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2005 Volume 22 Issue 5
2005, 22(5): 465-469
Abstract:
By means of UV-Vis spectrophotomeric technique,the thermodynamic behavior of chiral Salen iron (Ⅲ)) complexes 1,2 and 3 with imidazole in CHCl3 was studied.The results show that the association constants decrease in the order of K(sym-Salen FeⅢ)> K(unsym-Salen FeⅢ)> K(t-Bu-Salen FeⅢ) for the axial coordination reaction of different Salen iron (Ⅲ) complexes with the same imidazole ligands.The thermodynamic parameters ΔrHmθ,ΔrSmθ of the axial coordination process were determined,and it was found that the axial coordination reaction is an exothermic and entropy decrease process.The favourable enthalpy change compensates the unfavourable entropy change,and the compensatory enthalpy-entropy relationship contributes to the stability of the axial coordinated product.The results obtained from the circular dichroism spectra are consistent with those from the thermodynamics.
By means of UV-Vis spectrophotomeric technique,the thermodynamic behavior of chiral Salen iron (Ⅲ)) complexes 1,2 and 3 with imidazole in CHCl3 was studied.The results show that the association constants decrease in the order of K(sym-Salen FeⅢ)> K(unsym-Salen FeⅢ)> K(t-Bu-Salen FeⅢ) for the axial coordination reaction of different Salen iron (Ⅲ) complexes with the same imidazole ligands.The thermodynamic parameters ΔrHmθ,ΔrSmθ of the axial coordination process were determined,and it was found that the axial coordination reaction is an exothermic and entropy decrease process.The favourable enthalpy change compensates the unfavourable entropy change,and the compensatory enthalpy-entropy relationship contributes to the stability of the axial coordinated product.The results obtained from the circular dichroism spectra are consistent with those from the thermodynamics.
2005, 22(5): 470-474
Abstract:
The effects of the calcination temperature of precursor TiOx/SiO2 and the drying time for catalyst Rh-Mn-Li-Ti/SiO2(ω(Ti)=0.005%) on its performance for the synthesis of C2-oxygenates from syngas were investigated by means of CO hydrogenation,temperature-programmed reduction (TPR),and temperature-programmed desorption (CO-TPD).The results obtained show that the calcination temperature of the precursor TiOx/SiO2 has a significant effect on the catalytic activity of Rh-Mn-Li-Ti/SiO2 in the formation of C2-oxygenates.The catalyst calcined at 873 K yielded 395.0 g/(kg(cat)·h) C2-oxygenates with 46.1% selectivity toward C2-oxygenates based on carbon.When the drying time of the catalyst was prolonged properly,the yield of C2-oxygenates reached 425.8 g/(kg(cat)·h),with little change in the C2-oxygenates selectivity.The TPR results suggest that the calcination temperature of TiOx/SiO2 and the drying time of the catalyst Rh-Mn-Li-Ti/SiO2 could regulate the interaction between the Rh species with the Mn species,and weak interactions between the Rh species and the Mn species would lead to higher catalytic performance.CO-TPD results indicate that both CO desorption peaks shifted to lower temperatures when the calcination temperature of TiOx/SiO2 was higher.
The effects of the calcination temperature of precursor TiOx/SiO2 and the drying time for catalyst Rh-Mn-Li-Ti/SiO2(ω(Ti)=0.005%) on its performance for the synthesis of C2-oxygenates from syngas were investigated by means of CO hydrogenation,temperature-programmed reduction (TPR),and temperature-programmed desorption (CO-TPD).The results obtained show that the calcination temperature of the precursor TiOx/SiO2 has a significant effect on the catalytic activity of Rh-Mn-Li-Ti/SiO2 in the formation of C2-oxygenates.The catalyst calcined at 873 K yielded 395.0 g/(kg(cat)·h) C2-oxygenates with 46.1% selectivity toward C2-oxygenates based on carbon.When the drying time of the catalyst was prolonged properly,the yield of C2-oxygenates reached 425.8 g/(kg(cat)·h),with little change in the C2-oxygenates selectivity.The TPR results suggest that the calcination temperature of TiOx/SiO2 and the drying time of the catalyst Rh-Mn-Li-Ti/SiO2 could regulate the interaction between the Rh species with the Mn species,and weak interactions between the Rh species and the Mn species would lead to higher catalytic performance.CO-TPD results indicate that both CO desorption peaks shifted to lower temperatures when the calcination temperature of TiOx/SiO2 was higher.
2005, 22(5): 475-478
Abstract:
The rheology of Mg-Fe-HTlc/kaolin suspensions and that of pure kaolin suspensions were studied.The effects of mass ratio of HTlc to kaolin (R),pH,electrolyte (NaCl,MgCl2) and partially hydrolyzed polyacrylamide (PHPA) on the shear stress (τ) of the suspensions were studied.The results show that the τ value of Mg-Fe-HTlc/kaolin suspension decreased first and then increased with the increase of R.The increase in pH made the τ value of pure kaolin suspension increase first (pH<8) and then decrease (pH>8),but the τ value of Mg-Fe HTlc/kaolin suspension increased with the increase of pH all the time.The τ value of pure kaolin suspension decreased with addition of electrolytes.However,the τ value of HTlc/kaolin suspension with R=0.129 increased with the concentration of electrolytes.The τ values of the two suspensions were reduced by PHPA.The effect mechanism was discussed.
The rheology of Mg-Fe-HTlc/kaolin suspensions and that of pure kaolin suspensions were studied.The effects of mass ratio of HTlc to kaolin (R),pH,electrolyte (NaCl,MgCl2) and partially hydrolyzed polyacrylamide (PHPA) on the shear stress (τ) of the suspensions were studied.The results show that the τ value of Mg-Fe-HTlc/kaolin suspension decreased first and then increased with the increase of R.The increase in pH made the τ value of pure kaolin suspension increase first (pH<8) and then decrease (pH>8),but the τ value of Mg-Fe HTlc/kaolin suspension increased with the increase of pH all the time.The τ value of pure kaolin suspension decreased with addition of electrolytes.However,the τ value of HTlc/kaolin suspension with R=0.129 increased with the concentration of electrolytes.The τ values of the two suspensions were reduced by PHPA.The effect mechanism was discussed.
