Table of Content

10 August 2012, Volume 33 Issue 08

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Content

Cover and Content of Chemical Journal of Chinese Universities Vol.33 No.8(2012)

2012, 33(08):  0-0. 

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Preface

Supramolecular Nanovalve Systems Based on Macrocyclic Synthetic Receptors

SUN Yu-Long, YANG Ying-Wei, WU Wei, ZHANG Sean Xiao-An

2012, 33(08):  1635-1642.  doi:10.3969/j.issn.0251-0790.2012.08.001

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Supramolecular nanovalves, installed on the surface of mesoporous nanomaterials, could effectively control the targeted release of encapsulated cargo molecules, such as model drug molecules, anti-cancer drugs, oligonucleic acids and so on, under external stimuli, showing great potential in the fields of drug release, gene transfection, sensing etc. Herein, recent research progress on the chemical construction and function study of supramolecular nanovalves based on macrocyclic synthetic receptors was extensively reviewed, together with our own research accomplishment in the field.



Letter

Synthesis of Novel Mesoporous Silica Twist Nanofibers Through Co-condensation Method

CHEN Xi, CAI Qiang, SUN Lin-Hao, SHI Wei-Lin, QI Juan-Juan, WANG Song

2012, 33(08):  1643-1645.  doi:10.3969/j.issn.0251-0790.2012.08.002

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Novel mesoporous silica nanofibers(MSNF) were synthesized through co-condensation method, in which two organoalkoxysilanes, tetraethoxylsilane (TEOS) and 3-mercaptopropyl trimethoxysilane(MPTMS) as silica precursors simultaneously. The microstructure and porous character of the MSNF were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM), small-angle X-ray diffraction(XRD) and nitrogen sorption measurements. The results show that the single-axis-twist fibers with diameters of ca. 60-80 nm are obtained. The mesostructure of MSNF corresponds with that of MCM-41 and periodic mesopores fringes are 120 nm. The BET surface area and BJH pore size of the samples are 784 m²/g and 2.36 nm, respectively.



Preface

Synthesis and Characterization of a Novel Mixed-valence Vanadogermanate Cluster [Ge₆V₆^VV₉^ⅣO₄₂(OH)₆(H₂O)]

WANG Lei, WANG Yan-Yan, LI Yi, LIANG Zhi-Qiang

2012, 33(08):  1646-1650.  doi:10.3969/j.issn.0251-0790.2012.08.003

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A novel mixed-valence vanadogermanate cluster [Ge₆V₆^VV₉^ⅣO₄₂(OH)₆(H₂O)]·6(1,6-DAH)·21H₂O(1)(1,6-DAH: 1,6-diamimohexane) was hydrothermally synthesized and characterized by elemental analysis, IR, XPS and so on. Single crystal X-ray diffraction shows that compound 1 exhibits a heart-like shape derived from the spherical {V₁₈O₄₂} archetype. The magnetic study shows that there exists weak anterferromagnetic interaction within the cluster.



Synthesis and Surface Photovoltage Property of Tailed Histidine-linked Lanthanon Metalloporphyrins

SHAN Ning, WANG Bin-Bin, LIAN Wen-Hui, YU Miao, SHI Tong-Shun

2012, 33(08):  1651-1656.  doi:10.3969/j.issn.0251-0790.2012.08.004

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A histidine-linked porphyrin (1) and its lanthan on complexes[Ln=Sm(2), Eu(3), Er(4), Dy(5), Yb(6)] were prepared, purified and characterized by UV-Vis spectra. The correlation between the structures of the complexes and their UV spectra, IR spectra, elemental analysis and mass spectra were discussed and their specific spectra were explained. The fluorescence intensity and the quantum yield of porphyrin 1 were low because of the electron withdrawing group on peripheral porphyrin ring. The fluorescence intensity and the quantum yield of lanthanon metalloporphyrins 2-6 were much more different because of the property of lanthanon ions and intensity of the radiationless transition. Surface photovoltage spectra of porphyrins 1 and complexes 2-6 were influenced by the property of external electric field and intensity of external voltage.



Electrospinning Preparation and Properties of Eu(BA)₃phen/PANI/PVP Luminescence-electricity Bifunctional Composite Nanofibers

WANG Ying-He, WANG Jin-Xian, DONG Xiang-Ting, YU Wen-Sheng, LIU Gui-Xia

2012, 33(08):  1657-1662.  doi:10.3969/j.issn.0251-0790.2012.08.005

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Luminescence-electricity bifunctional Eu(BA)₃phen/PANI/PVP composite nanofibers were prepared through the doping of polyaniline(PANI) and rare earth complex in polyrinyl phrrolidone(PVP) via electrospinning. Scanning electron microscope(SEM), energy dispersive spectrometer(EDS), fluorescence spectrometer and broadband dielectric spectrometer were used to characterize the samples. The results indicated that the average diameter of the Eu(BA)₃phen/PANI/PVP composite nanofibers was (270±31) nm. Under excitation of 275 nm, the Eu(BA)₃phen/PANI/PVP composite nanofibers emitted the predominant emission at 580, 594 and 617 nm, corresponding to ⁵D₀→⁷F₀, ⁵D₀→⁷F₁ and ⁵D₀→⁷F₂ transitions of Eu³⁺, respectively. The strongest emission intensity occurred when the mass ratios of Eu(BA)₃phen: PANI: PVP was 15: 10: 100, the electric conductivity of the composite nanofibers increased with the increase of PANI content, and reached 1.5×10^-6 S/cm in high frequency electric field(10⁶ Hz) when the mass ratio of PANI to PVP was 50%.



Preparation and the Third-order Optical Nonlinearities of the Sodium Borosilicate Glass Doped with Cu_7.2S₄ Quantum Dots

ZHAO Hai-Jun, XIANG Wei-Dong, ZHONG Jia-Song, YANG Xin-Yu, GUO Yu-Qing, LIANG Xiao-Juan, HUANG Hai-Yu, LUO Hong-Yan, ZHAO Xiu-Li, CHEN Zhao-Ping

2012, 33(08):  1663-1669.  doi:10.3969/j.issn.0251-0790.2012.08.006

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Cu_7.2S₄ quantum dots glass was synthesized by both sol-gel and atmosphere control methods. The mechanism thermal decomposition of the stiff gel was studied by means of thermogravimetry-differential thermal analysis. The microstructures of Cu_7.2S₄ quantum dots in the glass were characterized by X-ray powder diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, energy dispersion X-ray spectra, high-resolution transmission electron microscopy, and selected-area electron diffraction. Meanwhile, the third-order nonlinear optical properties of the glass were measured in detail by the femtosecond Z-scan technique at a wavelength of 800 nm. The results show that Cu_7.2S₄ quantum dots have been formed in the glass, and the sizes of these Cu_7.2S₄ quantum dots having the tetragonal crystalline structure ranged from 9 nm to 21 nm, moreover, the glass exhibits the excellent third-order nonlinear optical properties, and the third-order nonlinear optical refractive index(γ), absorption coefficient(β) and susceptibility [X⁽³⁾] of the glass are determined to be 1.11×10^-15 m²/W, 8.91×10^-9 m/W, and 9.56×10^-18 m²/V², respectively. Because of so excellent third-order nonlinear optical properties of the glass doped with Cu_7.2S₄ quantum dots imply that the kind of material will be widely applied in nonlinear optical devices.



