Table of Content

10 October 2005, Volume 26 Issue 10

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Articles

Hydrothermal Synthesis and Characterization of a Novel Zinc Phosphite Compound

LIU Li, CHEN Chao, MENG He, ZHANG Feng, CUI Yan-Jie, PANG Wen-Qin

2005, 26(10):  1783-1786. 

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A novel 2D layer zinc phosphite compound Zn(DETA)Zn₂(HPO₃)₃ was hydrothermally synthesized.Single crystal X-ray diffraction reveals that the compound crystallized in the orthorhombic space group,Cmca,with a=1.889 25(1) nm,b=1.001 04(6) nm,c=1.630 32(8) nm,β=90°,V=3.083 3(3) nm³,Z=4,D_C=1.162 Mg·m^-3, R₁0.067 9 and wR₂0.158 3.The structure consists of {ZnO₄},{ZnO₂N₃} and {HPO₃} basic structural units.The vertexsharing {ZnO₄} and {HPO₃} units are connected forming an infinite 2D layer with four-,eight-and twelve-membered rings.It is very interesting that {ZnODETA}₂ dinuclear units are grafted in the twelve-membered ring channels.

Synthesis and Electroluminescence of a Novel Eu(Ⅲ) Ternary Complex

YUAN Ji-Bing, LI Jia-Hang, Liang Wan-li, Su Shu-jiang, YAO Jun-Hua, GONG Meng-Lian

2005, 26(10):  1787-1790. 

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An organic compound with both electron-transporting and hole-transporting groups,1-ethyl-2-(2-[(4-N,N'-diphenyl)-phenylamine]-5-phenyl-1,3,5-oxadiazole) imidazo[4,5]-1,10-phenanthroline(EtPOTIP),was designed and synthesized.With EtPOTIP as the secondary ligand and dibenzoylmethane(HDBM) as the first ligand,the corresponding europium(Ⅲ) ternary complex,Eu(DBM)₃EtPOTIP, was prepared.EtPOTIP and the complex were characterized by elemental analysis, ¹H NMR,IR and mass spectroscopy.TG and DSC analyses show that the complex exhibits high thermal stability and high T_g temperature.UV-Vis absorption and photoluminescence measurements demonstrate that the excitation light energy absorbed by the organic ligands was transferred to the central Eu³⁺ ion efficiently in the ternary complex,and the latter is an excellent red emitting material with a high quantum yield of 0.48.A bright tri-layer organic light-emitting diode(OLED) with structure of ITO/CuPC(15 nm)/TPD(45 nm)/Eu(DBM)₃EtPOTIP(20 nm)/Alq₃(40 nm)/Ca(30 nm)/Al(100 nm) was fabricated,and the electroluminescence measurements indicate that EtPOTIP exhibits both electron-transporting and hole-transporting properties and the latter is dominant.Existence of EtPOTIP in the complex obviously improves the performance of the device.

Synthesis and Electrical Properties of New Solid State Electrolyte Materials Ce_6-xSm_xMoO_15-δ(0≤x≤1.2)

ZHOU De-Feng, BO Qi-Bing, WANG Qiu-Yan, WANG Jing-Ping, LV Min-Feng, LIU Jian-Fen, CAO Xue-Qiang, XING Xian-Ran, MENG Jian

2005, 26(10):  1791-1794. 

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A new solid electrolyte series of oxides Ce_6-xSm_xMoO_15-δ(0≤x≤1.2) were synthesized by sol-gel method.The precursors and the resultant oxide powders were characterized by differential thermal analysis/thermogravimetry(DTA/TG),X-ray Diffraction(XRD) and X-ray Photoelectron Spectroscopy(XPS).The formation temperature of the compounds was found to be as low as 400 ℃.Ce_6-xSm_xMoO_15-δ crystallized to fluorite-related cubic structure.The electrical conductivity of samples was investigated by using AC impedance spectroscopy.Impedance spectra analyses show that the grain-boundary resistance of the solid electrolyte prepared by sol-gel method wad reduced or even eliminated.It shows that the presence of Sm is related with the oxygen-ion conductivity.The highest oxygen-ion conductivity is found in Ce_6-xSm_xMoO_15-δ(x=0.8) reaching 6.67×10^-3 S/cm at 800 ℃. The Ce_6-xSm_xMoO_15-δionic conductor shows a potential application in the intermediate-temperature solid oxide fuel cells(SOFCs).

Morphology Control of Lanthanum Hydroxide Nanorods Synthesized by Hydrothermal Microemulsion Method

YIN Yi-Dong, HONG Guang-Yan

2005, 26(10):  1795-1797. 

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Lanthanum hydroxide nanorods with a diameter of 10-20 nm and length up to 100-200 nm were synthesized through a direct reaction of La(NO₃)₃ and KOH under hydrothermal microemulsion conditions.X-ray diffraction(XRD) and scanning electron microscope(SEM) were employed for the characterization of the structure,compositions and morphology of the obtained products.The results showed that the molar ratio of water to the surfactant CTAB,concentration of La(NO₃)₃,reactant temperature and reactant time all could affect the morphology and size of the lanthanum hydroxide nanorods.

Pattern Feature Discovery for Metabonomics of Breast Cancer and HPLC/MS/MS Analysis of Characteristic Metabolites

SHEN Peng, KANG Yu-Fei, CHENG Yi-Yu

2005, 26(10):  1798-1802. 

