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    24 August 1999, Volume 20 Issue 8
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    Articles
    Barium Pyrovanadate Prepared from Thermal Decomposition of Barium Dimeric(citrato)oxovanadium(Ⅳ)
    ZHOU Zhao-Hui, MIAO Jian-Ying, ZHANG Hui, WAN Hui-Lin
    1999, 20(8):  1168-1171. 
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    Barium dimeric(citrato)oxovanadium(Ⅳ) tetrahydrates Ba2[VO(cit)]2·4H2O has been prepared by the reaction of sodium dimeric(citrato)oxovanadium(Ⅳ) and barium chloride. Its single crystal was obtained by diffusion method in silica-gel. The complex crystal-lizes in monoclinic space group P21/n with unit cell parameters: a=0.98960(9) nm, b=0.87746(5) nm, c=1.21075(8) nm, β=93.119(7)°, Z=2, R=0.045 for 1260 reflections with I≥3σ(I). Thermal decomposition shows the barium salt undergoes with three major processes, including dehydration, ligand elimination and formation of mixed oxide as its final step, in which the latter is confirmed as pure phase of barium pyrovanadate by XRD analysis.
    Synthesis and Characterization of Novel Double Tetrahedral Transition Metal Clusters
    ZHANG Jie, CHEN Xue-Nian, DING Er-Run, YIN Yuan-Qi, SUN Jie
    1999, 20(8):  1172-1178. 
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    The reaction of Co2(CO)8 and [C13CC(O)OCH2]2 gave a novel double tetrahedral cluster compound([(CO)9Co3(μ3-C)C(O)OCH2]2 1)containing two tetrahedral skeletons(Co3C) linked by a C(O)OCH2CH2OC(O) bridge. The reaction of 1 with different molecular ratios of Na[M(CO)3C5H4R][M=Mo, W; R=H, C(O)Me] gave the one-step exchange products (CO)9Co3(μ3-C)C(O)OCH2CH2OC(O)(μ3-C)Co2M(CO)8(C5H4R)[M=Mo, R=H(2); M=Mo, R=C(O)Me (3); M=W, R=H (4); M=W, R=C(O)Me (5)] or the two-step exchange products or the two-step exchange products [(C5H4R)(CO)8Co2M(μ3-C)C(O)OCH2]2[M=Mo, R=H(6); M=Mo, R=C(O)Me (7); M=W, R=H (8); M=W, R=C(O)Me (9)]. By treating. By treating5 or 9 with Na[Mo(CO)3C5H5] in 1/2 molecular ratio, the compound (C5H5)(CO)8Co2Mo(μ3-C)·C(O)OCH2CH2OC(O)(μ3-C)CoMoW(CO)7(C5H4C(O)Me)(C5H5)(10) or [(C5H5)(C5H4·C(O)Me)(CO)7CoMoW(μ3-C)C(O)OCH2]2 (11) which has one or two chiral tetrahedral skeletons(CoMoWC)was obtained. Compounds 1_11 were characterized by C/Hanalyses, IRand 1HNMR. The results indicate that the Co(CO)31/n (#14) and lattice parameters, a=0.9330(2) nm, b=1.5197(4) nm, c=1.1783(4) nm, β=91.16(2)°, Z=2, F (000)=972.
    Progress in Molecular Magnetism of Heteropolynuclear Complexes
    GAO En-Qing, LIAO Dai-Zheng
    1999, 20(8):  1179-1185. 
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    The recent progress in molecular magnetism of five types of heteropolynuclear complexes, which are most relevant to the design of molecular based magnets, and contain oxamato, oxamido, oxalato, oximato and cyano bridges, respectively, was reviewed, and a brief perspective in this field of research was also presented.
    Hydrothermal Synthesis and Crystal Structure of Co(En)3MoO4
    WANG Ren-Zhang, LI Ya-Feng, QIAO Xiao-Guang, YANG Guo-Yu, XING Yong-Heng, ZENG Qing-Xin, XU Ji-Qing, LIN Yong-Hua, XING Yan, JIA Heng-Qing
    1999, 20(8):  1186-1188. 
