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    24 October 1994, Volume 15 Issue 10
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    Articles
    Synthesis of Na5YSi4O12by Sol-Gel Method and Its Ionic Conductivity
    CUI De-Liang, MENG Xian-Ping, FENG Shou-Hua, XU Ru-Ren
    1994, 15(10):  1421-1424. 
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    High ionically conducting single-phase NYSsamples have been prepared by both the conventional solid state reaction and the Sol-Gel method.Because of the high sensitivity of phase purity and ionic conductivity of the samples to the composition of starting materials, we carefully controlled the procedure of syntheses in order to exclude impurity phases, i.e.Na3YSi3O9 and Na9YSi60O13. Ionic conductivity and conducting activation energy of samples prepared by these two methods have been determined by means of ACimpedance technique.From the analysis of their impedance spectra, we know that the sample prepared by conven tional solid state reaction has some what lower ionic conductivity and higher conducting acti vation energy. On the other hand, ionic conductivity of the sample prepared by Sol-Gel method is comparatively higher, and its conducting activation energy is lower.In accordance with the ionic conducting property, the microstructure observed by SEMof these two sam ples shows big difference, that is, the latter has small and uniform grains which connected more closely but the former has large and nonuniform grains packed loosely.Compared with the former, the latter has more conducting paths for the mobile ions, hence higher ionic conductivity.
    The Study of Extraction Mechanism with Amine
    GAO Hong-Cheng, SHEN Xing-Hai, WU Jie
    1994, 15(10):  1425-1428. 
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    In this paper through studying the extraction of uranium(Ⅵ)with some of amine, we have suggested and proved a new extraction mechanism of amine.The extraction reaction processes are considered in terms of the following steps:(1)The aggregation of ammonium salt and formation of reversed micelle in the extraction organic phase(see Eqn.1).(2)Metal ion Minteracts with monomeric amine to give an extraction complex(see Equ. 2).(3)The solubilization of extraction complex by the reversed micellar pseudophase(see Eqn.3).The distribution ratio Dof uranium can be described with Eqn.4.If the extraction complex does not bind significantly to the reversed micelle, i. e.Kc≈0 and Eqn. 4 reduces to:lgD = lgKc+ylg[N]。Therefore, under these conditions, a plot of lgD versus ylg[N]。 has a slope of y, y is the number of molecules of amine extractant in extraction complex.In the second case, the ex traction complex interacts very strongly with the reversed micelles, i.e.Ks has a high val ue, therefore, Eqn.4 can be approximated as D=constant·Cslg Cs, gives a slope of unity, i.e.Dhas a first order dependence on the concentration of mi cellized surfactant.Thus in this case the formation of extraction complex is not confirmed by the usual slope method.According to the new extraction mechanism, our experimental data and those results in literatures can be given a satisfactory explanation.
    Studies on the Photochemical Reactions Catalyzed by Metalloporphyrin Complexes(Ⅳ)─Kinetics of Photoassisted Reduction of Oxygen by Cobalt(Ⅱ)tetrakisphenylporphyrin
    WANG Qing-Min, YANG Guo-Yu, YU Lian-Xiang, SONG Yang, SUN Jin-Feng, CAO Xi-Zhang
    1994, 15(10):  1429-1432. 
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    In various organic solvents, the photochemical behavior of Co(Ⅱ)TPPhas been investigated.The experiment results suggested that in polar solvent the photooxidation reac tion of Co(Ⅱ)TPPtook place, while it did not take place in non-polar and halogenated sol vents. In polar solvent, the organic bases could increase the photooxidation reaction rate of Co(Ⅱ)TPP, but in non-polar and hologenated solvents, the reaction of Co(Ⅱ)TPPalso took place when the organic base existed.This was bacause that the adducts formed by an axially coordinated polar solvent or organic bases and Co(Ⅱ)TPPpromoted greatly forming complex between oxygen and Co(Ⅱ)TPP(L).The electron complete transfer reaction be tween oxygen and Co(Ⅱ)center was accelerated greatly when the light irradiated.The ex perimental results indicate that when Co(Ⅱ)TPPis coordinated by polar solvents or organic bases in the fifth coordination position, the sixth position was greatly activated, which is the premise and key that superoxide complex formed between oxygen and Co(Ⅱ)TPP.
