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Table of Content

    24 August 2000, Volume 21 Issue 8
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    Articles
    Synthesis of β Zeolite Using Tetraethylammonium Brom ide Together with Fluoride as Composite of Template(Ⅱ) ── Studies on Crystallization Process of β Zeolite
    QI Xiao-Lan, LIU Xi-Yao, CHEN Gang, CHEN Xue-Yi, LI Shi-Jie, LIN Bing-Xiong
    2000, 21(8):  1161-1166. 
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    The crystallization process of β zeolite has been investigated by using FT IR, XRD, TG, SEM, and ICP AES. The samples were obtained by hydrothermal synthesis at 140 ℃ and chemical composition of the mixture used for synthesis can be expressed as n(Al2O3)∶n(SiO2)∶n(TEABr)∶n(Na2O)∶ n(NaF) ∶n(H2O)∶n =1∶25∶7.5∶2.5∶3.75∶550∶6.25. The crystallization curve of zeolite β exhibits a typical Sshaped characteristic. The typical framework IRabsorptions at 567 and 518 cm-1 have different natures. The former is detected at the beginning of induction period and its intensity changes a little in induction period, but exhibits a direct correlation with crystallinity in growth period. The latter is not detected in the induction period, but exhibits the same trend in growth period. The large amorphous SiO2 Al2O3 particles which are visible at the beginning of crystallization change into small grains during the induction period. n(SiO2)/n(Al2O3) ratio of the solid phases obtained at different synthesis time changes significantly during the induction period, but changes a little in growth period. So the β zeolite crystal nucleus are formed via liquid phase synthesis mechanism. Atypical gel in synthesis of β zeolite is transformed initially into a solid, which contains richer aluminium, minor F- and occluded TEAspecies. The aluminosilicate gel particles are dissolved by F- during the induction period and the transition complex, which has a specific weak X-ray diffraction peak at 2θ=22.8° and specific DTGpattern, is formed at the turning point from induction period to growth period. During the growth period Si and Al transport from the liquid to the solid phase at almost the same rates. F- anion has greater influence on the formation and turning of transition complex.
    Preparation and Humidity Sensitive Property of LiCl/NaY Composite Materials
    LI Xiao-Tian, SHAO Chang-Lu, DING Hong, ZHANG Tong-LI Nan, QIU Shi-Lun, XIAO Feng-Shou
    2000, 21(8):  1167-1170. 
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    LiCl/NaY host-guest composite humidity-sensitive materials have been successfully prepared by dispersion of LiCl into the pores of zeolite. X-ray diffraction(XRD) and IRhave been used to investigate this system. LiCl/NaYmaterials can overcome the serious shortcomings of bulk LiCl, such as stability and durability at high humidity and at high temperature, contamination from dust or oil, etc. After a systematic investigation of LiCl/(NaY, ZSM-5, MOR), we have found that NaYis more suitable to be used as hosts, since NaYis characterized by a three-dimensional open framework structure, and composed of interconnected “super” cages.
    Synthesis and Magnetic Properties of Sm2Fe17-x Sbx
    ZHANG Jiang-Shan;CHEN Hong-Ji, LIN Jian-Hua
    2000, 21(8):  1171-1173. 
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    Sb substituted Sm2Fe17-xSbx materials have been synthesized by using modified reduction-diffusion process with superfine Fe metal powder as a starting material. This synthetic route is unique and particularly useful for the intermetallic compounds containing high volatile component. The substitution of Sb to the Sm2Fe17 significantly enhances the magnetic interaction between Fe atoms, which in turn, increases the Curie temperature of the materials. In addition, the chemical stability of Sm2Fe17 can also be improved by Sb substitution.
    Synthesis and Characterization for(η2-C60 )[Fe(CO)2(C5H5)]2
    LIU Xiang, GAO Yi-Ci, SU Zhong-Xing, WANG Yao-Yu, SHI Qi-Zhen
    2000, 21(8):  1174-1176. 
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    The first binuclear iron fullerene derivative of(η2-C60 )[Fe(CO)2(C5H5)]2 , which was yellow brown and sensitive to air and moisture, was prepared by the reaction of trans-[Fe(CO)2(C5H5)]2 with C60 in benzene under an atmosphere of dried nitrogen using conventional Schlenk techniques and has been characterized by using elementary analysis and IR, 1H NMR, 13C NMRand XPSspectra. The infrared spectrum of the title compound indicates the disappearance of νCO at 1760 cm-1 for bridge carbonyl and the appearance of the only terminal COlying at a higher wave number than that of the starting material, which reveals the electron-deficient behavior of C60 . And the important 1H, 13C NMRchemical shift and XPSof trans-[Fe(CO)2(C5H5)]2 , C60 and its novel complex along with their relative assignments are briefly discussed.
    Solution Synthesis and Structure of VPO Catalyst Precursor
    JIANG Ya-Qi, ZHOU Zhao-Hui, WEI Zan-Bin, WAN Hui-Lin
    2000, 21(8):  1177-1179. 
