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2001 Volume 18 Issue 3
2001, 18(3): 173-175
Abstract:
The phase separation ability of various salts and organic solvents for two phase aqueous extraction system was studied.There are many factors affecting the phase separation,such as the kind and concentration of solvent and salts.According to the variation of organic solvent phase volumes after separation,three categories of two phase aqueous extraction have been observed:type Ⅰ(Vinitial<Vend),type Ⅱ(Vinitial>Vend) and type Ⅲ(type Ⅰ and concurrently type Ⅱ).
The phase separation ability of various salts and organic solvents for two phase aqueous extraction system was studied.There are many factors affecting the phase separation,such as the kind and concentration of solvent and salts.According to the variation of organic solvent phase volumes after separation,three categories of two phase aqueous extraction have been observed:type Ⅰ(Vinitial<Vend),type Ⅱ(Vinitial>Vend) and type Ⅲ(type Ⅰ and concurrently type Ⅱ).
2001, 18(3): 176-179
Abstract:
The tribological properties of lamellar liquid crystal of OLA/TEA/LP/H2O system used as a lubricant for aluminum alloy surface was investigated.The structure of lamellar liquid crystal was characterized by 2H NMR and IR techniques.The experiments on the wear scar width and vertical load showed that the lamellar liquid crystal exhibited a higher load carrying capacity than paraffin oil and commercial lithium grease,indicating the lamellar liquid crystal of OLA/TEA/LP/H2O system could be a good lubricant for aluminum alloy.
The tribological properties of lamellar liquid crystal of OLA/TEA/LP/H2O system used as a lubricant for aluminum alloy surface was investigated.The structure of lamellar liquid crystal was characterized by 2H NMR and IR techniques.The experiments on the wear scar width and vertical load showed that the lamellar liquid crystal exhibited a higher load carrying capacity than paraffin oil and commercial lithium grease,indicating the lamellar liquid crystal of OLA/TEA/LP/H2O system could be a good lubricant for aluminum alloy.
2001, 18(3): 180-183
Abstract:
The kinetics and mechanism of the redox reaction between N,N-dimethylhydroxylamine (DMHA) and vanadium (Ⅴ) in nitric acid medium at 25.2℃ have been studied by spectrophotometry.By investigating the influences of the DMHA concentration,solutio acidity and reaction temperature on the reaction,the reaction rate equation is found to be-d[V (Ⅴ)]/dt=k[V(Ⅴ)][DMHA] where the k is calculated to be (9.95±1.0) L2/(mol2·s),ΔE=22.1 kJ/mol under experiment conditions.A single-electron transfer mechanism has been suggested based on the ESR results of (CH3)2NO radical.The following reaction is the rate controlling step:[HO-V-O…H…O-N (CH3)2]2+→(CH3)2NO+H2O+VO2+
The kinetics and mechanism of the redox reaction between N,N-dimethylhydroxylamine (DMHA) and vanadium (Ⅴ) in nitric acid medium at 25.2℃ have been studied by spectrophotometry.By investigating the influences of the DMHA concentration,solutio acidity and reaction temperature on the reaction,the reaction rate equation is found to be-d[V (Ⅴ)]/dt=k[V(Ⅴ)][DMHA] where the k is calculated to be (9.95±1.0) L2/(mol2·s),ΔE=22.1 kJ/mol under experiment conditions.A single-electron transfer mechanism has been suggested based on the ESR results of (CH3)2NO radical.The following reaction is the rate controlling step:[HO-V-O…H…O-N (CH3)2]2+→(CH3)2NO+H2O+VO2+
2001, 18(3): 184-187
Abstract:
Seven novel oxalate bridged heterotrinuclear complexes with general formula [M2Fe(C2O4)3Lx](ClO4)(M=Cu,L=bpy,Me2phen,NO2phen,x=2;M=Ni,Co,L=bpy,Me2phen,x=4) have been synthesized and characterized by elemental analysis,IR,electronic spectra,molar conductance and magnetic moments (at room temperature) measurements.The complexes are suggested to have oxalate-bridged structures.The preliminary biological tests indicated that the antibacterial activities of the heterotrinuclear complexes are superior to the ligand.