    Synthesis of Heteroatom-Containing Zeolites ZSM-5,ZSM-11 and ZSM-48
    ZHANG Chun-Lei, WU Zhi-Yun, KAN Qiu-Bin, ZHANG Fu-Shun, ZHAO Zhong-Qing
    1994, 15(10):  1433-1438. 
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    By means of pretreatment-grinding gel, Ti-ZSM-48 zeolite was synthesized in the presence of HMDAtemplate under dynamic and static conditions.Several zeolites having ZSM-5 structure and containing the fourth periodic transition metals were synthesized by us ing a mixture of 85% HMDAand 15% TPABr as the template for the first time under static conditions with previous aging at low temperature.Acompared investigation of the above synthesis and those of M-ZSM-5 and M-ZSM-11 with HMDAand TPABr as the template re spectively were carried out. XRDanalysis at the growing stages of crystals showed that the synthesis methods, pHvalues and content of sodium ions had great effects on crystallization dynamics, and the optimal synthesis conditions were found.Characterization of the prepared samples indicated that the heteroatoms were located in the zeolite frameworks.
    Extraction Equilibria of Hydrochloric Acid with Primary Amine N1923 in Various Diluents
    GAO Zi-Li, JIA Yong-Fen, SUN Si-Xiu, FENG Da-Cheng, SHEN Jing-Lan
    1994, 15(10):  1439-1442. 
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    The extraction equilibria of hydrochloric acid with primary amine N1923 in various diluents were studied by means of two-phase titration at 298 K.The results show that the aggregation of N1923 salts is decreased with the diluent polarity increasing.It may be considered that the interaction among aggregated amine salt molecules is just Vander Waal's force.
    Studies on the Solid State Reactions of Coordination Compounds(LXVII)─The Synthesis of Mixed Ligand Complexes in Solid State
    ZHANG Wei-Ling, ZHENG Li-Min, LEI Li-Xu, XIN Xin-Quan
    1994, 15(10):  1443-1445. 
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    The solid state reactions of diaqua bis(acetylacetonate)cobalt(II)[Co(acac)2(H2O)2]with organic ligands:2, 2'-bipyridyl, 1, 10-phenanthroline, 8-quinolinol and salicylaloxime have been investigated at room or near room temperature. The mixed ligand complexes:Co(acac)2(bipy), Co(acac)2(1, 10-phen), Co(acac)2(8-HQ)2·2H2O, Co(acac)·(SAO)(H2O)have been characterized by the results of UV, FTIR, XRDand elementary analyses.
    Studies on Expert System for the Elucidation of the Structures of Organic Compounds─Computer Perception of Topological Symmetry
    HU Chang-Yu, XU Lu
    1994, 15(10):  1446-1449. 
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    Anode library containing various kinds of nodes is built, and the index number of the library is used to discriminate the different types of non-hydrogen atoms.Two new matrices, node matrix(N)and bond matrix(B), are devised, and a new graph invariant, the weight of the node, is suggested to characterize topological equivalence classes of the nodes(non-hydrogen atoms)in molecular graphs or partial structures.
    The Influence of Guanidine Hydrochloride on the Retention of Proteins in Hydrophobic Interaction Chromatography
    FENG Wen-Ke, JIANG Xin-Qi, GENG Xin-Du
    1994, 15(10):  1450-1453. 
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    The retention behavior of five proteins in high performance hydrophobic interaction chromatography(HPHIC)under the mobile phase consisting of(NH4)2SO4-KH2PO4 containing guanidine hydrochloride was investigated.By using the stoichiometric displacement model for retention(SDM-R)of solute in liquid chromatography, and the measuring surface tension of the mobile phase in the presence of GuHCl, also and UVspectra, it was found that in the range of low concentraction of GuHCl, the hydrophobic irnteraction is considered as the main contribution to the retention of the proteins, However, whem the concentration of GuHCl in the mobile phase is getting higher, the changes of the molecular conformation of proteins by means of GuHCl in the HPHICbecome the most important factor to influecing the retention of proteins.