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    VPO polymer β-NH4(VO2)(HPO4) was synthesized from the mixture of NH4VO3 and NH4H2PO4 in aqueous acidic solution. This hydrogenphosphate vanadate crystallizes in the orthorhombic space group Pbca with a=0.68060(8) nm, b=0.92570(5) nm, c=1.77370(2) nm, V=1.1175(3) nm 3, Z=8, Dc=1.743 g·cm-3, μ=88.54 cm-1 and R=0.051. The structure is built up from VO5 square pyramid linked by trans-vertices through the bridged oxygen atom to form an one dimensional isolated chain of {VO2HPO4}nn- nunning along the a axis.
    Synthesis and Crystal Structure of [N(CH3)4]4 [H5PMo5V9O42 ] ·3.5H2O Containing Mixed valence Vanadium
    XU Jia-Ning, YANG Guo-Yu, LIN Ying-Jie, SHI Zhan, YU Jie-Hui, FENG Shou-Hua, XU Ji-Qing, XU Xin, LI Yan, CUI Xiao-Hui, HUANG Xiao-Ying, YANG Lan-Ping
    2000, 21(8):  1180-1182. 
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    The title compound [N(CH3)4]4[H5PMo5V9O42] ·3.5H2Owas synthesized by hydrothermal method and its structure was determined with single crystal X-ray analysis. The cluster anion is a bicapped Keggin polyanion, two vanadium atoms are distributed at two capping metal atom positions. The crystal is monoclinic, space group C2/c with a=1.2848(4) nm, b=2.3664(4) nm, c=2.1136(4) nm, β= 90.69(2)°, V=6.425(4) nm 3, Z=4, Dc=2.07 g·cm-3, R=0.066, Rw=0.069, S=1.33, {(Δ/σ)max=}004, {(Δρ)max =}91 e·nm-3.
    Separation of Proteins by Microemulsion Electrokinetic Chromatography
    ZHANG Xuan, HU Ya-Nan, WANG Yi-Ming, ZHOU Guo-Hua, LUO Guo-An
    2000, 21(8):  1183-1186. 
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    Microemulsion electrokinetic chromatography(MEEKC) is a new technique which was employed to separate both basic and acidic proteins simultaneously. Optimum separation conditions were investigated with respect to ionic strength and the composition of microemulsion. The results show that if a stable microemulsion formed, the efficiency of protein separation was slightly affected by the concentration of the background and the composition of microemulsion. The fundamental characteristics of MEEKCwere studied in comparison with micellar electrokinetic chromatography(MEKC). The mechanism of MEEKCwas also investigated. The results show that MEEKCis an alternative way for protein separations with a high efficiency.
    Studies on the Preparation and Characterization of Ethidium Bromide Labeled DNA Probe
    XU Chun, HE Pin-Gang, FANG Yu-Zhi
    2000, 21(8):  1187-1190. 
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    The preparation and characterization of an ethidium bromide labeled DNAprobe is studied. Ethidium bromide was labeled onto a 21-bases 5'-oligonucleotides by EDC. The electrochemical characterization and fluorescence of the probe is discussed. The accumulation of sample DNAis also discussed. Besides it, the effect of base amounts on labeling and hybridization were discussed. We think the bases between 15—200 are better for electrochemical labeled DNAprobe. The EBlabeled DNAprobe was successfully used to detect sequence specific DNA. It shows a high sensitivity and selectivity. It is hoped for commodity use.
    Studies on the Determination of Amino Acids by High Performance Liquid Chromatography with Laser Induced Fluorescence Intensified Charge Coupled Device Detector
    XIONG Shao-Xiang, HAN Hui-Wan, ZHAO Rui, WANG Guang-Hui, MA Hui-Min, CHEN Yi, LIU Guo-Quan
    2000, 21(8):  1191-1195. 
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    A High performance liquid chromatography-laser induced fluorescence-intensified charge coupled device(HPLC-LIF-ICCD) system was used for the analysis of amino acid. Using 3-(4-carboxybenzoyl)-2-quinoline-carboxyaldehyde(CBQCA) as a derivatizing agent, several factors influencing the derivatization and separation of amino acid were investigated in detail. The mass detection limit of glycine was 5×10-15 mol. The method was applied to the detection of amino acids in rat brain microdialysates.
    Preparation and Properties of Medium Polarity Sensitive Membranes
    NING Guang-Hui, LÜ Jiu-Ru, FANG Yu, HU Dao-Dao
    2000, 21(8):  1196-1199. 
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    A medium polarity sensitive membrane was prepared by embedding pyrene(Py), a polarity fluorescence probe, into a glutaraldehyde(Glu) crosslinked chitosan(CS) membrane. The composition and thermostability of the membrane were characterized by FTIRand TGAanalysis. It is shown that the composition of the membrane is close to that of CS. The introduction of micro amount of Py and crosslinker has little effect upon the composition of the membrane. However, the Glu crosslinked CSmembrane is more stable toward heating than the uncrosslinked CSmembrane. In addition, the crosslinked CSmembrane is also stable in acidic and basic media. The CS-Glu membrane containing Py was successfully used to monitor the polarities of various solvents including water, ethanol, and ethanol water mixtures. Based upon the measurement of polarity, the prepared membrane was also used to monitor the micellar formation in SDSsolution. Compared with the traditional solution fluorescence probing method, this new method is more simple and convenient, and can be recycled.
