the yields were 90%~97%.As a green and environmentally benign method,the Brominations of aromatic amines and phenols could be achieved at room temperature without using catalysts.In addition,the final products could be collected after filtration and washing process.
A new process for the Brominations of aromatic amines and phenols was reported.The reactions were carried out at room temperature with CHCl3, EtOH or EtOH/CHCl3 as solvent,selective monobromination of some aromatic amines and phenols occurred(five substrates were investigated) at a ratio of N-bromosuccinimide to substrate 1:1,the yields were 92%~98%.Dibromination of some aromatic amines and phenols occur smoothly(five substrates were investigated),at a ratio of N-bromosuccinimide to substrate 2:1,the yields were 90%~97%.As a green and environmentally benign method,the Brominations of aromatic amines and phenols could be achieved at room temperature without using catalysts.In addition,the final products could be collected after filtration and washing process.