    A Study of Ultramicroelectrode─Migrational Effects on Quasi-steady-state Linear Potential Sweep Voltammetric Current
    ZHANG Jian-Rong, YANG Xi, ZHANG Zu-Xun
    1994, 15(10):  1454-1458. 
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    An equation for quasi-steady-state linear potential sweep voltammetric current influenced by migration was presented.Aseries of ions with various charges, such as Fe(CN)64-, Fe3+, Ru(bpy)32+ and FeCp20, was employed to explore the migrational effects on voltammogram in different values of supporting electrolyte concentration.The theoretical predicated limiting currents are in good agreement with the experimental results.
    Real-Time Intelligent Background Correction in Inductirely Coupled Plasma Atomic Emission Spectrometry Using a Photodiode Array Spectrometer
    CHENY Yuan, SUN Da-Hai, HUANG Ying-Hui, ZHANG Zhan-Xia
    1994, 15(10):  1459-1463. 
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    Amodified method for real-time intelligent background correction in inductively coupled plasma atomic emission spectrometry using a laboratory-constructed photodiode ar ray spectrometer is proposed.Apolynomial model and a statistical model are used to fit the background, but better results can be obtained for the structured background and line wings by the statistical model.Prior knowledge of sample composition and visual inspection of the spectral window are not required.The method is evaluated by determining Al and La in Ca matrix.
    Calculation of Mass Transfer Coefficient of Coulometric Detector Based on a Porous Carbon Felt Working Electrode by Simplicial Nonlinear Fitting
    CHEN Guo-Nan
    1994, 15(10):  1464-1466. 
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    Based on the investigation of coulometric conversion efficiency of porous carbon felt electrode, a mathematical model for calculating the mass transfer coefficient of porous carbon felt electrode was developed.By using this mathematical model, a simplicial nonlinear fitting method for calculating the mass transfer coefficient of porous carbon felt electrode was proposed, and the process of nonlinear fitting was simulated by a computer.The program written in BASICcould be implemented on a IBMpersonal computer.The results obtained were very closed to the value in literature and the results of graphic method.
    investigation on the Self-Catalytic Reaction During the Series Electrochemical Oxidation of Bilirubin
    NIU Jian-Jun, DONG Shao-Jun
    1994, 15(10):  1467-1469. 
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    In DMFsolvent, the series electrooxidation of bilirubin were investigated using cyclic voltammetry, the experimental results shown that a catalytic reaction existed in these processes.The second oxidation step of bilirubin(the process of biliverdin→bile purpurin)was greatly promoted by this catalytic reaction.The mechanism of the catalysis was also proposed.
    Interaction of Proteins with Fe(Ⅲ)-Chrome Azurol S Complex
    WEI Yong-Ju, LI Ke-An, TONG Shen-Yang
    1994, 15(10):  1470-1472. 
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    In pH 3.0 solution, proteins may react with Fe(Ⅲ)-chrome azurol Sbinary complex to form stable ternary complexes.The maximum absorption wavelengths of the binary and ternary complexes are 570 nm and 660 nm, respectively.According to the absorption spectra of this system, we consider that the combination is primarily due to electrostatic forces between protonated ammonium group of proteins and sulfonic acid group and carboxyl group of chrome azurol S.The sensitiveties(Sandell index)of detection for bovine serum albumin and human γ-globulin are 0.04and 0.16μg/cm2, respectively, which are about 15 to 35 times as high as that of the bromocresol green method.
    Synthesis and Stereochemistry of 4-Substitutedphenyl -1,3,2-dioxaphosphorin Compounds(Ⅰ)─Reaction and Stereochemistry of Cyclic Phosphorochloridates and 3-Hydroxyisoxazole
    SHAO Rui-Lian, YANG Min-Hua, ZHI Cheng-Xin
    1994, 15(10):  1473-1476. 
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    Owing to the biological activities of 3-hydroxyisoxazole and cyclic phosphate derivatives, some compounds possessing the two moieties were synthesized, the structural elucidation of these diastereomers was made depending on spectral analyses.The mechanism could be illustrated by the theories of trigonal bipyramide intermediate and pseudorotation.