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A new pattern discovery method based on the best individual feature selection and BP neural network was proposed to select characteristic metabolites in urine which were most correlative with breast cancer.Four nucleosides(orotidine,1-methyladenosine,S-adenosylmethionine,and N²-methylguanosine),which were identified by using HPLC/MS/MS,were selected out and composed a characteristic pattern for diagnosis of breast cancer.Subsequently,BP neural network was investigated as potential tools to diagnose breast cancer by using those four nucleosides as the input features.The results of Leave-One-Out and independent cross validation show that the prediction rate of the model built with BP neural network is higher than 90%.As a consequence,those four selected nucleosides could be considered as a characteristic pattern for the diagnosis of breast cancer.

Influence of Ligustrazine on Trace Amino Acid Neurotransmitters in Striatum of Rats after Transient Focal Cerebral Ischemia by CZE-LIF

DANG Hong-Mei, MA Wan-Yun, HAN Hui-Wan

2005, 26(10):  1803-1807. 

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An effective coupling of microdialysis and capillary electrophoresis with laser induced fluorescence detection technique(CZE-LIF) was explored for the analysis of amino acid neurotransmitters in striatum of rat after transient focal cerebral ischemia in group treated with saline and group treated with hydrochloric acid(ligustrazine).The separation of amino acids was achieved within 30 min on an uncoated fused silica capillary(67 cm×50 μm i.d.) column with botate buffer(10 mmol/L,pH=10.35) and an applied voltage of(12.5 kV).With the current method,the fluorescence intensity has linear relationship with each amino acid concentration between 1×10^-6-8-9

Determination of Chemical Oxygen Demand by Flow Injection Analysis Using Amperometric Detector with Nano PbO₂ Modified Electrode

LI Jia-Qing, LI Luo-Ping, ZHENG Lei, XU Hai-Hong, JIN Li-Tong

2005, 26(10):  1808-1811. 

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An electrochemical detection system with a nanometer lead dioxide modified electrode for flow(injection) analysis to determine chemical oxygen demand(COD) is described.The measuring principle is based on the current response on the PbO₂ modified electrode which is proportional to the COD value of the standard water sample range of 50—1 200 mg/L.Under the optimized experiment conditions,and the detection limit is 20 mg/L.When this method was applied to the determination of real water samples,it has the advantage of no sample pretreatment,short analysis time,simplicity, a minimum sample and reagent consumption and easy automation.Additionally,the method for determination of COD is in excellent correspondence with the values obtained by conventional method.

Preparation of a Novel DNA Electrochemical Sensor and Its Application to Detection of DNA Oxidative Damage

WANG Gui-Xiang, PAN Qian-Xiu, WANG Huai-Sheng

2005, 26(10):  1812-1816. 

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A novel DNA electrochemical sensor was prepared by immobilizing dsDNA on the hydroxyapatite(HAp)-polyvinyl alcohol(PVA) coating which was prepared by sol-gel methold on the glass carbon electrode surface.The sensor was used to detect the oxidative damage to dsDNA mediated by Fe²⁺ Fenton reaction.The results clearly indicate that the DNA damage can be accelerated by the presence of excessive AA in this experiment.The lower concentration of EDTA and the relative higer concentration of Fe²⁺ in the Fenton reaction solution can produce more OH·,and then result in the deeper damage of DNA.

Isolation and Structure Identification of Novel Monoterpene Lactone from Ornithogalum Caudatum Ait

BAI Jin-Fa, LIU Zhi-Qiang, WANG Shu-Min, SONG Feng-Rui, LIU Shu-Ying

2005, 26(10):  1817-1819. 

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A kind of monoterpene lactone,6-hydroxy-4,4,7a-trimethyl-5,6,7,7a-tetrahydro-4H-benzofuran-2-one,was isolated from Ornithogalum Caudatum Ait,whose structure was confirmed by IR and NMR methods,and its fragmentation pathway was studied by ESI-MSⁿ.The stereo-structure of the compound was identified by the degree of specific rotation and ¹H NMR.The experimental results demonstrate that the compound is firstly found in this kind of plant.

Molecularly Imprinted Polymer with Bi-functional Monomers of Calix Arene Derivative and Acrylamide for Selective Recognition of Hydantoin-based Compounds

LU Chun-Yang, WANG Hua-Fang, HE Xi-Wen, CHEN Lang-Xing, LI Wen-You, ZENG Xian-Shun, ZHANG Yu-Kui

2005, 26(10):  1820-1824. 

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Using calix[4]arene derivative and acrylamide(AM) as the bi-functional monomers and 5-benzylhydantoin(R-BZH) as a template,a molecularly imprinted polymer was prepared to recognize hydantoin-based compounds selectively.The results of equilibrium binding experiments indicate that the selectivity of the MIP,which is synthesized with a single functional monomer(calix[4]arene derivative or acrylamide),is poor;while the selectivity of another MIP,which is synthesized with two functional monomers(both calix[4]arene derivative and AM),showed higher and better selective recognition abilities for R-BZH. It was entirely possible to separate and enrich R-BZH from hydantoin-based compounds by molecularly imprinting technique.