Seven novel oxalate bridged heterotrinuclear complexes with general formula [M2Fe(C2O4)3Lx](ClO4)(M=Cu,L=bpy,Me2phen,NO2phen,x=2;M=Ni,Co,L=bpy,Me2phen,x=4) have been synthesized and characterized by elemental analysis,IR,electronic spectra,molar conductance and magnetic moments (at room temperature) measurements.The complexes are suggested to have oxalate-bridged structures.The preliminary biological tests indicated that the antibacterial activities of the heterotrinuclear complexes are superior to the ligand.
2001, 18(3): 188-191
Abstract:
Since variable selection is important in quantitative structure-property/activity studies,in this paper comparison between the genetic algorithm and several common methods such as forward method,backward elimination and stepwise regression is performed.The results obtained by using the common methods are very close to each other and that obtained by using genetic algorithm are better than the former methods.Though genetic algorithm takes time than the common methods,it is more effective for variable selection,especially in the case that there are a lot of descriptors to be treated.
Since variable selection is important in quantitative structure-property/activity studies,in this paper comparison between the genetic algorithm and several common methods such as forward method,backward elimination and stepwise regression is performed.The results obtained by using the common methods are very close to each other and that obtained by using genetic algorithm are better than the former methods.Though genetic algorithm takes time than the common methods,it is more effective for variable selection,especially in the case that there are a lot of descriptors to be treated.
2001, 18(3): 192-195
Abstract:
The dynamic growth process of CaSO4·2H2O crystal was studied by seeded crystallization of the supersaturated solution.The induction periods of CaSO4·2H2O crystal under the condition of adding nine different scale inhibitors have been determined.It was found that PAA and PMAAA had a better inhibiting action to the scale formation of calcium sulfate.The higher solution pH and the lower solution temperature,the higher their inhibition ability.The PAA or PMAAA of lower molecular weight showed much higher inhibiting ability.It has been demonstrated that the possible mechanism of scale inhibition is the adsorption of inhibitors on the active sites of the surfaces of crystal CaSO4·2H2O.The adsorption of PAA and PMAAA on the crystal surfaces accorded with the characters of Langmuir model.
The dynamic growth process of CaSO4·2H2O crystal was studied by seeded crystallization of the supersaturated solution.The induction periods of CaSO4·2H2O crystal under the condition of adding nine different scale inhibitors have been determined.It was found that PAA and PMAAA had a better inhibiting action to the scale formation of calcium sulfate.The higher solution pH and the lower solution temperature,the higher their inhibition ability.The PAA or PMAAA of lower molecular weight showed much higher inhibiting ability.It has been demonstrated that the possible mechanism of scale inhibition is the adsorption of inhibitors on the active sites of the surfaces of crystal CaSO4·2H2O.The adsorption of PAA and PMAAA on the crystal surfaces accorded with the characters of Langmuir model.
2001, 18(3): 196-199
Abstract:
The influence of sulfuric acid concentration on the leaching rate of MgO from serpentine was studied,and the leaching rate equation of MgO can be expressed as rMgO=k1CHmCMgon in a large excess of sulfuric acid,where the reaction orders m=0.20~0.24,n=2,the apparent activation energy Ea=85~95 kJ/mol;at practical leaching conditions the leaching rate equation of MgO has the form:drMgO'/dt=k2(7.144-3.40rMgO')0.226(1-rMgO')2.
The influence of sulfuric acid concentration on the leaching rate of MgO from serpentine was studied,and the leaching rate equation of MgO can be expressed as rMgO=k1CHmCMgon in a large excess of sulfuric acid,where the reaction orders m=0.20~0.24,n=2,the apparent activation energy Ea=85~95 kJ/mol;at practical leaching conditions the leaching rate equation of MgO has the form:drMgO'/dt=k2(7.144-3.40rMgO')0.226(1-rMgO')2.
