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    10 May 2007, Volume 28 Issue 5
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    下期目次预览
    2007, 28(5):  0.  doi:
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    高等学校化学学报2007年第28卷第5期目次
    2007, 28(5):  0.  doi:
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    研究论文
    Synthesis and Characterization of Ordered Mesoporous Aluminosilicates Molecular Sieves with Highly Hydrothermal Stability
    LUO Yong-Ming1,2, HOU Zhao-Yin1, ZHENG Xiao-Ming1*
    2007, 28(5):  801-805.  doi:
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    Highly ordered mesoporous aluminosilicate molecular sieve MSAMS-4 was synthesized via multistage recrystallization. The reaction product was characterized by XRD, N2 adsorption-desorption, FTIR spectroscopy and 27Al MAS NMR. The hydrothermal stability tests exhibit that MSAMS-4 retained a well-ordered hexagonal symmetry mesostructure both after being treated with 100 ℃ water for 120 h and streamed at 800 ℃ for 6 h.
    Hydrothermal Synthesis of Fe and Mn Doped SnO2 and Its Magnetic Structures
    LIU Jian-Fen1,3, CHAI Ping1, WANG Zhong-Li1, LIU Xiao-Juan1, XING Xian-Ran2, MENG Jian1*
    2007, 28(5):  806-810.  doi:
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    The dilute magnetic semiconductor of Sn1-x-yMnxFeyO2(0≤x≤0.10, 0≤y≤0.10) were synthesized with the hydrothermal method using SnCl4, Mn(CH3COO)2·4H2O and FeCl3·6H2O as the raw materials. The structure, morphologies and magnetic properties of the sample were characterized via X-ray powder diffractometer(XRD), transmission electron microscopy(TEM), Raman spectrum and superconducting and quantum interference device(SQUIT), and Mssbeaur spectrum. No secondary phase was found in the XRD spectrum. The morphology of the samples is affected by the kind or the mount of transition metal. The local vibrating model of Mn Positioned SnO2 sites was found in Raman spectrum. The measured magnetic results indicate that when x=0.10, y=0, the sample exhibits strong magnetization in low-temperature(5 K), but the magnetization decrease rapidly at room temperature; In contrast, when x=0, y=0.1, the sample's magnetization and coercivity are both small, but being temperature independent. Mössbeaur spectra indicates that part of the Fe is ferromagnetic coupled, and the simulating results indicate that the ferromagnetic character is intrinsic. The magnetization of the Mn and Fe codoping system decrease with the decrease of x and increase of y, However, the coercivity is comparatively enhanced in the codoping system.
    Synthesis, Structure and Photophysical Properties of Zn-Ln(Ⅲ)(Ln=Eu, Tb) Heterometallic Coordination Complexes
    WANG Zhao-Long1, NIU Shu-Yun1*, JIN Jing1, LÜ Chun-Xin1, CHI Yu-Xian1, YANG Guang-Di2, YE Ling2
    2007, 28(5):  811-815.  doi:
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    Two d-f heterometallic coordination complexes EuZn(C8H7O3)5(phen)(H2O)(1) and TbZn(C8H7O3)5(phen)(H2O)(2) were synthesized with hydrothermal reaction. These two complexes exhibit strong luminesecent emission. The crystal structures of the two complexes were determined via X-ray diffraction. The two complexes are isomorphic. Zn(Ⅱ) ion is five-coordinated and Ln(Ⅲ) ion is eight-coordinated. Zn(Ⅱ) and Ln(Ⅲ) ions are bridged by 4-methoxybenzoic acid ligands. The UV-Vis-NIR, IR and fluorescence spectra of the complexes were measured. The influence of coordination environment on the luminescence property and intramolecular energy transfer of complexes were discussed.
    Phase Transformation Regularity of Synthesizing Zeolite with Kaolin as Raw Material
    SHANG Yun-Shuai, MENG Chang-Gong*
    2007, 28(5):  816-820.  doi:
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    Zeolites NaX, NaP and SOD were synthesized with hydrothermal treatment from the raw material of kaolin. The effects of temperature and the concentration of NaOH solution of the initial mixture on the crystallinity of zeolite were investigated via X-ray diffraction and water adsorption capacity. The binary crystallization phase diagram of three type zeolites and the rule of crystallization as well as phase transformation were obtained. Besides, the technical parameters of synthesizing zeolites were optimized to achieve the best synthetical conditions.
    研究简报
    Synthesis, Structure Characterization and Magnetic Properties of Single Crystal of Dimanganese Trioxide
    WANG Xiao-Feng, LI Guang-Hua, CHU Qing-Xin, LIU Xiao-Yang*, FENG Shou-Hua
    2007, 28(5):  821-823.  doi:
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    Dimanganese trioxide is an active catalyst for removing carbon monooxide and nitrogen oxide from waste gas as an important one of manganese oxides. Its single crystal was synthesized by flux method. Single crystal X-ray diffraction reveals that the compound crystallized in the cubic space group Ia-3 with a=0.94173(11) nm, V=0.83518(17) nm3, Z=48, Dc=5.022 Mg/m3, R(int)=0.0863, R1=0.0659[I>2σ(I)], wR2=0.1929[I>2σ(I)].
    Investigation of Novel Anode NiO-La0.3Ce0.7O2-δ of IT-SOFC with LSGM-based Electrolyte
    ZHU Xiao-Dong1, SUN Ke-Ning1*, ZHANG Nai-Qing1,2, CHEN Xin-Bing1, FU Qiang1, JIA De-Chang2
    2007, 28(5):  824-826.  doi:
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    NiO-La0.3Ce0.7O2-δ(LDC30) novel anode was investigated for IT-SOFCs(Intermediate Temperature-Solid Oxide Fuel Cells) with LaGaO3-based electrolyte. The results showed that LDC30 has a suitable chemical compatibility with NiO and NiO-LDC30 has a good thermal expansion matching with LDC30 interlayer and LSGM(La0.8Sr0.2Ga0.8Mg0.2O3-δ) electrolyte, so NiO-LDC30/LDC30 was considered as a feasible and novel anode system. It was also shown that NiO content plays a key role on polarization performance and morphology of the anode. When the content of NiO was 60%(mass fraction), the polarization loss of anode was the lowest. Next we will optimize the porosity and sintering procedure to modify the microstructure and performance of the anode.