2005, 22(5): 479-483
Abstract:
The effects of sodium lignosulphonate (MJ(0)) and its three fractions (MJ(1),MJ(2),MJ(3)) on the slurryabilities of Yangquan,Hebi,Huainan,Tangshan and Beisu coals as well as the rheological behavior of the coal water slurries (CWS) were studied.In comparison with MJ(0),MJ(1) can increase the CWS concentrations of above mentioned five coals by 0.8%~2.0% at a viscosity of 1 000 mPa·s,in particular by 2.0% and 1.3% for Beisu and Huainan coals,respectively.The saturated adsorption amounts of (MJ(1)) on Hebi and Huainan coals in the first step were increased,and the Zeta potential of the corresponding coal particles was increased as well.The dispersion ability of (MJ(3)) to coal particles,its adsorption amount on coal surface,and the Zeta potential of the corresponding system are lower than that for MJ(0).The lower the molecular weight and stronger the hydrophicility of the fraction,the poorer the dispersion ability.
The effects of sodium lignosulphonate (MJ(0)) and its three fractions (MJ(1),MJ(2),MJ(3)) on the slurryabilities of Yangquan,Hebi,Huainan,Tangshan and Beisu coals as well as the rheological behavior of the coal water slurries (CWS) were studied.In comparison with MJ(0),MJ(1) can increase the CWS concentrations of above mentioned five coals by 0.8%~2.0% at a viscosity of 1 000 mPa·s,in particular by 2.0% and 1.3% for Beisu and Huainan coals,respectively.The saturated adsorption amounts of (MJ(1)) on Hebi and Huainan coals in the first step were increased,and the Zeta potential of the corresponding coal particles was increased as well.The dispersion ability of (MJ(3)) to coal particles,its adsorption amount on coal surface,and the Zeta potential of the corresponding system are lower than that for MJ(0).The lower the molecular weight and stronger the hydrophicility of the fraction,the poorer the dispersion ability.
2005, 22(5): 484-488
Abstract:
A novel method was presented for simultaneous determination of nitrite,nitrate and chloro-phenols by means of capillary electrophoresis combined with a dual-channel electrochemical detection system.Two detectors,including an amperometric detector and a conductivity detector,were connected in parallel to the same capillary electrophoresis system and were simultaneously performed for detecting all the samples.The effects of some important factors such as buffer,working electrode,working potential and separation voltage on separation were investigated.The results show that under the optimum condition of 25 μm (i.d.)×70 cm (l.) capillary,13 kV separation voltage,15.0 mmol/L borax-15.5 mmol/L KH2PO4(pH=8.6) buffer,PAD modified carbon paste electrode and 1.0 V(vs.SCE) detection potential (amperometric detection),six samples were eluted in 14 min,and the detection limits were 0.02~0.05 mg/L.The response was linear in the range of 0.05~30.0 mg/L.The relative standard deviations (n=8) of peak current and migration time were 2.0%~3.4%.The method was successfully applied to analyze waste water samples with satisfactory assay results.Sample recovery rates were 97.2%~106%.
A novel method was presented for simultaneous determination of nitrite,nitrate and chloro-phenols by means of capillary electrophoresis combined with a dual-channel electrochemical detection system.Two detectors,including an amperometric detector and a conductivity detector,were connected in parallel to the same capillary electrophoresis system and were simultaneously performed for detecting all the samples.The effects of some important factors such as buffer,working electrode,working potential and separation voltage on separation were investigated.The results show that under the optimum condition of 25 μm (i.d.)×70 cm (l.) capillary,13 kV separation voltage,15.0 mmol/L borax-15.5 mmol/L KH2PO4(pH=8.6) buffer,PAD modified carbon paste electrode and 1.0 V(vs.SCE) detection potential (amperometric detection),six samples were eluted in 14 min,and the detection limits were 0.02~0.05 mg/L.The response was linear in the range of 0.05~30.0 mg/L.The relative standard deviations (n=8) of peak current and migration time were 2.0%~3.4%.The method was successfully applied to analyze waste water samples with satisfactory assay results.Sample recovery rates were 97.2%~106%.
2005, 22(5): 489-493
Abstract:
Chlorotriphenyltin (TPTCl) is one of the major components of ship fouling paints.The spectral characteristics of the interaction of TPTCl with Bovine Serum Albumin (BSA) were studied.The results show that BSA coordinates with the tin ion of the TPTCl,resulting in the exposure of aromatic heterocycle residues of tryptophane and tyrosine in BSA moledule,the benzene ring of TPTCl interacts with BSA through hydrophobic action,which leads to contraction of BSA molecules.The obvious hyperchromic effect was observed in the UV spectra at the beginning,which then weakened with the reaction time.In addition,the UV spectra and the CD spectra show that TPTCl mainly interacts with BSA through coordination when the TPTCl concentration is low,whereas the hydrophobic interaction dominates when the TPTCl concentration is high.The various buffer solutions added favors the interaction of TPTCl and BSA to different extent.The order from strong to weak of hyperchromic effects was KH2PO4-NaOH system,Tris-HCl system,HAc-NaAc system,and no buffer system.
Chlorotriphenyltin (TPTCl) is one of the major components of ship fouling paints.The spectral characteristics of the interaction of TPTCl with Bovine Serum Albumin (BSA) were studied.The results show that BSA coordinates with the tin ion of the TPTCl,resulting in the exposure of aromatic heterocycle residues of tryptophane and tyrosine in BSA moledule,the benzene ring of TPTCl interacts with BSA through hydrophobic action,which leads to contraction of BSA molecules.The obvious hyperchromic effect was observed in the UV spectra at the beginning,which then weakened with the reaction time.In addition,the UV spectra and the CD spectra show that TPTCl mainly interacts with BSA through coordination when the TPTCl concentration is low,whereas the hydrophobic interaction dominates when the TPTCl concentration is high.The various buffer solutions added favors the interaction of TPTCl and BSA to different extent.The order from strong to weak of hyperchromic effects was KH2PO4-NaOH system,Tris-HCl system,HAc-NaAc system,and no buffer system.