Preparation and Gas Separation of Organic-inorganic Hybrid Silica Membranes Modified by Perfluorodecyl Group

SONG Lin, WEI Qi, HAO Run-Qiu, NIE Zuo-Ren, LI Qun-Yan

2012, 33(08):  1670-1675.  doi:10.3969/j.issn.0251-0790.2012.08.007

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Hydrophobic organic-inorganic hybrid silica sols were prepared using 1,2-bis(triethoxysilyl)ethane(BTESE) and 1H,1H,2H,2H-perfluorodecyltriethoxysilane(PFDTES) as precursors under acidic condition, then the sols were deposited on γ-Al₂O₃/α-Al₂O₃ substrates by dip-coating under clean room condition. The cross-sectional morphology, particle size of the sols and hydrophobic property of the membranes were characterized by means of SEM, DLS, FTIR, water contact angle measurement and thermogravimetric analysis. The results show that the particle size of sols and the water contact angle of supported membranes increase with increasing the amount of PFDTES in the mixture. A narrow sol particle size distribution centered at 3.69 nm and a water contact angle of (112.0±0.4)º were obtained at a BTESE/PFDTES molar ratio of 0.25: 1. At 300℃, the membrane shows a high H₂ permeance of 5.99×10^-7 mol·m^-2·Pa^-1·s^-1 and a H₂/CO and H₂/CO₂ permselectivity of 9.54 and 5.20, respectively, which were higher than the corresponding Knudsen value(H₂/CO=3.74, H₂/CO₂=4.69). The H₂ transport in the modified silica membranes is subjected to a micropore diffusion mechanism.



Analytical Chemistry

Single-walled Carbon Nanotube/DNAzyme Complex-based Elctrochemical Biosensors

FENG Ke-Jun, YAO Yan-Ling, SHEN Guo-Li, YU Ru-Qin

2012, 33(08):  1676-1680.  doi:10.3969/j.issn.0251-0790.2012.08.008

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Taking advantage of the excellent catalytic redox activity andthe electrochemical property of DNAzyme and carbon nanotubes, a novel nano-complex of single-walled carbon nanotubes(SWNTs)/DNAzyme was prepared, and the obtained nano-complex was finally immobilized on the surface of glass carbon electrode(GCE) with the assistance of chitosan to fabricate electrochemical biosensing interface. The catalytic property of the SWNTs/DNAzyme complex was explored, and a glucose oxidase biosensor was then prepared based on the fabricated electrochemical biosensing platform. The SWNTs/DNAzyme complex-based biosensing platform can direct response to hydrogen peroxide at low potential of -0.24 V with high sensitivity(the detection limit is 1?10^-6 mol/L) and wide linear range(5?10^-6-1?10^-2 mol/L), and the prepared glucose oxidase biosensor was used to fast and sensitive detection of glucose.



Recognition of Flavonoids Towards to DNA G-quadruplexes and Duplexes by ESI-MS

LIU Zhen-Shuang, GAO Shang, ZHAO Wai-Ou, QIN Yu-Jiao, WANG Bing, GUO Xin-Hua

2012, 33(08):  1681-1685.  doi:10.3969/j.issn.0251-0790.2012.08.009

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Electrospray ionization mass spectrometry(ESI-MS) was used for the investigation of noncovalent interactions between flavonoids, including rutin, quercetin, naringin, puerarin, and two types of DNA quadruplexes as well as three kinds of DNA duplexes. Percentage bound of each compound towards to different DNA strands were calculated based on the ion abundances of each DNA strand and DNA-ligand complexes obtained in the mass spectra. The results show that rutin and quercetin selectively bound to the G-quadruplexes, meanwhile, they also show strong binding to the duplexes. In contrast, naringin and puerarin show less selectivity towards to the G-quadrulexes.



Application of Metabolic Profiling for Distinguishing Different Pathogenic Vibrio Parahaemolyticus

ZHAO Qiang, SUN Xiao-Hong, LU Ying, PAN Ying-Jie, ZHAO Yong

2012, 33(08):  1686-1691.  doi:10.3969/j.issn.0251-0790.2012.08.010

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Distinguish of different pathogenic vibrio parahaemolyticus are normally based on tdh, trh and tlhgenes. In this research, the metabolic profiles were obtained by liquid chromatography(LC) and gas chromatography/mass spectrometry(GC-MS), and they were used for distinguishing different pathogenic vibrio parahaemolyticus. The results were compared with E. coli gene sequence between the repeat PCR(ERIC-PCR) and DNA repeats-PCR(REP-PCR). The similarity was calculated by NTsys2.10e software. The results showed that different pathogenic Vibrio parahaemolyticus could be distinguished by LC and GC/MS. Potential biomarkers of different pathogenic strains were found by GC-MS. Strain of tdh⁺, trh^-, tlh⁺ have 3 kinds of potential biomarkers, strain of tdh^-, trh⁺, tlh⁺ have 2 kinds of potential biomarkers, strain of tdh^-, trh^-, tlh⁺ have 3 kinds of potential biomarkers.



Novel Fluorescent Technique for Detecting Adenosine Based on DNA Strand Displacement Induced by Target-aptamer Complex and Metal Deposition Catalyzed by Gold Nanoparticles

LIU Xue-Ping, OUYANG Xiang-Yuan, WU Hui-Wang, SHEN Guo-Li, YU Ru-Qin

2012, 33(08):  1692-1697.  doi:10.3969/j.issn.0251-0790.2012.08.011

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Using adenosine as model analyte, a novel homogeneous fluorescent method with high sensitivity and specificity was proposed. It involves two kinds of DNA probe conjugated nanoparticles-aptamer modified magnetic nanoparticles and capture DNA probe derivatized gold nanoparticles(GNPs), which were connected together via hybridization. The conformational transition of aptamer induced by adenosine-aptamer complex contributes to the displacement of probe conjugated GNP, which further catalyzes the reduction of Cu²⁺ by ascorbic acid, causing the deposition of Cu atom on the surface of GNP. The fluorescence quenching of calcein was restored as the consumption of Cu²⁺. The experimental results demonstrated that the dynamic range for adenosine detection was from 100 pmol/L to 10 nmol/L, with a detection limit of 80 pmol/L. The proposed method shows high selectivity for the specific recognition of adenosine by its aptamer.