2001, 18(3): 200-203
Abstract:
Synthesis and fractionation of copolymes of tri-n-butyltin methacrylate (TBTMA) with MMA have been investigated.The fractionated molecular weight and corresponding [Z] of copolymers and K and T values in Mark-Houwink equation of copolymers have been determined.In case of TBTMA:MMA=1:1(feed molar ratio),K=0.225,T=0.46,the distribution of molecular weight d is 2.32 and in case of TBTMA:MMA=1:2(feed molar ratio),K=1 69×10-4,T=1.18,d=1.23.
Synthesis and fractionation of copolymes of tri-n-butyltin methacrylate (TBTMA) with MMA have been investigated.The fractionated molecular weight and corresponding [Z] of copolymers and K and T values in Mark-Houwink equation of copolymers have been determined.In case of TBTMA:MMA=1:1(feed molar ratio),K=0.225,T=0.46,the distribution of molecular weight d is 2.32 and in case of TBTMA:MMA=1:2(feed molar ratio),K=1 69×10-4,T=1.18,d=1.23.
2001, 18(3): 204-207
Abstract:
A Zn-PTFE (Zinc-polytetrafluoroethylene) composite electrode with well-dispersed PTFE fine particle has been prepared in conditions of 5.0 A/dm2,22.5C,and PTFE 30 mL/L at 25℃.The composite electrode was used as cathode in electrosynthesis of pinacol from acetone in yield of 53.6%,much higher than that by using Zn electrode as cathode (25.1%).
A Zn-PTFE (Zinc-polytetrafluoroethylene) composite electrode with well-dispersed PTFE fine particle has been prepared in conditions of 5.0 A/dm2,22.5C,and PTFE 30 mL/L at 25℃.The composite electrode was used as cathode in electrosynthesis of pinacol from acetone in yield of 53.6%,much higher than that by using Zn electrode as cathode (25.1%).
2001, 18(3): 208-211
Abstract:
The core-shell Y2O3:Eu3+/polystyrene particles were prepared by surface modification with citric acid,followed by emulsion polymerization of styrene.For the core-shell particles the carbonyl stretching vibration band shifted to low wavenumber in FTIR spectrum and the binding energy of Y3d5/2 upfield shifted to high energy band in XPS spectrum,showing that the citric acid is bonded to the particle surface through chemical binding by the mechanism of adsorption layer medium.The hydrophilic surface of Y2O3:Eu2+ particles becomes amphiphilic by citric acid modification that makes the styrene adsorbed on particle surface to form emulsion structure with inorganic core inside.EDS spectra showed a uniform polystyrene coating on Y2O3:Eu3+ surface.
The core-shell Y2O3:Eu3+/polystyrene particles were prepared by surface modification with citric acid,followed by emulsion polymerization of styrene.For the core-shell particles the carbonyl stretching vibration band shifted to low wavenumber in FTIR spectrum and the binding energy of Y3d5/2 upfield shifted to high energy band in XPS spectrum,showing that the citric acid is bonded to the particle surface through chemical binding by the mechanism of adsorption layer medium.The hydrophilic surface of Y2O3:Eu2+ particles becomes amphiphilic by citric acid modification that makes the styrene adsorbed on particle surface to form emulsion structure with inorganic core inside.EDS spectra showed a uniform polystyrene coating on Y2O3:Eu3+ surface.
2001, 18(3): 212-215
Abstract:
The extraction equilibrium of leucine with di-(2-ethylhexyl) phosphoric acid (D2EHPA) dissolved in n-heptane,n-octane and kerosene respectively was studied in neutral condition.The values of extraction equilibrium constant Kex and other thermodynamical data were obtained.The results show that one leucine molecule is extracted by complexing with two dimeric D2EHPA molecules,and the solvents do not affect the equilibrium in the conditions of the experiments.
The extraction equilibrium of leucine with di-(2-ethylhexyl) phosphoric acid (D2EHPA) dissolved in n-heptane,n-octane and kerosene respectively was studied in neutral condition.The values of extraction equilibrium constant Kex and other thermodynamical data were obtained.The results show that one leucine molecule is extracted by complexing with two dimeric D2EHPA molecules,and the solvents do not affect the equilibrium in the conditions of the experiments.
