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1994 Volume 11 Issue 1
1994, 11(1): 1-6
Abstract:
A novel acyclic β-diketone type quadridentate chelating agent,bis-(1'-phenyl-3'-methyl-5' oxopyrazol-4'-yl)phthaldione(BPMOPP,H2A) was synthesized from 1-phenyl-3-methylpyrazolone and o-phthalyl chloride. The valency behaviour of cerium ion and thesynergistic extraction of cerium by BPMOPP and 1, 10-phenathroline from aqueous hydrochloric acid or hydrochloric acid and sodium formate buffer solution have been investigated. By using the slope analysis method the solid mixed-ligand synergic adduct showed a constitution of CeA·HA·phen with an extraction equilibrium constant ks,e=1.21×10-2. Allthe compounds obtained have been characterized by elemental an alvsis, UV, IR,1H NMR,and TG-DTA measurements. The molar conductivity of the complexes in chloroform was 0.1~0.2 S·cm2/mol indicating that they are nonelectrolytes.
A novel acyclic β-diketone type quadridentate chelating agent,bis-(1'-phenyl-3'-methyl-5' oxopyrazol-4'-yl)phthaldione(BPMOPP,H2A) was synthesized from 1-phenyl-3-methylpyrazolone and o-phthalyl chloride. The valency behaviour of cerium ion and thesynergistic extraction of cerium by BPMOPP and 1, 10-phenathroline from aqueous hydrochloric acid or hydrochloric acid and sodium formate buffer solution have been investigated. By using the slope analysis method the solid mixed-ligand synergic adduct showed a constitution of CeA·HA·phen with an extraction equilibrium constant ks,e=1.21×10-2. Allthe compounds obtained have been characterized by elemental an alvsis, UV, IR,1H NMR,and TG-DTA measurements. The molar conductivity of the complexes in chloroform was 0.1~0.2 S·cm2/mol indicating that they are nonelectrolytes.
1994, 11(1): 7-11
Abstract:
The eqtiibrium solubilities of title quaternary system were studied at 50,75℃ by the isothernlal method. The phase diagrams of the system consist of seven solubility branch-es and have five crvstallization fields:KLiSO4, Li2SO4·H2O, KCl,K2SO4, and LiCl·H2O.The first one is the largest. Three invariant points exist in the system:LiCl·H2O+KCl+Li2SO4·H2O,KCl+K2SO4+KLiSO4,and KCl+KLiSO4+Li2SO4·H2O. The first one is acongrLient eutonic point, and the others are incongruent. The ion interaction pararneters of the Pitzer model for rnixed electrolyte solution at 50℃ and 75℃ were obtained by fitting the determined solubility data. The water activity of the equilibrium liquid, and the solubility product of salts were calculated. The empirical eqtiations of density and refractive index of the solution in relationto to its composition were used to correlate the data. The results arein good agreement.
The eqtiibrium solubilities of title quaternary system were studied at 50,75℃ by the isothernlal method. The phase diagrams of the system consist of seven solubility branch-es and have five crvstallization fields:KLiSO4, Li2SO4·H2O, KCl,K2SO4, and LiCl·H2O.The first one is the largest. Three invariant points exist in the system:LiCl·H2O+KCl+Li2SO4·H2O,KCl+K2SO4+KLiSO4,and KCl+KLiSO4+Li2SO4·H2O. The first one is acongrLient eutonic point, and the others are incongruent. The ion interaction pararneters of the Pitzer model for rnixed electrolyte solution at 50℃ and 75℃ were obtained by fitting the determined solubility data. The water activity of the equilibrium liquid, and the solubility product of salts were calculated. The empirical eqtiations of density and refractive index of the solution in relationto to its composition were used to correlate the data. The results arein good agreement.
1994, 11(1): 12-15
Abstract:
The adsorption of 12-sillicotungstic acid(SiW12) on the active carbon has been investigated in water, ethanol, acetic acid and butyl acetate medium. A diffusion model forSiW12 adsorption in the micropore of active carbon has been proposed. The middle-micropore of the active carbon plays an important role as a molecular sieve for adsorption of SiW12,The water-solvated SiW12 molectiles can smoothly get into the micropore of diameter~1.7nm. However, for the SiW12 molecules solvated by other solvents only the micropores ηgreater diameter wotild be fifled.