2005, 22(5): 494-497
Abstract:
Chitosan schiff-base was synthesized via the reaction of chitosan with salicylaldehyde,which reacted with a palladium salt to obtain a chitosan schiff-base coordinated palladium catalyst.Using the reaction between iodobenzene and acrylic acid as a model,we studied the activity of this catalyst.The effects of different reaction conditions (reaction temperature,molar ratio of iodobenzene to acrylic acid,catalyst loading,kind and quantity of base and solvent) on the yield were investigated.The best conditions for the reaction were established as PhI 10 mmol;n(PhI):n(AA)=1:1.5;Et3N 27 mmol;catalyst (mass fraction 2%) 0.1 g;solvent DMF 6 mL;70℃ for 7 h.Under the above best conditions,the yield was 90.7%.The catalyst was separated from the reaction mixture via filtration washed with solvent,and then reused.After 6 cycles no significant loss of catalyst activity was observed.
Chitosan schiff-base was synthesized via the reaction of chitosan with salicylaldehyde,which reacted with a palladium salt to obtain a chitosan schiff-base coordinated palladium catalyst.Using the reaction between iodobenzene and acrylic acid as a model,we studied the activity of this catalyst.The effects of different reaction conditions (reaction temperature,molar ratio of iodobenzene to acrylic acid,catalyst loading,kind and quantity of base and solvent) on the yield were investigated.The best conditions for the reaction were established as PhI 10 mmol;n(PhI):n(AA)=1:1.5;Et3N 27 mmol;catalyst (mass fraction 2%) 0.1 g;solvent DMF 6 mL;70℃ for 7 h.Under the above best conditions,the yield was 90.7%.The catalyst was separated from the reaction mixture via filtration washed with solvent,and then reused.After 6 cycles no significant loss of catalyst activity was observed.
2005, 22(5): 498-501
Abstract:
Resonance Light Scattering (RLS) probe technique was applied in the quantitative determination of proteins in the binding media of different dyes in Dunhuang Wall Painting via the interaction between Bromophenol Blue (BPB) and the proteins.In the Britton-Robinson buffer solution (pH=4.06),BPB combines with proteins via intermolecular forces,resulting in resonance light scattering.Bovine serum albumin (BSA) was employed as an analogue of the proteins in the wall paintings.It was found that RLS intensity at 345 nm is proportional to the concentration of the proteins in the range of 0.34×10-6~18.30×10-6 g/mL.The method is suitable for the determination of proteins in the binding media of the wall paintings,and 9.393 8×10-6 g/mg),4.868 8×10-6 g/mg),1.945 4×10-6 g/mg and 1.092 0×10-6 g/mg proteins were detected respectively in the red,white,black and green pigments of the wall paintings.The method is simple,rapid and sensitive.The relative standard deviation was 3.1%.The standard addition recovery rate of proteins was between 95.63% and 104.68%.
Resonance Light Scattering (RLS) probe technique was applied in the quantitative determination of proteins in the binding media of different dyes in Dunhuang Wall Painting via the interaction between Bromophenol Blue (BPB) and the proteins.In the Britton-Robinson buffer solution (pH=4.06),BPB combines with proteins via intermolecular forces,resulting in resonance light scattering.Bovine serum albumin (BSA) was employed as an analogue of the proteins in the wall paintings.It was found that RLS intensity at 345 nm is proportional to the concentration of the proteins in the range of 0.34×10-6~18.30×10-6 g/mL.The method is suitable for the determination of proteins in the binding media of the wall paintings,and 9.393 8×10-6 g/mg),4.868 8×10-6 g/mg),1.945 4×10-6 g/mg and 1.092 0×10-6 g/mg proteins were detected respectively in the red,white,black and green pigments of the wall paintings.The method is simple,rapid and sensitive.The relative standard deviation was 3.1%.The standard addition recovery rate of proteins was between 95.63% and 104.68%.
2005, 22(5): 502-506
Abstract:
The present paper deals with the preparation and characterization of new tris-cyclometalated iridium complexes with p-substituted-2-phenylbenzothiazol ligands.The device performance was tested with a general OLED architecture of ITO (indium tin oxide)/poly (3,4-ethylenedioxythiophene)(PEDOT)/Ir (bpmp)3/Ca/Al,where PEDOT was used as the hole transporting layer and Ir-complex as the emissive layer.The Orange-red electrophosphorescence (emission peak at 550~650 nm) turned at around 5 V,with a maximum brightness of 20 cd/m2 at 19 V.Both the current efficiency (4×10-3 cd/A) and the power efficiency (9×10-4 lm/W)) were low due to the triplet-triplet annihilation and concentration quenching arising from strong bimolecular interactions when only using Ir-complex as the emissive layer.Further optimization of OLED performance can be expected by blending conjugated polymers with Ir-complexes and by better engineering of the device structure.
The present paper deals with the preparation and characterization of new tris-cyclometalated iridium complexes with p-substituted-2-phenylbenzothiazol ligands.The device performance was tested with a general OLED architecture of ITO (indium tin oxide)/poly (3,4-ethylenedioxythiophene)(PEDOT)/Ir (bpmp)3/Ca/Al,where PEDOT was used as the hole transporting layer and Ir-complex as the emissive layer.The Orange-red electrophosphorescence (emission peak at 550~650 nm) turned at around 5 V,with a maximum brightness of 20 cd/m2 at 19 V.Both the current efficiency (4×10-3 cd/A) and the power efficiency (9×10-4 lm/W)) were low due to the triplet-triplet annihilation and concentration quenching arising from strong bimolecular interactions when only using Ir-complex as the emissive layer.Further optimization of OLED performance can be expected by blending conjugated polymers with Ir-complexes and by better engineering of the device structure.
2005, 22(5): 507-510
Abstract:
In the traditional oxidation process an Fe(Ⅲ) compound is put into a high-alkali solution of sodium hypochorite to produce a ferrate (Ⅵ) solution.In this work ferric chloride was converted into potassium fluoferrite,which was used to produce a ferrate (Ⅵ) solution.The results show that the yield was obviously improved,and the product stability was increased.The process conditions were optimized.Ferric chloride and potassium fluoride were mixed in a mole ratio of 1:9 to produce potassium fluoferrite,which was put into a high-alkali solution of sodium hypochlorite at a constant temperature of 45℃ for 90 min,and the product concentration of the Ferrate (Ⅵ) solution reached about 0.2 mol/L.