    Studies of Tri[(trimethylsilyl)methyl]tin Arylcarboxylates
    XIE Qing-Lan, LIN Sen, SHA Yin-Lin
    1994, 15(10):  1477-1480. 
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    Fourteen tri[(trimethylsilyl)methyl ]tin arylcarboxylates have been synthesized.The results of IR, NMR(1H, 13C.119Sn)and MSindicated that all of these compounds are four-coordinated and there is a good linear relationship between δ119Sn and the Hammett constant(σ)of the para-substituents of the corresponding compounds.The preliminary bioassay tests demonstrated that this kind of compounds have more extensive activity than the compounds of tri[(phenyldimethylsilyl)methyl]tin carboxylates.
    The Stereo-selective Synthetic Method of 2E-Unsaturated Amides
    DU Jing-Xing, HUANG Xian
    1994, 15(10):  1481-1483. 
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    The coupling reaction of arylhalide with N, N-diethyl acrylamide under solid-liquid phase-transfer conditions with bis(benzonitrile)dichloropalladium as catalyst gave the corresponding(E)-α, β-unsaturated amides.Good yields were obtained with aryliodide as substrate.Hence this paper presents a simple stereo-selective synthetic method for 2E-unsatu-rated amides.
    Intramolecular Reaction and Intramolecular Catalysis(Ⅳ)─Inductive Effect of Hydroxy Group on the Intramolecular General-base Catalyzed Hydrolysis of Ethyl 3-(2'-benzimidazolyl)-3-hydroxy Propionate by Benzimidazolyl Group
    XIA Dao-Hong, XIA Chi-Zhong
    1994, 15(10):  1484-1488. 
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    Benzimidazolyl group exhibits catalytic activity in the way as intramolecular general-base catalysis in the hydrolysis of 3-(2'-benzimidazolyl)-3-hydroxy propionate. Although the presence of hydroxy group in the molecule didn't change the catalytic way of benzimidazolyl group, but affected its catalytic activity evidently, Discussion for the experimental results in view of inductive effect and hydrogen bond of hydroxy group is presented.
    Synthesis and Spectra Determination of 5,10,15,20-Tetrakis-(2-alkylphenyl)porphyrins and Their Ferric Complex Salts
    GUI Ming-De, JIANG Du-Xiao, ZHU Shen-Jie
    1994, 15(10):  1489-1493. 
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    Six different 5, 10, 15, 20-tetrakis(2-alkylphenyl)porphyrins(T(O-R)PPH2)and their ferric complex salts T(O-R)PPFeCl(R=Me, Et, n-Pr, i-Pr, n-Bu, t-Bu)were synthesized.Besides R=Me is known, all others are new compounds.We found that T(O-i-Pr)PPH2, T(O-t-Bu)PPH2, and T(O-i-Pr)PPFeCl, T(O-t-Bu)PPFeCl were more difficult to formation than other T(O-R)PPH2 and T(O-R)TTPFeCl.Their IRand UV-Vis spectra were determined and the relationship between the structures and the spectral properties was discussed.
    A New Approach to Selective Deoxygenation of Bile Acids
    LIKai-Xi, XU Zheng-Bang, YU Rui, ZHAO Hua-Ming
    1994, 15(10):  1494-1496. 
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    Selective deoxygenation of four bile acids with K/18-Crown-6/But NH2 was first reported.It can be accomplished by four steps:methylesterification, diacylation or selective diacylation, selective hydrolysis and reduction.The products formed in formal three steps were not isolated(not necessary).The last step is carried out rapidly at room temperature, with a little by-product.The present approach is straight forward, practicable and with high over all yields, 70% 75%.
    Studies on Allylzincation of Alkynes and Its Synthetic Applications
    WEI Yun-Yang
    1994, 15(10):  1497-1499. 
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    Butenylzinc chloride was added to ω-iodo terminal alkynes in the absence of any kinds of transition metal complexes.The reactions proceed with clean allylic rearrangement and a mechanism via six-centered transition state is proposed. Some new monocyclic and bicyclic alkenes(13)were synthesized via allylzincation.