2001, 18(3): 216-219
Abstract:
Four cyanine-dye IR absorbing agents used in CTP (Computer-to-Plate) preparation were synthesized.Their structures and purity were confirmed by IR,1H NMR and HPLC.Their electronic absorption spectra,solubilities,photostability and sensitizing properties were studied.
Four cyanine-dye IR absorbing agents used in CTP (Computer-to-Plate) preparation were synthesized.Their structures and purity were confirmed by IR,1H NMR and HPLC.Their electronic absorption spectra,solubilities,photostability and sensitizing properties were studied.
2001, 18(3): 220-224
Abstract:
The new complexes M7-mHm[XW9Nb3O40]·nH2O and M7[XW9(NbO2)3O37]·nH2O(X=Si,Ge;M=K,Me4N,Bu4N),were synthesized and characterized by IR,UV and 183W NMR spectrometry.Complex K4H12[Si2W14Nb10O79]·13H2O was determined by XRD to be of Keggin structure.Its crystal belongs to monoclinic space group C2,with a=1.9226(4) nm,b=3.3134(7) nm,c=1.2497(3) nm,Dc=3.240 g/cm3,Z=3,_=15.886 mm-1,F(000)=6920,R=0 0565,WR2=0.0972.It was found that the complex has an excellent anti-virus activity to tomato mosaic virus.
The new complexes M7-mHm[XW9Nb3O40]·nH2O and M7[XW9(NbO2)3O37]·nH2O(X=Si,Ge;M=K,Me4N,Bu4N),were synthesized and characterized by IR,UV and 183W NMR spectrometry.Complex K4H12[Si2W14Nb10O79]·13H2O was determined by XRD to be of Keggin structure.Its crystal belongs to monoclinic space group C2,with a=1.9226(4) nm,b=3.3134(7) nm,c=1.2497(3) nm,Dc=3.240 g/cm3,Z=3,_=15.886 mm-1,F(000)=6920,R=0 0565,WR2=0.0972.It was found that the complex has an excellent anti-virus activity to tomato mosaic virus.
2001, 18(3): 225-227
Abstract:
Ten N-(4'-substituted pyrimidin-2'-yl)-2-trifluoroacetylamino benzenesulfonylureas were synthesized.Their structures were confirmed by elemental analysis and 1H NMR.Some of the compounds showed good herbicidal activity.
Ten N-(4'-substituted pyrimidin-2'-yl)-2-trifluoroacetylamino benzenesulfonylureas were synthesized.Their structures were confirmed by elemental analysis and 1H NMR.Some of the compounds showed good herbicidal activity.
2001, 18(3): 228-230
Abstract:
Six complexes of tetra (4-p-decanoyloxyphenyl) porphyrin (TDPPH2) with Mn(Ⅲ),Fe(Ⅲ),Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ) and Zn(Ⅱ) have been synthesized in a mixed solvents of CH2Cl2 and DMF.The compounds were characterized by elemental analysis,UV-Vis,FTIR photoacoustic spectrometry,1H NMR and molar conductance measurements.The optical textures of the isotropic liquid crystals of TDPPH2 and TDPPZn on cooling were observed by polarized light microscope.
Six complexes of tetra (4-p-decanoyloxyphenyl) porphyrin (TDPPH2) with Mn(Ⅲ),Fe(Ⅲ),Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ) and Zn(Ⅱ) have been synthesized in a mixed solvents of CH2Cl2 and DMF.The compounds were characterized by elemental analysis,UV-Vis,FTIR photoacoustic spectrometry,1H NMR and molar conductance measurements.The optical textures of the isotropic liquid crystals of TDPPH2 and TDPPZn on cooling were observed by polarized light microscope.
2001, 18(3): 231-232
Abstract:
The L-phenylalanine was prepared in high optical purity by treating N-acetylphenylalanine ethyl ester in water or in water-octanol biphase medium using free aminoacylase as a catalyst.The kinetic behavior of the free enzymatic reaction was investigated and the reaction mechanism has been discussed.