    研究论文
    Direct Determination of Reserpine in Urine Using Excitation-Emission Fluorescence Combined with Three-dimensional Chemometric Calibration Methodologies
    HAN Qing-Juan, WU Hai-Long*, NIE Jin-Fang, XIA A-Lin, ZHU Shao-Hua, ZHANG Yan, YU Ru-Qin
    2007, 28(5):  827-830.  doi:
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    The concentration of reserpine in urine was directly and quantitatively measured with the excitation-emission fluorescence(EEM) combined with three-dimensional calibration methodologies. Two calibration methodologies are based on the alternating trilinear decomposition(ATLD) and the self-weighted alternating trilinear decomposition(SWATLD) algorithms, respectively. The satisfactory results of both methods are obtained, when the component number was chosen to be 3(N=3). This experiment is easily carried out without time-consuming and complicated pretreatment. It proved that ATLD and SWATLD based three-dimensional calibration methodologies can be feasible to directly quantify the medical content of reserpine in urine
    Preparation of Zwitterionic Ion Exchange Packings Based on Monodisperse Hydrophilic Macroporous Resins and Their Application to Separation of Proteins
    GONG Bo-Lin1,2*, REN Li1, YAN Chao2, HU Wen-Zhi3
    2007, 28(5):  831-836.  doi:
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    Monodisperse, macroporous hydrophilic poly(glycidylmethacrylate-co-ethylene dimethacrylate) particles with a diameter of 5.0 μm were prepared via a one-step swelling method combined with dispersion polymerization and technique of polymeric solution porogens, then they were characterized with various measurements. The resins were modified to be strong/strong ziwitterioic stationary phase for high performance liquid chromatography(HPLC) in the following steps. First, a tertiary amine was introduced on the particles by dimethylamination, followed by quaternizing sulfoalkylation with 1,3-propane sultone. The zwitterionic ion exchange stationary phase was evaluated in light of the separability and hydrophilicity on the separation and retention of standard proteins in detail. Three acid proteins and two basic ones were quickly separated in 4.0 min with 3 mL/min linear gradient elution by using the synthesized zwitterionic ion exchange stationary phase.
    Resonance Rayleigh Scattering Spectra Method for the Determination of Anthracycline Anticancer Drugs with CdS Nanoparticles as Probe
    WANG Qi, LIU Zhong-Fang, LIU Shao-Pu*
    2007, 28(5):  837-842.  doi:
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    In water solution with pH=5.0—9.0, the CdS nanoparticles[(CdS)n] can react with a kind of anthracycline anticancer drugs such as MXT, DNR and EPI to form the larger aggregates by virtue of electrostatic attraction and hydrophobic force. The aggregates arouse Resonance Rayleigh scttaring(RRS) instancing greatly, and the new RRS spectra appeared. The maximum RRS peaks are at 292 nm for MXT system, 285 nm for DNR system and 315 nm for EPI system, respectively. At the same time, the Second-order Scattering(SOS) and Frequency-double Scattering(FDS) are also enhanced obviously. The maximum SOS peaks are at 540 nm for MXT system, 560 nm for EPI system and DNR system, but their maximum FDS peak are at 320 nm for EPI system, 330 nm for DNR system and 330 nm for MXT system, separately. The enhancements of three scattering(ΔI) are directly proportional to the concentration of anthracycline drugs in a certain ranges. The reactions have high sensitivities, the detection limits for different drugs are 3.6—9.1 ng/mL. Among them, (CdS)n-MXT system is the most sensitive, its limits for MXT are 4.1 ng/mL for RRS method, 3.8 ng/mL for SOS method and 3.6 ng/mL for FDS method, respectively. So a new method for the determination of the anthracycline anticancer drugs with CdS nanoparticles as probe is developed, the method is highly sensitive, and it is very simple and fast.
    Detecting Tumor of Parotid Gland Using FT-mid-IR Fiber Optics Spectroscopy
    PAN Qing-Hua1,2, WANG Bing-Bing1, LAI Guo-Qiao2, XU Yi-Zhuang1*, ZHANG Yuan-Fu1, WU Qi-Guang3, SUN Kai-Hua3, PENG Xin3, YU Guang-Yan3, LIU Yu-Feng1, WU Jin-Guang1
    2007, 28(5):  843-846.  doi:
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    The modified WQF-500 FTIR spectrometer from the Second Optical Instrumental Factory and an accessory(SpecTech)of mid-IR fiber optics with an ATR probe were used to detect the skin covering a parotid gland using. In this investigation, forty patients with tumor of salivary gland were performed with FTIR fiber optics measurement. The differential diagnosis from the obtained FTIR spectra of benign and malignant tumors of salivary gland was compared with pathological diagnosis, which is considered as the standard. Good agreements were found between the results of pathological diagnosis and those of spectral detection. The results show that the difference lied in the obtained FTIR spectra of the skin covering benign and malignant tumors of salivary gland and normal parotid gland. And the difference can be characterized by the band width, peak position and peak intensity. Based on the difference of the bands in the range of 1500—1000 cm-1, malignant tumor can be classified into two types. The first type of tumor(for example acinic cell carcinoma, oxyphilic cell adenocarcinoma, adenoid cystic carcinoma and so on) possesses the above spectra feature. Along with the variation of species(for example malignant lymphoma, lympho-epithelial carcinoma and so on), great changes take place in band width, peak position and relative intensity of the bands between 1500 and 1000 cm-1 in spectra of the other kind of malignant tumor. So the FT-mid-IR spectroscopy is a promising technique which will become a non-invasive, quick, accurate and convenient method to diagnose malignant and benign tumor of salivary gland early.
    Nondestructive Quantitative Analysis of Norvasc in Medicine Tablets by PLS-ANN Arithmetic Combined with NIR Spectroscopy
    LÜ Hui-Ying1, REN Yu-Lin2, LIU Ming-Yang3,4*
    2007, 28(5):  847-850.  doi:
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    Artificial neural network(ANN) algorithm combined with partial least squares(PLS) was used to parse near infrared(NIR) reflectance spectra of Norvasc medicine in tablets. The nondestructive and quantitative determination of the contents of amlodipine besylate, which is an effective component in the Norvasc tablets, were accurately carried out. The best model of PLS-ANN was designed. The effect of the best wavelength range, derivative NIR spectrum, input nodes and hidden nodes on the predicted results was discussed respectively. Compared the results with those of HPLC, the relative errors(RE) of mlodipine besylate are less than 3.5%. The analytical results could be applied to the quality control of Norvasc medicines in practical manufacture.
    Pb and Cu Adsorption to Main Components of Suspended Particulate in Natural Water——Comparison of Adsorption Characteristic and Enrichment Characteristic
    LIU Liang, DONG De-Ming*, LU Yong-Zheng, HUA Xiu-Yi, GAO Qiu-Ju
    2007, 28(5):  851-855.  doi:
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    Selective extraction techniques followed by adsorption experiment and statistical analysis were applied to investigate the relative adsorption contribution of different components of suspended particulate for Pb and Cu and direct extraction method was employed to study the enrichment characteristic of suspended particulate. By comparison of adsorption characteristic and enrichment characteristic, the roles of main components of suspended particulate for Pb and Cu adsorption onto suspended particulate were confirmed. The results indicate that the adsorption characteristic of components was comparable to enrichment characteristic of them. Pb tends to bind with Fe oxides. Organic materials were most important adsorbents for Cu adsorption and enrichment.