In the traditional oxidation process an Fe(Ⅲ) compound is put into a high-alkali solution of sodium hypochorite to produce a ferrate (Ⅵ) solution.In this work ferric chloride was converted into potassium fluoferrite,which was used to produce a ferrate (Ⅵ) solution.The results show that the yield was obviously improved,and the product stability was increased.The process conditions were optimized.Ferric chloride and potassium fluoride were mixed in a mole ratio of 1:9 to produce potassium fluoferrite,which was put into a high-alkali solution of sodium hypochlorite at a constant temperature of 45℃ for 90 min,and the product concentration of the Ferrate (Ⅵ) solution reached about 0.2 mol/L.
2005, 22(5): 511-516
Abstract:
This paper presents a high-performance liquid chromatography-UV detection analytical method for the determination of tris (2,4-di-tert-butylphenyl) phosphite (TBP) and its poisonous impurity 2,4-di-tert-butylphenol (DBP).The separation between TBP and DBP was performed on a Kromasil C18 column,5 μm,150 mm×4.6 mm (i.d.),and the quantitation was achieved with UV detection at 275 nm.The column temperature was maintained at 30℃.The mobile phase was a mixture of methanol and water and run at a flow rate of 1.0 mL/min,and a two-step linear gradient elution,0~5 min,V(methanol):V(water)=95:5;5~25 min,V(methanol):V(water)=100:0,was adopted.The calibration curves were linear in the concentration ranges of 1.0×10-6~1.0×10-3 g/mL of TBP and 1.0×10-7~1.0×10-4 g/mL of DBP,respec-tively,with correlation coefficients of 0.999 94 and 0.999 95.The detection limits were 1.0×10-7 g/mL for TBP and 1.0×10-8 g/mL for DBP.Good reproducibility was obtained for the determinations of TBP and DBP in real industrial samples with relative standard deviations of 0.1% and 1.8%,respectively.The DBP analysis result obtained by HPLC were compared with that by spectrophotometry,and it was found that the spectrometric method was unable to determine DBP in TBP accurately.Two impurities were identified by LC-MS.The structure of another impurity was estimated according to its UV-Vis spectrum and chromatographic behavior.All these three impurities in antioxidant 168 were TBP derivatives with fewer tert-butyl substituents.When an isocratic elution was used:(0~20 min,V(methanol):V(water)=100:0),this method was applied to analyze TBP in composite antioxidants with a relative standard deviation of 0.7% and a recovery rate of 101%.
This paper presents a high-performance liquid chromatography-UV detection analytical method for the determination of tris (2,4-di-tert-butylphenyl) phosphite (TBP) and its poisonous impurity 2,4-di-tert-butylphenol (DBP).The separation between TBP and DBP was performed on a Kromasil C18 column,5 μm,150 mm×4.6 mm (i.d.),and the quantitation was achieved with UV detection at 275 nm.The column temperature was maintained at 30℃.The mobile phase was a mixture of methanol and water and run at a flow rate of 1.0 mL/min,and a two-step linear gradient elution,0~5 min,V(methanol):V(water)=95:5;5~25 min,V(methanol):V(water)=100:0,was adopted.The calibration curves were linear in the concentration ranges of 1.0×10-6~1.0×10-3 g/mL of TBP and 1.0×10-7~1.0×10-4 g/mL of DBP,respec-tively,with correlation coefficients of 0.999 94 and 0.999 95.The detection limits were 1.0×10-7 g/mL for TBP and 1.0×10-8 g/mL for DBP.Good reproducibility was obtained for the determinations of TBP and DBP in real industrial samples with relative standard deviations of 0.1% and 1.8%,respectively.The DBP analysis result obtained by HPLC were compared with that by spectrophotometry,and it was found that the spectrometric method was unable to determine DBP in TBP accurately.Two impurities were identified by LC-MS.The structure of another impurity was estimated according to its UV-Vis spectrum and chromatographic behavior.All these three impurities in antioxidant 168 were TBP derivatives with fewer tert-butyl substituents.When an isocratic elution was used:(0~20 min,V(methanol):V(water)=100:0),this method was applied to analyze TBP in composite antioxidants with a relative standard deviation of 0.7% and a recovery rate of 101%.
2005, 22(5): 517-520
Abstract:
2-Sulfanilylpyrimidine (sulfadiazine) sodium was used to initiate the ring-opening polymerization of ethylene oxide to form sodium sulfadiazine poly (ethylene oxide)(PEO) inhomogeneously,and the polymerization was terminated with 3,5-di-(N-acetamino)-2,4,6-triiodobenzoyl chloride to form a bifunctional PEO with a targeting and a contrast-medium group.The reaction time was about 96 h at 80℃.The yield was 87%~90%.The PEO was characterized with IR,1H NMR,and UV.The PEO molecular weights were determined with VPO and GPC.The products with different molecular weights were obtained with different amounts of initiator in the reaction.The molecular weight distribution was narrower when a less amount of initiator was used.The molecular weight range of PEO was from 2 692 to 11 040,and the molecular weight distribution was from 1.195 to 1.704.The content ranges of sulfadiazine group and 3,5-di (N-acetamino)-2,4,6-(triiodobenzoyl) acyl group in PEO with different molecular weights were 2.13%~8.98% and 5.25%~21.72%,respectively.At room temperature,the products dissolve easily in water,DMSO,DMF,THF,chloroform,ethanol,pyridine,propanone,benzene,toluene,etc.
2-Sulfanilylpyrimidine (sulfadiazine) sodium was used to initiate the ring-opening polymerization of ethylene oxide to form sodium sulfadiazine poly (ethylene oxide)(PEO) inhomogeneously,and the polymerization was terminated with 3,5-di-(N-acetamino)-2,4,6-triiodobenzoyl chloride to form a bifunctional PEO with a targeting and a contrast-medium group.The reaction time was about 96 h at 80℃.The yield was 87%~90%.The PEO was characterized with IR,1H NMR,and UV.The PEO molecular weights were determined with VPO and GPC.The products with different molecular weights were obtained with different amounts of initiator in the reaction.The molecular weight distribution was narrower when a less amount of initiator was used.The molecular weight range of PEO was from 2 692 to 11 040,and the molecular weight distribution was from 1.195 to 1.704.The content ranges of sulfadiazine group and 3,5-di (N-acetamino)-2,4,6-(triiodobenzoyl) acyl group in PEO with different molecular weights were 2.13%~8.98% and 5.25%~21.72%,respectively.At room temperature,the products dissolve easily in water,DMSO,DMF,THF,chloroform,ethanol,pyridine,propanone,benzene,toluene,etc.