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    Co(En)3MoO4 was synthesized by using the method of hydrothermal synthesis and characterized by elemental analysis, IR, ESRand single-crystal X-ray methods. It crystal-lizes in hexagonal space group P3C1 with a=1.5964(2) nm, b=1.5964(2) nm, c=0.9935(2) nm, α=β=90°, γ=120°, Mc=399.18, V=2.1926(6) nm3, Dc=1.814 g/nm3, Z=6, F(000)=1218, R1=0.0703, Rw=0.2207. According to separation of anion which acted on electrostatic potential, the anion and cation ions formed a type of organic and inorganic material.
    Studies on the On-line Anion Exchange Preconcentration for Graphite Furnace Atomic Absorption Spectrometry
    SU Xing-Guang, ZHANG Han-Qi, LIANG Feng, JIN Qin-Han, BAI Suo-Zhu
    1999, 20(8):  1189-1193. 
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    Flow injection preconcentration system was introduced into graphite furnace atomic absorption spectrometry in this study. Strongly basic anion exchange fiber was selected as the absorption material, concentrated HCl as complex agent, diluted HCl as eluant. Volume-based elution technique was proposed and applied in this study. Cd, Fe and Zn were determined by the proposed method. The enrichment factors are 19, 17 and 15 (compared with 40 μLsample), the detection limits for the Cd, Pb and Zn are 1.1, 8.2 and 2.6 ng/L, respectively.
    Label of AFP Antibody and Electrochemiluminescence Immunoassay
    ZHUANG Hui-Sheng, WANG Qiong-E, CHEN Guo-Nan, HUANG Jin-Ling, LIN Pei-Cheng
    1999, 20(8):  1194-1199. 
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    Anew chemiluminescent reagent isothiocyanato-isoluminol (ITCI) was used to label Anti-AFP. The molar incorporation ratios are estimated to be 0.25～0.50 mole of ITCI per mole Anti-AFP. The results show that there are no apparent changes in the immunoreactivity of the labeled Anti-AFPand the quantum efficiency of ITCIattached to the Anti-AFP. In addition, the conditions of labeling reaction,sandwich immunoassay and electrochemiluminescent reaction were studied. Morever, a new sandwich electrochemiluminescence immunoassay(ECLIA) is firstly established, and used to detect AFP in human serum. The calibration ranges is 5.0～100.0 ng/mLand the minimal detection concentration is 2.0 ng/mL.
    Electrochemistry and Electrochemical Catalysis of Cobalt Phthalocyanine Tetrasulfonate-DDAB Surfactant Film Electrodes
    HU Nai-Fei, HUANG Rong, YANG Jing
    1999, 20(8):  1200-1204. 
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    Cobalt phthalocyanine tetrasulfonate (CoPcTS4-) anions in aqueous solutions could enter the films of cationic surfactant didodecyldimethylammonium bromide (DDAB) films by ion exchange and form CoPcTS4--DDABfilm electrodes. Cyclic voltammetry (CV) showed in pH7.0 blank buffers, the films were quite stable and had two pairs of quasireversible redox peaks. The first pair shown at Epc1= -0.28 Vand Epa1=-0.18 V (vs. SCE) was attributed to the redox couple of Co(II)/Co(I) of CoPcTS4-, while the second set at Epc2=-1.30 Vand Epa2=-1.18 Vcorresponds to the redox process of phthalocyanine ring. The charge transport diffusion coefficient, Dct, and apparent heterogeneous electrode reaction rate constant, ko', were estimated by CV. CoPcTS4--DDAB films could be used to catalyze electrochemical reduction of trichloroacetic acid (TCA). Catalytic current had a linear relationship with the concentration of TCAin the range of 4×10-5-1×10-3 mol/L.
    Design and Characterization of a Versatile, Thin-layer Spectroelectrochemistry Cell
    YANG Chen, YU Jun-Sheng, ZHOU Tao-Yu, FANG Hui-Qun
    1999, 20(8):  1205-1209. 
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    The design of a versatile, thin-layer cell to perform in situ spectroelectrochemistry is discussed. The cell is simple in structure, easily disassembled and particularly no need for optical transparence of working electrode. The use of this cell to monitor the electrochemical reactions of o-tolidine by in situ UV-V is and fluorescence and pyridine by FT-Raman is demonstrated.
    Interactions Between DNA and DNA-Targeting Molecules
    ZHANG Rong-Ying, PANG Dai-Wen, CAI Ru-Xiu
    1999, 20(8):  1210-1217. 