    研究简报
    Influence of BSA on Cu2+-SCN--H2O2 Chemical Oscillating System
    SUN Tao1, GUO Hong-Rui2, XU Huan-Lin1, ZHOU Bao-Kuan1*
    2007, 28(5):  856-858.  doi:
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    The influence of bovine serum albumin (BSA) on Cu2+-SCN--H2O2 chemical oscillating system was studied. The stable oscillating system contains 0.004 mol/L NaSCN, 0.066×10-3 mol/L CuSO4 and 0.111 mol/L H2O2, and it was injected during the peak of the third cycle of BSA. The electrode potential-time(E-t) curve was recorded and analyzed. The influence of the concentration of BSA on the chemical oscillating system's cycle prolonging(cycle-slope rate, RS) can be indicated in a quadratic term equation:
    RS=1.94×10-3ρ(BSA)2+0.000595ρ(BSA)+0.059292
    Protein may affect the chemical oscillation through midbody interference, binding with certain metallic ions, or alteration of solution's physical characteristics, but infraprotein may weaken the physical interference of the chemical oscillation by BSA. A linear relationship between infraprotein of BSA and oscillation cycle is derived with a coefficient correlation of R=0.996, and a linear range of 1—100 mg/L. Therefore, it is a new dynamic quantitative assay for the analysis of protein.
    Electrochemical Study on the Interaction of Sodium Cholate with a Supported Lipid Bilayer Membrane
    WANG Jian-Guo*, YANG Wei-Wei, JIANG Li-Li, LÜ Hui, SUN Qiao-Hua, MA Yong, JIANG Yu-Chun, ZANG Shu-Liang
    2007, 28(5):  859-861.  doi:
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    The supported bilayer lipid membrane(s-BLM) was served as a biomembrane model. The interaction between sodium cholate(NaC) and s-BLM was investigated by cyclic voltammetry and alternating current(AC) impedance spectroscopy. The following conclusions were obtained: NaC can decrease the orderliness of lecithin molecule arrangement and induce pores or defects on s-BLM and the interaction between them depends on time, concentration and cholesterol. In addition, the defective s-BLM after interaction can be self-repaired in 0.1 mol/L KCl solution, which indicates that the interaction is reversible. Moreover, a possible mechanism of the interaction was proposed finally.
    Determination of Captopril in Human Serum and Urine Samples by HPLC with On-line Electrogenerated Mn(Ⅲ) Chemiluminescence Detection
    ZHANG Yan-Tu1,2, ZHANG Zhu-Jun1*, SUN Yong-Hua1, WEI Yue1
    2007, 28(5):  862-864.  doi:
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    The separation and determination of captopril in human serum and urine samples by means of high performance liquid chromatography(HPLC) with on-line electrogenerated Mn(Ⅲ) chemiluminescence detection was carried out. The method was based on the direct chemiluminescence reaction between captopril and Mn(Ⅲ), which was on-line electrogenerated by constant current electrolysis. The chromatographic separation was performed on a nucleosil RP-C18(250 mm×4.6mm i.d., 5 μm) column with an isocratic mobile phase consisting of acetonitrile-1% aqueous acetic acid(volume ratio 6∶4) at a flow-rate of 1.2 mL/min. The temperature was 25 ℃. The effects of several parameters on the HPLC resolution and CL emission were studied systematically. Under the optimal conditions, the linear range and detection limit for captopril are 5—800 ng/mL and 0.9 ng/mL, respectively. The relative standard derivation for 10.0 ng/mL captopril is 2.2％(n=11). The average recoveries for captopril in human serum and urine samples ranged from 94.8% to 103.2%, and the relative standard deviations of the quantitative results are below 3.4%. The proposed method had been applied to the determination of captopril in human serum and urine samples.
    Derivative Waves of Seven Eelements in Identical Substrate Solution and Their Application to the Simultaneous Determination of the Microelements in Chinese Traditional Medicines
    ZHANG Tai-Ming*, CAO Juan, LIANG Yi-Zeng
    2007, 28(5):  865-867.  doi:
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    Sensitive second derivative waves of Cu(Ⅱ), Pb(Ⅱ), Cd(Ⅱ), Ni(Ⅱ), Zn(Ⅱ), Fe(Ⅱ) and Mn(Ⅱ) can form in the substrate solution(pH=9.26) containing NH3, NH4Cl, gelatin and ascorbic acid, and the peak potentials of the polarogram of the seven ions are about -0.48, -0.63, -0.79, -1.04, -1.28, -1.44 and -1.60 V, respectively. Therefore, a new method for simultaneous determination of the seven micro-elements in aqueous solutions was developed.The operation of the method is rapid, simple and convenient. The method was used successfully in rapid and simultaneous determination of 7 microelements in Chinese Traditional Medicines.
    研究论文
    Influence Mechanism of a Kind of Exopolysaccharides on Yogurt Curd
    LI Quan-Yang1*, XIA Wen-Shui2, ZHU Li-Xiang3, DAI Yang-Yong1, CHEN Wei1
    2007, 28(5):  868-871.  doi:
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    Different yogurt curd samples were manufactured by lactic acid bacteria strains and the ropy-strain exopolysaccharides, furthermore, the microstructure and texture properties of the samples were measured. The results indicate that, the mechanism of lactic acid exopolysaccharides reacting with yogurt curd mainly was space baffle effect resulting from the size of the neutral exopolysaccharides themselves which were exclusive from casein in yogurt curd, the space baffle effect interrupted the link ways of casein micelles and thereby dynamically influence the construction of three-dimensional net structure of casein micelle. A novel view point was brought forward that the influence effect of the lactic acid bacteria exopolysaccharides from yogurt on yogurt curds had great things to do not only with the size and structure of exoploysaccharides but also more importantly with the adding ways, time, speed, concentration of exopolysaccharides. Furthermore, the reasons were made clear that the effect of using ropy starter and making a ropy yogurt could not be replaced by adding stabilizer reagents directly.
    Synthesis and Characterization of Tridentate Polypyridyl Cobalt(Ⅲ) and Ruthenium(Ⅱ) Complexes and Its Interaction with DNA
    YANG Hao
    2007, 28(5):  872-876.  doi:
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    Two novel tridentate polypyridyl mixed-ligand cobalt(Ⅲ) [Co(PhTPY)(H2Bzimpy)]3+(A) and ruthenium(Ⅱ) [Ru(PhTPY)(Bzimpy)](B) complexes were synthesized and characterized via elemental analysis and 1H NMR. The crystal structure of complex B was determined. The interactions between the complexes and calf thymus DNA were investigated with absorption and fluorescence spectroscopys. Photoactivated cleavage of pBR322DNA by the synthesized complexes were studied. The spectrophotometric studies show that the modes of these two complexes interacting with DNA were electrostatic interaction. The agarose gel electrophoresis results show that complex A and complex B converted supercoiled pBR322DNA to nicked and linear DNA when irradiated by the light with a wavelengths 310 nm for 15 min, 450 nm for 4 min, respectively.
    Synthesis and Biological Activities of Cyclic Analogues of Thymosin α1 Active Fragment
    JIANG Zhi-Long, QIE Jian-Kun, LIANG Yuan-Jun, LIU Ke-Liang*
    2007, 28(5):  877-880.  doi:
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    Thymosin α1(Tα1) is an immunomodulating peptide isolated from thymic extracts containing 28 amino acid residues. It has been demonstrated that the C-terminal fragment of Tα1 is responsible for its activity. In order to increase bioactivity and improve stability to proteolytic enzymes of this fragment, a series of cyclic peptides based on the active fragment were designed, and synthesized through formation of thioesters with various amount of residues or a flexible linker. The resulting cyclic peptides were determined via ESI-MS and HPLC. The bioactivity was assayed in vitro through T-lymphocyte proliferation testing. Data from this test show that most of the cyclic analogs retained the immunoactivity, and some of them better than the original fragment. It can be concluded that cyclizations of this active fragment lead to the increasing of the bioactivity.