Thin Film Electrode Based Cell Electrofusion Chip

ZHANG Xiao-Ling, YANG Jun, HU Ning, HOU Wen-Sheng, ZHENG Xiao-Lin, XIE Lin, YANG Zhong, CHEN Jie

2012, 33(08):  1698-1702.  doi:10.3969/j.issn.0251-0790.2012.08.012

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A microfluidic chip based on thin film microelectrode structure was developed for high efficiency cell electrofusion. The top/bottom thin film microelectrode array and the discrete thin film microelectrodes sputtered on the sidewalls of the polymer(Durimide 7510) microchannel constructed the discrete "sandwich" microelectrode structure. As the traditional protruding microelectrodes, this structure could generate nonuniform electric field for dielectrophoresis-based cell alignment/pairing between the microchannel. The cavity between two adjacent microeledctrodes was also filled using the Durimide 7510. It could overcome the shortcoming in the traditional protruding cell-electrofusion chip where many cells could not be aligned and fused in the unfilled cavity. Experimental investigation of cell alignment based on dielectrophoresis and cell electrofusion based on reversible electroporation were conducted using K562 cells and good results were achieved. Low voltage pulses (ca. 10 V) series could produce a strong enough electric field for reversible electroporation. Most cells (ca. 99%) were trapped on the surface of the thin film microelectrodes and almost no cells were docked between two adjacent electrodes on the same sidewall. More than 60% cells were aligned as cell-cell twins and about 40% cells were fused. Thus, compared with traditional cell electrofusion method and protruding microelectrode structures, higher alignment and fusion efficiency were achieved.



Investigation on Glioma Using FT-mid-IR Spectroscopy

PAN Qing-Hua, WAN Wei-Qing, JIA Gui-Jun, XU Yi-Zhuang, LAI Guo-Qiao, HUA Xiao-Hui, LIU Shao-Xuan, CHEN Jing, YANG Li-Min, ZHANG Yuan-Fu, WENG Shi-Fu, WU Jin-Guang

2012, 33(08):  1703-1707.  doi:10.3969/j.issn.0251-0790.2012.08.013

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Nineteen cases of glioma tissues(including 10 cases of astrocytic tumors and 9 cases of oligoastrocytic tumors) were detected using FT-mid-IR spectroscopy linked with attenuated total reflectance(ATR) accessory. In the astrocytic tumors cases, there were 4 cases of pure astrocytic tumors(WHOⅠ and Ⅱ), 2 cases of anaplastic astrocytic tumors(WHO Ⅲ) and 4 cases of glioblastoma(WHO Ⅳ). The FTIR spectra obtained from the brain tumor tissues were analyzed and compared. Significant differences were found in the peak position, band shape and intensity of infrared absorption spectra between the different grades of astrocytic tumors. The intensity of the band at ca. 1400 cm^-1 band is increased with the malignancy grade of astrocytic tumors. In addition, some spectral differences between astrocytic tumors and oligoastrocytic tumors were observed. In the spectra of oligoastrocytic tumors, the peak position of 1240 and 1300 cm^-1 shifted to low wavenumbers. And the band at ca. 1270 cm^-1 appeared in the spectra of oligoastrocytic tumors which was not observed in the astrocytic tumors. These results demonstrate that FT-mid-IR spectroscopy exhibits prospect to develop a novel, non-invasive and rapid method for the detection of brain tumors.



Electrochemical Sensor for Caffeine Detection Based on Molecularly Imprinted Polymer with Maleic Rosin Acrylic Acid Glycol Ester as Cross-linker

WANG Lin, TAN Xue-Cai, ZHAO Dan-Dan, LIU Li, LEI Fu-Hou, HUANG Zai-Yin, GONG Qi

2012, 33(08):  1708-1713.  doi:10.3969/j.issn.0251-0790.2012.08.014

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A novel polymer based on the molecular imprinting technique was prepared using ethylene glycol maleic rosinate acrylate acid glycol ester as the cross-linker, caffeine as template and methyl acrylic acid as functional monomer. A molecularly imprinted polymer membrane was synthesized in vacuum drying oven by free radical polymerization. The electrochemical behavior of the membrane was characterized by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS). Under the optimal conditions, the peak currents and the analytical concentration have a good linear relationship over the range of 3.00?10^-3 to 2.73 mmol/L(R=0.9966) with a detection limit of 1.12?10^-4 mmol/L(S/N=3). The electrochemical sensor displayed excellent repeatability, high sensitivity, long-term stability, and good selectivity. The developed sensor was successfully applied to the determination of caffeine in coca-cola samples with average recovery of 98.7%.



Organic Chemistry

Electroluminescent Property of a Beryllium Metal-chelate Complex Used as the Electron-transporting Host Material

SUN Yi-Fu, YE Ling, YE Kai-Qi

2012, 33(08):  1714-1717.  doi:10.3969/j.issn.0251-0790.2012.08.015

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A simple and highly efficient single-emitting-layer phosphorescent organic light-emitting diode(PHOLED) that used bis beryllium(Bempp) as the electron-transporting host material and bis(pyridylphenyl) iridium(Ⅲ)(N,N'-diisopropyl-benzamidine)(PPP) as the phosphorescent dye to enhance the electro-luminescence (EL) performance was presented. This PHOLED device exhibited substantially lower driving voltage (2.5 V) and higher EL efficiencies than those based on the CBP host. It showed dramatically enhanced peak values of more than 63.1 cd/A for luminous efficiency, 54.0 lm/W for power efficiency. The high EL performance was attributed to the well-matched energy levels of Bempp with the hole/electron-transporting (HT/ET) materials as well as the highly efficient and complete energy transfer between the host and the guest. The results demonstrate that Bempp is a promising host material to replace the commonly used CBP because of its higher EL efficiency and its relative high triplet energy(ca.2.6 eV).



Synthesis and Antibacterial Activities of Some Indolizine Carboxylic Acids

JIANG Yu-Liang, XU Zhu-Xiong, WANG Bing-Xiang

2012, 33(08):  1718-1721.  doi:10.3969/j.issn.0251-0790.2012.08.016

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A new procedure for the synthesis of indolizine carboxylic acids were developed. In the presence of tetrakispyridinecobalt(Ⅱ) dichromate (TPCD), indolizine carboxylic acid esters were readily synthesized by a one-pot reaction sequence which consists of a 1,3-dipolar cycloaddition of pyridinium N-ylides to alkenes, followed by an aromatization. Eigth indolizine carboxylic acids 3a-3c and 5a-5e were obtained in good yields by the direct hydrolysis of the crude indolizine carboxylic acid esters, and characterized by IR, ¹H NMR, MS and elemental analysis. The study on the antibacterial activity of these compounds against escherichia coli and staphylococcus aureus indicated that compounds 3a, 3c, 5a, 5c and 5d had a certain inhibitory effect on escherichia coli, while compounds 3a and 3c showed some inhibitory effect on staphylococcus aureus. Compound 3c showed good antimicrobial properties on these two strains.