    The Analysis of Through-Space and Through-Bond Interactions in[2,2] Paracyclophanes and Derivatives
    LIU Han-Xing, SUN Jia-Zhong
    1994, 15(10):  1500-1505. 
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    Through-space interactions and through-bond interactions in[2,2]paracyclophane and its derivatives are studied by means of the improved overlapping Muffin-Tin Xa method, and the influence of the interactions on the orders of the energy levels are discussed.The energy levels correlation diagram and the interactions influenced by different connecting bridges are shown, Furthermore, the ionization potentials of the molecular orbitals are calculated, and the results are in good agreement with the experimental ones.
    Studies on the Growth Process of PbO2 on the Lead-Antimony Electrodes
    WEI Guo-Lin
    1994, 15(10):  1506-1509. 
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    The potential-step and impedance tracing methods were used to study the growth process of PbO2 on lead-antimony electrodes with the oxidation current of lead substrate being considered.The influence of antimony on the growth process was investigated.The growth process of PbO2 on the lead-antimony electrodes obeys the rule of two dimentional instantaneous nucleation and growth process and the antimony will retard this process.
    Dynamic Nuclear Magnetic Resonance of In(Ⅲ)and Y(Ⅲ)-1,2-Propanediaminetetraacetic Acid
    SONG Rui-Fang, QIN Song-Yan, LIU Qun, LIU Guang-Min
    1994, 15(10):  1510-1513. 
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    The temperature dependence of 1H NMRspectra of the In(Ⅲ)and Y(Ⅲ)complexes of 1, 2-propanediaminetetraacetic acid(1 , 2-PDTA)was observed and investigated.The four different ABquartets reveal that the eight acetate methylenic protons of In(Ⅲ)and Y(Ⅲ)-1, 2-PDTAare in different magnetic environment.The ABinterchange phenomena due to nitrogen inversion were observed in the temperature range of 90-140℃.The rate constants and the activation parameters were derived. The Natom near the methyl group has smaller inversion rate than that a little far away the methyl group.In addition, the linear relation between activation energy(Ea)and metal ion potential(z/r)is established for In(Ⅲ), Y(Ⅲ), Zn(Ⅱ), Mg(Ⅱ)and Cd(Ⅱ)-1, 2-PDTA.
    Influence of Surface Gas-Atmospheric Treatment on Characteristics of Gas Sensing Element
    QUAN Bao-Fu, LU Ge-Yu, SUN Liang-Yan
    1994, 15(10):  1514-1517. 
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    Choosing suitable gas for the surface treatment of gas sensing elements is one of the important technologies on the surface modification of the gas sensing elements, In the present paper, H2Sgas sensing element has been treated with SO2 gas under different conditions by which both sensitivity and selectivity of the gas sensing elements have been improved considerably.
    Studies on Localized Molecular Orbitals for Compounds of Mn Dimer
    LI Qian-Shu, LI Song, TANG Ao-Qingg
    1994, 15(10):  1518-1520. 
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    The canonical and localized molecular orbitals of Mn2( μ-Cl)2(CO)8 and Mn2(CO)10 have been calculated by using the UHF INDOsemiempirical method and via the Edmiston-Ruedenberg localization method.The electronical configuration, geometry struc ture and chemical bonding properties as well as the relationship between them are discussed.
    Electrochemical and Spectroelectrochemical Characterization of PHB Material:Zinc Tetrabenzoporphyrins
    SUN Hao-Ran, SHI Tong-Shun, CAO Xi-Zhang
    1994, 15(10):  1521-1524. 
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    The redox properties and electronic spectra of different oxidation state of PHBmaterials(ZnTBP, where TBPrepresents the dianion of meso-tetramethyl-tetrabenzoporphyrin or meso-tetraphenyl-tetrabenzoporphyrin or meso-tetra(p-toly)-tetrabenzoporphyrin or meso-tetranaphthyl-tetrabenzoporphyrin)were investigated by electrochemistry and in-situ UV-visible spectroelectrochemistry in CH2Cl2, THFand DMSO.The redox potentials of ZnTBPseries and electronic absorption spectra of ZnTBP+ and ZnTBP2+ were obtained, and the relationship between excited state redox properties and photochemical spectral hole burning was discussed.