The L-phenylalanine was prepared in high optical purity by treating N-acetylphenylalanine ethyl ester in water or in water-octanol biphase medium using free aminoacylase as a catalyst.The kinetic behavior of the free enzymatic reaction was investigated and the reaction mechanism has been discussed.
2001, 18(3): 233-235
Abstract:
The component of the surface and profile of AlN films have been investigated using X-ray photoelectron spectrometry (XPS).The results show that the surface of the films was composed by Al,N,O and C elements.C and O contaminations are attributed both to the sputtering chamber venting and to exposure of the films to air.According XPS depth profile analysis,it is found that the composition of the film along the growth axis is nearly uniform,and Al/N ratio is close to that in the AlN stoichiometry.Beneath the surface,the amount of O in the film is found below 5%.
The component of the surface and profile of AlN films have been investigated using X-ray photoelectron spectrometry (XPS).The results show that the surface of the films was composed by Al,N,O and C elements.C and O contaminations are attributed both to the sputtering chamber venting and to exposure of the films to air.According XPS depth profile analysis,it is found that the composition of the film along the growth axis is nearly uniform,and Al/N ratio is close to that in the AlN stoichiometry.Beneath the surface,the amount of O in the film is found below 5%.
2001, 18(3): 236-238
Abstract:
Oleate/PSt/TiO2 nanosphere composites were prepared by seeding polymerization and characterized by TEM、FTIR、DSC and TGA.The antiwear ability of the oleate/PSt/TiO2 nanospheres as additives in base oil was evaluated.The results indicate the oleate/PSt/TiO2 nanosphere composites have good wear and extreme pressure resistance.
Oleate/PSt/TiO2 nanosphere composites were prepared by seeding polymerization and characterized by TEM、FTIR、DSC and TGA.The antiwear ability of the oleate/PSt/TiO2 nanospheres as additives in base oil was evaluated.The results indicate the oleate/PSt/TiO2 nanosphere composites have good wear and extreme pressure resistance.
2001, 18(3): 239-240
Abstract:
6-Methoxy-2-acyl naphthalene and 2-methoxy naphthalene was chlorinated with cupric chloride in different solvents.For 6-methoxy-2-propionylnaphthalene in methanol and ethanol,6-methoxy-2-(2'-chloropropionyl) naphthalene was obtained in yield of 90%~98 4%.For 2-methoxy naphthalene in chlorobenzene,1-chloro-2-methoxy naphthalene was obtained in yield of 97.5%.
6-Methoxy-2-acyl naphthalene and 2-methoxy naphthalene was chlorinated with cupric chloride in different solvents.For 6-methoxy-2-propionylnaphthalene in methanol and ethanol,6-methoxy-2-(2'-chloropropionyl) naphthalene was obtained in yield of 90%~98 4%.For 2-methoxy naphthalene in chlorobenzene,1-chloro-2-methoxy naphthalene was obtained in yield of 97.5%.
2001, 18(3): 241-243
Abstract:
Mercury ion separation from another metal ions has been carried out in phase system consisted of propanol,NaCl and KI.The results showed that propanol could extract the associates formed by mercury with iodide.Hg(Ⅱ) can be separated completely from Fe(Ⅲ),Co(Ⅱ),Mn(Ⅱ),Mo(Ⅵ) and Zn(Ⅱ) in solution system of pH=2.0.
Mercury ion separation from another metal ions has been carried out in phase system consisted of propanol,NaCl and KI.The results showed that propanol could extract the associates formed by mercury with iodide.Hg(Ⅱ) can be separated completely from Fe(Ⅲ),Co(Ⅱ),Mn(Ⅱ),Mo(Ⅵ) and Zn(Ⅱ) in solution system of pH=2.0.
2001, 18(3): 244-245
Abstract:
Isoamyl acetate was catalytically synthesized by SnCl4·5H2O.The effects of reaction time,catalyst amount,and ratio of glacial acetic acid to isoamyl alcohol were investgated.The results showed that at condition of molar ratio of HAc to isoamyl alcohol=1:1.08,that of SnCl4·5H2O to HAc=1:100,150℃,1 h isoamyl acetate can be obtained in yield of 95.6%.