Preparation of Hybrid Fucoidan-derived Oligosaccharides and Their Structural Analysis by Negative-ion Electrospray Tandem Mass Spectrometry

WANG Pei-Pei, LV You-Jing, CAO Huan, ZHAO Xiao-Liang, LI Guang-Sheng, WU Jian-Dong, YU Guang-Li

2012, 33(08):  1722-1726.  doi:10.3969/j.issn.0251-0790.2012.08.017

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Acomplex sulfated fucoidan (SPF) was obtained by hot water extraction from Sargassum pallidum. A series of hybrid oligosaccharides were acquired by mild acid hydrolysis with low pressure gel permeation chromatography(LPGPC). Based on the monosaccharides composition, methylation and electrospray collision-induced dissociation mass spectrometry(ES-CID-MS/MS) analysis, 21 kinds of oligosaccharides were sulfated hybrid fucoidan-derived oligosaccharides. The resulted oligosaccharides were mainly composed of α1→3 linked Fuc, β1→4 linked Xyl and β1→6 linked Gal. The sulfation occurred at C4 or C2 of fucose, C2 of xylose and C4 of galactose residue, respectively. Most of fucose residues were present in nonreducing terminal of oligosaccharides. The technique of ES-CID-MS/MS was suitable for the sequences analysis of other hybrid oligosaccharides of various fucoidans. More importantly, all these diverse sulfated oligosaccharides can be printed onto the glycol-chip, and studying their interactions with proteins.



Synthesis of Chiral (-)-Bis(menthylformyl)phenylphosphine Oxide and Its Helix-sense-selective Initiating Function for Radical Photopolymerization

ZHANG Jia-An, YANG Nian-Fa, YANG Li-Wen, GONG Hang, LIU Yan-Ling

2012, 33(08):  1727-1732.  doi:10.3969/j.issn.0251-0790.2012.08.018

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In order to synthesize chiral bisacylphosphine oxide photoinitiator and investigate its excess one-handed helicity induction ability, (-)-bis(menthylformyl)phenylphosphine oxide was synthesized from P,P-dichlorophenylphosphine and (-)-menthylformic acid. The structure of the compound was confirmed by NMR, MS and elemental analysis. The results showed that (-)-BMPPO had helix-sense-selective ability in the initiating the radical photopolymerization of bulky monomer 1-phenyldibenzosuberyl methacrylate(PDBSMA). Highly isotactic, optically active polymers having a helical conformation with one-handed helicity were obtained. Lower feed ratio of the monomer to initiator and higher polymerization temperature were favorable to the increase of the helix-sense-selectivity. The photopolymerization of PDBSMA in chiral menthol initiated by (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (TPO) was also helix-sense-selective, but the helix-sense-selectivity was less.



New Method for Synthesis of Antitumor Drug Capecitabine

ZHAO Ming-Li, ZHAO Yu-Tao, ZHANG Zhao, GAO Jie, QU Wen, XU Jin-Mei, LIU Hong-Min

2012, 33(08):  1733-1737.  doi:10.3969/j.issn.0251-0790.2012.08.019

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Capecitabine, a prodrug of antitumor agent 5-fiuorouracil, is currently to be approved for use as therapy in metastatic breast cancer, colorectal cancer, and other solid malignancies. This drug can be orally home-administered, which offers patients more freedom and reduces the costs of therapy. Here a novel method for synthesis of capecitabine was reported. The key intermediate, 1,2,3-tri-O-acetyl-5-deoxy-β-D-ribose, was prepared from D-xylose. Capecitabine was synthesized through Vorbrueggen reaction, amidation and hydrolization of acetyl group with 29.8% overall yield. The key steps, the configuration change of the 3-hydroxy group through oxidation and reduction and the deoxygenation of sulfonyloxy activated sugar hydroxyl groups by reductive displacement employing NaBH₄, were optimized. This method has the advantages of easily available and cheap starting materials, simply conducted procedures, relatively high yield and easy purification. So this new method is more suitable for scale-up production.



Coordination and Crystal Structure of β-Ketoanilides

CHAI Wei, LI Yue-Jie, XIE Zhuo-Feng, HUANG Yao-Dong, CHANG Ji-Young

2012, 33(08):  1738-1744.  doi:10.3969/j.issn.0251-0790.2012.08.020

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β-Ketoanilide derivatives are useful ligands with variable coordination. To identify the exact coordinating sites of complexes formed by β-ketoanilide derivatives and cupric cation, six β-ketoanilide ligands were synthesized and reacted with copper(Ⅱ) acetate, respectively. The yielding complexes were cultivated in various solvents and expected to form single crystals. Only the single crystal Cu(L₆)₂, a Cu(Ⅱ) complex of 2-benzoylacetanilide, was obtained and characterized by single crystal X-ray diffraction. The results showed that Cu(L₆)₂ crystallized into the monoclinic space group P2(1)/c with a=1.3064(7) nm, b=0.4822(3) nm, c=2.0140(10) nm, α=90.00º, β=106.079(9)º, γ=90.00º. Four oxygen atoms from two ligands coordinated a cupric cation and neither copper-carbon bond nor copper-nitrogen bond was found. The existence of non-classical intramolecular C-H…O hydrogen bonds, intermolecular N-H…O hydrogen bonds and π-π stacking were observed.



Design, Synthesis and Biological Activities of Novel Ortho-dicarboxyamides

YAN Tao, LIU Peng-Fei, ZHANG Ji-Feng, YU Shu-Jing, XIONG Li-Xia, LI Zheng-Ming

2012, 33(08):  1745-1750.  doi:10.3969/j.issn.0251-0790.2012.08.021

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In order to look for novel potential active pesticides, a series of ortho-dicarboxyamides developed from structures of chlorantraniliprole and fipronil, were designed and synthesized according to the bio-rational design principle. Their structures were characterized by ¹H NMR and HRMS. The preliminary results of biological experiments indicated that the title compounds exhibited unsatisfactory insecticidal activities against Mythimna separata Walker at 200 mg/L, however, at 50 mg/L, compounds 6e and 6f exhibited a fungicidal activity of 45.0% against Alternaria solani which is higher than the other compounds. The results indicated that the compounds contained 2,4,6-trichlorobenzene group showed the best fungicidal activities against Alternaria solani; compound 6g exhibited a fungicidal activity of 51.9% against Physalospora piricola which is better than the other compounds. The results indicated that the compounds contained the larger steric group showed the excellent fungicidal activities against Physalospora piricola.