Direct Electrochemistry and Electrocatalysis of Myoglobin Immobilized on Nano-alumina-gold Colloid Assembly System

GUAN Xiao-Hui, QIN Yu-Hua, ZHANG Shu-Yong, GUO Jun, LI Jing-Hong

2005, 26(10):  1825-1828. 

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Mb/AAO/Au colloid /GC electrodes were made by immobilizing Mb on the surface of Au colloid modified glassy carbon electrode covered with AAO templates.The cyclic voltammgram of Mb/AAO/Au colloid/GC films shows a pair of well-defined and nearly reversible peaks at about-0.21 V(vs.Ag/AgCl) in acetic acid-sodium acetate buffers with pH=5.4,being the characteristic peaks of the Mb heme Fe(Ⅲ)/Fe(Ⅱ) redox couples.In the microenvironment of the AAO/Au colloid film,the electron transfer between Mb and the electrode was greatly enhanced.The hydrogen peroxide and oxygen were catalytically reduced at(Mb/AAO/Au) colloid/GC electrodes.

Studies on the Interaction of α₁-Acid Glycoprotein and Drugs by Electrospray Ion Trap Mass Spectrometry

CHEN Yong, QI Chun-Hua, HAN Feng-Mei

2005, 26(10):  1829-1831. 

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In this paper,the noncovalent interactions between α₁-acid glycoprotein(AAG) and the drugs,such as ketoprofen(KP) and anisodine hydrobromide(AN) were studied by using electrospray ion trap mass spectrometry method.The results show that both of the drugs had a strong coalescent interaction with AAG,the(dissociation) constants(K_d) and the apparent stoichiometric ratio of noncovalent complexes AN-AAG were(1.75×10^-3 mol/L) and 1∶7,and those for KP-AAG complex were 4.95×10^-4 mol/L and 1∶4,respectively.According to the thermodynamic parameters of the noncoralent complexes,the main sorts of binding force were static-electricity gravitation for KP-AAG and Van der Waals force for AN-AAG,respectively. The experiment proves that ESI-MS technology as a new method for studying the drug-protein noncoralent binding can offer some advantages in sensitivity,speed,accuracy and directness particularly in the determination of the stoichiormetry of the complex compared to other well-established methods such as circular dichroism and fluorescence spectroscopy,etc.

Establishment of a New On-line Coupled Supercritical Fluid Extraction(SFE) with High Performance Liquid Chromatography(HPLC) System

ZHANG Jie, DUAN Ji-Cheng, LIANG Zhen, ZHANG Li-Hua, ZHANG Wei-Bing, HUO Yu-Shu, ZHANG Yu-Kui

2005, 26(10):  1832-1834. 

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A new on-line coupled supercritical fluid extraction(SFE) with high performance liquid chromatography(HPLC) system was developed.Two three-port valves were used as an interface to connect SFE and HPLC.In this design,the two important processes including sample preparation and sample analysis were(integrated) into a system.Compared with off-line system,the on-line system has many advantages,such as high sensitivity,short analysis time,avoiding sample pollution,easily operation and ease to automation etc.Its application in the extraction and analysis of triterpenoids to the fruiting bodies of Ganoderma Lucidum was also described.Under the optimized extraction conditions,the similar chromatogram of the extract with on-line SFE- HPLC system was observed as well as that with off-line SFE followed by HPLC.The result showed the great potential of the on-line system in the extraction and analysis of tradition Chinese medicine.

Inclusion Complexing Behavior of Cucurbit[n] urils with Some Quinoline Derivatives

MOU Lan, XUE Sai-Feng, ZHU Qian-Jiang, TAO Zhu, ZENG Xi

2005, 26(10):  1835-1839. 

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The interaction of cucurbit[n=6,7,8]urils(Q[6],Q[7],Q[8]) with some quinoline derivatives,such as 2-phenylquinoline,N-propylquinoline,3-aminoquinoline and 7,8-phenylquinoline,were studied by using ¹H NMR technique and fluorometric analysis.The experimental results of both methods reveal that 2-phenylquinoline can form stable inclusion complex with Q[6],Q[7],Q[8] with a ratio of 1∶1,1∶1 and 2∶1 respectively,and the inclusion constants of 2-phenylquinoline-Q[6] or Q[7] was 1.6×10⁴ and 3.2×10³ L/mol respectively.¹H NMR results also show that Q[6],Q[7],Q[8] could form inclusion complex with N-propylquinoline with a ratio of 2∶1 repectively,and Q[7] could form inclusion complex with 7,8-phenylquinoline with a ratio of 1∶1.Fluorometric analysis reveal that the host-guest complexes of Q[8] and the title quinoline derivatives were formed with a ratio of 1∶2 repectively,and the fluorescence of the interacted quinoline derivatives was queched by Q[8].Also the interaction models were suggested for the above hous-guest inclusion complexes.

Synthesis and Analgesic Activity of Novel Open-chained Epibatidine Analogues

ZHANG Chuan-Xin, ZHANG Hong-Mei, LI Chang-Ling, GE Ze-Mei, CHENG Tie-Ming, LI Run-Tao

2005, 26(10):  1840-1844. 