The adsorption of 12-sillicotungstic acid(SiW12) on the active carbon has been investigated in water, ethanol, acetic acid and butyl acetate medium. A diffusion model forSiW12 adsorption in the micropore of active carbon has been proposed. The middle-micropore of the active carbon plays an important role as a molecular sieve for adsorption of SiW12,The water-solvated SiW12 molectiles can smoothly get into the micropore of diameter~1.7nm. However, for the SiW12 molecules solvated by other solvents only the micropores ηgreater diameter wotild be fifled.
1994, 11(1): 16-19
Abstract:
The adsorption and desorption be haviour of macroporous adsorbent AB-8 for ste-vioside were investigated. The effects of pH, eluents and flow rate on the adsorption and desorption properties were studied. The results show that the adsorbent Ab-8 has a high adsorption capacity for stevioside and the elution is easy.
The adsorption and desorption be haviour of macroporous adsorbent AB-8 for ste-vioside were investigated. The effects of pH, eluents and flow rate on the adsorption and desorption properties were studied. The results show that the adsorbent Ab-8 has a high adsorption capacity for stevioside and the elution is easy.
1994, 11(1): 20-23
Abstract:
The complexes of rare earth (Ln=La~Nd)with saturated urushiol crown ether(DSU30C10) have been synthesized in acetonitrile solution. The complexes have been char-acterized by elemental analysis, IR and UV spectra, molar conductance and differential ther-mal analvsis,The lanthanutn iOn selective electrode with saturated urushiol crown ether as aneutral carrier exhibited linear responses in 1×102~1×106 mol/L La(NO3)3. The electrode;howed better selectivity than other La(Ⅲ)electrodes reported in literature。
The complexes of rare earth (Ln=La~Nd)with saturated urushiol crown ether(DSU30C10) have been synthesized in acetonitrile solution. The complexes have been char-acterized by elemental analysis, IR and UV spectra, molar conductance and differential ther-mal analvsis,The lanthanutn iOn selective electrode with saturated urushiol crown ether as aneutral carrier exhibited linear responses in 1×102~1×106 mol/L La(NO3)3. The electrode;howed better selectivity than other La(Ⅲ)electrodes reported in literature。
1994, 11(1): 24-27
Abstract:
The effects of the conditioiis of reaction between MoCl5 and,n-C7H15COOH on thenumber of chlorine atorn in MoCl5 substituted by functional group C7H15 COO have beenstudied. The UV-Vis spectra of the exchange products MoCl5 m(n-C7H15COO)m were dis-cussed and assigned. The catalytic activity of the molybdenum catalyst system containing MoCl5 m(n-C7H15COO)m for butadiene polymerization was found to be decreased rapidly withincreasing the number of substituted chlorine atoms in MoCl5.
The effects of the conditioiis of reaction between MoCl5 and,n-C7H15COOH on thenumber of chlorine atorn in MoCl5 substituted by functional group C7H15 COO have beenstudied. The UV-Vis spectra of the exchange products MoCl5 m(n-C7H15COO)m were dis-cussed and assigned. The catalytic activity of the molybdenum catalyst system containing MoCl5 m(n-C7H15COO)m for butadiene polymerization was found to be decreased rapidly withincreasing the number of substituted chlorine atoms in MoCl5.