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    Studies on interactions between DNAand DNA-targeting molecules are of great importance not only to elucidating the action mechanisms of some anti-tumor and anti-viral drugs and some carcinogens, but also to the design of artificial nucleases and probes for DNA structures. In this article, recent advances in the studies of interactions between DNA and DNA-targeting molecules with different structures are reviewed.
    Investigation of the Association Between Bovine Serum Albumin(BSA) and Aluminum Tetrasulfonated Phthalocyanine(AlS4Pc) by Fluorescence Anisotropy
    LI Dong-Hui, PENG Xing-Yue, YE Dong, XU Jin-Gou
    1999, 20(8):  1218-1220. 
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    Fluorescence anisotropy was employed for the investigation of the association between AlS4Pc and BSA. The average binding number of AlS4Pc to BSAwas calculated and the constants of association reaction occurring in the medium of pH7.0 were shown. The results revealed that the interaction between AlS4Pc and BSAwas strong, which implied that AlS4Pc may be stored and transferred by serum albumin. The merits of the method used were also pointed out.
    The Analysis of Heavy Oil by On-line Coupled Packed Capillary Liquid Chromatography and High Temperature Capillary Gas Chromatography
    JIANG Tao, GUO Rong-Bo, GUAN Ya-Feng 
    1999, 20(8):  1221-1223. 
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    The heavy oils from petrochemicaLINdustry were analyzed by an on-line coupled packed capillary high performance liquid chromatography(μ-HPLC) and high temperature capillary gas chromatograph(HTGC). An aminosilane silica packed μ-HPLC column separates the sample into aliphatics, one-to five-ring polycyclic aromatic hydrocarbons and resin ect.. The volume of each fraction is about 30～60 μL, which is stored in turn in a multi-loop interface from a single LCinjection, and then transfered into GCfor quantitative analysis. The content and the carbon number distribution of each chemical class are obtained. The RSD is less than 5%. Examples were given to demonstrate the applicability of the method.
    Synthesis of Two New Chiral Blocks for the Construction of Peptide Nucleic Acid(PNA)
    ZHANG Li-Gang, MIN Ji-Mei, ZHANG Li-He 
    1999, 20(8):  1224-1229. 
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    Protected (L-) and (D-)-lysine were used respectively as starting materials to syn-thesize two new types of chiral blocks for the construction of PNA. Nucleobase was linked to α-NH2 of lysine via _CH2C(O)_ spacer in type Ⅰ, and _C(O)_ was used in type Ⅱ.
    Preparation and Hepatocyte Culture on Agar-based Microcarriers
    XU Tao, LI Shao-Lin, PAN Ji-Lun, YU Yao-Ting
    1999, 20(8):  1230-1232. 
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    Using agar as raw materials and toluene as oil phase medium, agar-based microcarriers was prepared by suspension method. The diameter are 100_180μm and the surface was modified by amino groups. Rat hepatocyte was cultured on the microcarriers. Morphology and metabolize function of hepatocyte were studied and tested.
    Synthesis of 3-Alkyl/Aryl-6-(1’-N-β-D or α-L-Acetylated glycopyranosyl)-s-triazolo[3,4-b]-1,3,4-thiadiazoles
    YU Jian-Xin, LIU Fang-Ming, LU Wen-Jie, LI Yan-Ping, TIAN Li-Li, LIU Yu-Ting, LIU Cong, CAI Meng-Shen
    1999, 20(8):  1233-1237. 
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    3-Alkyl/aryl-4-amino-5-mercapto-1,2,4-triazoles(5) were condensed with 2,3,4,6-tetra-Oacetyl-β-D-glucopyranosyl isothiocyanate(3) or 2,3,4-tri-O-acetyl-α-L-rhamnopyranosyl isothiocyanate(4) in anhydrous EtO Hunder reflux to afford 14 novel 3-alkyl/aryl-6-(1'-N-2',3',4',6'-tetra Oacetyl-β-D-glucopyranosyl or 1'-N-2',3',4'-tri-O-acetyl-α-L-rhamnopyranosyl)-s-triazolo[3,4-b]-1,3,4-thiadiazoles(6a_6i, 7a_7e). Their structures were confirmed by elemental analysis, IRand 1HNMR spectral data.
    Studies on Synthesis and Spectral Character of New Schiff Base Mono- and Heterodinuclear Complexes
    CHEN Xin-Bin, GUI Ming-De, ZHU Shen-Jie, YANG Yan, GUO Can-Cheng
    1999, 20(8):  1238-1241. 