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Based on the structure of the leading compound ABT-594 and the bioisosteric replancement rule,ten new open-chain EP analogues were designed and synthesized by the PTC and Mitsunobo reactions.Their structures were confirmed by ¹H and ¹³C NMR,elemental analysis,MS or HRMS.All the target compounds were evaluated for their analgesic activity in vivo.The result revealed that most of them showed some activity.Though their analgesic activity was not so satisfactory,some interesting SAR was found.The compounds containing furan ring exhibited a higher activity than others.Replaced 2-chloropyridine in ABT-594 with 2-methyl-5-nitroimidazole or 5-methyl tetrazole,and(or) instead of the CH₂O with CH₂ as linking arm,the analgesic activity didn't obviously decrease.Additionally,the toxicity of all tested compounds was lower than epibatidine itself significantly.

Synthesis and Characterization of Acrylic Ester Bridged γ-Substituted β-Diketone Pyrazole and Isoxazole Derivatives

GUO Hui, HAN Jie, PANG Mei-Li, MA Yu-Xin, MENG Ji-Ben

2005, 26(10):  1845-1848. 

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Synthesis and characterization of a series of long-chain conjugated pyrazoles and isoxazoles were(achieved) through reaction the of acrylic ester bridged γ-substituted β-diketone with hydrazine hydrate and(hydroxylamine) hydrocholoride respectively.The influence of different solvents on the reactions was studied and the results reveal that the reaction outcome depends on the solvent.When alcohol was used as the solvent,isoxazoles were obtained via reaction of γ-substituted β-diketone and hydroxylamine hydrocholoride,while no target pyrazole compounds but α,β-saturated hydrazines were formed via reaction of γ-substituted β-diketone and hydrazine hydrate.When using acetic acid as the solvent,the target pyrazole compounds were obtained.The reaction mechanisms for the formation of α,β-saturated hydrazines were discussed.

Synthesis of Polystyrene-supported Selenovinyl Bromide and Its Application in the Solid-phase Synthesis of Polysubstituted Olefins

TANG E, XU Jian-Feng, HUANG Xian

2005, 26(10):  1849-1851. 

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Organoselenium reagents are powerful tools for the preparation of small organic molecules.A simple preparation of polystyrene-supported(E)-1-bromo-2-selenoethylene was reported.In the presence of NiCl₂(PPh₃)₂ catalyst,polystyrene-supported(E)-1-bromo-2-selenoethylene reacted with different Grignard reagents to offer(E)-1,2-disubstituted ethenes or trisubstituted ethenes.The evident advantages of this reaction are easy operations,odorlessness,good yields of the products.

Stability of Penicillin G Acylase Immobilized on Different Silica Mesoporous Materials

GAO Bo, ZHU Guang-Shan, FU Xue-Qi, XIN Ming-Hong, CHEN Jing, WANG Chun-Lei, QIU Shi-Lun

2005, 26(10):  1852-1854. 

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Silica mesoporous materials were synthesized and used as the supporting materials for immobilization of enzyme.Penicillin G acylase,an enzyme which was used to produce 6-APA in pharmaceutical industry,was immobilized in the mesoporous materials by the immersion method.The stabilities of the immobilized penicillin G acylase were studied.After incubation at 60 ℃ for 2 h,the activity of immobilized penicillin G acylase remained 80% in the best case.At higher or lower pH,the free enzyme was deactivated quickly,while the immobilized enzyme still retained active.The result of operational stability showed that the immobilized(enzyme) retained 70% of its initial activity after operating for 6 times.These results showed that the stabilities of immobilized penicillin G acylase,related to the pore size of mesoporous materials,were increased significantly compared with those of free enzyme.The improvement of stabilities of immobilized enzyme was significant when the pore size of the mesoporous materials matched the enzyme molecule size.

Determination and Forecast of Secondary Structure of Uremic Toxic Polypeptide

LI Guo-Hua, LI Ji-Hong, YANG Mei, WANG Wei, SUN Ping-Chuan, YUAN Zhi

2005, 26(10):  1855-1857. 

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A uremic toxic compound with molecular weight 1007.94 was determined to be an octapeptide by mass spectrometry.Its amino-acid sequence was given as follos: Val-Val-Arg-Gly-Cys-Thr-Trp-Trp.Spin systems for amino acid residues in the octapeptide were identified through analysis of 2D NMR ¹H-¹H DQF-COSY,TOCSY and ROESY spectra acquired in H₂O and D₂O.Moreover,the complete assignment of proton resonances for the backbone and side chain was achieved.Based on the secondary chemical shift(Δδ) of the residues,the secondary structure of octapeptide was surveyed.Conformational analyses according to Chemical Shift Index(CSI) showed that the secondary structure of the octapeptide was principally α-helix.The CD spectra of the peptide in aqueous solution gave the same result.Additions of linear polymers made the conformations of octapeptide stretch.These experimental results provide a basis for further comprehension of interaction regulation between biomacromolecule and polymer absorbing materials.

Electrooxidation Study of 3-Picoline at PbO₂-Solid Polymer Electrolyte Composite Electrode

ZHANG Yu-Min, ZHANG Heng-Bin, XU Yu-Ling, CAO Xue-Jing, LIN Hai-Bo

2005, 26(10):  1858-1860. 