    Studies on Cyclopalladated Ferrocenylimine-phosphine Complexes by Electrospray Ionization Trap Mass Spectrometry
    YU A-Juan, WEI Kun, WU Yang-Jie*
    2007, 28(5):  881-884.  doi:
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    The mass spectrometric characteristics of ten cyclopalladated ferrocenylimine-phosphine complexes were investigated via electrospray ionization trap mass spectrometer(ESI-MS) in a multi-stage MS full scan mode. The mass spectra were interpreted according to the fragments of these compounds and their fragmentation patterns were proposed. The results indicate that the strong [M-Cl]+ ion cluster was obtained in the positive mode. The positive ion produced by full scan ESI-MSn(n=1—3) of each compound gave charac-teristic fragment ions formed via the cleavages of the C—P bond and Pd—C bond in these molecules. These characteristics can be applied further to the elucidation of fragmentation of this analogue.
    Synthesis and Amino Acids Complexation Properties of Thiacalix-1,3-2,4-aza-bis-crowns
    YANG Fa-Fu1*, HUANG Cui-Yu1, ZHAO Xia1, ZHENG Si-Ning1, PENG Qi2
    2007, 28(5):  885-888.  doi:
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    Thiacalixarene is an interesting novel member of the calixarene family. Thiacalixcrowns were paid much attention due to their particular structures and excellent complexation capabilities. In this paper, by reacting p-tert-butylthiacalixarene tetrahydrazide derivative 2 with o-phthalaldehyde, the first example of thiacalix-1,3-2,4-aza-bis-crowns with 1,3-alternate conformation was prepared with “1+2” condensation mode in a 65% yield. Its structure was characterized by elemental analysis, ESI-MS, 1H NMR spectrum. Its complexation properties for series of α-amino acids were studied via UV-Vis and 1H NMR spectra. Their high complexing constants suggest novel thiacalixbiscrown 3 possessed excellent comple-xation abilities for tested amino acids. The correlation coefficients and the 1H NMR spectra change of comple-xation experiments indicate that compound 3 formed 1∶1 stoichiometric complex with amino acids.
    Ionization Rate and Absolute Intensity of Peptides Enhanced with Matrix-assisted Laser Desorption/Ionization in the Presence of Proteins
    ZHUO Hui-Qin1,2, HUANG He-Qing1,2*, WENG Lu-Na1,2, HUANG Hui-Ying1,2
    2007, 28(5):  889-893.  doi:
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    Human serum transferrin(HTF), bovine serum albumin(BSA), and horse spleen ferritin(HSF) have capacities of assisting the matrix to enhance ionization rate and absolute intensity both insulin(INS) and aplysia acidic peptide(AP) by laser desorption/ionization, and this enhancement can be up to 10 and 4 times, respectively. This phenomenon was independent on the concentration of INS, but dependent on these intensifiers strongly. Moreover, the similar enhancing rate of absolute intensity of INS was observed by both SZLF- and apoSZLF-assisted matrix, indicating that this effect was not relative to the metal ions of proteins, but their compositions and structures. The fragment numbers of HTF lysised with endopeptidease and matching rate with reference transferrin were greatly improved in the presence of SZLF, apoSZLF and HSF, when HTF was identified by a combined techniques, lysis enzyme and peptide mass fingerprinting(PMF). This novel effect might play an important role in enhancing the reliability for identifying protein.
    研究快报
    Crystal Structure and DNA Cleavage of Pseudorotaxane Composed of Cucurbituril
    HUO Fang-Jun, YIN Cai-Xia, YANG Pin*
    2007, 28(5):  894-896.  doi:
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    The pseudorotaxane of cucurbituril(CB) with guest molecule 1,6-bis(imidazol-1-yl)hexane dihydrochloride(BIMH-Cl) made pBR322 DNA hydrolyzed efficiently in physiological environment. The cleavage mechanism was proposed that was a cooperation process of the CB molecule and the guest BIMH molecule. In this mechanism, the protonated imidazole might bind DNA via the electrostatic interactions and the CB glycoluril carbonyl oxygen atoms activated a water molecule to attack the phosphorus atom.
    研究简报
    A New Method for Synthesis of Mcrocyclic Lactones via Malania Olceifera Chum Oil
    LIU Xiong-Min*, LI Wei-Guang, LI Piao-Ying, ZHOU Yong-Hong
    2007, 28(5):  897-899.  doi:
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    Synthesis of mcrocyclic lactones has been applied to medical and flavor field. Triglycerides(2) of ω-hydroxycarboxylic acids synthesized from malania oleifera chum oil(1) via ozonization and reduction, and compound 2 were catalytically transformed to macrocyctic lactones(3). This is a new method involving fewer steps and a 61% yield of cyclopentadecanolide was obtained. The reactive properties of macrolactonization of ω-hydroxycarboxylic acids were also studied. The result obtained shows that the priority order of macrolactonization as follows: 11-undecalactone>cyclotridecanolide>cyclopentadecanolide, i.e. the short chain ω-hydroxycarboxylic acids were preferentially cyclized.
    研究论文
    Theoretical Studies on the Ground and Excited States for a Series of Terpyridyl Platinum(Ⅱ) Complexes
    ZHOU Xin1, PAN Qing-Jiang2, LI Ming-Xia1,2, ZHANG Hong-Xing1*, TUNG Au-Chin1
    2007, 28(5):  900-903.  doi:
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    To explore the substituents how to affect the excited state for the the terpyridyl Pt(Ⅱ) complexes, we calculated a series of complexes [Pt(trpy)C≡CC6H4R]+[trpy=2,2',6',2″-Terpyridine; R=NO2(1), Cl(2), H(3) and CH3(4)]. MP2 and CIS methods were used to optimize the ground and excited states for the four complexes, and TDDFT method at B3LYP level was employed to obtain their phosphorescent emission spectra. The results reveal that the lowest-energy phosphorescence of compound 1 can be assigned as the Pt—C≡C→trpy charge transfer(3MLCT/3LLCT) transitions and perturbed by the π→π* transition localized on the C6H4NO2 moiety, due to the stronger electron-withdrawing ability of NO2 and the possible resonance structures in C≡CC6H4NO2. But the other three complexes were only attributed to 3MLCT/3LLCT characters. In addition, the excited-state structures are similar to those of the ground-state ones, which is in agreement with the small Stokes-shift in the experiments.