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    This paper first reports the syntheses and spectral character of bis[ N,N′-ethy-lene-2,2′-(phenylmethylene)bis(3,4-dimethylpyrrole-5-aldimino)]monometallic complexes MH2L[M=Mn(Ⅱ), Fe(Ⅲ)Cl, Cr(Ⅲ)Cl, Cu(Ⅱ), Co(Ⅱ), Ni(Ⅱ), Zn(Ⅱ)] and dimetallic complexes MnML[M=Fe(Ⅲ)Cl, Cr(Ⅲ)Cl, Cu(Ⅱ), Co(Ⅱ), Ni(Ⅱ), Zn(Ⅱ)].
    Synthesis of Heterocyclic Compounds from 2-Trifluoromethyl Benzimidazol-1-acetic Acid Hydrazide
    LIU Fang-Ming, LU Wen-Jie, ZHANG Zhen-Fang, WANG Bao-Lei, LIU Yu-Ting
    1999, 20(8):  1242-1247. 
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    Aseries of new 1,3,4-oxadiazoline and 1,2,4-triazolo[3,4-b][1,3,4]thiadiazole derivatives were synthesized from 2-trifluoromethylbenzimidazol-1-acetic acid hydrazide, Their structures were identified by IR, 1HNMR, MSand elementary analysis. Their spectral properties were also discussed.
    Studies on Synthesis and Fungicidal Activities of β-Substituted Phenyl(phnoxyl) Acrylate Esters(amides)
    WANG Zhong-Wen, LI Zheng-Ming, CHEN Han-Song, LIU Tian-Lin, LI Shu-Zheng
    1999, 20(8):  1248-1253. 
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    β-methoxyl acrylate esters are a new type of fungicides appeared recently. By summarizing the relationship of the structure and bioactivity of this type of synthesized fungicides, we proposed that by changing the ester group and β-group of β-substituted acry-late esters, the fungicidal activity of this type of compounds would be increased. Twenty-two β-aroxylethoxyl acrylate esters and eight β-methoxyl acrylate amides were synthesized. In the synthesis of the target products, when the carbon-increasing regent is ethyl formate instead of methyl formate, the analogues ethyl β-aroxyethoxy acrylate were obtained instead of the methyl esters. There's a ester-exchanging process in the reactions, the mechanism of which had been proposed. The preliminary bio-assay indicated that these new compounds possessed some fungicidal activities. The bio-assay also indicated that these new compounds showed different activities on sensitive fungi and the fungi with resistance.
    Synthesis of Single-chain Amphiphiles Containing 2,7-Substituted Naphthalene Rigid Segment and Self-organization of the Amphiphiles in Dilute Aqueous Solution
    LI Guo-Wen, LIU Xi-Yu, WU Li-Xin, SHEN Jia-Cong, LIANG Ying-Qiu
    1999, 20(8):  1254-1258. 
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    Aseries of single-chain amphiphile containing 2,7-substituted naphthalene rigid segment, alkyl tail chain and spacer portion, CnH2n+1OC10H6O(CH2)6N+(CH3)3Br-(n=16, 12, 10, 7, 4), has been synthesized. The aggregate morphology of the amphiphiles in dilute aqueous solution was observed by electron microscopy, and found to form aggregate global-shaped vesicles with 200-400nm when n≥7 and unstable dispersion when n=4. The gel to liquid crystal phase transition of the bilayer membranes was studied by means of differential scanning calorimmetry(DSC). The molecular motion in the membranes was investigated by 1HNMR. The experiment results indicate that the amphiphiles are of practical bilayer forming, capable of organizing biomembrane mimetic agent and suggest that the vesicle structure are composed of the bilayer structure similar to that of biomembranes.
    Synthesis and Properties of Silica Pillared Sulfonated Zirconium Phosphate-phenylphosphonates
    XIAO Jin-Bing, XU Jin-Suo, TANG Yi, GAO Zi
    1999, 20(8):  1259-1261. 
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    Silica pillared zirconium phosphate-phenylphosphonate was synthesized and characterized. After the sulfonation of phenyl groups, the samples have abundant acidic sites. The catalytic activity of the samples in the esterification of acetic acid and ethanol is equal to sulphuric acid.