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The PbO₂-SPE(Solid Polymer Electrolyte) composite electrode was prepared by hot pressed method.The electrooxidation reactions of 3-picoline at the electrode was studied with the cyclic voltammetric and steady state polarization curves.The relationships between the current density and overpotential and between the overpotential and cell voltage were examined in the different catholyte as well as in the anolytes with or without the liquid supporting electrolyte.The possibility for producing nicotinic acid from 3-picoline at the(electrode) without the supporting electrolyte in the liquid phase was explored.The selectivity and the current (efficiency) under the specific conditions were given.

Effect of Platinum Loading on Lifetime of Photogenerated Charge Carriers of TiO₂ Studied by Time-resolved Photoconductivity

ZHANG Wen, WANG Xu-Xu, FU Xian-Zhi

2005, 26(10):  1861-1864. 

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Time-resolved photoconductivity(TRPC) was used to study the photoconductivity decay of TiO₂ and the lifetime of the photogenerated charge carriers.Also,we investigated the influence of platinum loading on the characters of the photogenerated charge carriers of TiO₂.The results showed that the decay tendency of TiO₂ was delayed with the increase of platinum loading and the effective lifetime of the photogenerated charge carriers of TiO₂ containing 1.0%Pt(mass fraction) was prolonged to 1.57 ms from 0.16 ms without Pt loading.The mentioned results suggested that in the presence of Pt the photogenerated electrons of TiO₂ transfer to Pt from semiconductor rapidly,resulting in achieving the effective separateness between the photogenerated(electrons) and holes,prolonging the effective lifetime of the photogenerated carriers,decreasing the recombination rate of photogenerated electrons and holes,and increasing the quantum efficiency of the photocatalytic(reaction).

Supramolecular Structure and Properties of Fluorescent Acridine Compound Based on Intermolecular π-π Interaction

SUN Ying-Hui, ZHANG Hui-Dong, YE Kai-Qi, ZHANG Jing-Ying, LI Wei, YANG Bai, WANG Yue

2005, 26(10):  1865-1868. 

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10-Methyl-benzoacridine(MBA) was synthesized and its crystal structure was characterized by the X-ray crystal diffraction method.The crystals of MBA exhibited monoclinic,space group P2(1)/c,a=0.584 890(1) nm, b=1.486 250(1) nm,c=1.451 62(3) nm,β=98.835(2)°,V=1.247(3) nm³,Z=4.The data of the crystal structure show that one-dimensional infinite columns based on intermolecular(ππ) interactions formed in MBA crystal.The rectangular and wire-like microcrystals of MBA were successfully prepared and characterized by fluorescent microscope.The study of photoluminescence spectra demonstrate that MBA is an organic blue light emitting material.

Electrochemical Preparation and Spectral Properties of Au-Hg Core-shell Nanoparticles

LI Xiao-Wei, ZHOU Qun, ZHUANG Yan, ZHENG Jun-Wei, LU Tian-Hong

2005, 26(10):  1869-1872. 

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Gold nanoparticles were assembled on the polyvinylpyridine modified ITO electrode to form a particle monolayer.Mercury nanoshell on the surface of the gold nanoparticles was obtained by electrochemical deposition.The formation of the mercury nanoshell resulted in a red shift and damping of the surface plasmon resonance of the inner gold nanoparticles.Molecules adsorbed on the mercury nanoshell can still experience the enhanced electric field from the gold core,as a result,the Raman scattering of the adsorbed molecules can be greatly enhanced.

Properties of Ionic Liquid BMIInCl₄ of Rare Metal at Room Temperature

YANG Jia-Zhen, ZHANG Qing-Guo, HUANG Ming, XUE Feng, ZANG Shu-Liang

2005, 26(10):  1873-1876. 

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Recently,ionic liquids(ILs) have received more attention because of their unusual properties and have great potential as "green" solvents for industrial processes.In particular,the ILs based on AlCl₃ have been most widely studied.However,there are a limited number of reports of ionic liquids based on elements of group Ⅲ other than aluminum.To expand our knowledge of IL chemistry and as a continuation of our previous investigations this paper reports that an ionic liquid(IL),BMIInCl₄,was prepared by directly mixing InCl₃ and 1- methyl-3-n-butylimidazolium chloride with molar ratio 1∶1 under dry argon atmosphere.The densities and surface tension of the pure IL were determined in the temperature range from 278.15 to 343.15 K.The properties for the ionic liquid based on group Ⅲ were discussed by using Glasser's theory.The values of volume of anion AlCl^-₄ and InCl^-₄ were obtained,respectively.The mean contribution of per methylene((—CH₂—)) group to the molecular volume of ionic liquid based on AlCl₃ is 0.028 6 nm³ and is in good agreement with the contribution of 0.028 0 nm³ from n-alcohols. And the standard entropy,the surface energy and the crystal energy of the ionic liquid were calculated,respectively.The crystal energy of the ionic liquid is much lower than that of ionic solid and this is the underlying reason for forming ionic liquid at room temperature.In addition,a new theoretical model of ionic liquid,that is an interstice model,was applied to calculating the thermal expansion coefficient of BMIInCl₄.And the magnitude order of the thermal expansion coefficient,α,calculated by the theoretical model is in good agreement with the experimental value.The result shows that there is much reasonableness for the interstice model of ionic liquid.

Preparation and Properties of Mg_1.75Al_0.25Ni_1-xCr_x(0 ≤x≤ 0.2) Alloys

WANG Mei-Han, ZHANG Lian-Zhong, SUN Li-Xian, ZHANG Yao, XU Fen, TAN Zhi-Cheng, YUAN Hua-Tang, ZHANG Tao

2005, 26(10):  1877-1880. 