    Syntheses of IrOx-TiO2 Nano-powers from TiN via Impregnation-thermal Decomposition Method and Its Characterization
    SUN Ren-Xing1, XU Hai-Bo1*, WAN Nian-Fang2, WANG Jia1
    2007, 28(5):  904-908.  doi:
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    Nano IrOx-TiO2 catalyst with a n(Ir)∶n(Ti) ratio of 1∶6.5 was synthesized from the TiN nano-particle precursors via the impregnation-thermal decomposition method. XPS, XRD, TEM and anodic polarization curve techniques were used to characterize the composition, size, distribution and morphology of the catalyst. The results indicate that TiN were converted to TiO2 rutile-type phase at 350 ℃ and Ir presented as multi-value oxides. TiO2 and IrOx formed a binary solid solution in a rutile phase. A great number of Ir particles with an average crystal size of about 5—10 nm were rich on the surface of the solid solution. After annealing at 500 ℃ for 1 h, a partly sintering of the oxides could be observed and part of Ir was separated from the solid solution. The polarization curves measured in 0.5 mol/L H2SO4 also proved the high-temperature treatment would reduce the activity but beneficial to stability. The catalyst samples annealed at 500 ℃ were achieved. The electrolytic voltage was 1.6 V at 1 A/cm2 and 80 ℃, with Ir loading of only 1.2 mg/cm2. These results suggest that this new method is an efficient way to synthesize noble metal oxides catalyst with a high activity and low cost for water electrolysis.
    Studies on the Effect of Different Coherer Counter-ions on Forming Rule and Stability of Cyhalothrin Microemulsion
    LIU Yu, LU Fu-Sui*, CHEN Tian-Tian, GAO Cui-Li, ZHU Heng-Ying, ZHAO Hui
    2007, 28(5):  909-912.  doi:
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    The differences of electric mechanism, phase behavior and high temperature stability of cyhalothrin drug-loading microemulsion were investigated when the dodecyl benzenesulfonic salts(DBS-) combined with five coherer counter-ions and polyoxyethylene styrenyl ether were mixed at the same molar ratio. The results show that K+ and Na+ were propitious to the formation of O/W microemulsion because DBSK and DBSNa had the strong water-solubility, and the hydrated radius of K+ and Na+ were small,which induced big bingding degrees of the counter-ions with the hydronium garret group. The O/W microemulsion could also form when the counter-ion was Li+, but it was worse than K+ and Na+. Ca2+ and Mg2+ dodecyl benzenesulfonic salts are lipophilic surfactants, and thus were not propitious to the formation of O/W microemulsion.
    Studies on NMR Behavior of Ofloxacin in Different pH Environment
    QI Jian1, GAO Xiu-Xiang1, ZHAO Mei-Xian2, XIANG Jun-Feng3, LIN Chong-Xi1*, XU Yi-Zhuang1*, WU Jin-Guang1
    2007, 28(5):  913-917.  doi:
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    Systematic NMR spectroscopic investigation on ofloxacin in both acidic and alkaline solutions was carried out via 1H, 13C NMR, DEPT, COSY, HSQC spectra together with HMBC techniques. Complete assignment on 1H and 13C NMR of ofloxacin was obtained in different pH environments where the coupling constant between 13C and 19F was found to be very helpful for the assignment of aromatic 13C NMR signals. Additionally, the chemical shifts of 1H from the complex spin systems such as AA'BB' were obtained using HSQC technique. Comparisons were made among the NMR spectra in acidic solution and those in alkaline solution, which demonstrate that: (1) deprivation of H+ from COOH in alkaline solution destroys the hydrogen bond between COOH and carbonyl group in ofloxacin. This brings about the redistribution of π elelctrons around the carboxyl and carbonyl groups so that significant variations of 13C NMR chemical shift and coupling constant JFC are observed. (2) In the alkaline solution, the removal of proton from N4 in piperazine ring induces considerable variation of chemical shift of methylene groups and causes remarkable changes of dynamic behavior of the piperazine ring.
    Catalytic Activity Improvement of Platinum Toward Oxygen Reduction Reaction Promoted by Hydrogen Molybdenum Bronze
    HUANG You-Ju, LI Wei-Shan*, HUANG Qing-Dan, LI Wei, ZHANG Qing-Long, JIANG La-Sheng
    2007, 28(5):  918-921.  doi:
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    Platinum catalyst(Pt) and its composite catalyst with hydrogen molybdenum bronze(Pt-HxMoO3) were prepared on a glass carbon electrode with cyclic voltammetry, in 0.5 mol/L H2SO4 solution containing 5 mmol/L H2PtCl6 and 5 mmol/L H2PtCl6+5 mmol/L Na2MoO4, respectively. Their catalytic activity toward the oxygen reduction reaction(ORR) in 0.5 mol/L H2SO4 solution saturated with oxygen was studied with rotating disk electrode. The result shows that the catalytic activity of platinum toward ORR can be improved by HxMoO3. The catalytic mechanism was understood, based on the analysis on the relationship between the peak current of ORR and scan rate on the quiescent electrodes and the relationship between the current of ORR and rotating speed on the rotating electrodes. The transfer coefficient of charge transfer step for ORR on Pt is improved by HxMoO3, thus the kinetics of ORR is enhanced significantly. The transfer coefficient on Pt-HxMoO3 for ORR is 1.2 times that on Pt, and the kinetic current on Pt-HxMoO3 at 0.3 V(vs. SCE) is 5 times that on Pt.
    Effect of Hydrothermal Treatment of MCM-22 Catalyst on the Acidity, Pore Structure and Alkylation Properties of Toluene with Methanol
    DING Chun-Hua, WANG Xiang-Sheng*, GUO Xin-Wen
    2007, 28(5):  922-927.  doi:
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    The change of acidity and pore structure of MCM-22 zeolite catalysts treated by pure steam and ammonia steam(mass fraction, 6%) were studied by means of XRD, NH3-TPD, IR and N2 adsorption. And the catalytic performance of catalysts was investigated via alkylation of toluene with methanol as the probe reaction. The results show that the total acid amount changed indistinctively and strong acid sites increased relatively if the treated temperature was not higher than 400 ℃ even in two different treated media. However, the total acid amount decreased obviously and strong acid sites nearly disappeared as the treated temperature was beyond 500 ℃, and the second pore with different pore sizes formed and average pore diameter enlarged of MCM-22 zeolite catalysts after hydrothermal treatment. The catalytic activity declined as the selectivity of para-xylene and ortho-xylene improved with increasing treated temperature. The acid strength and acid distribution of MCM-22 catalyst treated by pure steam for 5 h were appropriate for alkylation of toluene with methanol, and the catalyst maintained relatively high catalytic activity and processed some para-xylene selectivity(the toluene conversion and para-xylene were 29.22% and 42.16%, respectively).
    Degradation of Electrocatalysts Performance in Direct Methanol Fuel Cells
    CHEN Wei-Min1,2,3, SUN Gong-Quan1, ZHAO Xin-Sheng1, SUN Pi-Chang1, YANG Shao-Hua1, XIN Qin1*
    2007, 28(5):  928-931.  doi:
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    A discharge test was conducted to evaluate the degradation of the performance of electrocatalysts in direct methanol fuel cells(DMFCs). The results of transmission electron microscopy(TEM) and X-ray diffraction(XRD) analyses show that after the test, the mean particle size of the anode electrocatalyst did not change, while that of the cathode electrocatalyst increased remarkably. The main reason for the sintering of electrocatalysts is the existence of liquids. Amorphous Ru species in the anode catalyst inhibit the growing of Pt crystallites. The electrochemical surface area(ECSA) decreased after the discharge test, with a degree higher than the specific surface area(SSA), both for the anode and the cathode. Part of ruthenium was lost from the anode electrocatalyst during the discharge test.