    MAP-H2O2-HRP Voltammetric Enzyme linked Immunoassay for Trace Southern Bean Mosaic Virus
    ZHANG Shu-Sheng, JIAO Kui, CHEN Hong-Yuan, WANG Man-Xia, ZHANG Cheng-Liang, ZHANG Zuo-Fang
    2000, 21(8):  1200-1204. 
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    Avoltammetric enzyme-linked immunoassay based on the new system of m-aminophenol(MAP)-H2O2-horseradish peroxidase(HRP) has been developed and used for the detection of HRPand southern bean mosaic virus(SBMV). HRPor labelled HRPcatalyzes the oxidation reaction of MAPwith H2O2, the product of which produces a sensitive voltammetric peak at potential of -0.46V(vs. SCE ) in Britton-Robinson(B-R) buffer solution.By using this voltammetric peak, HRPcan be measured with a detection limit of 38×10-9 g/Land a linear range of 10×10-8 —10×10-6 g/L. The detection limit for the clarified SBMVis 4.0 ng/mLand the linear range of 4.0—5000 ng/mL. The highest dilution ratio detected for the infected leaf sap is 1∶1.5×105.
    Indirect Differential Pulse Voltammetric Determination of Aluminum in Biological Samples with L-Dopa
    ZHANG Fu-Ping, BI Shu-Ping, LIU Feng, BIAN Ning-Sheng
    2000, 21(8):  1205-1207. 
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    Electroanalytic direct determination of aluminum is a difficult subject because of the highly negative reductive potential of Al(Ⅲ) and interference of H+. But developing methods for the determination of trace amount of aluminum in environmental and biological samples is a hot topic in recent decades owning to the recognition of the potential toxic effects of aluminum. In this paper, the indirect differential pulse voltammetric(DPV) determination of aluminum with L-dopa(3,4-dihydroxyphenylalanine) on glass carbon working electrode has been reported. This novel method bases on the linear decrease of DPVanodic peak current of Ldopa with the concentration of aluminum added. Under the optimum experimental conditions (pH8.5, 0.08 mol/Lbuffer solution, 4×10-4 mol/L Ldopa), the linear range and the detection limit are (2—18)×10-7 and 7.6×10-8 mol/L Al(Ⅲ) respectively, the relative standard deviation for 2×10-5 mol/L Al (Ⅲ) is 2.4%(n=10). Anumber of foreign species, especially those necessary components in human body such as ascorbic acid, citrate, phosphate, Fe(Ⅲ), Fe(Ⅱ), Cu(Ⅱ), Zn(Ⅱ), Ca(Ⅱ) and Mg(Ⅱ) for interference have been studied. Satisfactory recoveries have been obtained by applying this method to determining aluminum in biological samples including mineral water, synthetic renal dialysate, urine and hair. The significance of the method and solutions to possible interference encountered in in vivo detection are discussed. Anew direction for further development of the in vivo determination of aluminum is provided in this studies.
    The Application of Artificial Neural Networks in Optical Quantitative Determination of Pulp Kappa Number
    SHEN Wen-Hao, XIE Yi-Min, LIU Huan-Bin
    2000, 21(8):  1208-1210. 
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    The pulp kappa number is determined quantitatively by measurement of absorbance of cooking liquor. Three methods, artificial neural networks (ANN), stepwise regression analysis-artificial neural networks (SRA-ANN) and principal component regression-artificial neural networks (PCA-ANN), are applied to data processing. The results of data processing show that the predicting models determined by three methods all have good learning accuracy and predicting accuracy, and the best model of all is determined by principal component regression-artificial neural networks.
    Studies on the Synthesis and Photochemical Properties of Chain Linked Bisheteroarylethenes
    ZHANG Wen-Qin, WANG Shu-Li, ZHAO Hai-Tao, ZHUANG Jun-Peng, SUN Hao, ZHAO Shu-Na, ZHENG Yan, LI Chun-Bao
    2000, 21(8):  1211-1215. 
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    1,n-Bis[trans-4-[2-[2-(5-methylbenzoxazolyl)]ethenyl]phenoxy]alkanes[n=3(Ⅰa), 4(Ⅰb), 6(Ⅰc)] and 2,2'-bis[trans-4-[2-[2-(5-methylbenzoxazolyl)]ethenyl]phenoxy]ethyl ether(Ⅰd) were synthesized. Their structures were identified by elemental analysis, IR, UV, 1H NMR, 13C NMRand MS. The UVspectra were used to illustrate the change of compounds Ⅰa_Ⅰd under the irradiation of high pressure mercury lamp. It was found that these compounds undergo two kinds of reactions, the trans cis isomerization and intramolecular photodimerization. The former is fast and reversible, and the latter is slow and irreversible. The speed of intramolecular photodimerization will increase with increasing the length of the carbon chain between the two 2-[2-(5-methylbenzoxazolyl)]ethenyl]phenyl group. The fact that the photodimerization is not affected by oxygen shows that the reaction proceeds through an excited singlet state. It is also revealed that compounds Ⅰa_Ⅰd undergo [2+2] photolysis easily when irradiated under short UVlight. That the intramolecular photodimerization and photolysis of these compounds can repeat many times indicate that these compounds have a high photostability.