    The Kinetics of the Formation of Sodium Aluminosilicate Hydrate in Strong Caustic Solutions
    LIU Gui-Hua, LI Xiao-Bin, PENG Zhi-Hong, ZHAGN Chuan-Fu
    1999, 20(8):  1262-1265. 
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    The kinetics of the formation of sodium aluminosilicate hydrate in strong caustic solutions at high mole ratio(between Na2O and Al2O3) were studied. It was one order for Al(OH)4- and SiO2(OH)22- ion respectively. The value of apparent active energy was 86.42 kJ/mol. Based on the analysis of the structure of the aluminate solution and the mechanism of the formation of zeolite, the mechanism of five-ligand intermediate state was set up. It was advantageous for the formation of sodium aluminosilicate hydrate to increase the temperature, or to decrease the caustic concentration, or to intensify the agitation, or to add the seed(or impurities) in the alumina production.
    Coordination Field Analysis of the Polarized Luminescence Spectra of Tb3+ in Trigonal Na3[Tb(C4H4O5)3]·2NaClO4·6H2O
    FAN Ying-Fang, YANG Pin
    1999, 20(8):  1266-1270. 
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    The coordination field perturbation energies of Tb3+ in single crystals of trigonal dihedral(D3) symmetry Na3[Tb(C4H4O5)3]·2NaClO4·6H2Oare calculated and the polar-ized luminescence spectra in the 7FJ→5D4(J=1～6) transition regions are assigned theoreti-cally. The results of the double-sphere coordination point-charge field (DSCPCF) model are in reasonably good agreement with the experimental observation and are superior to that of the simple static coordination point charge field(PCF) model.
    Fabrication and Crystalline Structure of Ca Modified Lead Titanate Nanocrystals
    FU Hong-Gang, YU Hai-Tao, ZHANG Xin, ZHANG Yan-Xi, ZHANG Zhi-Qian, XU Chong-Quan, QIANG Liang-Sheng
    1999, 20(8):  1271-1275. 
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    Calcium modified lead titanate nanocrystal materials have been prepared by using a sol-gel method. Different thermal treatment conditions have been used for the research of the crystalline structure of Pb1-xCaxTiO3 powders. The lattice parameters and c/a ratios were determined by using XRDmethod. The grain sizes of powders were detected by TEM photographs and X-ray diffraction. The influence of thermal treatment conditions on crys-talline structure, lattice parameters, tetragonolity(c/a) and the relationships of a, c, c/a with Ca content were discussed.
    Studies on the Redox Reactions of Cobalt Electrodes in Alkaline Solution by Using In-situ Confocal Microprobe Raman Spectroscopy
    NAN Jun-Min, YANG Yong, YOU Jin-Kua, LIN Zu-Geng
    1999, 20(8):  1276-1279. 
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    The redox reaction processes and Raman spectra of reaction products of cobalt electrodes in 30% KOH+1% LiOHsolution were studied by using in-situ Confocal Microprobe Raman Spectroscopy. It is shown that the oxidation reaction at -0.64 Vcan be ascribed to the formation of Co(OH)2 and CoO. Co3O4 was formed with increasing the potential, and Co3O4, CoOOH and CoO2 form composite oxides surface layer in positive potential region. In the course of potential sweeping from the positive to the negative, the higher valent oxides were reduced to Co3O4 and Co(OH)2 successively, and they were reduced to Co finally. From the Raman spectra at different potentials of cobalt electrodes, it is proposed that the redox reactions are continuous processes with the changing of potentials, and the surface layer of cobalt electrode is composed of composite oxides.
    Effect of External Electric Field in Electron Transfer ——An Ab Initio Calculation for Electron Transfer Between Benzene and Benzene Cation Radical
    LI Xiang-Yuan, TANG Xing-Shuo, XIAO Shun-Qing, ZHAO Xin-Shun, HE Fu-Cheng
    1999, 20(8):  1280-1284. 
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    Based on the semiclassical theory of electron transfer, quantum chemical calcula-tions at HF/DZP level were performed for the study of intramolecular electron transfer between parallel benzene and benzene cation radical. After the geometric optimizations of the donor and the acceptor, a linear reaction coordinate ξ was introduced to determine the transition state. The variation principle applied to the two diabatic states and Koopmans theorem used in the calculation of molecular orbital transition energy, were invoked to evaluate the electron transfer matrix element VAB. The exponential falloff of VAB with increasing d, the distance between the center of the donor and that of the acceptor, was discussed. The influence of external electric field on the exothermicity of the electron transfer was investigated with d=0.6 nm, and then the rate constant k of the intramolecular gas-phase electron transfer was estimated for different values of the external electric field strength.