    Mixed Monolayers of Quaternary Ammonium Gemini Surfactants with Octadecyl Alcohol
    ZHOU Dong-Liang1, YANG Hong-Wei1, ZHU Pu-Xin1*, SUN Yu-Hai2, FENG Yu-Jun2, WU Da-Cheng1
    2007, 28(5):  932-935.  doi:
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    π-A isotherms were studied for mixed monolayers formed from each of two cationic gemini surfactants(dissymmetrical gemini surfactant 12-2-16 and symmetrical gemini surfactant 12-2-12) with octadecyl alcohol(C18H37OH) on air-water interface. The mixed surface excess free energy, ΔGMexo, was analyzed for each mixed monolayer with various mixed molar ratios at different surface pressures under the point of phase separation, to analyze the compatibility of each of the gimini surfactants and the fatty alcohol in the monolayer. The results show that ΔGMexo changes with the nature of the mixed molecules, mixed molar ratio, and surface pressure. Mixed monolayers of 12-2-16 and C18H37OH were considered as incompatible because ΔGMexo>0 in all mixed molar ratios. While for a system where 12-2-12 is mixed with C18H37OH, the compatibility of the mixed monolayer lies mostly on the mixed molar ratio. The values of ΔGMexo augment with increasing the C18H37OH molar ratio, changing from a net attractive interaction to a net repulsive interaction between 12-2-12 and C18H37OH with a critical point of C18H37OH molar ratio 0.65 added in the mixed system. When the mixing system is thermodynamically favored, increasing surface pressure will promote the mixing; In contrast, increasing surface pressure for a repulsive mixed system will be more thermodynamically unfavorable.
    Effect of Structure of Carbon Nanotubes on Electrocatalytic Performance of Carbon Nanotubes Supported Pt Catalysts
    TANG Ya-Wen1, CAO Shuang1, CHEN Yu1, BAO Jian-Chun1, LU Tian-Hong1,2*
    2007, 28(5):  936-939.  doi:
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    The effect of the tube diameter of the carbon nanotubes(CNTs) as the supporter of Pt catalyst on the electrocatalytic activity of the CNTs supported Pt(Pt/CNTs) catalysts was studied based on the preparation of CNTs with the single, double and multi walls. The Pt/CNTs catalysts were prepared using liquid phase reduction method. The XRD results demonstrate that the average sizes of the Pt particles in the Pt/CNTs catalysts with different tube diameters are almost the same(3.6 nm). However, the electrochemical results indicate that the electrocatalytic activity of the Pt/CNTs catalysts for the methanol oxidation increases with the decrease of the tube diameters of CNTs. The reason can be attributed to that CNTs with the small tube diameter possess large specific surface area and more oxygen-containing groups, which are favorable for the dispersion of the Pt particles in the Pt/CNTs catalysts. In addition, it has been reported in the literature that the resistance of CNTs with the single wall is smaller than that of CNTs with multi walls. Therefore, the above three factors lead to that the electrocatalytic activity of the Pt/CNTs catalysts with the small tube diameter of CNTs for the methanol oxidation is higher than that with the large tube diameter of CNTs.
    Performance of Methanol Oxidation on Pt-M(M=Ni, Fe, Mo) Electro-Catalysts in Alkaline Media
    LIU Shi-Bin, LIU Yong, SUN Yan-Ping*, ZHANG Zhong-Lin, HAO Xiao-Gang, LI Yi-Bing
    2007, 28(5):  940-943.  doi:
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    Carbon supported Pt-M(M=Ni, Fe, Mo) catalysts were prepared with colloidal method. The catalysts were characterized by TEM and XRD, and the activities of different catalysts were measured via the cyclic voltammetry under an alkaline condition for methanol electro-catalytic oxidation. The results show that Pt-based alloys are distributed homogeneously on carbon, the particle sizes are about 2—4 nm, and the activities order of Pt-based alloys is Pt75Ni25/C>Pt75Fe25/C>Pt50Mo50/C. The doping of Ni in the nano-particles of Pt was able to markedly enhance the catalytic activities of Pt/C, and the peak current of Pt75Ni25/C catalyst reached 726.9 mA/mg in 1.0 mol/L NaOH+1.0 mol/L CH3OH solution in this experiment.
    Stochastic Bi-resonance in Non-isothermal CO Surface Catalytic Oxidation System
    GONG Yu-Bing*, XU Bo, XU Qiang, LIU Sheng-Dian
    2007, 28(5):  944-947.  doi:
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    The system of Pt(110)/CO+O2 involving chemical reaction heat, heat conduction and radiation heat transfer is non-isothermal. Its temperature periodically varies in time and space, and thus affects the oscillatory behavior of the system. Our goal is to investigate the effect of the support temperature(ST) noise on the oscillatory dynamics of the system. Taking support temperature(ST) as the control parameter, we studied, via numerical simulation, the effect of ST noise on the dynamic behavior of the non-isothermal surface reaction system. The noise-induced reaction oscillations and stochastic bi-resonance(SBR) are observed, which show that the system can bi-selectively employ the temperature noise to enhance its reaction oscillations. It is also found that the increase of ST can lead to the change of the type of stochastic resonance(SR), namely, the change from the SBR to single SR.
    Surface-enhanced Raman Spectroscopic Studies on the Inhibition Mechanisms for Imidazole on Zinc Surfaces
    GU Ren-Ao*, BAO Fang, SHEN Xiao-Ying, CUI Yan, YAO Jian-Lin
    2007, 28(5):  948-951.  doi:
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    Surface-enhanced Raman spectroscopy(SERS) was employed to study the surface layers formation and inhibition behavior of imidazole at zinc electrode. The inhibition mechanism of imidazole on zinc surfaces was investigated with the variations in potential and pH. The results reveal that imidazole absorbed on the zinc surface by its N atom with perpendicular orientation in a wide potential region in the solutions with pH=8.53. In alkaline solution with pH=11.40, imidazole was absorbed on the zinc surface by its N atom in a perpendicular position at a relative positive potential. With the negative movement of potential, the orientation was changed in which the ring was slightly tilted on the surface. Imidazole exhibited a higher effective inhibition on zinc in neutral solution than that in alkaline solution due to the strong interaction with zinc for the former.
    Theoretical Study on the Electron Transport of Oligophenylene Derivatives Molecular Devices
    OUYANG Sheng-De, YI Yuan-Ping, GENG Hua, SHUAI Zhi-Gang*
    2007, 28(5):  952-954.  doi:
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    By applying the hybrid density functional theory coupled with Green's function method, we investigated the conjugation length dependence of the electron conductance by calculating the current-voltage characteristics of the molecular junctions composed of benzene derivatives. At low bias, we found a perfect exponential decay form with an exponent 0.47 for the system.