    The Kinetic Study on Collisional Quenching of CH(B2Σ-)by Halomethane,CS2,O2 and Ar Molecules
    CHEN Cong-Xiang, SHENG Yue, DAI Ji-Xun, MA Xing-Xiao
    1994, 15(10):  1525-1528. 
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    CH(B2Σ-)radical was produced by quadrupuled YAGlaser(266 nm)photolysis of CHBr3 molecules.The quenching rate constants by halomethane(CH2Cl2, CHCl3, CCl4 and CHBr3), CS2, O2, and Ar were determined at room temperature by monitoring the time-resolved emission CH(B→X)signals.The measured results(in10-10cm3·molec-1·s-1)are 4.4±0.7(CH2Cl2), 5.2±0.4(CHCl3), 5.0±0.7(CCl4), 8.2±0.3(CHBr3), 7. 9±0.7(CS2), 0.19±0.02(O2), and(1.1±0.1)×10-2(Ar), respectively。It is shown that the quenching rate constant of CH(B)is faster than that of CH(A)except for O2 molecule.The quenching rate constant of CH(B)increases with increasing the number of chlorine atoms contained in chloromethane molecules and an interpretation of this result based on complex model is presented.
    Dissociation Excitation of CHnCl4-n(n=1-4)by the Energy Transfer of He(23 s)Under a Beam-Gas Condition
    LI Quan-Xin, LAI Re, CHEN Cong-Xiang, MA Xiang-Xiao, LI Xue-Chu, SHEN Guan-Lin
    1994, 15(10):  1529-1533. 
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    The kinetic processes of dissociation excitation of CHnCl4-n(n=1-4)colliding with He(23s)were studied by observing the emissions of products。The formation rate constants of CH(A), CH(B), CH(C), Hand CCI(A)from He(23s)/CHnCl4-n(n=1-4)reaction were determined by using the reference reaction method.The rovibrational distribution of CH(A2Δ, v′=0-2)and CH(B2Σ, v′=0)was also obtained by a computer simulation of CH(A-X, B-X)emission. The experimental results showed that the rotational distribution of CH(A2Δ, v′=0)from He(23s)and CHnCl4-n(n=1-3)was expressed as the double Boltzmann temperature, which is different from that of He(23s)/CH4.It is also noted that the major available energies of the reactions are deposited into relative translational energy of products.The mechanism of the reactions He(23s)with CHnCl4-nhas been suggested.
    Ab Initio Calculations of 1Σ+ Ni─CO Molecular Cluster
    XU Xin, WANG Nan-Qin, LU Xin, ZHANG Qian-Er
    1994, 15(10):  1534-1537. 
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    UHFand UMP2 are employed to investigate the bonding mechanism of 1Σ+Ni-COmolecular cluster.The calculation results show that, in 1Σ+Ni─CO σ subspace, CO5σ→Ni4sσ donation dominates in Ni1 S(d10 )derived state, while 4spσpolarization dominates in Ni1D(d9s1)derived state.The π backdonation is greater than σ donation in d10 derived state, while σ donation is more important than π backdonation in d9s1 derived state, The calculation results demonstrate that it is important to perform a counterpoise calculation because there must exist an orbital overlapping in a donor-acceptor bonding mechanism.
    Interaction Energy Between Spherical Colloidal Particles─The Improvement On Derjaguin Method
    WANG Hao-Ping, Jin Jun, L. Blum
    1994, 15(10):  1538-1542. 
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    The correction to classical Derjaguin method has been made in the formulae for the double layer interaction at constant surface potential between two identical and between two dissimilar spheres.The expressions which can be applied to any ka and kHare obtained, in which k is Parameter, a is the radius of particles, His the shortest distance between the two spheres.The improved Derjaguin approximation opens up a usual area of familiar Derjagain formulae, and gives the exact results.
    Experimental Study of Oxidation Dynamics of IR Laser-Induced SiO2 Films
    XU Zhu-De, CHEN Wan-Xi, DING Ji-Cheng
    1994, 15(10):  1543-1546. 