    Ultraviolet Photoelectron Spectrum and Bonding Studies on the Silatranes: Experimental and Theoretical Studies
    SUN Zheng, ZHENG Shi-Jun, MENG Ling-Peng, WANG Dian-Xun
    1999, 20(8):  1285-1290. 
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    The Ultraviolet Photoelectron Spectra(UPS) of 10 silatranes are recorded in this paper. The configurations of ten molecules are optimized at RHF/3-21Glevel. The assignment of the UPSbands has also been done with the aid of the bands shape and RHF/6-31G* calculation. The electronic charge density topological analysis of the compounds shows that there is a bond critical point between Si and Nof each compound, which suggests the existence of a Si-N bond in these compounds. The σN→Si in the silatranes is weaker than σN→B in the boratranes, and the bond strength of σN→Si is affected with the addition of the substituents at Si atoms. Aspecial substituent effect is also found as the substituents are F, Cl, Br and I. The above substitution effect is confirmed by UPS, SCF MO calculation and electronic charge density topological analysis.
    Theoretical Study for Potential Energy Surface and Vibrational Excited States of CO2
    LU Yu-Hui, XIAN Hui, XIE Dai-Qian, YAN Guo-Sen
    1999, 20(8):  1291-1294. 
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    The potential energy surface for the electronic ground state of the CO2 molecule was optimized by using the self-consistent field-configuration interaction method and involving the 49 observed vibrational energy levels below 20000 cm-1. The root-mean-square error of this fitting is 1.50 cm-1. The rovibrational energy levels for the Σ and Π vibrational states are calculated to test the refined potential.
    A Remarkable Synergic Effect of Metal Phthalocyanine and High Valence Metal Salt or Oxide in the Selective Oxidation of Ethylbenzene
    HAN Xiao-Xiang, JIANG Heng, GONG Hong, QIAO Qing-Dong
    1999, 20(8):  1295-1297. 
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    The liquid phase oxidation of ethylbenzene catalyzed by metal phthalocyanine(CoPc, MnPC, FePc) was investigated at an atmospheric pressure of oxygen at 100 ℃. The catalytic activity of CoPc is higher than that of MnPc and FePc. The addition of catalytic amount of K2Cr2O7, MnO2 or V2O5 to the catalytic system can lead to a remarkable increase in the catalytic activity or acetophenone selectivity, compared with those of the metal ph-thalocyanine and catalytic amount of K2Cr2O7, MnO2 or V2O5 used alone.
    Monte Carlo Simulations of Adsorption of Diblock Copolymers at Solid-liquid Interface(Ⅰ)——The Configuration Distribution of Adsorbed Chains
    CHEN Ting, LIU Hong-Lai, HU Ying
    1999, 20(8):  1298-1302. 
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    Monte Carlo simulation method was used to simulate the adsorption of diblock copolymers at solid-liquid interface. The microstructure information of adsorbed layer, such as adsorbed segment profile and the distribution of size of various adsorption configurations, was obtained. In this work, the effect of attractive segment content and its adsorption energy on the adsorbed segment profile and distribution of size of configuration have been inspected. It is shown that the adsorbed layer thickness is mainly determined by the length of non-attractive segment.
    Influence of CuBr2 on Atom Transfer Radical Polymerization in the Presence of Al(OPri)3
    GUO Jian-Hua, WU Ping-Ping, HAN Zhe-Wen
    1999, 20(8):  1303-1306. 
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    Atom transfer radical polymerization of methyl methacrylates(MMA) has been achieved with ethyl-2-bromoisobutyrate[(CH3)2CBrCO2C2H5] as an initiator and CuBr, 2,2′-bipyridine(bPy) and aluminum triisopropoxide [Al(OPri)3] as an ternary catalyzing system in cyclohexanone at 40 ℃. MMA can be polymerized in a living fashion at low temperature with Al(OPri)3 as a catalytic promoter. The influence of CuBr2 on the ATRP of MMA was discussed in detaiLIN this paper. The radical concentration reduced with the addition of CuBr2, so bimolecular termination was suppressed. Without the addition of CuBr2, the produced polymers had high polydispersities(Mw/Mn=1.94). The polymerization of MMA became slower and more controlled with CuBr2 than without CuBr2. The produced PMMA had low polydispersities(Mw/Mn=1.2-1.5) and controlled molecular weights which were nearly proportional to monomer conversion. The logarithmic conversion data plotted against time (ln([M]0/[M])vs. t) displayed current first order kinetics in monomer.