    Theoretical Studies on the Ground State and Excited State of Poly(3,9-carbazole)
    BO Dong-Sheng1, REN Ai-Min1*, FENG Ji-Kang1,2*, YANG Li1
    2007, 28(5):  955-959.  doi:
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    The geometries of the oligomers of(3,9-carbazole)n(n=1,2,3,4,6,8) were fully optimized with the density functional theory/B3LYP . On the basis of the optimized geometries, we calculated the ionization potentials(IP), electron affinities(EA) and other related energies . And we also obtained the absorption spectra using time-dependent density functional theory(TD-DFT) and ZINDO. The properties of poly(3,9-carbazole) were extrapolated by the relationships between the properties of oligomers and the polymerizing chain length n. The results above are studied comparing to those of poly(2,7-carbazole) and similar polymers. The analysis results indicate that the conjugations of poly(3,9-carbazole) are destroyed partly and absorption spectra blue-shift. In addition, the IP value of poly(3,9-carbazole) was similar to that of polyfluorene and thus the poly(3,9-carbazole) can be used as hole transport materials in multilayer electroluminescent devices. Finally we calculated the excited geometries of carbazole and its dimmer by CIS/6-31G and the emission spectra by TD-DFT and ZINDO.
    Intermolecular Interaction Potential Surface of the He2F- Complex
    SUN Xiao-Ying, WANG Qin, LI Zhi-Ru*, WU Di, SUN Chia-Chung, TANG Au-Chin
    2007, 28(5):  960-963.  doi:
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    High level ab initio intermolecular interaction potential surfaces of a fluoride anion with two He atoms were obtained via CCSD(T) calculations. The computations include full counterpoise and employ large basis sets aug-cc-pVXZ(X=D, T) and d-aug-cc-pVTZ. An isosceles triangular stable structure corresponding to the global potential minimum was found on the He2F- interaction potential surface, where the He…F- bond length is 0.334 nm, the He…He bond length is 0.295 nm and the bond angle HeF-He is equal to 52.5°. The frequencies, the interaction energy, the pair and the three-body interaction energies were calculated at the global minimum. The interaction energy ΔE is -1.727 kJ/mol at CCSD(T)/ d-aug-cc-pVTZ level.
    Quantitative Structure-activity Relationships Studies on Oxytocin Analogues
    MEI Hu1,2, YANG Li1,2, SHU Mao1,2, LIU Li2, LI Zhi-Liang1,3*
    2007, 28(5):  964-967.  doi:
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    VHSE; 后叶催产素; 肽; 定量构效关系; 偏最小二乘
    Characteristics of Structure and Texture of Modified Alumina Prepared by Peptizing Method
    ZHANG Li-Juan, DONG Wen-Ping, CHEN Yao-Qiang, SHI Zhong-Hua, LIU Zhi-Min, ZHAO Ming, GONG Mao-Chu*
    2007, 28(5):  968-970.  doi:
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    Alumina prepared by peptizing method with a high specific surface area, moderate pore structure and pore size distribution was studied. Furthermore, the effects of additives La and PEG on thermal stability, particle size, structure and texture of alumina were investigated. The results of characterization of BET and XRD show that the addition of La greatly inhibits the loss of specific surface area and α phase transformation of alumina under the hydrothermal and high temperature conditions. At the same time, PEG as an additive can apparently increase pore volume and pore diameter of alumina. The more the La and PEG content is, the larger the surface area, pore volume and average diameter of alumina are. However, when the quantity ratio of La2O3 to Al2O3 or PEG to Al2O3 is excessive, the negative action of La and PEG are stronger. When the quantity ratio of La2O3/Al2O3 is 2.5%—3.0%, thermal stability of γ-Al2O3 is the best and specific surface area of alumina is more than 140 m2/g after hydro thermally being aged at 1000 ℃ for 5 h. Though PEG plays a good role on making pore and aggregation when the value of quantity ratio of PEG/Al2O3 is 80%, the thermal stability of alumina is worse and specific surface area is only 136.4 m2/g, pore volume is 0.41 mL/g and pore diameter is 9.38 nm under the same aging condition. Fortunately, after hydro thermally being aged at 1000 ℃ for 5 h, the alumina containing 2.5%La2O3 and 80%PEG of quantity of alumina has the best thermal stabilization and the largest specific surface area, pore volume and pore diameter that are 156.2 m2/g, 0.57 mL/g and 11 nm, respectively.
    研究简报
    Characteristics of Structure and Texture of Modified Alumina Prepared by Peptizing Method
    ZHANG Li-Juan, DONG Wen-Ping, CHEN Yao-Qiang, SHI Zhong-Hua, LIU Zhi-Min, ZHAO Ming, GONG Mao-Chu*
    2007, 28(5):  968-970.  doi:
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    Alumina prepared by peptizing method with a high specific surface area, moderate pore structure and pore size distribution was studied. Furthermore, the effects of additives La and PEG on thermal stability, particle size, structure and texture of alumina were investigated. The results of characterization of BET and XRD show that the addition of La greatly inhibits the loss of specific surface area and α phase transformation of alumina under the hydrothermal and high temperature conditions. At the same time, PEG as an additive can apparently increase pore volume and pore diameter of alumina. The more the La and PEG content is, the larger the surface area, pore volume and average diameter of alumina are. However, when the quantity ratio of La2O3 to Al2O3 or PEG to Al2O3 is excessive, the negative action of La and PEG are stronger. When the quantity ratio of La2O3/Al2O3 is 2.5%—3.0%, thermal stability of γ-Al2O3 is the best and specific surface area of alumina is more than 140 m2/g after hydro thermally being aged at 1000 ℃ for 5 h. Though PEG plays a good role on making pore and aggregation when the value of quantity ratio of PEG/Al2O3 is 80%, the thermal stability of alumina is worse and specific surface area is only 136.4 m2/g, pore volume is 0.41 mL/g and pore diameter is 9.38 nm under the same aging condition. Fortunately, after hydro thermally being aged at 1000 ℃ for 5 h, the alumina containing 2.5%La2O3 and 80%PEG of quantity of alumina has the best thermal stabilization and the largest specific surface area, pore volume and pore diameter that are 156.2 m2/g, 0.57 mL/g and 11 nm, respectively.
    Molecular Docking of Xylitol and Xylose Isomerase from Thermus thermophilus and Model Analysis
    XU Wei1,2, CAI Ping1, YAN Ming1*, XU Lin1, OUYANG Ping-Kai1
    2007, 28(5):  971-973.  doi:
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    Xylose isomerase from Thermus thermophilus is widely used in the production of high-fructose corn syrup and the construction of xylose via recombinant strains. In this paper, the positions of Mg ions and xylitol in 1BXB were established by structure analysis, molecular docking and computing. The Complex of 1BXB with xylitol was modeled and analyzed. Comparing the structure of 1BXB complex with 1S5N, it was found that the overall structure of them showed a high similarity. The residues around xylitol were highly conserved in xylose isomerase, and the orientation and positions of xylitol were very similar in both structures. The coordination bonds formed between Mg1 and O2 or O4 of xylitol stabilized the conformation of xylitol at the active site of 1BXB.