2005, 22(5): 521-524
Abstract:
The water-soluble amphiphilic derivatives of carboxymethylchitosan (CMCHS),(2-hydroxyl-3-butoxyl) propyl-carboxymethylchitosan (HBP-CMCHS) were prepared via the reaction of CMCHS with butyl glycidol ether.The structure of the resulting derivatives were identified by means of IR,NMR and X-ray diffraction.The surface tension and surface pressure were measured.The results show that HBP-CMCHS can adsorb to the surface to decrease the surface tension of the solution,and the surface pressure of the adsorbed film increases dramatically with the decrease of the surface area.The surface activity increases with the increase of the degree of substitution (DS).For the derivative with DS=42.2%,the surface tension decreased to 32.5 mN/m,which (indicates) that the derivative can be used as a polymeric surfactant.
The water-soluble amphiphilic derivatives of carboxymethylchitosan (CMCHS),(2-hydroxyl-3-butoxyl) propyl-carboxymethylchitosan (HBP-CMCHS) were prepared via the reaction of CMCHS with butyl glycidol ether.The structure of the resulting derivatives were identified by means of IR,NMR and X-ray diffraction.The surface tension and surface pressure were measured.The results show that HBP-CMCHS can adsorb to the surface to decrease the surface tension of the solution,and the surface pressure of the adsorbed film increases dramatically with the decrease of the surface area.The surface activity increases with the increase of the degree of substitution (DS).For the derivative with DS=42.2%,the surface tension decreased to 32.5 mN/m,which (indicates) that the derivative can be used as a polymeric surfactant.
2005, 22(5): 525-529
Abstract:
Magnetic powder particles,which were used for the preparation of magnetic fluids,were modified with a surfactant,oleic acid.The coating on the surface of the magnetic particles was evaluated by UV,and the effects of pH,temperature and time on the surface treatment were analyzed.The results indicate that UV spectral analysis can be used to quantitatively characterize the coating on the magnetic particles.The appro-priate conditions for the surface treatment were identified to be pH=6.90,coating temperature of 80℃,and coating time of 60 min.
Magnetic powder particles,which were used for the preparation of magnetic fluids,were modified with a surfactant,oleic acid.The coating on the surface of the magnetic particles was evaluated by UV,and the effects of pH,temperature and time on the surface treatment were analyzed.The results indicate that UV spectral analysis can be used to quantitatively characterize the coating on the magnetic particles.The appro-priate conditions for the surface treatment were identified to be pH=6.90,coating temperature of 80℃,and coating time of 60 min.
2005, 22(5): 530-533
Abstract:
A new extractant (NPPFA) was synthesized from 2-pyridinecarboxylic acid and pyrrolidine,and its extraction behavior for phenol was studied.The results show that the distribution ratio of phenol is high,and there is no emulsion and the two phases separate easily.By application of the methods of double-logarithmic slope and continuous variation,the composition of the extracted species was determined to be C6H5OH·NPPFA.The enthalpy of the extraction reaction was calculated to be ΔH0=-42.59 kJ/mol based on the Van't Hoff equation.The structure of the extracted species and the mechanism of the extraction reaction were investigated by infrared spectroscopy.
A new extractant (NPPFA) was synthesized from 2-pyridinecarboxylic acid and pyrrolidine,and its extraction behavior for phenol was studied.The results show that the distribution ratio of phenol is high,and there is no emulsion and the two phases separate easily.By application of the methods of double-logarithmic slope and continuous variation,the composition of the extracted species was determined to be C6H5OH·NPPFA.The enthalpy of the extraction reaction was calculated to be ΔH0=-42.59 kJ/mol based on the Van't Hoff equation.The structure of the extracted species and the mechanism of the extraction reaction were investigated by infrared spectroscopy.
2005, 22(5): 534-537
Abstract:
A nano-size TiO2 photocatalyst was prepared readily by the Sol-gel method,and was used to catalyze the degradation of PE films under UV (15 W intensity) irradiation for 240 h in air.The properties of the catalyst and the degraded PE films were characterized by XRD,FT-IR and SEM.The results show that PE films lose only 7.66% of its mass under UV irradiation for 240 h,while Rutile style TiO2 and Anatase TiO2 photocatalysts can increase the mass loss to 14.93%,and 23.97%,respectively,indicating that TiO2 speeds up the breaking and photo oxidation of PE chains.The SEM micrograph of the PE film after photodegradation shows a large number of pits on the film surface.The XRD patterns indicate there was more wax in the degradation products in the presence of TiO2.Anatase style TiO2 exhibited a higher activity than Rutile style TiO2 for the photodegradation of PE films.
A nano-size TiO2 photocatalyst was prepared readily by the Sol-gel method,and was used to catalyze the degradation of PE films under UV (15 W intensity) irradiation for 240 h in air.The properties of the catalyst and the degraded PE films were characterized by XRD,FT-IR and SEM.The results show that PE films lose only 7.66% of its mass under UV irradiation for 240 h,while Rutile style TiO2 and Anatase TiO2 photocatalysts can increase the mass loss to 14.93%,and 23.97%,respectively,indicating that TiO2 speeds up the breaking and photo oxidation of PE chains.The SEM micrograph of the PE film after photodegradation shows a large number of pits on the film surface.The XRD patterns indicate there was more wax in the degradation products in the presence of TiO2.Anatase style TiO2 exhibited a higher activity than Rutile style TiO2 for the photodegradation of PE films.