    Studies of α- Thiocarbonyl Phosphonic Acid Derivative Quinazolone Analogues Containing Phosphorus
    HUANG Jun-Min, CHEN Ru-Yu
    2000, 21(8):  1216-1220. 
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    Aseries of N-substituted 1-methoxycarbonylmethyl-3-substituted-2,4-dioxo-1,3,2-benzodiazaphosphorin-2-carboxamides(2a_2q) have been designed and synthesized by two methods, and their structures were confirmed by elemental analysis, NMR, IRand MS. On the basis of X-ray diffraction analysis, we discussed stereochemistry of the title compounds, and studied their 1H NMRmagnetic nonequivalent phenomenon which agrees with the results of X-ray analysis. The preliminary bioassay shows that some of the title compounds have a good plant hormone activity.
    Synthesis and Antifungal Activities of1-[2-(N-methyl-N- substituted- benzyl)amino-2-(4-tert- butylphenyl)ethyl]-1H- 1,2,4- triazoles
    FENG Zhi-Xiang, ZHANG Wan-Nian, ZHOU You-Jun, LU Jia-Gou, ZHU Ju, LI Ke
    2000, 21(8):  1221-1226. 
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    Benzylamine and azole compounds respectively inhibit squelene exoxidase and cytochrome P450 monooxygenase which are two key enzymes in biosynthesis of fungal membrances. According to the structure-activitity relationships and antimycotic mechanism of azole and benzylamine compounds, we combined the feature of structure of those two kinds of compounds to design and synthesize twenty three 1-[2-(N-methyl-N-substituted-benzyl)amino-2-(4-tert-butylphenyl)ethyl] -1-H-1,2,4-triazoles. All of them were first reported and their structures were confirmed by elementary analysis, IRand 1H NMRspectra. The results of preliminary antifungal tests in vitro showed that all the compounds were active against the nine pathogenic fungi to some degrees. The activities against shallow fungi are greater than those of the deep ones. Compounds 3, 4, 6, 10, 12, 14 and 15 exhibited potent activities against microsporum canis.
    Investigation of Carcinognic Non-aminoazo Dyes with Nitrosulfophenol S as Their Chemical Model
    ZHU Min, HAN Shu-Bo, ZHANG Shu-Sheng, YUAN Zhuo-Bin, SHEN Han-Xi
    2000, 21(8):  1227-1230. 
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    Nitrosulfophenol Sis advocated as the chemical model in the investigation of carcinogenic non-aminoazo dyes. Oxidative cleavage reaction of Nitrosulfophenol Sis carried out in the enzymic biotransform model-HRP/ H2O2 system, and the product, ultimate carcinogens aromicdiazonium ions, which bind to DNAis identified by visible spectra, capillary zone electrophoresis, electroanalytical chemical and other methods. The rate of oxidative cleavage depends on pH, temperature, and the concentrations of HRPand H2O2, then their optional oxidative conditions are discussed in detail. The inhibition and activation of various biological substances to the reaction is also investigated.
    Synthesis and Characterization of Triphenylgermaniumdithiocarbamates
    YIN Han-Dong, WANG Yong, ZHANG Ru-Fen, MA Chun-Lin
    2000, 21(8):  1231-1233. 
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    Thirteen title compounds Ph3GeS2CNR2(1—13) were synthesized by the reaction of corre-sponding triphenylgermanium chloride with dithiocarbamates. Their structures were confirmed by elemen-tal analysis, IR, 1H NMR, UVand MS. Some of these compounds showed antitumor activities in vitro.
    Syhthesis and Superoxide Dismutase Activity Studies of β-Cyclodextrin Derivatives Containing1,2- Benzisoselenazol-3(2H)-one
    LI Bin, LI Li, LIU Yu, ZHENG Hao, DUAN Zhi-Yong
    2000, 21(8):  1234-1236. 
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    Two novelβ-cyclodextrin derivatives containing 1,2 benzisoselenazol-3(2H)-one have been synthesized by a convenient method in 60% and 55% yields, respectively, and characterized by elemental analysis, IRand 1H NMR. The superoxide dismutase (SOD) activity of these modified β cyclodextrins has been determined by the method of autooxidation of pyrogallol at 298.15 Kin buffer solution(pH = 8.20). The results obtained indicate that these cyclodextrin derivatives possesses relatively high SODactivity up to 179~330 U/mg.
    Highly Stereoselective Synthesis of (E,E)- 3,7-Dimethyl-2,6- decadiene-1,10-diol
    LIU Zuo-Sheng, LAN Jiong, PENG Li-Zeng, LI Yu-Lin, XING Ya-Cheng, CEN Wen
    2000, 21(8):  1237-1239. 
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    (E,E)-3,7-Dimethyl-2,6-decadiene-1,10-diol(3), a terpenoid diol component of pheromonal secretion of the male queen butterfly, was synthesized stereoselectively from geraniol in seven steps. The key steps were the iodization-rearrangement of 2,3-epoxy alcohol 6 and Claisen rearrangement of allyl vinyl ether 8.