    Ester-ether Liquid Crystal with Oligo(oxyethylene) Middle Units
    ZHANG Zi-Yong, LIN Shang-An
    1999, 20(8):  1307-1311. 
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    Anew series of ester-ether liquid crystal compounds with oligo(oxyethylene) mid-dle units has been synthesized by using 4-(4′-alkoxybenzoyloxy)benzoic acids as a liquid crystaLINtermediate. Chemical structures and liquid crystal behavior of the compounds were characterized by elemental analysis, 1HNMR spectroscopy, DSCand polarizing microscopy. All the compounds, except Ⅰf, exhibit thermotropic liquid crystalline properties.
    Synthesis and Structure of Chemical Crosslinked Poly(vinyl chloride) Resin
    BAO Yong-Zhong, WENG Zhi-Xue, HUANG Zhi-Ming, PAN Zu-Ren
    1999, 20(8):  1312-1316. 
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    Chemical crosslinked PVCresin was synthesized by VC/crosslinking monomer copolymerization in suspension process. Effects of crosslinking monomer structure, initial concentration of crosslinking monomer and polymerization temperature on the structure of PVCresin were investigated. It showed that the gel fraction and crosslinking density of geLINcreased as the concentration of diallyl phthalate(DAP) increased and decreased with the increasing of polymerization temperature. Physical entanglements had great contribution to the crosslinking density of gel. The crosslinking density increased rapidly with the increasing of gel fraction when the gel fraction was high. Since diallyl maleate had three double bonds and close reactivity ratio to VC, it had a higher crosslinking efficiency than DAP. Ethylene glycol dimethacrylate(EGDMA) was used up at the early stage of VC/EGDMAcopolymerization due to its higher reactivity compared with VC, so its crosslinking efficiency was much lower than that of DAPand DAM.
    Studies on the Affinity Membrane for Adsorption and Purification of Lysozyme(Ⅰ)——Influence of Low-temperature Oxygen Plasma Treatment on Surface Structure and Adsorption Properties of the Affinity Membrane
    ZHENG Yu, CHEN Huan-Lin, LI Jing, CHAI Hong, LIU Mo-E
    1999, 20(8):  1317-1321. 
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    In this paper, low-temperature oxygen plasma method was used to modify the surface of PP(polypropylene) microporous membranes. The influence of oxygen plasma on the chemical structure and physical performance of the membrane was investigated with SEM, XPSand IRspectra. The results of XPSand IRshowed that polar groups, —OH, —COOH, C=O were created on these membrane surfaces. The groups —OH and —COOH were useful for activation and grafting process for affinity membrane with Cu2+ as a metal-chelating ligand. The influence of plasma treatment condition on the adsorbability of affinity membrane for lysozyme was carried out. The optimal adsorbability of lysozyme was 8μg/cm2 on the affinity membrane prepared for 20 min and under 68 Wplasma condition.
    Studies on the Affinity Membranes for Adsorption and Purification of Lysozyme(Ⅱ)——Adsorption Characteristics of Metal Chelating Affinity Membranes for Lysozyme
    LI Jing, CHEN Huan-Lin, CHAI Hong
    1999, 20(8):  1322-1327. 
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    Based on activation, coupling and chelating processes, PP(polypropylene) microporous membranes whose surface was treated by low temperature plasma were used for preparation of affinity membranes with Fe3+, Ni2+, Cu2+ and Zn2+ metal chelating ligand respectively. Those affinity membranes have been used for adsorption desorption experiments of lysozyme. The experimental results showed that adsorption capacity of the membranes with Ni2+ or Cu2+ metal chelating ligand is higher than that with Fe3+ or Zn2+ metal chelating ligand. The adsorption capacity of affinity membrane made in Cl- ion solution is also higher than that made in SO24- ion solution. The experimental results also showed that affinity membranes with Ni2+ or Cu2+ can be reused several times while affinity membrane with Fe3+ ion can not. Adsorption amount of lysozyme can be partly restored by addition of metal ions on the reused affinity membranes.
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