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    IRlaser-assisted SiO2 thin films were grown on the clean surface of Si(100)at a low substrate temperature(from room temperature to about 200℃), using 10.6 μm CW CO2 laser by self-established laser surface reaction device, The influence of different experimental conditions, such as reaction gas percentage, substrate temperature, incident laser intensity, and laser exposure time etc.on SiO2 thin films was investigated.The reaction dynamics of oxidation of IRlaser-assisted SiO2 films was discussed and the idea of reaction inducement period in the thin oxidation area(<30 nm)was suggested.
    Effect of Preparation Methods for Cu/ZnO/Al2O3 Catalyst on Methanol Synthesis from CO2+H2
    ZHANG Yu-Long, WANG Huan, Deng Jing-Fa
    1994, 15(10):  1547-1549. 
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    Cu/ZnO/Al2O3 ultrafine particle catalysts were prepared by various methods such as coprecipitation, supercritical fluid drying, vacuum freezing drying and organic cpmplex decomposing.The characterization of catalysts and performance of methanol synthesis from CO2+H2 over these catalysts at 2 MPa were also investigated.The results indicate that the catalyst prepared by oxalate gel-coprecipitation shows higher BETarea and smaller particle size than by the other methods, and it also shows the highest activity and methanol selectivity.Methanol is directly formed from CO2 other than from CO via reverse water gas shift reaction.Thermodynamic equilibrium was reached at about 230℃, 2 MPa and GHSVof 3600 h-1。
    Derivative Temperature-Programmed Reduction Spectra of Cu-Based Catalysts for Methanol Synthesis
    HU Yun-Hang, WAN Hui-Lin, CAI Qi-Rui(TSAI Khi-Rui)
    1994, 15(10):  1550-1552. 
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    Derivative temperature-programmed reduction spectra(DTPR)were first proposed.In order to obtain DTPRspectra from experiments, a series of computer programs was edited in ASSEMBLEand SOFT BASIClanguages.With the aid of computer, the DTPRspectra of Cu-based catalysts for methanol synthesis were successfully obtained.Although it was very difficult to know how many kinds of of Cu oxide species there are in the Cu/Zn/Al catalyst(Sanming Chemical Factory)from TPRspectrum, The DTPRspectra showed obviously that there were three kinds of Cu oxide species in the catalyst.Both TPRand DTPRshowed there was one kind of Cu oxide species in MK-101 Cu/Zn/Al catalyst(Topose).The results indicated that MK-101 was easier to be reduced and more homogeneous than the catalyst of Sanming Chemical Factory, It has been found that the resolving power of DTPRis better than that of TPR.
    Synthesis and Characterization of a Novel Interpenetrating Polymer Network PP/PnBA
    LUO Xiao-Lie, LIU Jin, FAN Zhong-Dong, MA De-Zhu, ZNAO Chun-Tian, HOU Jian-An, CUI Di, XU Mao
    1994, 15(10):  1553-1558. 
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    Anovel interpenetrating polymer network(IPN)of isotactic polypropylene/poly n-butyl acrylate(PP/PnBA)was prepared by in-situ polymerization of n-butyl acrylate in the pores of matrix polypropylene(PP)microporous membrane.The composite IPNmembrane was characterized by using the methods of FT-IR, polarized light microscope(PLM), SEM, XPS, WASDand stress-strain measurements。It has been found that the PnBAcomposition in the surface of the composite membrane was depedent on the pore number in the surface of the matrix PPmembrane.The structure of the matrix PPmicroporous membrane was preserved in a great extent.Almost all the pores were filled with crosslinked PnBAso that a continuous PnBAphase formed which was interpenetrated with PPphase。The mechanical properties of composite IPNmembrane were improved in some aspects in comparison with the matrix membrane.
    Studies on the Spectra of PVK/C60* Charge-Transfer Complex
    WANG Chang-Chun, DENG Bo-Juan, FU Shou-Kuan
    1994, 15(10):  1559-1562. 