2005, 22(5): 538-542
Abstract:
A series of interpenetrating polymer networks of o-cresol-formaldehyde epoxy resin (o-CFER)/(polyurethane)(PU) were prepared.The mechanical properties of the interpenetrating polymer network were (optimized) at m(o-CFER):m(PU)=80:20 and the components were synergistic.The morphology was studied by means of SEM and the results show that at this ratio the two phases had good compatibility,and the degree of interpenetration between the two phases was high,which suggests that the synergistic effect on the mechanical performance may be correlated to the ratio and the interpenating degree of o-CFER/PU.The TBA analysis indicates that the glass transition temperature (Tg) increased with the PU content when it was within 30%.The TG result shows that when m(o-CFER):m(PU)=90:10,the stability of the material was the best.
A series of interpenetrating polymer networks of o-cresol-formaldehyde epoxy resin (o-CFER)/(polyurethane)(PU) were prepared.The mechanical properties of the interpenetrating polymer network were (optimized) at m(o-CFER):m(PU)=80:20 and the components were synergistic.The morphology was studied by means of SEM and the results show that at this ratio the two phases had good compatibility,and the degree of interpenetration between the two phases was high,which suggests that the synergistic effect on the mechanical performance may be correlated to the ratio and the interpenating degree of o-CFER/PU.The TBA analysis indicates that the glass transition temperature (Tg) increased with the PU content when it was within 30%.The TG result shows that when m(o-CFER):m(PU)=90:10,the stability of the material was the best.
2005, 22(5): 543-547
Abstract:
Trace amount of copper ions in water was enriched and separated via emulsion membrane,and an atomic absorption spectrophotometry (AAS) method was established for the analysis of the copper ions.The influences of different conditions to the process of enrichment and separation by emulsion membrane are discussed in detail.The experimental results indicate that the copper ions in water can be efficiently enriched and separated by emulsion liquid membrane in the presence of higher concentrations of other heavy metal ions,such as Pb2+,Cd2+,and Cr2O72-.
Trace amount of copper ions in water was enriched and separated via emulsion membrane,and an atomic absorption spectrophotometry (AAS) method was established for the analysis of the copper ions.The influences of different conditions to the process of enrichment and separation by emulsion membrane are discussed in detail.The experimental results indicate that the copper ions in water can be efficiently enriched and separated by emulsion liquid membrane in the presence of higher concentrations of other heavy metal ions,such as Pb2+,Cd2+,and Cr2O72-.
2005, 22(5): 548-550
Abstract:
Seven thermosetting polyimides (PI) were synthesized via the reactions of oxydiphthalic anhydride,thioetherdiphthalic anhydride and active end cap.It was found that the lowest viscosities of the two PI resins end-capped with NA were both under 10 Pa·s,while the lowest viscosities of the PI resins end-capped with phenylethynyl were all around 1~2 Pa·s,and the cure temperature increased to 350℃,which basically meets the requirments of the RTM technology.
Seven thermosetting polyimides (PI) were synthesized via the reactions of oxydiphthalic anhydride,thioetherdiphthalic anhydride and active end cap.It was found that the lowest viscosities of the two PI resins end-capped with NA were both under 10 Pa·s,while the lowest viscosities of the PI resins end-capped with phenylethynyl were all around 1~2 Pa·s,and the cure temperature increased to 350℃,which basically meets the requirments of the RTM technology.
2005, 22(5): 551-553
Abstract:
3-Acetyl-4-hydroxyl coumarin was synthesized by acetylation and acyl chlorination of salicylic acid followed by the cyclocondensation of acetacetic ester.Its condensation with each of three aldehydes,N,N-dimethy-4-aminobenzaldehyde,N,N-di(4-methyphenyl)-4-aminobenzaldehyde and N,N-diphenyl-4-aminobenzaldehyde affords three 4-hydroxyl coumarin derivatives,i.e.,3[(para-dimethyamino)-cinnhyl]-4-hydroxyl coumarin[TM1],3{[para-di(4-methyphenyl) amino]-cinnhyl}-4-(hydroxyl) coumarin[TM2],and 3[(para-diphenylamino)-cinnhyl]-4-hydroxyl coumarin[TM3].The three derivatives have high extinction coefficients in UV-vis absorption,which were 5.25×104 L/(mol·cm),3.39×104 L/(mol·cm),and 3.24×104 L/(mol·cm),respectively,and intensive luminescence in both the THF solution and solid state.Derivatives TM1 and TM2 emit intensive orange red luminescence with the same absorption peak at 500 nm and the identical small Stoke shift of 85 nm in the emission spectra in THF.The photoluminescence peaks of the three derivatives in solid state are at 705,643,and 660 nm,respectively.Derivative TM3 displays intensive red luminescence with the peak at 486 nm and a large Stoke shift of 152 nm in the emission spectrum in THF,which makes it a novel red luminescent material that may be used in OLEDs.
3-Acetyl-4-hydroxyl coumarin was synthesized by acetylation and acyl chlorination of salicylic acid followed by the cyclocondensation of acetacetic ester.Its condensation with each of three aldehydes,N,N-dimethy-4-aminobenzaldehyde,N,N-di(4-methyphenyl)-4-aminobenzaldehyde and N,N-diphenyl-4-aminobenzaldehyde affords three 4-hydroxyl coumarin derivatives,i.e.,3[(para-dimethyamino)-cinnhyl]-4-hydroxyl coumarin[TM1],3{[para-di(4-methyphenyl) amino]-cinnhyl}-4-(hydroxyl) coumarin[TM2],and 3[(para-diphenylamino)-cinnhyl]-4-hydroxyl coumarin[TM3].The three derivatives have high extinction coefficients in UV-vis absorption,which were 5.25×104 L/(mol·cm),3.39×104 L/(mol·cm),and 3.24×104 L/(mol·cm),respectively,and intensive luminescence in both the THF solution and solid state.Derivatives TM1 and TM2 emit intensive orange red luminescence with the same absorption peak at 500 nm and the identical small Stoke shift of 85 nm in the emission spectra in THF.The photoluminescence peaks of the three derivatives in solid state are at 705,643,and 660 nm,respectively.Derivative TM3 displays intensive red luminescence with the peak at 486 nm and a large Stoke shift of 152 nm in the emission spectrum in THF,which makes it a novel red luminescent material that may be used in OLEDs.