1994, 11(1): 28-32
Abstract:
The (RCp)2TiCl2(R=H, Me)-acetylacetone system reacts with potassium thiocyanate, sodium thiocarbamate or sodium 2-substituted benzoates in aqueous medium, giving (RCp)2Ti(SCN)2,(RCp)Ti(S2CNR2)3 and (RCp)2Ti(O2C(2-X)C6H4)2 respectly,(X=OH,CI,NH2) except for bis(methylcyclopentadienyl)salicylatotitanium. The structure of titanocene bis(salicylate) single crystal was determined by X-ray diffraction. The compoundcrystallizes in orthorhombic space group Pccn with a=1.3538(3)nm,b=1.4273(5)nm,c=2.1506(7)nm, z=8,R=0.042 and Rw=0.039。
The (RCp)2TiCl2(R=H, Me)-acetylacetone system reacts with potassium thiocyanate, sodium thiocarbamate or sodium 2-substituted benzoates in aqueous medium, giving (RCp)2Ti(SCN)2,(RCp)Ti(S2CNR2)3 and (RCp)2Ti(O2C(2-X)C6H4)2 respectly,(X=OH,CI,NH2) except for bis(methylcyclopentadienyl)salicylatotitanium. The structure of titanocene bis(salicylate) single crystal was determined by X-ray diffraction. The compoundcrystallizes in orthorhombic space group Pccn with a=1.3538(3)nm,b=1.4273(5)nm,c=2.1506(7)nm, z=8,R=0.042 and Rw=0.039。
1994, 11(1): 33-37
Abstract:
Lead dioxide and manganese dioxide were used as mediator for indirect oxidation of cinnarnic alcohol on solid polymer electrolyte(SPE)composite electrode prepared by depositing a porous platnium layer on Nafion. When MnO2 was used, cinnamic aldehyde was the main product of oxidatiorl with current efficieny up to 80%。In the case of PBO2 a further oxidatinn of aldehvde to cinnamic acid and an obvious decrease of reaction selectivity on the electrode were observed.
Lead dioxide and manganese dioxide were used as mediator for indirect oxidation of cinnarnic alcohol on solid polymer electrolyte(SPE)composite electrode prepared by depositing a porous platnium layer on Nafion. When MnO2 was used, cinnamic aldehyde was the main product of oxidatiorl with current efficieny up to 80%。In the case of PBO2 a further oxidatinn of aldehvde to cinnamic acid and an obvious decrease of reaction selectivity on the electrode were observed.
1994, 11(1): 38-41
Abstract:
The relation between the content of YF3 and oxygen in the host lattice and luminescence change of Eu2+ in BaF2-xYF3 has been studied. The energy transfer frotn Eu2+ to Tb3 in Ti-doped BaYF, was observed. The emission strength of Eu2+ was found to be reduced greatly and the decay time of the luminescence of the luminescence of Eu2+ was shortened due to the energytransfer from Eu2+ to Tb3+.
The relation between the content of YF3 and oxygen in the host lattice and luminescence change of Eu2+ in BaF2-xYF3 has been studied. The energy transfer frotn Eu2+ to Tb3 in Ti-doped BaYF, was observed. The emission strength of Eu2+ was found to be reduced greatly and the decay time of the luminescence of the luminescence of Eu2+ was shortened due to the energytransfer from Eu2+ to Tb3+.
1994, 11(1): 42-45
Abstract:
The electrocatalytic action of polyaniline(PAn) and polypyrrole(PPy) film electrode on Fe(Ⅱ) and Sb(Ⅲ) has been studied by cyclic voltammetry. The redox currents ofFe(Ⅱ) and Sb(Ⅲ) at the polymer film electrodes are twice or several times greater than those at bare Pt electrode. The difference between the redox peak potentials at the polymer film electrode becomes obviously less than that at the bare Pt electrode. The results show that the PAn and PPy film electrodes exhibit catalytic activity for electrode reacti On of Fe(Ⅱ) and Sb(Ⅲ).Anodic and cathodic currents of Fe(Ⅱ) and Sb(Ⅲ) at two polvmer electrodes appeared identical at low potential sweep rate, The peak current linearly depends on the square root of potential sweep rate, indicating that the electrode process at polymer filmis a diffusion controlled one.