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Mg_1.75Al_0.25Ni_1-xCr_x(0 ≤x≤ 0.2) alloys were synthesized by diffusing method(DM) on the basis of the ternary Mg_1.75Al_0.25Ni alloy.The X-ray diffraction showed that the structure of the Cr-partially-substituted alloy did not differ from that of Mg_1.75Al_0.25Ni alloy but there was a change in the lattice parameter.It was found that the Cr-substituted alloys showed enhanced discharge capacities.The cycle life of the alloys was(improved) when x(Cr) reached 0.1. The anti-corrosion order was Mg_1.75Al_0.25Ni_0.9Cr_0.1>Mg_1.75Al_0.25Ni>Mg_1.75Al_0.25Ni_0.8Cr_0.2>Mg₂Ni.The result of the charge-discharge experiment also supported the conclusion.The structure and the component of alloy phase were changed after ball milling but the discharge capacity of the Mg_1.75Al_0.25Ni_0.9Cr_0.1 alloy was not enhanced.

Characteristics of Bound Micelle in the Ternary Mixing System of Alkali Metal Sulfate-SDS-PEG

HUANG Sheng-You, FANG Yun, CHEN Fang-Bo, FU Shan-Shan, REN Guo-Qiang

2005, 26(10):  1881-1885. 

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The ternary systems composed of some alkali metal(Li,Na and K) sulfate with sodium dodecyl sulfate(SDS) and polyethylene glycol(PEG) were studied by means of surface tension,steady-state fluorescence quenching and fluorescent molecule probe.The results show that the soft cluster formed spontaneously by PEG and the bound micelle of SDS in cases with or without alkali metal sulfate addition.The first critical concentration c₁ decreased while the second critical concentration c₂ increased slightly with ever-increasing level of alkali metal sulfate c_e,therefore,the clusterization boundary of SDS-PEG extended.The specific saturation capacity of clusterization increased with the addition of alkali metal sulfate and it even increased 40% when 50 mmol/L Li₂SO₄ was added to.The aggregation number of bound micelle N_b decreased linearly with the increase of PEG c_p while increased linearly as a function of c of SDS and increased monotonously as a function of c_e.Since the radius of alkali metal hydrated ion increased in the order as follows: K⁺(0.232(nm)<)Na⁺(0.276 nm)<Li⁺(0.34 nm),the capability of them to made N_b increased in the reversed order: K⁺>Na⁺>Li⁺.The characteristic fluorescence of the solubilized pyrene reveals that the polarity of bound(micelle) microenvironment decreased with the increase of the level of both c of SDS and c_e(Na₂SO₄),whereas(increases) with the increase of level of c_p.

Calculation of Charge Distribution in Iron(Ⅱ) Complexes by Using ABEEM Model

XIAO Hong-Yan, YANG Zhong-Zhi

2005, 26(10):  1886-1889. 

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Based on density functional theory and electronegativity equalization principle,the parameters of atoms and bonds in the model were determined by applying an atom-bond electronegativity equalization model and using a separated program,and through linear regression and least-squares optimization.By employing these parameters,the charge distributions of iron(Ⅱ) complexes were calculated.The results of calculation may be well relevant to those of ab initio method.

Oil-water Separation Performance of Anti-fouling α-Cellulose Hollow Fiber Ultrafiltration Membrane

LI Hong-Jian, CAO Yi-Ming, YANG Lin-Song, YUAN Quan

2005, 26(10):  1890-1895. 

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With cellulose as the polymer materials,monohydrate N-methylmorpholine-N-oxide(NMMO·(H₂O)) as the solvent,polyethylene glycol(PEG400) as the additives,asymmetric hollow fiber ultrafiltration membranes were prepared by the immersion phase inversion technique.Water was used as both the internal and external coagulant.The performances of the membrane were characterized by pure water flux.Experimental researches on treatment of oil-water emulsion by using cellulose hollow fiber membranes were performed.The results show that the treatment of oily wastewater by cellulose membrane is feasible and desirable.The oil eliminating efficiency of over 99% and oil concentration of less than 10 mg/L after the filtration were achieved, which can meet the requirement of drainage.The influences of different cleaning methods(physical cleaning,physical cleaning and 0.1 mol/L HCl solution,physical cleaning and 0.1 mol/L NaOH solution) on the cleaning of fouled cellulose membranes were investigated.The results show that the flux recovery of physical cleaning and 0.1 mol/L NaOH processes is 99%.

Quantum Chemistry Studies on Mechanism of Gas Phase Photochemical Chlorination of 2-Chloropyridine

HAO Jin-Ku, HUA Fang, YANG En-Cui, CAO Ying-Yu, YANG Kun, ZHAO Yan

2005, 26(10):  1896-1899. 

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The gas phase reaction mechanism of the photochemical chlorination of 2-chloropyridine was theoretically studied by using DFT B3LYP/3-21G~* method.The activation energy leading to 2,3-dichloropyridine,2,4-dichloropyridine,2,5-dichloropyridine and 2,6-dichloropyridine were also calculated respectively.The calculated results consistently show that the energy of transition state and the activation energy for the formation of 2,6-dichloropyridine were the lowest among the four reaction pathways.Therefore,the main product should be 2,6-dichloropyridine.The IRC result showed that the breaking of C—H and the forming of C—Cl were concerted but not synchronous.The structure of the transition state was near to 2,6-dichloropyridine,which showed that it was a late transition state.During the whole reaction processing,the Cl· acted as a nucleophilic specie,donating the electron.Therefore,S_N2 mechanism was speculated for the reaction of Cl· with 2-chloropyridine.