    研究论文
    Preparation of “Micelles Enhanced” Polyelectrolyte Capsules
    YANG Xiao-Feng1, LI Xiao-Dong1,2*, SHEN Jia-Cong2
    2007, 28(5):  974-977.  doi:
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    LbL技术; 聚电解质微胶囊; 模板; 自组装; 胶束增强
    Spherical Micro-lens Array of Polystyrene Made by Micro-molding Method
    SHI Jin-Xia, HE Ping-Sheng*
    2007, 28(5):  978-981.  doi:
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    Polystyrene (PS) micro-cubic poles array was fabricated with the micro-molding of the soft lithography. Based on that the principle of liquid or melting matter will be the most stable state by means of reducing its surface energy to minimum, the PS micro-cubic poles array shrunk into the micro-hemispheroid array through the heating to the temperature over PS softening point. The optical imaging testing indicates that the PS micro-hemispheroid array had a good optical behavior of being able to image the “H” or “Y” type objects and could be used as micro-lens array. The microfabrication technology to fabricate polymer micro-lens array is easy and low-cost with a high precision and can be suitable for other transparent plastics. In addition, due to flexibility of PDMS stamp the micro-lens array would be possible to fabricate on a curved surface.
    Controlled Release for Drug by Complex Micelles of Block Copolymers with Tunable Channels
    LÜ Juan, AN Ying-Li, HUANG Nan, CHEN Xi, LI Jun-Bo, SHI Lin-Qi*
    2007, 28(5):  982-986.  doi:
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    Complex micelles with insoluble PtBA block as core and PEG as well as P4VP as mixed shell were prepared with self-assembling of poly(tert-butyl acrylate)-b-poly(ethylene glycol)(PtBA45-b-PEG114) and poly(tert-butyl acrylate)-b-poly(4-vinylpyridine)(PtBA60-b-P4VP80) in water at pH=2.5. The result of dynamic light scattering(DLS) indicates that the complex micelles show a larger size than that of the individual micelles comprised of PtBA45-b-PEG114 or PtBA60-b-P4VP80 respectively. Increasing the pH value from 2.5 to 12, the P4VP chains will collapse upon the PtBA core because of their deprotonation, and hydrophilic PEG chains will pass through collapsed P4VP layer from the core and stabilize the whole micelle. Thus, channels inside the P4VP layer will form around insoluble PEG chains. Ibuprofen is loaded in these complex micelles at pH=2.5, and then releasing with increasing pH value to 12. The results indicate that channels on the surface of PtBA core can control the release of ibuprofen, and the release velocity is directly proportional to the percentage of channels on the micelles.
    Studies on Degradable Poly(ether-anhydride) Photocrosslinked Gels to Increase the Solubility of Poorly Water-soluble Drugs
    WANG Zheng*, YANG Ji, GAO Zhao
    2007, 28(5):  987-991.  doi:
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    PEG-based macromers containing anhydride bonds were synthesized and photopolymerized to form degradable gels and characterized via FTIR and 1H NMR. Indomethacin as a model of poorly water-soluble drug was embedded in the degradable poly(ether-anhydride) photocrosslinked network, which had good swelling properties. The drug was proved to be distributed in an amorphous or molecular state in the crosslinked network and the physical morphology of the drug remained stable after two months storage demostrated by employing X-ray diffraction. Dissolution tests showed that the drug in the network displayed a better dissolution rate and more cumulative drug release than the crystal raw indomethacin. This method could increase the dissolution rate and inhibit recrystallization of indomethacin in the degradable photocrosslinked gels.
    Molecular Dynamics Simulation of Confined Polymer Melts
    LI Yi-Jie1, 2, WEI Dong-Shan1, 2, JIN Xi-Gao1, Han Charles C.1, LIAO Qi1*
    2007, 28(5):  992-995.  doi:
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    We present the results of molecular dynamics simulations of polymer melts confined between two rough walls. Simulations were performed for the coarse-grained bead-spring chains of Lennard-Jones particles. The results show that, the longest relaxation time decreases with increasing the film thickness for the confined polymer melt systems with relative short chains; while for the confined systems with longer chains, the relaxation time decreases first and then increases to the bulk value when increasing the film thickness. We speculate on the origin of this unique phenomenon and conclude that longer chains in the confined systems change from the entangled state in three-dimensional space to the segregated state in nearly two-dimensional space with the decrease of film thickness. The overlap parameter is used to interpret this transitional process. We find that, for the longer polymer chains, entanglement effect determines the relaxation time in thicker films, while confinement effect dominates the relaxation in thinner films.
    研究简报
    Preparation of Super-hydrophobic PDMS Films and Study on Surface Adhesion
    JIN Mei-Hua1*, LIAO Ming-Yi1, JIANG Lei2*
    2007, 28(5):  996-998.  doi:
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    Cabbage-like polydimethysiliconalkly(PDMS) films were prepared via a laser cutting method. The as-prepared special “micro-submicro-nano structures” PDMS films have a very low adhesive force to water. The force is merely about 6.5 μN, and appears at the time just before the water droplet leaves the surface. The super-low adhesive force of rough PDMS surface results from the distinct decrease of the real contact area between the surface and water drop. The sliding feature is strongly affected by microstructure of surface. That rough structure induced on the surface of PDMS is due to the thermo-reaction of laser with transparent elastomer. This information is useful for the designing of bio-mimetic hydrophobic surface structure for various applications. These surfaces may provide very effective water-repellent and anti-adhesive properties against particular contamination. Such properties can greatly extend its applications to many other areas such as lost less liquid transportation without loss, and micro-pump(creating pushing-force) needless micro-fluidic devices etc..
    Structure and Properties of Triphenylphosphine-contained Poly(ether ether ketone ketone)
    CHEN Xiao-Ting, SUN Hao, TANG Xu-Dong*, WANG Chun-Ying
    2007, 28(5):  999-1001.  doi:
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    A novel triphenylphosphine-contained poly(ether ether ketone ketone) was synthesized from bis[4-(p-fluorobenzoyl)-phenyl]phenylphosphine oxide and hydroquinone by nucleophilic copolycondensation with sulfolane as the solvent. The structure was confirmed via FTIR, 31P NMR and 1H NMR. Electrical property, mechanical property, heat-resistance property, flame resistance and solubility were also evaluated. The results show that the polymer has an excellent heat-resistance, the glass transition temperature(Tg) is 212.6 ℃. The 5% mass loss of the polymer in nitrogen atmosphere took place at 476 ℃. The polymer is soluble in many organic solvents, such as CH2Cl2, CHCl3, Cl2(CH)2Cl2, Cl(CH2)2Cl, DMF, and NMP at room temperature, the polymer possesses well film ability, good mechanics property, electrical property, and the LOI is 44 which indicates that it possesses an excellent flame retardancy.
    Synthesis of Dendrimers Skeleton-Constructed with Azobenzene Moiety
    ZHANG Wen-Quan, SHI Wen-Fang*
    2007, 28(5):  1002-1004.  doi:
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    A series of novel dendrons and dendrimers skeleton-constructed with azobenzene moiety were synthesized with 4-carboxy-4'-(1,2-propanediolether)-azobenzene as an AB2 monomer and 4-carboxy-4'-(n-butylether)-azobenzene as a peripheral monomer via a convergent approach and proceeding in a repeated stepwise growth manner. The NMR, GPC, and MALDI-TOF-MS measurements show that the obtained products possess regular molecular architecture and thus monodispersed molecular weights. It will be of interest to investigate the self assemble behavior of the polymers and the promising applications for the dendrimers as the dendritic boxes in the subsequent works.
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