The electrocatalytic action of polyaniline(PAn) and polypyrrole(PPy) film electrode on Fe(Ⅱ) and Sb(Ⅲ) has been studied by cyclic voltammetry. The redox currents ofFe(Ⅱ) and Sb(Ⅲ) at the polymer film electrodes are twice or several times greater than those at bare Pt electrode. The difference between the redox peak potentials at the polymer film electrode becomes obviously less than that at the bare Pt electrode. The results show that the PAn and PPy film electrodes exhibit catalytic activity for electrode reacti On of Fe(Ⅱ) and Sb(Ⅲ).Anodic and cathodic currents of Fe(Ⅱ) and Sb(Ⅲ) at two polvmer electrodes appeared identical at low potential sweep rate, The peak current linearly depends on the square root of potential sweep rate, indicating that the electrode process at polymer filmis a diffusion controlled one.
1994, 11(1): 46-49
Abstract:
The surface active properties of aqueous solution of the long chain alkoxymethylcrown ethers and corresponding open chain compounds alkoxymethyl oligoethylene glycols,have been investigated by surface tension measurement. The results show that compounds 1 and 2,where the number of carbon atoms in the side chain(n) exceeds 8,can form micelles inaqueous solution, and their CMC values decrease with the increase of n. Correlation of thelog(CMC)values of a homologous series of surface active agents for the same temperatare with n gives a satisfactory linear relationship with the correlation coeffecients generally beinggreater than 0.99. The effects of NaCl on the surface properties of the long chainalkoxy methyl substituted oligoethylene glycols and corresponding crown ether compounds also have been investigated.
The surface active properties of aqueous solution of the long chain alkoxymethylcrown ethers and corresponding open chain compounds alkoxymethyl oligoethylene glycols,have been investigated by surface tension measurement. The results show that compounds 1 and 2,where the number of carbon atoms in the side chain(n) exceeds 8,can form micelles inaqueous solution, and their CMC values decrease with the increase of n. Correlation of thelog(CMC)values of a homologous series of surface active agents for the same temperatare with n gives a satisfactory linear relationship with the correlation coeffecients generally beinggreater than 0.99. The effects of NaCl on the surface properties of the long chainalkoxy methyl substituted oligoethylene glycols and corresponding crown ether compounds also have been investigated.
1994, 11(1): 50-53
Abstract:
The electrochemical perforrnances of all-solid state lithium battery using polyaniline positive electrode and γ-ray crosslinked PEO electrolyte containing LiClO4/PC solutionhave been studied.It showed that the ambient temperature conductivity of PEO was over 10-4 S/cm as a result of γ-ray irradiation. The capacity of over 60mAh/g and the charge-dis-charge life of over 68 cycles were achieved for the poly aniline lithium battery. The acimpedance at the Li/PEO interface was much greater than that at PEO/PAn. The result of cyclic voltammetry showed good reversibility of the polyaniline electrode in the lithium battery.
The electrochemical perforrnances of all-solid state lithium battery using polyaniline positive electrode and γ-ray crosslinked PEO electrolyte containing LiClO4/PC solutionhave been studied.It showed that the ambient temperature conductivity of PEO was over 10-4 S/cm as a result of γ-ray irradiation. The capacity of over 60mAh/g and the charge-dis-charge life of over 68 cycles were achieved for the poly aniline lithium battery. The acimpedance at the Li/PEO interface was much greater than that at PEO/PAn. The result of cyclic voltammetry showed good reversibility of the polyaniline electrode in the lithium battery.
1994, 11(1): 54-57
Abstract:
The mechanical properties of cured polypropylene carbonate(PPC)/epoxy resin(EP)system were investigated by means of dynamic mechanical analysis and stress-straincurves. The influences of molecular weight and contents of PPC on the properties were alsostudied. The results showed that the half width of tan peak increases with the increase ofPPC content. The optimum mechanical properties would be achieved when the contents ofPPC reach to 20~30 phr.
The mechanical properties of cured polypropylene carbonate(PPC)/epoxy resin(EP)system were investigated by means of dynamic mechanical analysis and stress-straincurves. The influences of molecular weight and contents of PPC on the properties were alsostudied. The results showed that the half width of tan peak increases with the increase ofPPC content. The optimum mechanical properties would be achieved when the contents ofPPC reach to 20~30 phr.