    Studies on MCM-41 Supported SO42-/ZrO2 Solid Superacid Catalysts
    LEI Ting, HUA Wei-Ming, TANG Yi, YUE Ying-Hong, GAO Zi
    2000, 21(8):  1240-1243. 
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    Aseries of new superacid catalysts MCM-41 supported SO42-/ZrO2(SZ) were prepared first by an impregnation calcination method. The variation roles of their texture constructions and acid properties were investigated in detail. It was shown that, a high amount of ZrO2 could result in the damage of the pore system of MCM-41, however, superacid sites could not formed under a low amount of SZon MCM-41. The proper amount of SZis about 40%. The superacidities of samples were increased with the increas|ing of ZrO2 contents. Both medium strong acidities and weak acidities of samples were enhanced with the introducing of SZ. The acidities of samples can be adjusted by changing the amount of SZon MCM-41. This may be valuable in designing catalysts for the cracking reaction of large molecule hydrocarbon.
    Studies on Human Breast Cancer Tissue With Infrared Spectrometry
    HUO Hong, HU Xiang, GUAN Hong-Wei, WANG Xing-Fu, CHE Xun, HUANG Wei-Dong
    2000, 21(8):  1244-1247. 
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    The normal, benign and malignant human breast tissues have been studied by means of infrared spectroscopy. Some remarkable spectral differences (shape, peak positions and relative intensities) are observed among these three types of the samples. In the malignant breast tissues, these mainly characteristic changes involve: (1) In comparison with the normal breast tissues, the band near 1162 cm-1 from the stretching modes of C—O(H) group in proteins evidently shifts to a higher wavenumber, which suggests that the intermolecular hydrogen bonds are almost broken; The band near 3310 cm-1 from the stretching modes of the hydrogen bonded N—Hin protein molecules shifts to a lower wavenumber, which indicates that the intensity of the hydrogen bonds on the NH…O=Cis stronger in protein molecules of malignant breast tissues. (2) The intensity of the symmetric stretching modes of νPO2- at 1080 cm-1 from the phosphodiester groups in cellular nucleic acids is remarkably stronger, which suggests that the relative contents of DNAin cancer cellular increase. The symmetric stretching modes of PO3- at 970 cm-1 from the phosphorylated proteins become stronger, which suggests that the relative contents of phosphorylated protein increase. (3) The change of the intensity of collagen bands indicates the increase of its relative contents. This investigation shows that Infrared spectrometry can represent the characteristic of the breast tumor at the molecular level.
    Synthesis, Characterization and Catalytic Activity for Phenol Hydroxylation of Rare Earth Molybdovanadophosphate Tetrabasic Heteropoly Complexes with Keggin Structure
    LIN Shen, ZHENG Ying, XU Li-Min, WANG Shi-Ming
    2000, 21(8):  1248-1251. 
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    Five rare earth molybdovanadophosphate heteropoly complexes were synthesized. Their general molecular formulas are (NH4)15 [RE(PMo9V2O39 )2]·xH2O(RE=La3+ , Ce3+ , Gd3+ , Y3+ , Yb3+ ). Their structures and properties were investigated by IR, UV, XRD, ICP, TG DTA, and cyclic voltammogram. The results show that these five complexes have the same Keggin structure and excellent catalytic activity for phenol hydroxylation with H2O2 to diphenol.
    The Photocatalytic Oxidation Degradation of NOx in the Air with TiO2 Thin Films
    XU An-Wu, LIU Han-Qin, LI Yu-Guang
    2000, 21(8):  1252-1256. 
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    The gas-solid heterogeneous photocatalytic oxidation using TiO2/UVwas conducted, and it was found that the degradation efficiency of NOx in air was very high, reaching 97% in the ranges of experimental concentration. Some factors affecting NOphotocatalytic destruction were investigated. The adsorption of NOx on TiO2 thin film surface in the dark, photocatalytic reaction kinetics and mechanism were studied, and some important conclusions were drawn. The product of NOx photocatalysis was detected to be HNO3 by FTIR. The greater part of HNO3 was adsorbed on TiO2 surface, causing catalyst deactivation, but when the catalyst was washed by water, its activity was regenerated as usual. In the end, NOx photocatalytic oxidation experiments were performed under sunlight irradiation, and NOx photocatalytic degradation yields remained high. The results showed that this process has potential applications to the elimination of NOx from the air.
    Formation of OTS Self-assembled Monolayer on Glass Surface Investigated by AFM
    XU Guo-Hua, Higashitani Ko
    2000, 21(8):  1257-1260. 
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    By using AFM, the process of the OTSmonolayer formation on glass substrate surface by self assembly from 1×10-3 mol/L OTStoluene solution at 18 ℃ was revealed. The analyses of AFMimages as well as the surface mean roughness Ra of the sample surfaces indicated that, after 15 min reaction a smooth OTSmonolayer with a Ra of 0.156 nm/4 μm2 could be obtained on the glass surface. However, this freshly formed OTSmonolayer was unstable, as the reaction proceeds, the Ra of the monolayer would slightly increase within the succeeding 15 min, and finally keep a constant value about 0.170 nm/4 μm2 even for 2 h reaction. The advancing contact angle measurement showed that after~15 min reaction, a completely hydrophobic surface formed with an advancing contact angle of 105°. Our research also showed that during the initial reaction period, most of the adsorption molecules just adsorbed on the substrate surface physically. But some kinds of very strong combination between a few of adsorption molecules and the substrate surface was established, which was much stronger than physical interaction.