Isoamyl acetate was catalytically synthesized by SnCl4·5H2O.The effects of reaction time,catalyst amount,and ratio of glacial acetic acid to isoamyl alcohol were investgated.The results showed that at condition of molar ratio of HAc to isoamyl alcohol=1:1.08,that of SnCl4·5H2O to HAc=1:100,150℃,1 h isoamyl acetate can be obtained in yield of 95.6%.
2001, 18(3): 246-247
Abstract:
The polymerization of MMA catalyzed by bridged lanthanocene amide as single-compoent catalyst has been investigated.The polymers obtained were characterized by GPC,FT-IR,1H NMR and DSC.The results indicated that the conversion and the molecular weight decreased with decrease in polymerization temperature.The PMMA obtained was mainly in syndiotactic structure.
The polymerization of MMA catalyzed by bridged lanthanocene amide as single-compoent catalyst has been investigated.The polymers obtained were characterized by GPC,FT-IR,1H NMR and DSC.The results indicated that the conversion and the molecular weight decreased with decrease in polymerization temperature.The PMMA obtained was mainly in syndiotactic structure.
2001, 18(3): 248-250
Abstract:
The adsorption isotherm and adsorption reaction kinetics of carboxymethyl chitosan (CMCS) for Fe2+ have been studied.The results showed that CMCS appeared a good adsorbent for Fe2+ in solution with pH 6~8 and the adsorption capacity of CMCS increased with the increase in its carboxyl groups.The adsorption isotherm of CMCS for Fe2+ at 20℃ was fitted good for the Langmuir equation.
The adsorption isotherm and adsorption reaction kinetics of carboxymethyl chitosan (CMCS) for Fe2+ have been studied.The results showed that CMCS appeared a good adsorbent for Fe2+ in solution with pH 6~8 and the adsorption capacity of CMCS increased with the increase in its carboxyl groups.The adsorption isotherm of CMCS for Fe2+ at 20℃ was fitted good for the Langmuir equation.
2001, 18(3): 251-253
Abstract:
The interaction between DNA and twenty three D-glucosamine-contained metal complexes has been investigated by electronic and fluorescence spectrophotometry.The results show that 7 of the 23 complexes combined with DNA strongly.
The interaction between DNA and twenty three D-glucosamine-contained metal complexes has been investigated by electronic and fluorescence spectrophotometry.The results show that 7 of the 23 complexes combined with DNA strongly.
2001, 18(3): 254-256
Abstract:
The synthesis of a Schiff base macrocyclic polyamine ligand and its five 1:1 complexes with transition metals are reported.All compounds were characterized by elemental analysis,IR,UV-Vis,1H NMR,13C NMR,MS and molar conductance measurements.The results showed that[CuL](ClO4)2 is a square planar complex.The others are octahedral complexes.
The synthesis of a Schiff base macrocyclic polyamine ligand and its five 1:1 complexes with transition metals are reported.All compounds were characterized by elemental analysis,IR,UV-Vis,1H NMR,13C NMR,MS and molar conductance measurements.The results showed that[CuL](ClO4)2 is a square planar complex.The others are octahedral complexes.
2001, 18(3): 257-258
Abstract:
The O-ethyldichlorothiophosphate has been synthesized from thiophosphoryl chloride and ethyl alcohol.The reaction order,preexponential factor,activation energy and rate constant of the reaction are determined.At the condition of n(ethyl alcohol):n(thiophosphoryl chloride)=3:1,10℃ and 2 h,the reaction gave O-ethyldichlorothiophosphate in yield more than 99.7%.
The O-ethyldichlorothiophosphate has been synthesized from thiophosphoryl chloride and ethyl alcohol.The reaction order,preexponential factor,activation energy and rate constant of the reaction are determined.At the condition of n(ethyl alcohol):n(thiophosphoryl chloride)=3:1,10℃ and 2 h,the reaction gave O-ethyldichlorothiophosphate in yield more than 99.7%.