1994, 11(1): 58-62
Abstract:
The deactivation of two commercial Co-Mo/MgO-Al2O3 type WGS catalyst has been studied by XRD, SEM, Raman spectroscopy,and ICP techniques. The results showed that the deactivation is mainly due to the formation of MoS2 and MgAl2O4. Roasting athigher temperatures makes catalysts crystalizable.The strticture of catalysts direetly depends on the method of their preparation.Catalysts of strip shape powderized more easily.Process of regeneration lowers the stability of catalysts,The second-important reason of deactivation of catalysts is the preseence of inorganic impurities.
The deactivation of two commercial Co-Mo/MgO-Al2O3 type WGS catalyst has been studied by XRD, SEM, Raman spectroscopy,and ICP techniques. The results showed that the deactivation is mainly due to the formation of MoS2 and MgAl2O4. Roasting athigher temperatures makes catalysts crystalizable.The strticture of catalysts direetly depends on the method of their preparation.Catalysts of strip shape powderized more easily.Process of regeneration lowers the stability of catalysts,The second-important reason of deactivation of catalysts is the preseence of inorganic impurities.
1994, 11(1): 63-66
Abstract:
The kinetics of thermal degradation and thermal stability of boron-containing phe-nol-formaldehyde resin were investigated by thermal analysis and infrared spectroscopy. Theresins showed a higher decomposition temperature and oxidative resistance than commonphenol-formaldehyde resins due to the presence of benzyl borate as well as phenyl boratelinkages after curing.
The kinetics of thermal degradation and thermal stability of boron-containing phe-nol-formaldehyde resin were investigated by thermal analysis and infrared spectroscopy. Theresins showed a higher decomposition temperature and oxidative resistance than commonphenol-formaldehyde resins due to the presence of benzyl borate as well as phenyl boratelinkages after curing.
1994, 11(1): 67-71
Abstract:
The Iuminophors which have composition of 0.701MgO-0.175CaO1.25SiO2:0.06Eu3+,0.002Bi3+ and doped Li-ion as charge compensator were synthesized for the firsttime from Mg(NO3)2, Ca(NO3)2, Eu(NO3)3, LiNO3 and Si(OC2H5)4 via the sol-gel methodat the temperature much lower than that by the traditional solid state reaction。The optimumconditions of preparation are reported. Both the transition from sol to gel and the transitionprocess from gel to luminescent crystal were studied. The luminescence character of the lu-minophors excited by different wavelength light, as well as the luminescence behavior in different concentrations of the activators and sensitizers were explored. The energy transferfrom Bi3+ to Eu3+ in the luminophors was also discussed。
The Iuminophors which have composition of 0.701MgO-0.175CaO1.25SiO2:0.06Eu3+,0.002Bi3+ and doped Li-ion as charge compensator were synthesized for the firsttime from Mg(NO3)2, Ca(NO3)2, Eu(NO3)3, LiNO3 and Si(OC2H5)4 via the sol-gel methodat the temperature much lower than that by the traditional solid state reaction。The optimumconditions of preparation are reported. Both the transition from sol to gel and the transitionprocess from gel to luminescent crystal were studied. The luminescence character of the lu-minophors excited by different wavelength light, as well as the luminescence behavior in different concentrations of the activators and sensitizers were explored. The energy transferfrom Bi3+ to Eu3+ in the luminophors was also discussed。
1994, 11(1): 72-75
Abstract:
Oxotitanium phthalocyanine was synthesized from phthalonitrile and titanium te-trachloride in bicyclohexyl.It is much more convenient to separate and purify the productsby using bicyclohexyl as a solvent. Five polymorphs were obtained and characterized by X-ray powder diffractometry and FTIR spectroscopy. The absorption spectra of the poly-morphs in silicone rubbers were recorded.
Oxotitanium phthalocyanine was synthesized from phthalonitrile and titanium te-trachloride in bicyclohexyl.It is much more convenient to separate and purify the productsby using bicyclohexyl as a solvent. Five polymorphs were obtained and characterized by X-ray powder diffractometry and FTIR spectroscopy. The absorption spectra of the poly-morphs in silicone rubbers were recorded.