    The Effect of Benzyl Alcohol on the Rheology and1H NMR Spectra of CTAB of CTAB/KBr Micellar System
    ZHANG Wei-Can, LI Gan-Zuo, JI Ke-Jian, SHEN Qiang
    2000, 21(8):  1261-1264. 
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    The influence of benzyl alcohol on the rheology and 1H NMRspectra of CTABof CTAB/KBr micellar system has been investigated. The addition of benzyl alcohol induces the viscosity of 0.01 mol/L CTAB/KBr micellar system to go through a marked maximum. In terms of 1H NMRspectra of CTAB, it is argued that a little amount of alcohol solubilized in the interfacial region of CTAB/KBr micelles will promote these micelles to be longer and overlapping. This process makes the viscosity of the system rise. With increasing alcohol concentration continuously, it will be dissolved in the palisades of micelles and induces the rod-like micelles to be transformed into small sphere ones and disentanglement. Then the viscosity of this micellar system decreases.
    Effect of Acrylic Copolymers on the Surface Properties of Alumina and the Fractal Characteristics of the Sediments
    LIU Yang-Qiao, GAO Lian, GUO Jing-Kun
    2000, 21(8):  1265-1268. 
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    An acrylic copolymer was employed as a dispersant for Al2O3 aqueous suspensions. Surface chemistry of the suspensions was evaluated via isotherm adsorption, FTIRand ζ potential measurments. The optimum amount of dispersant was 2.0%. The fractal theory was used to analyze the surface morphology of the sediments. The results showed that the fractal dimension value of sediments increased with increasing dispersant amount in the experimental range.
    The Metallization and Interface Reaction Between Diamond Particle and Cr Layer
    ZHU Yong-Fa, WANG Li, YAO Wen-Qing, CAO Li-Li
    2000, 21(8):  1269-1272. 
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    A Cr layer with thickness of 150 nm was successfully deposited on the surface of diamond particles using DCmagnetron sputtering technique. The interface diffusion and reaction between Cr and diamond was promoted by annealing in the range from 300 ℃ to 600 ℃ in high vacuum. The Auger profile results showed that the width of interface layer was more than 90 nm. A Cr2Ccarbide layer was formed after Cr/diamond annealed above 500 ℃. The formation of Cr2Con the interface was confirmed by Auger line shapes. When the annealing temperature was below 500 ℃ and annealing time less than 4 h, Cr2C3 interface species was formed. Higher temperature and longer time resulted in Cr2Cinterface species. The chemical reaction suggested that there was a strong chemical bond on the interface of Cr/diamond, which was one of the important factors for the high adhesion strength between metal and diamond. The interface diffusion and reaction was governed by the diffusion of carbon from diamond substrate. The activation energy of the interface diffusion reaction was 38.4 kJ/mol. The interface species varied with annealing temperature and time.
    Quantum Chemical Study of Structures and Vibrational Spectra on Silicon-sulfur Clusters(SiS2)n- (n=1—5)
    WANG Su-Fan, FENG Ji-Kang, LIU Jian-Jun, SUN Chia-Chung, LIU Peng, GAO Zhen, KONG Fan-Ao
    2000, 21(8):  1273-1277. 
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    The initial geometrical structures and relative stability of silicon-sulfur clusters(SiS2)n-(n=1—5) are explored by means of density functional theory(DFT) quantum chemical calculations. The effects of polarization functions, diffuse functions and electron correlation are included in those calculations. The electronic structures and vibrational spectra of the most stable geometrical structures of (SiS2)n- are analyzed by the same method. As the result, the regularity of the (SiS2)n- clusters growing is obtained, and the calculated results can be used to predict the formation mechanism of the (SiS2)n- clusters.
    Photoluminescence and Electroluminescence of Pyrazoline Monomers and Dimers
    ZHANG Xiao-Hong, WU Shi-Kang, GAO Zhi-Qiang, LEE Zhen-Sheng, LEE Shu-Tang
    2000, 21(8):  1278-1282. 
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    The photo-lummescence behavior of seven kinds of pyrazoline monomer and dimer in solution and film has been studied comparatively in this work, The electro-luminescence properties of the material containing dopant in ELdevice, in which the structure[ITO/TPD/TPBI∶EP/TPBI/Mg∶Ag] was employed, have also been investigated. The results indicated that the ELdevices composed of pyrazoline compounds showed itself a very good ability on the electro-luminescence, especially, of the pyrazoline compound in which a 5-position substitution existed. The devices obtained also showed itself a good stability due to their excellent film formation and high Tg transition temperature of the compounds used. The results demonstrated that the fluorescence quantum yields of mono-pyrazoline compounds in solution were higher than that of pyrazoline dimer. The identical tendency in the emission intensity has also been observed when the ELdevices were composed of them.