Biological Chemistry

Morphology and Mechanics Character of PVP-Modified Liposome

ZHANG Xiao-Fei, SUN Run-Guang, HAO Chang-Chun, YANG Qian, ZHAO Yan

2012, 33(08):  1751-1756.  doi:10.3969/j.issn.0251-0790.2012.08.022

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The stability and mechanics character of liposome are very important in the chemical biology and biomedical field as a carrier of drug and gene. The liposome modified by polyvinylpyrrolidone(PVP) was prepared by sonication method, and the size ranges were examined by dynamic light scattering(DLS). The morphology and nanometer mechanics character were studied by atomic force microscopy(AFM) and force curves respectively. The results showed that compared with normal liposome, the degree of aggregation of PVP-modified lipsome was obviously lower and its structure became more stable and regular. In the force curve(FC) experiments, the elastic force in the approaching process and the adhesion force in the retracting process increased. The hysteretic case disappeared due to the interaction between tip and samples. PVP-modification could improve the stability of the nano-liposome in inner environment, reduce the number of lipsome that phagocytosed by the immune system and greatly enhance the therapy function.



Novel Pullulan-based Non-virus Cationic Gene Delivery Vector

WANG Jing-Yun, DOU Bai-Rui, BAO Yong-Ming, LI Sen-Wu

2012, 33(08):  1757-1764.  doi:10.3969/j.issn.0251-0790.2012.08.023

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A novel non-virus gene delivery vector(P-PEI) was synthesized by grafting low-molecular branched PEI(molecular weight: 1000) onto the backbone of pullulan with succinic acid as a spacer. ¹H NMR, FTIR, particle size analysis and zeta-potential measurements, TEM and gel electrophoresis were performed to characterize P-PEI and P-PEI/pDNA complexes. Gel electrophoresis retardation assay demonstrated that P-PEI can wrap pDNA with electrostatic interaction excellently even in the presence of heparin, and protect pDNA from the degradation by DNase I and serum. Compared with PEI/pDNA complexes, the P-PEI/pDNA complexes show relative lower cytotoxicity against MCF-7, HeLa and COS-7 cells, even at high N/P(up to 12.5) demonstrated by MTT assay. Flowcytometry revealed that the highest transfection efficiency for P-PEI as a delivery agent was obtained at N/P ratio of 6.25, which was comparable with that of Lipofectamine 2000, and consistent with the results of luciferase expression. These results suggest that the pullulan-grafted branched polyethylenimine polymer (P-PEI) might be an excellent biocompatible candidate for gene delivery systems.



Physical Chemistry

Ab initio Investigation on Unhydrated Ion-associated Species Between Na⁺, Li⁺, Mg²⁺ Ions and ClO₄^-, NO₃^-

WAN Su-Qin, ZHANG Yi, ZHANG Hao, SUN Chia-Chung

2012, 33(08):  1765-1770.  doi:10.3969/j.issn.0251-0790.2012.08.024

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The structures of ion-associated species between Na⁺, Li⁺, Mg²⁺ ions and ClO₄^-, NO₃^- were optimized via ab initio calculations. The influences of the cations to the ν₁-frequencies were also investigated and compared with those in SO₄^2- system. For the ion-associated structures, when the numbers of metal ions are not more than 2, the systems of ClO₄^- and NO₃^- are analogous to the SO₄^2- system. That is, the bidentate associated structures are easy to form between the anions and cations. When the numbers of metal ions are more than 2, especially for the clusters with more Mg²⁺ ion which has more positive charge, the repulsions between metal ions will make the clusters instable in the ClO₄^- and NO₃^- systems, while more monodentate structures will form in the SO₄^2- system. The influences of metal ions to the ν₁-frequencies of all three anions are similar, which can confirm the changes of frequencies in unhydrated clusters are less influenced by the characteristic of anion but more by the polarization of cation and associated structures.



Urease-catalyzed Reactions Inhibited by Heavy Metals Ion with Micro-calorimetry

WANG Li-Ping, XU Yi, ZHENG Yi-Hua, LI Dai-Xi, XU Fei

2012, 33(08):  1771-1776.  doi:10.3969/j.issn.0251-0790.2012.08.025

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Inhibiting effects of heavy metal ions on urease-catalyzed reaction were investigated with micro-calorimetry. Further, the joint inhibition effects of two heavy metal ions on urease-catalyzed reaction were also conducted. The results indicate that, with a wide range of concentration(0.1, 1, 10, 100 and 10³ mg/L), heavy metal ions not only inhibit urease hydrolysis reaction, but also can promote this reaction in some concentration range. For instance, inhibition rate is (0.49?0.20)% and (-11.93?1.34)% when Cu²⁺concentration is 100 and 1000 mg/L, respectively. The correlation between urease inhibition rate and concentration of heavy metal ion is very significant, and the inhibition effects are: As³⁺>Pb²⁺>Cd²⁺>Cu²⁺. The joint inhibition is close to that with higher inhibition when two heavy metal ions are used together. This work proves that the micro-calorimetry may be a potential method to rapidly and accurately detect heavy metals.



Removal of Crude Oil from Oily Sludge by Microemulsion

YAN Dong-Dong, DU Na, HOU Wan-Guo

2012, 33(08):  1777-1781.  doi:10.3969/j.issn.0251-0790.2012.08.026

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Kerosene as oil phase, sodium dodecyl benzene sulfonate(SDBS) as the major surfactant, and pentanol as co-surfactant, three types of microemulsions, i.e. lower-phase(O/W), middle-phase(biconti-nuous) and upper-phase(W/O), were obtained upon the changing of NaCl concentration. The removal of crude oil from oily sludge by the microemulsions was studied, and the effects of microemulsion type, oily sludge concentration, time and temperature on crude oil removal efficiency were examined. The results show that the crude oil removal of the oil phase in lower-phase microemulsiom from the oily sludge is most efficient, followed by middle-phase microemulsion, and upper-phase is the lowest. Meanwhile, a good linear relationship between the crude oil removal efficiency of oil phase and oily sludge concentration is observed. When the detergency time varied between 10-60 min and temperature between 20-70℃, there is no remarkable change observed. Thus, the oily sludge can be treated fast by the studied microemulsion at room temperature.



Performance of Fe-N_x/C Electrocatalysts for Oxygen Reduction Reaction and the Effect of Ligand Stucture on the Catalytic Activity

LI Shang, ZHU Guang-Wen, CHEN Rui-Xin, WANG Jia-Tang, ZHAO Wei, PAN Mu

2012, 33(08):  1782-1787.  doi:10.3969/j.issn.0251-0790.2012.08.027

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2,6-Diaminopurine was used as a ligand to prepare Fe-Hdap complexes for the development of a new oxygen reduction reaction(ORR) catalyst. The prepared Fe-Hdap complexes were heat-treated at 600, 700, 800 and 900℃ to optimize their activity for ORR. It was found that the 800℃ heat-treatment yielded the most active Fe-N_x/C catalyst. Fe-N_x/C catalyst with several Fe loadings(3%, 4%, 5%, 6%, 7%, mass fraction) were also synthesized and a 5% Fe loading yielded the best catalytic ORR activity. XRD, TG, TEM, XPS and line-scan voltammograms techniques were used to characterize the structural changes in these catalyst after heat-treatment, including the catalyst composition, structure, morphologe and the electrochemical activity. As observed by XRD, when the heat-treatment temperature or Fe content was too high, Fe₃O₄ could be produced. This would lead to a decrease in ORR activity. XPS analysis revealed that the catalyst surface consisted of 0.61%(mass fraction) N(largely pyrrolic-like). The ORR activities of catalysts synthesized using ligands with different structures were studied. The result indicated that the catalyst prepared using the compound containing more pyridinic N as ligand had enhanced activity, and the S element in ligand can improve the activity of Fe-N_x/C catalyst. The stability of the Fe-N_x/C catalyst in the voltage region having ORR kinetic limiting was tested by fixing a electrode potential to record the change in current density with time. The obtained degradation rates for this catalyst is 0.0048 mA/(cm²\5h).