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    The system of PVK/C60* has been studied by UVand fluorescence spectra, The result proves the existence of PVK/C60* charge-transfer complex(CTC).The UVresult shows the absorption peak of CTC of PVK/C60* is about 474 nm and the calculation result is quite consistent with the experimental result.We also found that the best ratio of PVK/C60* to obtain their CTCis about 5:1.The fluorescence result also proves further the existence of PVK/C60* charge-transfer complex.
    Studies on Photochromic Liquid Crystalline Polymers(Ⅳ)─Liquid Crystalline Behavior of Side-Chain Copolysiloxanes Cotaining 4-Methoxyphenyl Benzoate Mesogens and Azobenzene Photochromic Groups
    ZHANG Qi-Zhen, WANG Yan, Hou Jian-An, Xu Mao
    1994, 15(10):  1563-1566. 
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    The liquid crystalline properties of side-chain copolysiloxanes containing 4-methoxyphenyl benzoate mesogens and azobenzene photochromic groups were characterized by polarized microscopy with a hot stage(POM)and DSC.On incorporation of nonmesogenic units into polysiloxane PS Ⅱ-1 the type of mesophase did not chang for copolymers PS Ⅱ-2 and PS Ⅱ-3, but smectic texture is only preserved for copolymer PS Ⅱ-4.The mole fraction limit of mesogenic units needed for mesophase existence of copolysiloxanes of mesogenic monomers with monomers, which do not contain mesogenic fragments, is to be 80 mol%;In the composition region of mesophase existence the lowering of melting temperature is accompanied by the increasing of nonmesogenic component content of copolymers and their isotropic temperature, enthalpy and entropy pass through a minimum at 10 mol%of nonmesogenic units of PS Ⅱ-3, as shown in Fig, 3.
    Laser Light-Scattering Characterization of the Molecular Weight Distribution of Poly(N-isopropylacrylamide)
    ZHOU Shui-Qin, WU Chi
    1994, 15(10):  1567-1571. 
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    Poly(N-isopropylacrylamide)(PNIPAAM)was synthesized by free radical polymerization.Laser light scattering(LLS)including the angular dependence of the absolute integrated scatterred intensity(static LLS)and of the line-width distribution(dynamic LLS)has been successfully used to characterize the molecular weight distribution of PNIPAAM sample.By doing the Laplace transform of precisely measured intensity-intensity time correlation function, we can get a translational diffusion coefficient distribution G(D);After combining the static and dynamic LLS results, i.e.Mw and G(D), we were able to convert G(D)into a molecular weight distribution Fw(M).During this conversion, a calibration of D/cm2·s-1=2.84×10-4M-0.55was established.
    Studies on Morphologies of PBD-b-PMMA Block Copolymer
    ZHOU Qing-Ye, ZHANG Bang-Hua, SONG Mou-Dao, HE Bing-Lin
    1994, 15(10):  1572-1574. 
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    The poly(butadiene-b-methyl methacrylate)copolymer(PBD-b-PMMA)were synthesized by anionic polyfmerization method.The results of 1HNMRand FTIRshow that the products are block copolymers.The studies on copolymer by DMAand TEMdemonstrate that the block copolymers are microphase separation, that is, the polybutadiene phase and polymethyl methacrylate phase were formed.The molecular weight of copolymer and solvent do not have significant effects on the morphologies of copolymer, The morphologies of copolymer are dependent on structures of copolymers.
    Radiation Induced Precipitation Copolymerization of Acrylonitrile,Methyl Acrylate and Itaconic Acid
    ZHANG Zhi-Cheng, GE Xue-Wu, GE Min, ZHANG Jian
    1994, 15(10):  1575-1577. 
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    The radiation induced precipitation copolymerization of acrylonitrile(AN)/methyl acrylate(MA)/itaconic acid(IA)in certain solvents was studied.High molecular weight AN/MA/IAcopolymer(Mw≥5×105)fitted for high property carbon fibre has been synthesized.The effects of dose, dose rate, monomer concentration and the composition of mediums on the molecular weight of copolymers have been investigated to determine the best polymerization conditions.The system with 25%monomer(AN/MA/IA=97/2/1), 30%DMFand 45%H2Ois a favorable one, D=22 Gy/min, R=2.2 kGy are the reasonable radiation conditions.
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