2005, 22(5): 554-556
Abstract:
ZnO nanorods were successfully synthesized by thermal decomposition of Zn(OH)2 in the ionic liquid 1-buty -3-ethylimidazolium tetrafluoroborate,and the growth mechanism of ZnO micro-crystallites was presumed.Their structure and morphology were characterized by means of transmission electron microscopy (TEM),infrared spectroscopy (IR),and X-ray powder diffraction (XRD).The TEM results indicate that the diameters and lengths of the ZnO nanorods were ca.25 nm and ca.150 nm,respectively.The IR spectra show that the ZnO nanorods were modified by 1-butyl-3-ethylimidazolium tetrafluoroborate.The XRD pattern reveals that the prepared ZnO nanorods belong to the hexagonal crystal system.The above-mentioned results indicate that ionic liquid can not only act as a reaction medium but also modify ZnO nanorods in the reaction.
ZnO nanorods were successfully synthesized by thermal decomposition of Zn(OH)2 in the ionic liquid 1-buty -3-ethylimidazolium tetrafluoroborate,and the growth mechanism of ZnO micro-crystallites was presumed.Their structure and morphology were characterized by means of transmission electron microscopy (TEM),infrared spectroscopy (IR),and X-ray powder diffraction (XRD).The TEM results indicate that the diameters and lengths of the ZnO nanorods were ca.25 nm and ca.150 nm,respectively.The IR spectra show that the ZnO nanorods were modified by 1-butyl-3-ethylimidazolium tetrafluoroborate.The XRD pattern reveals that the prepared ZnO nanorods belong to the hexagonal crystal system.The above-mentioned results indicate that ionic liquid can not only act as a reaction medium but also modify ZnO nanorods in the reaction.
2005, 22(5): 557-559
Abstract:
The enzymatic (Alcalase 3.0T) hydrolysis process of isolated soybean protein (ISP) and radius distribution of its hydrolysis product were investigated and characterized by laser light scattering (LLS) and ζ-potential methods.With the increase of hydrolysis time,the average hydrodynamic radius of hydrolyzed ISP aggregates decreased from 160 nm to 110 nm,and the hydrodynamic radius distribution of ISP aggregates broadened,and the ζ-potential decreased from -24 mV to about -37 mV.The enzymatic (Alcalase 3.0T) hydrolysis reaction finished within 3h.FTIR spectra of ISP before and after the hydrolysis indicate that the hydrolyzates of ISP had much more non-associated O-H and N-H groups than native ISP.
The enzymatic (Alcalase 3.0T) hydrolysis process of isolated soybean protein (ISP) and radius distribution of its hydrolysis product were investigated and characterized by laser light scattering (LLS) and ζ-potential methods.With the increase of hydrolysis time,the average hydrodynamic radius of hydrolyzed ISP aggregates decreased from 160 nm to 110 nm,and the hydrodynamic radius distribution of ISP aggregates broadened,and the ζ-potential decreased from -24 mV to about -37 mV.The enzymatic (Alcalase 3.0T) hydrolysis reaction finished within 3h.FTIR spectra of ISP before and after the hydrolysis indicate that the hydrolyzates of ISP had much more non-associated O-H and N-H groups than native ISP.
2005, 22(5): 560-562
Abstract:
A concise route for the total syntheses of benzopranylchalcones from 2,4,6-trihydroxyacetophone (3) and citral (8),by means of cyclization,methoxy-protection and aldol-condensation is described.Two benzopranylchalcones,Boesenbergin B(1) and Boesenbergin A(2) were synthesized from 2,4,6-(trihydroxyacetophone)(3),citral (8) and benzaldehyde (9) via the route.The total yields of compounds 1 and 2 were 26% and 11%,respectively.In the cyclization step,the yields of key intermediates 4 and 7 were 40% and 42%,respectively.
A concise route for the total syntheses of benzopranylchalcones from 2,4,6-trihydroxyacetophone (3) and citral (8),by means of cyclization,methoxy-protection and aldol-condensation is described.Two benzopranylchalcones,Boesenbergin B(1) and Boesenbergin A(2) were synthesized from 2,4,6-(trihydroxyacetophone)(3),citral (8) and benzaldehyde (9) via the route.The total yields of compounds 1 and 2 were 26% and 11%,respectively.In the cyclization step,the yields of key intermediates 4 and 7 were 40% and 42%,respectively.
2005, 22(5): 563-565
Abstract:
The optimum conditions for the synthesis of borneol via the reaction of α-pinene and oxalic acid in the presence of nanometer solid superacid catalyst SO42-/ZrO2 were obtained.The results show that when the mole ratio of α-pinene to oxalic acid was 1:0.4,the mass fraction of the catalyst SO42-/ZrO2 to α-pinene 3%,the reaction time 6 h,and the reaction temperature program was 65℃ for 1 h,75℃ for 4 h,90℃ for 1 h,the yield of crude product (borneol) reached 70.9%.This method offers little pollution,high yield,mild reaction condition,good processing safety,and catalyst reusability.
The optimum conditions for the synthesis of borneol via the reaction of α-pinene and oxalic acid in the presence of nanometer solid superacid catalyst SO42-/ZrO2 were obtained.The results show that when the mole ratio of α-pinene to oxalic acid was 1:0.4,the mass fraction of the catalyst SO42-/ZrO2 to α-pinene 3%,the reaction time 6 h,and the reaction temperature program was 65℃ for 1 h,75℃ for 4 h,90℃ for 1 h,the yield of crude product (borneol) reached 70.9%.This method offers little pollution,high yield,mild reaction condition,good processing safety,and catalyst reusability.
2005, 22(5): 566-568
Abstract:
2-[(4-Hydroxyphenyl) sulfonyl]phenol (2,4'-HPSP),a developer for thermo-sensitive record paper,was prepared from phenol and H2SO4 with pseudocumene as solvent.The effects of catalyst type,catalyst amount and reaction time on the yield of 2,4'-HPSP were investigated.Under the optimum conditions,the content of 2,4'-HPSP was 37.52% in the product and the total yield was 95.9%(based on H2SO4).The crude product was purified successively with 2% methanol in o-dichlorobenzene and 30% methanol in water.The purity of the final (2,4'-) HPSP was 95.52%,and the total yield was 26.4%.The solvents used in the purification process could be recycled.