1994, 11(1): 76-79
Abstract:
The kinetics of polycondensation of lactic acid has been investigated. The results showed that in the absence of catalyst the polycondensation proceeds as a third order reaction at 124℃ with 10%~60% conversion:(-d[COOH])/(dt)=1.32×10-5[COOH]3. In the pres-nce of ca.1%(wt) of a strong acid ion-exchange resin at 120℃ and 10%~50% of conver-sion the polycondensation follows a second order equation:(-d[COOH])/(dt)=1.51×10-4[COOH]2.Addition of the catalyst decreased the activation energy of the reaction and the polycondensation could be initiated at a lower temperature. The reaction showed a maximum rate as the amount of the catalvst was about 1%(wt) of the lactic acid.
The kinetics of polycondensation of lactic acid has been investigated. The results showed that in the absence of catalyst the polycondensation proceeds as a third order reaction at 124℃ with 10%~60% conversion:(-d[COOH])/(dt)=1.32×10-5[COOH]3. In the pres-nce of ca.1%(wt) of a strong acid ion-exchange resin at 120℃ and 10%~50% of conver-sion the polycondensation follows a second order equation:(-d[COOH])/(dt)=1.51×10-4[COOH]2.Addition of the catalyst decreased the activation energy of the reaction and the polycondensation could be initiated at a lower temperature. The reaction showed a maximum rate as the amount of the catalvst was about 1%(wt) of the lactic acid.
1994, 11(1): 80-83
Abstract:
The adsorption and desorption on "Fengqin" green tea from aqueous solution containing Ag-were studied; The adsorption equilibrium constant(b) and maximum adsorption capacity(qm) in Langmuir equation and the experimental constants K and 1/n in Freundlich equation were determined. The effects of temperature and pH on the adsorption of Ag-were also examined.A 0.1mol/L Na2S2O3 solution could quantatively desorb Ag.
The adsorption and desorption on "Fengqin" green tea from aqueous solution containing Ag-were studied; The adsorption equilibrium constant(b) and maximum adsorption capacity(qm) in Langmuir equation and the experimental constants K and 1/n in Freundlich equation were determined. The effects of temperature and pH on the adsorption of Ag-were also examined.A 0.1mol/L Na2S2O3 solution could quantatively desorb Ag.
1994, 11(1): 84-87
Abstract:
Integrally skinned asymmetric poly(ether sulfone)membranes were made by dry/wet phase inversion processes. The effects of the dry phase inversion conditions,e.g. evapo-ration time and temperature on the morphology and N2、H2 permeability of the membranes. were studied. The results indicated that the structure of the membranes, thickness and den-sity of the skin layer were all affected by the dry phase inversion conditions. Preferable mem-brane properties would be obtained by appropriately controlling the evaporation conditions.For the casting system used a shorter evaporation time and lower evaporation temperature(about 20℃) are in favour of making the membranes have better gas separation properties.
Integrally skinned asymmetric poly(ether sulfone)membranes were made by dry/wet phase inversion processes. The effects of the dry phase inversion conditions,e.g. evapo-ration time and temperature on the morphology and N2、H2 permeability of the membranes. were studied. The results indicated that the structure of the membranes, thickness and den-sity of the skin layer were all affected by the dry phase inversion conditions. Preferable mem-brane properties would be obtained by appropriately controlling the evaporation conditions.For the casting system used a shorter evaporation time and lower evaporation temperature(about 20℃) are in favour of making the membranes have better gas separation properties.
1994, 11(1): 88-91
Abstract:
In this paper,4,4'-dichlorodiphenylsulfone,4,4'-dihydroxyldiphenylsulfone and 4-chloro-4'-hydroxyldiphenylsulfone were separated completely by HPLC. From the relations between the reacting conditions and yields of 4-chloro-4'-hydroxyldiphenylsulfone by hydrolysis of 4,4'-dichlorodiphenylsulfone,it was found that the larger the amount of NaOH and the higher the temperature, the faster the hvdrolvsis and the lower the yield. The amount of the by product 4,4'-dihydroxyldiphenylsulfone increases with reaction time. After the highest point the yield of 4-chloro-4' hydroxyldiphenylsulfone decreases as increase of by-product. The optimum hydrolysis conditions are:135~140℃, NaOH/4,4'-dichlorodiphenylsulfone=3.25:1(molar ratio), reaction time 2,5~3.0h. The yield was above 90%. The condensation polymerization occurred in the hydrolysis and the purification of product also has been disctissed.