    Studies on Electrocatalytic Performance of Titanium Oxide Electrode Modified with Pt Toward the Oxidation of Methanol
    YANG Hui, LU Tian-Hong, LIU Chang-Peng, LIU Jing-Hua, SUN Gong-Quan
    2000, 21(8):  1283-1287. 
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    Electrocatalytic performance of the Pt-TiOx /Ti electrode prepared with electrochemical reduction-oxidation method toward the oxidation of methanol has been studied. The experimental results showed that the Pt-TiOx /Ti electrode has a high electrocatalytic activity and good stability for the electrocatalytic oxidation of methanol. By means of electrochemical, XPS, STMand in-situ FTIRtechniques, it was found that one reason for the electrode to exhibit an excellent performance is attributed to the high dispersion between nanosized Pt and TiOx particles. The low adsorption ability of the intermediate derived from methanol, such as linearly adsorbed COspecies on the electrode surface due to the interaction between Pt and TiOx , also results in the excellent performance.
    In situ FTIR Spectroscopic Investigations of Dissociative Adsorption and Electrooxidation of Glycine at the Pt Electrode in Alkaline Solutions
    XIAO Xiao-Yin, SUN Shi-Gang, WU Qi-Hui, ZHOU Zhi-You, CHEN Sheng-Pei
    2000, 21(8):  1288-1292. 
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    The dissociative adsorption and electrooxidation of glycine on Pt electrode in 0.1 mol/L NaOHsolutions were studied using cyclic voltammetry and in situ FTIRspectroscopy. The results demonstrated that a strong interaction exists between glycine and Pt surface, leading to dissociate easily glycine on Pt surface at potentials below 0.2 Vto form cyanide and carboxylate ions. The strongly adsorbed cyanide species on the electrode surface can inhibit the oxidation of glycine, and are considered as poison species for the reaction. The oxidation of glycine at potentials above 0.2 Vyielded solution species of cyanate and carboxylate. The cyanide species derived from dissociative adsorption of glycine can be isolated on electrodes of smooth Pt and nanometer thin Pt film supported on glassy carbon(nm-Pt/GC), and has been determined by in situ FTIRSas showing a band at around 2100 cm-1 . The intensity of IRabsorption band of cyanide on nm-Pt/GCsurface is 14 times larger than that on a smooth Pt surface, and the IRband is in the opposite direction to that obtained on Pt surface, confirming the adsorption of cyanide species and the abnormal IReffects. The IRabsorption of cyanate and carboxylate produced in the oxidation of glycine yields infrared bands at around 2169 and 1390 cm-1 , respectively. The present study revealed the interaction between glycine and Pt electrode surface, and suggested the adsorption modes and oxidation mechanism of glycine on Pt electrode as well.
    Density Functional Theory Studies on Molecular Structure and IR Spectra of GuanineA Scaled Quantum Mechanical Force Field Approach
    XUE Ying, XU Ding-Guo, XIE Dai-Qian, YAN Guo-Sen
    2000, 21(8):  1293-1298. 
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    Density functional theory with the combined Becke 3-LYP exchange-correlation energy function using the 6-31G* basis set was applied to study the structures and vibrational IRspectra of am ino-oxo and am ino-hydroxy forms of guanine. The calculated force fields were corrected by scaling the forces fields over a convenient set of local internal coordinates. The scale factors were determined by least-squares fitting of the theoretical frequencies to the experimental ones of the two parent molecules, isocytosine and imidazole. The predicted vibrational frequencies of two tautomers of guanine were compared with the available observed matrix-isolated IRspectra with mean deviations of about 6.6 cm-1 for amino oxo form and 6.0 cm-1 for am ino-hydroxy form. The results made it possible to give reliable assignments of the IRspectra of isolated guanine. This study shows that the scaled density functional force field approach enables us to give a good interpretation of vibrational spectra of large molecules through the transferability of scale factors.
    Studies on Photocatalytic Oxidation Reaction of SO2 over TiO2
    SHANG Jing, XU Zi-Li, DU Yao-Guo, GUO Hai-Chen
    2000, 21(8):  1299-1300. 
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    The influence of the baked temperature for TiO2 ultrafine particles on the photocatalytic oxidation reaction of SO2 was investigated. The photocatalytic activity of TiO2 baked at 320 ℃ is higher than that at other temperatures(480 ℃, 550 ℃). It may be explained by the surface state of TiO2, increasing the content of surface hydroxyl is helpful to enhance the photocatalytic activity. According to the experimental results, the first order kinetic reaction and the mechanism of the reaction were suggested, also the rate constants and half-life time were reported.
    Synthesis and Electroluminescence of Oxadiazole-substituted Ionic Conductive Poly(phenylene vinylene)
    CHEN Xi-Wen, LI Zhong-Xiao, XIE Hong-Quan, LI Yong-Fang
    2000, 21(8):  1301-1304. 
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    Through copolymerization, a new ionic conductive hybrid conjugated polymer, polyoxyethylene side chains containing poly(phenylene vinylene)(PPV) with electron-transporting oxadiazoles Ⅴ(DTEO-O-PPV), was synthesized, characterized and applied in light emitting devices(LEDand LEC). PPVwithout oxadiazoles but with the same side chains as polymer Ⅴ was chosen for comparison.