Structure Prediction and Molecular Docking Studies on the Inhibitory Effect of Several Hydrolyzate on a Novel Feruloyl Esterase

CHENG Fan-Sheng, ZHANG Mao-Qiu, CHENG Fan-Jie, SHENG Ji-Ping, CHEN Jing-Yu, ZHENG Yan-Yan, SHEN Lin

2012, 33(08):  1788-1793.  doi:10.3969/j.issn.0251-0790.2012.08.028

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Feruloyl esterases, one of the key enzymes in biomass degradation, show great prospects in food, textile, forge and pulp industries. In this study, a feruloyl esterase with low sequence identity was studied, which was originated from China Holstein cow rumen metagenomic library. Possible catalytic mechanisms were discussed based on conserved domains and tertiary structure modelling. Molecular docking studies show that the predicted affinity energy exhibits liner relations to experimental V_max values and hydrogen bond may play a key role on catalytic efficiency. In addition, molecular docking study indicates that L-arabinobiose, D-xylose, D-glucose and trans-ferulic acid may have inhibitory effect on feruloyl esterase activity and the inhibition studies verify this hypothesis. This study may pave a way on rational design of feruloyl esterase and provide guidance on ferulic acid production from lignocellulose materials.



QSAR Studies of HIV-1 Reverse Transcriptase Inhibitory Activity of Benzoxazine Derivatives with Method of Polarizable Continuum Model

XIA Jian, LI Jiang-Bo

2012, 33(08):  1794-1798.  doi:10.3969/j.issn.0251-0790.2012.08.029

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In order to find better anti-human immunodeficiency virus (HIV) drugs, quantum chemical para-meters of nineteen benzoxazine derivatives were calculated using polarizable continuum model (PCM) method. An excellent partial least square (PLS) regression equation (r=0.976,s=0.111) was established. The squared cross-validation correlation coefficient(Q²=0.914) was obtained using the leave-one-out method. The results are useful for designing more effective anti-HIV drugs.



Theoretical Design of a New N-Heterocyclic Carbene Complex Based on Non-heme Iron Complex [Fe^Ⅳ(O)(N4Py)]²⁺

WANG Yi, ZHANG Peng, YANG Kun, HOU Ying-Min

2012, 33(08):  1799-1803.  doi:10.3969/j.issn.0251-0790.2012.08.030

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Based on non-heme iron complex [Fe^Ⅳ(O)(N4Py)]²⁺, a new designed iron-carbene complex [Fe^Ⅳ(O)(N4Py)]²⁺ was theoretically designed. The geometric and electronic structures of [Fe^Ⅳ(O)(N4Py)]²⁺ were studied via density functional theory and B3LYP method, and the [Fe^Ⅳ(O)(N4Py)]²⁺ catalytic properties versus cyclohexane were investigated. The calculation results show that the energy of the quintet spin state of [Fe^Ⅳ(O)(N4Py)]²⁺ is ca. 4.8 kJ/mol higher than that of the triplet ground state, suggesting that the quintet spin state can hardly participate in the reaction. The N-heterocyclic carbene (NHC) equatorial ligand was found to have stronger σ-donating and greater steric hindrance than N4Py ligand, indicating that the complex [Fe^Ⅳ(O)(N4Py)]²⁺ is more stable than [Fe^Ⅳ(O)(N4Py)]²⁺ complex. Moreover, on the triplet spin surface, the energy barrier of [Fe^Ⅳ(O)(N4Py)]²⁺ has higher activation energy than that of [Fe^Ⅳ(O)(N4Py)]²⁺ by 2.0 kJ/mol via a single-state reactivity pattern, implying that [Fe^Ⅳ(O)(N4Py)]²⁺ complex is more reactive than [Fe^Ⅳ(O)(N4Py)]²⁺ complex.



Preparation and Conductive Behavior of Graphene by Electrochemical Method

ZHU Long-Xiu, LI Ying-Zhi, ZHAO Xin, ZHANG Qing-Hua

2012, 33(08):  1804-1808.  doi:10.3969/j.issn.0251-0790.2012.08.031

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A one-step electrochemical approach was employed to produce graphene dispersion with the perfect structure and excellent conductive property by exfoliation of graphite in electrolyte. Transmission electron microscopy and Raman spectroscopy were used to characterize morphology and structure of the as-prepared graphene. Four-probe method was employed to measure the conductivity of the graphene, and the temperature dependent conductivity was investigated by model fitting. At low temperature range of 100 K<T<120 K, carrier transport behavior is explained by two-dimensional variable range hopping based on the σ-exp temperature dependence. At high temperature range of 200 K<T<500 K, the dependence of conductivity on the temperature is consistent with the express of σ-exp(-ΔE/k₀T), and thus carrier transport behavior is well described by thermal activation model. In addition, the outstanding electrical properties suggest that high quality of graphene with less defect can be obtained. This simple method offers a great promise in production of large-scale graphene platelets to meet extensive applications.



Fabrication of Highly Transparent Regular Ag Arrays

JIA Ruo-Kun, LIN Song-Zhu, HE Ai-Min, ZHAO Qing-Xiao, BAI Yu-Bai

2012, 33(08):  1809-1812.  doi:10.3969/j.issn.0251-0790.2012.08.032

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Polycaprolactam lactone(PCL) ordered porous membrane were prepared by solvent evaporation self-organization. Water drops could condenser in cold water to form regular arrays. After solvent evaporating, polymers separate and formed regular arrays on the basis of water arrays. PCL transparent films were obtained by change volume of evaporation solution. After sputtering of metal and a replacement reaction, PCL films change into Ag films. Experimental results show that the silver nets array can not only conductive than PCL array but also has higher pervious to light quality.