In this paper,4,4'-dichlorodiphenylsulfone,4,4'-dihydroxyldiphenylsulfone and 4-chloro-4'-hydroxyldiphenylsulfone were separated completely by HPLC. From the relations between the reacting conditions and yields of 4-chloro-4'-hydroxyldiphenylsulfone by hydrolysis of 4,4'-dichlorodiphenylsulfone,it was found that the larger the amount of NaOH and the higher the temperature, the faster the hvdrolvsis and the lower the yield. The amount of the by product 4,4'-dihydroxyldiphenylsulfone increases with reaction time. After the highest point the yield of 4-chloro-4' hydroxyldiphenylsulfone decreases as increase of by-product. The optimum hydrolysis conditions are:135~140℃, NaOH/4,4'-dichlorodiphenylsulfone=3.25:1(molar ratio), reaction time 2,5~3.0h. The yield was above 90%. The condensation polymerization occurred in the hydrolysis and the purification of product also has been disctissed.
1994, 11(1): 92-95
Abstract:
The temperature dependence of the infrared and Raman spectra of anhydrous dimyristoylphosphatidylethanolamine(DMPE) was investigated in the temperature rangefrom 290 to 405K. The spectra of the C-H,C=O and PO2- stretching mode regions reflectthat a cooperative phase transition occurs at about 365K. During the transition a significantlateral expansion of the lipid bilayer is present and accompanied both by an increased number of gauche rotamers within the hydrocarbon chain region and by muItiple conformers in boththe head group and glycerol backbone moieties. When the lipids are rapidly cooled,the acylchain region reorders without a concomitant reordering of the head group and interface region.
The temperature dependence of the infrared and Raman spectra of anhydrous dimyristoylphosphatidylethanolamine(DMPE) was investigated in the temperature rangefrom 290 to 405K. The spectra of the C-H,C=O and PO2- stretching mode regions reflectthat a cooperative phase transition occurs at about 365K. During the transition a significantlateral expansion of the lipid bilayer is present and accompanied both by an increased number of gauche rotamers within the hydrocarbon chain region and by muItiple conformers in boththe head group and glycerol backbone moieties. When the lipids are rapidly cooled,the acylchain region reorders without a concomitant reordering of the head group and interface region.
1994, 11(1): 96-98
Abstract:
The porous alumina menbranes supported on porous ceramic of pore size 1.1~1.6um were prepared by the sol-gel method,following repeated impregnating-drying-calcin-ing procedures. The number of repeating cycles could be reduced when the sols were modified by PVA and La (NO3)3.
The porous alumina menbranes supported on porous ceramic of pore size 1.1~1.6um were prepared by the sol-gel method,following repeated impregnating-drying-calcin-ing procedures. The number of repeating cycles could be reduced when the sols were modified by PVA and La (NO3)3.
1994, 11(1): 99-101
Abstract:
An anionic complex Li(DME)3 η5-MeCp)Nd(t-Bu)3 was obtained by the reaction of MeCpNdCl2·nLiCl·nTHF with 2 mols of t-BuLi in the mixed solution of THF andpentane.The complex was characterized by elemental analysis and IR spectroscopy. The complex is soluble in styrene and able to catalyze its polymerization in bulk to give an atacticpolystyrene.
An anionic complex Li(DME)3 η5-MeCp)Nd(t-Bu)3 was obtained by the reaction of MeCpNdCl2·nLiCl·nTHF with 2 mols of t-BuLi in the mixed solution of THF andpentane.The complex was characterized by elemental analysis and IR spectroscopy. The complex is soluble in styrene and able to catalyze its polymerization in bulk to give an atacticpolystyrene.