Synthesis and Unitization of Novel Electroluminescent Material Monodisperse Oligofluorenes

HU Xiao-Dan, SU Li, LIAO Qi, ZHEN Chang-Gua, CHUAI Yu-Tao, ZOU De-Chun

2005, 26(10):  1900-1904. 

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A series of novel electroluminescen material monodisperse oligofluorenes,were synthesized by modified Sonogashira reaction.The resulting oligomers were characterized by NMR,elemental analysis,DSC and MS.The products showed a strong PL emission and good solubility in common organic solvents.Light(emitting) diodes(LED) with the configuration ITO/NPB/OF/BCP/Alq/Mg∶Ag were fabricated.The LED based on OF4R4 exhibited highly efficient and stable electroluminescence and reached its maximum of 5 795 cd/m² at 20 V,on the other hand,the LED based on OF4R6 reached its external quantum efficiency of 1.0% at 11 V whereas the luminance was 511 cd/m² and the maximum was 2 690 cd/m².

Synthesis and Electrochemical Performance of Olivine LiFePO₄-based Composite Cathode Materials

TANG Zhi-Yuan, RUAN Yan-Li, SONG Quan-Sheng, LU Xing-He

2005, 26(10):  1905-1908. 

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Olivine LiFePO₄/C composite cathode materials were synthesized by a solid state method in an inert atmosphere.The effects of the calcined temperature on the properties of as-synthesized cathode materials were investigated.The crystal structure and the electrochemical performance were characterized by XRD,SEM,TG-DSC,laser particle-size distribution measurement and electrochemical performance testing.The results demonstrate that pure and well-crystallized powders,smaller particle size and intimate carbon contact are necessary for optimizing electrochemical performance.The material calcined at 750 ℃ had a complete olivine structure,uniform surface morphology,better particle-size distribution and excellent electrochemical performances.The initial discharge capacity,namely 142.5 mA·h/g,was obtained at room temperature and 0.05 C charge-dischange rate.After 50 cycles,there was no obvious capacity fade.

Molecular Recognition and "On-off" Switching of 30-Crown-10 to Biological-polar Guest Molecules

QI Li-Ya, TENG Qi-Wen, WU Shi, LIU Zheng-Zheng

2005, 26(10):  1909-1912. 

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Theoretical studies on the coordinations between 30-crown-10 and benzene derivatives,2-deoxyribose,ribose or fructofuranose,are carried out with AM1,MNDO and PM3 methods and the stability energy is obtained.It is indicated that 30-crown-10 recognizes polar guests especially 2-deoxyribose.The electronic spectra of the complexes are computed by INDO/SCI method.The blue-shift of absorption peaks of electronic spectra for the complexes takes place compared with that of the host. The molecular "On-off" switching is designed and the potential curve of the proton transfer is calculated.

Synthesis of Novel Amphiphile Containing Adenine and Molecular Recognition in Phosphatidylcholine/Cationic Amphiphilic Coliposomes

SONG Li-Ming, YU Jing-Sheng, QI Hai-Xia, WANG Qiu-Sheng, LI Guo-Wen

2005, 26(10):  1913-1916. 

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A novel amphiphile,N⁶-myristoyl-9-[8-(1-trimethylamino)octyl] adenine bromide(MTOAB,amphiphile 4),was synthesized as a receptor.The coliposomes were prepared from phosphatidylcholine(PC) and MTOAB by sonication of CHCl₃-cast films of amphiphiles mixtures\∶n(MTOAB)=10∶1] in doubly distilled water with a bath-type sonicator at 80 W for 3 h.The UV-Vis spectroscopic behavior of PC/MTOAB/fluorouracil coliposomes(molar ratio of 10∶1∶1) decreased slowly with the increase of time.The hypochromic effect can be ascribed to the hydroger bond formation between both adenine and fluorouracil group in the coliposomes.The intensity of the absorption band decreased to about 87.9% of its initial value and the coliposome can be stabilized for several weeks.These results demonstrate that it is possible to reproduce the recognition process of life system in the artificial chemical systems,which was performed in aqueous environment.

Synthesis and Fluorescence Properties of Fulleride Encapsulated in Mesoporous SBA-15 Host

GUO Zhuo, ZHU Guang-Shan, XIN Ming-Hong, LIU Cheng-Zhan, QIU Shi-Lun

2005, 26(10):  1917-1920. 

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The hybrid materials C₆0/SBA-15-NH₂ were synthesized by modifying the channel surface with amino-functional group.These materials were characterized by XRD,FTIR,UV-Vis and TG/DGA analysis.Furthermore,the fluorescence(FL) spectra of C₆0 in mesoporous materials were investigated.The FL emission of C₆0/SBA-15-NH₂ was observed at 554 nm,which is different from that of SBA-15-NH₂ at 575 nm.The emission band has blue-shifted 21 nm.