In situ Thermokinetic Investigation on the Growth of MnMoO₄稨₂O Nanorods

MA Yu-Jie, FAN Gao-Chao, CHEN Jie, HUANG Zai-Yin

2012, 33(08):  1813-1819.  doi:10.3969/j.issn.0251-0790.2012.08.033

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A novel method utilizing in situ microcalorimetry to monitor the instantaneous information of MnMoO₄稨₂O nanorods growth process in microemulsion was reported. We presented the microcalorimetric heat flow(MCHF) curve which traced the energy evolution of MnMoO₄稨₂O nanorods growth process. The MCHF curve revealed that an exothermic peak appeared firstly, and then followed by an endothermic peak and a second exothermic peak. Combined with the performance of microemulsion and the MCHF curve, we discussed the morphology evolution and the thermokinetic information of MnMoO₄稨₂O nanorods growth process. The whole process contained the collision and coalescence-exchange of drops, reaction, nucleation, crystal crystallization and the secondary growth. The rate constant of the reaction and nucleation, crystal crystallization, and the secondary growth were found to be 6.35?10^-3, 7.18?10^-4, and 9.16?10^-5 s^-1, respectively. The growth rate was less than the nucleation rate and it was helpful for the formation of nanoparticles, which further proved microemulsion as soft template for the controlled synthesis of nanomaterials had a scienti-fic significance.



Adsorption Characteristics of Lignosulfonates on the Surface of Dimethomorph

PANG Yu-Xia, LIU Lei, LOU Hong-Ming, YI Cong-Hua, QIU Xue-Qing

2012, 33(08):  1820-1825.  doi:10.3969/j.issn.0251-0790.2012.08.034

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Dispersion stability of pesticide suspensions has a great impact on their application performance. The adsorption of dispersing agent on pesticide particles is the key factor of determining the stability of the suspension systems. In order to explore the action of dispersant adsorption on the physical and chemical properties of pesticides and help to develop new dispersants, the adsorption performance of common dispersant sodium lignosulfonate (SLS) on dimethomorph (DMM) was investigated, and the zeta potential and contact angle changes after adsorbing SLS on DMM particles were measured. The results showed that when the concentration of SLS was 0-10 g/L, a double-layer absorption occurred on DMM surface. With low concentration of 0-1.0 g/L, the adsorption isotherm was agree with Langmuir equation. The adsorption of SLS on the surface of DMM is a spontaneous, exothermic process, and the interaction between SLS and DMM included hydrophobic interaction, van der Waals force and hydrogen bond. The zeta potential of DMM particles was improved after adsorbing SLS and the higher sulfonated degree of SLS, the greater of this zeta potential improvement. With the increasing of SLS concentration, the contact angle of DMM in water solution reduced firstly and then increased to 70º-80º.



NO_x Adsorption and Decomposition over H₃PW₁₂O₄₀/CNTs and the Effect of Microwave Irradiation

ZHANG Xue-Yang, CHENG Lin, YANG Feng, WANG Rui, Korchak Vladimir

2012, 33(08):  1826-1834.  doi:10.3969/j.issn.0251-0790.2012.08.035

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A series of HPW/CNTs catalysts was prepared by impregnation and mechanical grinding methods. For this purpose, CNTs was pretreated separately by nitric acid vapor, mixture of nitric acid and sulphuric acid, and subsequently calcined. The performances of catalysts on NO_x adsorption-decomposition were studied. The 0.5 g catalyst was used to adsorb 1696 mg/m³ NO_x under the space velocity of 1000 h^-1 at 200℃, and the results showed that the catalyst prepared by mechanical grinding methods supporting HPW on CNTs pretreated by nitric acid vapor and calcined at 300℃ had the highest NO_x adsorption efficiency and capacity of 54% and 16.6 mg NO_x/(g\5h). Temperature-programmed desorption-mass spectroscopy(TPD-MS) was carried out on the catalyst adsorbed NO_x, and the result showed that N₂, O₂ and N₂O were formed during rapid heating, among which O₂ was observed for the first time. Two modes of decomposition were adopted, one is by electric oven at a ramping rate of 150℃/min, and the other, by microwave oven. Compared to the mode of the former, the latter has higher N₂ yield with a N₂ yield upto 33.3% corresponding to the power of microwave oven being 700 W. The catalyst used can be reused by water vapor reactivation, and the recycling results showed that there were no significant performance degradation on NO_x adsorption and catalytic decomposition.



HRhCO(TPPTS)₃/HAP Hydroformylate 1-Hexene High Selectivity and Special Isomerization Performance

ZHANG Ding-Lin, FU Hai-Yan, ZHAO Xian-Ying, ZHAO Hua-Wen, CHEN Hua, LIU Yi-Min, LI Xian-Jun

2012, 33(08):  1835-1841.  doi:10.3969/j.issn.0251-0790.2012.08.036

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Water-soluble rhodium-phoshpine complex HRhCO(TPPTS)₃ and TPPTS were supported by hydroxyapatite(HAP). The catalysts were characterized by FTIR, solid state ³¹P CP-MAS NMR, SEM, ICP-OES, and N₂ adsorption-desorption measurements. The catalysts showed special isomerization performance for 1-hexene, 2-hexene and 3-hexene. The results show high activity and selectivity in the hydroformylation of 1-hexene. Selectivity of 100% of aldehydes and high turnover frequency(TOF=2465 h^-1) were obtained under optimum condition. The catalysts could be easily separated from organic products and reused. The mechanism of isomerization performance of the catalyst and supporting HRhCO(TPPTS)₃ on HAP were discussed.



Synthesis and Properties of PVA/QHECE/PEG Anion-exchange Membranes for Potential Fuel Cells

LIU Ling-Ling, ZHANG Jing, QIAO Jin-Li

2012, 33(08):  1842-1849.  doi:10.3969/j.issn.0251-0790.2012.08.037

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The alkaline anion-exchange membranes were developed from poly(vinyl alcohol)/quaterized hydroxyethylcellulose ethoxylate (PVA/QHECE) by incorporating polyethylene glycol (PEG) as a plasticizer using chemical and physical cross-linking method. The PVA/QHECE/PEG membranes were characterized in detail at structural and hydroxyl ion (OH^-) conducting property by AC-impedance spectroscopy, FTIR spectroscopy, scanning electron microscopy (SEM), thermal gravity analysis(TG), gas chromatogram (GC) and tensile strength technique. The results show that the membrane flexibility and mechanical property are highly improved by incorporating PEG, especially for the membranes with high content of QHECE. The thermal stability of the membranes with PEG (300℃) is 40℃ higher than that of without PEG (260℃). No decreaes in OH^- condutivity was observed for the membranes after conditioning in 80℃, 6 mol/L KOH for 264 h. On the contrary, the OH^- conductivity increased from 1.06×10^-3 S/cm (before conditioning) to 3.88×10^-3 S/cm(after conditioning), while no obvious change in water uptake was observed. In addition, the methanol permeability of the PVA/PAADDA/PEG membranes are all lower than 10^-7 cm²/s, which is only 1/20-1/40 of Nafion^®117 under the same measuring conditions, indicating that the membranes are promising for potential use in alkaline direct methanol fuel cells.