1994, 11(1): 102-104
Abstract:
CuInSe2 thin films were prepared by electrodeposition technique, The effects of annealing on the composition,morphology,and structure change of the films were discussed. The optimum annealing temperature was obtained on the basis of photoelectrochemical characterization of the samples.
CuInSe2 thin films were prepared by electrodeposition technique, The effects of annealing on the composition,morphology,and structure change of the films were discussed. The optimum annealing temperature was obtained on the basis of photoelectrochemical characterization of the samples.
1994, 11(1): 105-107
Abstract:
p-Chlorophenoxy acetic acid was prepared by reaction of chloroacetic acid and p-chlorophenol in the presence of polyethylene glycol PEG800 and KI with powdery K2CO3 in toluene. When the reaction was carried out at 105~110℃ for 2 hours, the yield of p-chlorophenoxy acetic acid was 94.8%.
p-Chlorophenoxy acetic acid was prepared by reaction of chloroacetic acid and p-chlorophenol in the presence of polyethylene glycol PEG800 and KI with powdery K2CO3 in toluene. When the reaction was carried out at 105~110℃ for 2 hours, the yield of p-chlorophenoxy acetic acid was 94.8%.
1994, 11(1): 108-110
Abstract:
Powdery complex oxides CdO-SnO2 have been prepared through coprecipitation and solid state reaction. Cd2SnO4 and CdSnO3 of both ilmenite and per of skite type were fpund in the complex oxide systems.Different composition of the phases obtained by controlling the molar ratio of Cd/Sn and calcination temperature showed an obvious influence on the conductivity and gas sensing property of the products.
Powdery complex oxides CdO-SnO2 have been prepared through coprecipitation and solid state reaction. Cd2SnO4 and CdSnO3 of both ilmenite and per of skite type were fpund in the complex oxide systems.Different composition of the phases obtained by controlling the molar ratio of Cd/Sn and calcination temperature showed an obvious influence on the conductivity and gas sensing property of the products.
1994, 11(1): 111-113
Abstract:
The effects of γ-ray irradiation on the mechanical properties of HIPS/SBS blends have been investigated. The results indicate that suitable irradiation results in an increase of hardness and thermal deformation temperature of the blends with tensile strength and impact strength being remained uilchanged. When the dose of irradiation was too large the tensile strength and impact strength decreased markedly,the hardness and thermal deformation temperature increased too.
The effects of γ-ray irradiation on the mechanical properties of HIPS/SBS blends have been investigated. The results indicate that suitable irradiation results in an increase of hardness and thermal deformation temperature of the blends with tensile strength and impact strength being remained uilchanged. When the dose of irradiation was too large the tensile strength and impact strength decreased markedly,the hardness and thermal deformation temperature increased too.
1994, 11(1): 114-115
Abstract:
Diacetals of 2,2-bis(hydroxymethyl)-11,3-propanediol were prepared by condensation of aldehydes with 2,2-bis(hydroxymethyl)-1,3-propanediol in benzene. Thev were characterized by 1H NMR,IR and elemental analysis.
Diacetals of 2,2-bis(hydroxymethyl)-11,3-propanediol were prepared by condensation of aldehydes with 2,2-bis(hydroxymethyl)-1,3-propanediol in benzene. Thev were characterized by 1H NMR,IR and elemental analysis.
1994, 11(1): 116-117
Abstract:
The title metavanadates were prepared in argon atmosphere using vanadiumsesquioxide as a starting material. The optimum preparation conditions are:V2O3:Ln2O3=1:0.99,pass argon gas for 45 min at 0.5L/min,heat to 1300℃ for 5h.XRD analysis indi-cated the products were monophase.
The title metavanadates were prepared in argon atmosphere using vanadiumsesquioxide as a starting material. The optimum preparation conditions are:V2O3:Ln2O3=1:0.99,pass argon gas for 45 min at 0.5L/min,heat to 1300℃ for 5h.XRD analysis indi-cated the products were monophase.