2-[(4-Hydroxyphenyl) sulfonyl]phenol (2,4'-HPSP),a developer for thermo-sensitive record paper,was prepared from phenol and H2SO4 with pseudocumene as solvent.The effects of catalyst type,catalyst amount and reaction time on the yield of 2,4'-HPSP were investigated.Under the optimum conditions,the content of 2,4'-HPSP was 37.52% in the product and the total yield was 95.9%(based on H2SO4).The crude product was purified successively with 2% methanol in o-dichlorobenzene and 30% methanol in water.The purity of the final (2,4'-) HPSP was 95.52%,and the total yield was 26.4%.The solvents used in the purification process could be recycled.
2005, 22(5): 569-571
Abstract:
Demecolcine was synthesized from colchicine in two steps.The methylation of colchicine with iodomethane was carried out in a THF solution of potassium t-butoxide at -20℃ for 4 h.The product was isolated on a silica gel flash column with a yield of over 78%.N-Methylcolchicine was then hydrolyzed in i-propanol and aqueous solution of sodium hydroxide under refluxing temperature to give demecolcine.The overall yield was 69%.The structures of the two products were confirmed by IR and 1H NMR.
Demecolcine was synthesized from colchicine in two steps.The methylation of colchicine with iodomethane was carried out in a THF solution of potassium t-butoxide at -20℃ for 4 h.The product was isolated on a silica gel flash column with a yield of over 78%.N-Methylcolchicine was then hydrolyzed in i-propanol and aqueous solution of sodium hydroxide under refluxing temperature to give demecolcine.The overall yield was 69%.The structures of the two products were confirmed by IR and 1H NMR.
2005, 22(5): 572-574
Abstract:
2-Hydroxy-4-octyloxybenzophenone was synthesized from 2,4-dihydroxybenzophenone and octyl chloride in the presence of N-octyl-diethanolamine borate,which was synthesized from diethanolamine borate and octyl bromide.When the molar ratio of 2,4-dihydroxybenzophenone to octyl chloride was 1:1.05,reaction temperature was 155~160℃,reaction time was 8 h and m(N-octyl-diethanolamine borate)/m(2,4-dihydroxybenzophenone)=0.05,the purity of the alkylated product was 98.5%,and the yield was 92.3%.
2-Hydroxy-4-octyloxybenzophenone was synthesized from 2,4-dihydroxybenzophenone and octyl chloride in the presence of N-octyl-diethanolamine borate,which was synthesized from diethanolamine borate and octyl bromide.When the molar ratio of 2,4-dihydroxybenzophenone to octyl chloride was 1:1.05,reaction temperature was 155~160℃,reaction time was 8 h and m(N-octyl-diethanolamine borate)/m(2,4-dihydroxybenzophenone)=0.05,the purity of the alkylated product was 98.5%,and the yield was 92.3%.
2005, 22(5): 575-577
Abstract:
Diacetylenic glycerophosphatidylhydroxyethanol was synthesized from diacetylenic glycerophosphatidylcholine in the presence of phospholipase D from peanut seeds.The product structure was characterized by elemental analysis,IR,1H NMR and 13C NMR.The effects of the reaction conditions on the enzyme-catalyzed reaction are discussed.The results show that the enzyme activity was greatly increased by adding SDS.The yield of the reaction was increased compared with that reported in the literature under the conditions of pH=5.6,temperature 30℃,Ca2+ 40 mmol/L,n(substrate):n(SDS)=(2:1),reaction time 8 h.The cost was lower.The melting point of the product was 69.5℃.
Diacetylenic glycerophosphatidylhydroxyethanol was synthesized from diacetylenic glycerophosphatidylcholine in the presence of phospholipase D from peanut seeds.The product structure was characterized by elemental analysis,IR,1H NMR and 13C NMR.The effects of the reaction conditions on the enzyme-catalyzed reaction are discussed.The results show that the enzyme activity was greatly increased by adding SDS.The yield of the reaction was increased compared with that reported in the literature under the conditions of pH=5.6,temperature 30℃,Ca2+ 40 mmol/L,n(substrate):n(SDS)=(2:1),reaction time 8 h.The cost was lower.The melting point of the product was 69.5℃.
2005, 22(5): 578-580
Abstract:
A highly selective and rapid anodic adsorptive voltammetric method was developed for the determination of ultra trace amount of ofloxacin at a carbon paste electrode (CPE).The ofloxacin adsorbed on the surface of the CPE in a 0.096 mol/L KHP-NaOH buffer solution (pH=5.6) could produce one oxidation peak at 0.92 V(vs.SCE) when scanning was performed from 0.4 to 1.4 V.The relationship between the peak current and the ofloxacin concentration was linear in the ranges of 5.5×10-9~5.5×10-8 mol/L (75 s accumulation) and 3.3×10-8~3.3×10-7 mol/L (30 s accumulation).The correlation coefficients were 0.996 and 0.998,respectively.Its detection limit was 9.0×10-10 mol/L (S/N=3) for 150 s accumulation.The electrode reaction mechanism of ofloxacin was investigated.The proposed method was applied to analyze trace ofloxacin in urine samples.The result was in good agreement with that obtained by spectrophotometry determination.
A highly selective and rapid anodic adsorptive voltammetric method was developed for the determination of ultra trace amount of ofloxacin at a carbon paste electrode (CPE).The ofloxacin adsorbed on the surface of the CPE in a 0.096 mol/L KHP-NaOH buffer solution (pH=5.6) could produce one oxidation peak at 0.92 V(vs.SCE) when scanning was performed from 0.4 to 1.4 V.The relationship between the peak current and the ofloxacin concentration was linear in the ranges of 5.5×10-9~5.5×10-8 mol/L (75 s accumulation) and 3.3×10-8~3.3×10-7 mol/L (30 s accumulation).The correlation coefficients were 0.996 and 0.998,respectively.Its detection limit was 9.0×10-10 mol/L (S/N=3) for 150 s accumulation.The electrode reaction mechanism of ofloxacin was investigated.The proposed method was applied to analyze trace ofloxacin in urine samples.The result was in good agreement with that obtained by spectrophotometry determination.