    Studies on the Phase Separation of Poly(ether imide) Modified by Tetraglycidyl-4,4′-diaminodiphenylmethane Epoxy Resin
    WU Xian-Guo, CUI Jun, TANG Xiao-Lin, YU Ying-Feng, LI Shan-Jun
    2000, 21(8):  1305-1308. 
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    Different polyetherimides of varied chemical structure were synthesized to toughen tetraglycidyl-4,4′-diaminodiphenylmethane(TGDDM) epoxy resin. The effects of miscibility and viscosity of polyetherimide on the phase separation and morphological evolution during the cure reaction of the toughened system were characterized by using DSC, time-resolved light scattering(TRLS) and SEM. Both thermodynamic and dynamic factors were emphasized to control the morphology of cure reaction induced phase separation system.
    Synthesis and Properties of Fast Responsive, Temperature Sensitive P(NIPA-co- AA) Hydrogel
    ZHANG Xian-Zheng, ZHUO Ren-Xi 
    2000, 21(8):  1309-1311. 
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    Poly(N-isopropylacrylamide-co-acrylamide)[P(NIPA-co-AA)] hydrogels were synthesized by carrying out the polymerization at 48 ℃. These hydrogels show large equilibrated swelling ratio(SR) at the temperature below their lower critical solution temperature(LCST) or phase transition temperature(Ttr). The LCSTof the gels is increased as the content of the hydrophilic monomer (AA) is increased. Based on our experimental results, these hydrogels exhibit a fast responsive rate to the external temperature changes. The endowed properties of these hydrogels may be useful in biotechnological and biomedical fields.
    Charge Transfer in Organic Semiconductive Materials
    ZHOU Xue-Qin, WANG Mang, YANG Shi-Lin
    2000, 21(8):  1312-1317. 
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    In this paper, the basic theory of charge transfer in organic semiconductive materials was introduced, and the recent progress in studies of the conductive, photoconductive and luminescent properties for organic semiconductors was reviewed with 50 references. It was believed that charge transfer was a dominant factor to understand these characteristics of organic semiconductive materials. Studying on charge transfer was very important to explore physical origins of some new phenomena and some new effects, as well as to find effective methods to predict the properties of organic semiconductive materials.
    New Development in Photoinitiated Cross-Linking of Polyethylene and Its Industrial Applications
    QU Bao-Jun, WU Qiang-Hua
    2000, 21(8):  1318-1324. 
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    Combined with the recent series of work made by the authors, the new development and major breakthroughs in the photoinitiated cross-linking of polyethylene and its industrial application are reviewed, such as the enhanced photoinitiation system, mechanism of photocross-linking, crosslink microstructures, morphology and properties. Anew technique of photocross-linked insulated XLPEcables and its future applications are promising.
    Synthesis and Characterization of Novel PEEK with Pendant Group Containing Fluorine
    WANG Gui-Bin, CHEN Chun-Hai, ZHOU Hong-Wei, JIANG Zhen-Hua, ZHANG Wan-Jin, WU Zhong-Wen
    2000, 21(8):  1325-1327. 
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    A fluorine-containing monomer was synthesized and its polymer was prepared by aromatic nucleophilic substitution polycondensation of the monomer and 4,4′-difluorobenzophenone using potassium carbonate as the catalyst and tetramethylene sulfone as solvent. The polymer properties were characterized by FTIR, NMR, DSCand the results showed that the Tg of the polymer is 141 ℃ and the solubility of the polymer was obviously improved due to the introduction of (3-trifluoromethyl)phenyl group.
    A Study of the Crystallographic Equivalence of Ether and Ketone Groups in Poly(aryl ether ketone)s
    QIU Zhao-Bin, ZHOU Hong-Wei, MO Zhi-Shen, ZHANG Hong-Fang, WU Zhong-Wen
    2000, 21(8):  1328-1330. 
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    Crystallographic equivalence of ether and ketone in all para-substituted PAEKs crystallized in form Ⅰ was discussed in this paper. In a word, crystallographic equivalence between ether and ketone groups is tenable when polymer contains only phenyl rings in the repeat unit. If a polymer contains a diphenyl group in the repeat unit, two cases should be distinguished. In the case of PEDEKKand PEEKDK, crystallographic equivalence between ether and ketone linkages is untenable. However, in the case of PEDKand PEDEKDK, crystallographic equivalence between ether and ketone linkages is still tenable.
    Photoconductivity of Polystyrene with C60 in the Side Group
    WANG Chang-Chun, SHU Chang, FU Shou-Kuan, JIANG Ke-Jian, CHEN Hong-Zheng, WANG Mang
    2000, 21(8):  1331-1333. 
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    A series of polystyrene resin with C60 in the side group were prepared by chloromethylation, azidation and cycloaddition. In these C60-containing polystyrene resins, the C60 contents are about 2.9% , 6.7% and 11% (mass fraction), respectively. With the increase of C60 content in the C60-containing polystyrene resin, the photoconductivity increases obviously. α-NP as the charge transport material is better than DMMP, which proves that it is very important that charge transport material(CTM) match the charge generation material(CGM). If no charge transport layer in the photoreceptor exsist, the polystyrene resin with C60 in the side group could not show any photoconductivity at all.
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