Polymer Chemistry

Synthesis and Properties of Ethylene-polyhedral Oligomeric Silsesquioxane Copolymer with Bis(cyclopentadienyl) Zirconium Dichloride Catalyst

ZHANG He-Xin, ZHANG Hao, ZHANG Chun-Yu, HAO Xiu-Feng, ZHANG Xue-Quan

2012, 33(08):  1850-1853.  doi:10.3969/j.issn.0251-0790.2012.08.038

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An organic/inorganic hybrid copolymer was prepared with a bis (cyclopentadienyl) zirconium dichloride (Cp₂ZrCl₂) in conjunction with modified methylaluminoxane (MMAO) cocatalyst. Two kinds of monovinyl substituted polyhedral oligomeric silsesquioxane(POSS) monomers were used to copolymerize with ethylene(E). The copolymers were characterized with ¹H NMR, DSC, TGA and GPC to know the composition, thermal properties, molecular weight and its distribution, respectively. The comonomer content (POSS) was in the range of 0.01%-0.30%(molar fraction). With the increase of POSS content in copolymer, the melting temperature and heat of fusion decreased. Thermogravimetric analysis of E/POSS copolymers exhibited an improved thermal stability with a higher degradation temperature and char yields, demonstrating that the inclusion of inorganic POSS nanoparticles made the organic polymer matrix more thermal robust. Increasing the feed ratio of POSS, the molecular weight increased, while the molecular weight distribution broadened.



Folate-conjugated Micelles Based on Star-shaped PLGA-PEG-NH₂ Copolymers as Novel Tumor-targeted Nanocarriers

MA Gui-Lei, ZHAO Shun-Xin, JIN Xu, CHEN Min-Min, ZHANG Zheng-Pu, SONG Cun-Xian

2012, 33(08):  1854-1859.  doi:10.3969/j.issn.0251-0790.2012.08.039

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A new type of folic acid(FA)-conjugated amphiphilic 4-arm star-shaped PLGA-PEG-NH₂(4s-PLGA-PEG-NH₂) micelles was prepared as a doxorubicin(DOX)-loaded nanocarrier for tumor-targeted drug delivery. The 4s-PLGA-PEG-NH₂ micelles were prepared by a solvent evaporation method; then, FA was conjugated onto the surface of the micelles using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride(EDC) conjugation chemistry. The structure of the synthesized 4s-PLGA-PEG-NH₂ copolymer was characterized by ¹H NMR and gel permeation chromatography(GPC). The prepared micelles properties were determined by dynamic light scattering, UV spectra and TEM observation. The cellular uptake and cytotoxicity of FA-conjugated DOX-4s-PLGA-PEG-NH₂ micelles were assessed using confocal laser scanning microscopy(CLSM) and the cell counting kit-8 assay. The results show that compared with the nontargeted DOX-micelles, FA-DOX-micelles have higher cellular uptake of DOX, and subsequently a higher cytotoxicity to tumor cells. In conclusion, the FA-conjugated 4s-PLGA-PEG-NH₂ micelles could be an excellent nanocarrier to deliver anticancer drugs specifically inside the cell via FA-receptor-medicated endocytosis.



Stabiliby of Chitosan-stablized Nanosilver Solutions and Its Application for Antibacterial Durability of Cotton Fabrics

ZHANG Yu-Fei, LI You-Liang, YAO Yuan, LI Wen-Yu, HU Qiao-Ling

2012, 33(08):  1860-1865.  doi:10.3969/j.issn.0251-0790.2012.08.040

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The chitosan-based nanosilver solutions were synthesized by chemical reduction method with chitosan as the stabilizing agent and sodium borohyride as the reducing agent. The obtained chitosan-stablized nanosilver solutions were characterized by ultraviolet-visible spectrophotometer, atomic absorption spectroscopy, and transmission electron microscope. The antibacterial activities of these chitosan-stablized nanosilver solutions toward E. coil and S. aureus were investigated. This research found that with increasing chitosan concentration, the obtained silver nanoparticles became much more stable. And cotton fabrics treated with these chitosan-stablized nanosilver solutions exhibited superior antibacterial activity and antibacterial durability compared with the fabrics treated by chitosan solution only.



Polymerization System and Properties of Anionic Polyamide-6 for Vacuum Infusion Process

KAN Ze, LIU Zheng-Ying, ZHANG Kai, CHEN Hong, HU Jia-Yang, HOU Meng, YANG Ming-Bo

2012, 33(08):  1866-1871.  doi:10.3969/j.issn.0251-0790.2012.08.041

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To explore the polymerization system suitable for vacuum infusion anionic polyamide-6(APA-6), the conversion-time relations of different activator-initiator combinations for APA-6 were investigated. Accor-ding to the conversion-time relations during the reaction, it indirectly reflected the viscosity-time relations. The results show that the systems of C10/C20(100℃) and C10/TDI are desired for vacuum infusion of anionic polyamide-6 composites, because both of them show slow linear conversion increase at the beginning of the reaction. However, after a while, the polymerization rate increased rapidly and that the degree of conversion increased exponentially in time. On the basis of the previous research, the reason that the systems of C10/TDI was more suitable for manufacturing thicker, lager and more complicated textile fiber reinforced thermoplastic composites were discussed using differential scanning calorimeter(DSC) thermal analysis from the mechanism of the generation of active center. In addition, compared with traditional nylon 6, the degree of crystallinity, modulus and the temperature of glass transition(T_g) of vacuum infusion APA-6 exhibit remarkably improved. And there are also different properties between two kinds of ideal system of anionic polyamide-6 for vacuum infusion process, the reason was preliminary discussed from mechanisms of blocking and de-blocking of the activator.



Properties of Poly(vinyl alcohol) Plasticized by Magnesium Chloride

JIANG Xian-Cai, XIA Chao, YE De-Zhan, LIU Lei, DAI Hua, ZHANG Xi

2012, 33(08):  1872-1876.  doi:10.3969/j.issn.0251-0790.2012.08.042

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The plasticized poly(vinyl alcohol)(PVA) films were prepared by the casting method using magnesium chloride(MgCl₂) as the plasticizer. The interaction between MgCl₂ and PVA was analysised by Fourier transform infrared(FTIR) spectroscopy. The change of the crystalline and thermal properties of PVA with the content of MgCl₂ were measured by X-ray diffraction measurements(XRD), differential scanning calorimetry and thermogravimetric analysis(TGA) respectively. The mechanical properties were measured as a function of MgCl₂ content. It was found that MgCl₂ could form considerable interaction with PVA and form a complex. The XRD showed that the crystallinity of PVA film decreased with the content of MgCl₂, which would be ascribed to the interaction of MgCl₂ with PVA molecules, causing the destroying of the intra/inter molecular hydrogen bonding between PVA chains. The glass transition temperature of PVA also decreased with the content of MgCl₂. The TGA results show that the thermal stabilities of PVA decreased with the addition of MgCl₂ and the thermal degradation process was changed. The mechanical testing showed that PVA become soft, with lower tensile strength and higher elongation at break after modification.