Resonance Raman Intensity Analysis of Charge-transfer Vibrational Reorganization Energies of I₂-1-Hexene Complex

ZHU Hong-Feng, ZHENG Xu-Ming

2005, 26(10):  1921-1925. 

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The absorption cross section and absolute resonance Raman cross section at three excitations within ca. 270 nm absorption band of the complex were obtained.Excitation near the maximum of the charge-transfer absorption results in a significant resonance enhancement of fundamentals ν_I-I and ν_CC,and their overtones and combination bands.The reorganization energy in each vibrational mode and homogeneous broadening contribution to the electronic linewidth are determined through quantitative modeling of the absorption and resonance Raman spectra by time-dependent wave-packet theory and using simple model.Total vibrational reorganization energy is measured to be 3 700 cm^-1,which is distributed to four Franck-Condon vibrational modes.The largest contribution is from I-I stretching vibrational mode with reorganization energy 2 490 cm^-1.The second is from CC stretching vibrational mode with reorganization energy 1 170 cm^-1.These two vibrational modes possess 98% of the total reorganization energy.The remaining 2% reorganization energy is partitioned into alkyl CH₃ and CH₂ twist vibration modes of 1-hexene moiety.

Photoluminescence Property of InAs Quantum Dots with In_xGa_1-xAs Layer Inserted

YANG Jing-Hai, GONG Jie, YANG Li-Li, FAN Hou-Gang, ZHAO Qing-Xiang

2005, 26(10):  1926-1929. 

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InAs quantum dots(QDs) have been grown on the GaAs(001)substrates by the method of molecular beam epitaxy.The emission of InAs QDs can be turned to about 1 300 nm by the introduction of a 10ML In_0.4Ga_0.6As layer.The photoluminescence of the samples were studied before and after being treated by(hydrogen) plasma.The results show that the enhancement of the PL intensity after H-plasma treatment(depends) on the excitation power,from about a factor of 12 at the low excitation limit to about a factor of 2 at the highest excitation power used in this study,which are probably due to competition between carrier capture by nonradiative centers and InAs QDs.PL intensity variation with the chauge of time and temperature were also investigated,and the results of them clearly illustrate that there indeed exist interface defects,both on the interface(between) the InAs dots and surrounding layers and in the GaAs layers,which can be suppressed heavily by H-treatments so that the PL intensity can be enhanced greatly.

Effects of Silver Films with Different Nano-particle Sizes on SERS of Single-walled Carbon Nanotubes

LIU Bing-Bing, YU Miao, LI Dong-Mei, CUI Tian, WANG Lin, YAO Ming-Guang, YU Shi-Dan, ZOU Guang-Tian, WANG Xu, ZHAO Bing, SUNDQVIST Bertil

2005, 26(10):  1930-1933. 

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Surface-enhanced Raman Scattering(SERS) spectra of single-walled carbon nanotubes(SWCNTs) on silver films with different nano-particle sizes from 20-100 nm deposited on quartz and glass substrates were studied systematically.The characteristic Raman spectral features of SWCNT G-band and D-band were analyzed.The two bands show a similar tendency with the change of nano-particle size of silver on quartz and glass substrates.The position and the intensity of the G-band are less sensitive to the films silver particle sizes in the studied range,indicating that hexagonal carbon rings are stable and have a weak interaction with silver films.The shape of the D-band is dependent on the silver size.The smaller the silver particle size,the more the contribution of high frequency vibrations to the D-band,indicating that disorder carbon has a strong interaction with the active silver films.

Dye-sensitized Nano-TiO₂ Thin Memberane Solar Cells Based on P(VDF-HFP)-type Gel Electrolytes

GUO Li, DAI Song-Yuan, WANG Kong-Jia, FANG Xia-Qin, SHI Cheng-Wu, PAN Xu

2005, 26(10):  1934-1937. 

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The I^-₃/I^-redox behavior for gel electrolytes and liquid electrolyte was studied by cyclic voltammetry.It is found that the apparent diffusion coefficient(D) values of triiodide and iodide ions in gel electrolytes were apparently lower than those in liquid electrolyte,the former were about third of the latter.The conductivity measurement of the gel electrolyte containing different sum of P(VDF-HFP) shows that the conductivity decreases with increasing the sum of P(VDF-HFP) in gel electrolyte.It may be due to that the pore is not well connected and the ionic transport is hindered by the pore blockage.We fabricated quasi-solid state dye-sensitized nano-thin membrane solar cells using gel electrolyte containing poly(vinylidenefluoride-co-hexafluoropropylene)(PVDF-HFP) which showed an comparable photo-electric conversion efficiency to the liquid cell.The quasi-solid state solar cell with 5%P(VDF-HFP) showed the values of 0.70 V for open-circuit voltage,15.52 mA/cm² for short-circuit photocurrent density,0.62 and 6.61% for Fill Factor and photo-electric conversion efficiency under the illustration of AM 1.5(100 mW/cm),respectively.

Monte Carlo Simulation of Acrylonitrile Solution Polymerization Initiated by Y(OAr)₃

ZHENG Hao, LING Jun, SHEN Zhi-Quan

2005, 26(10):  1938-1940. 

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The acrylonitrile solution polymerization was discussed based on experiments and Monte Carlo simulation.The simulation results indicated that anionic active species also present in the system.The polymerization is a rapid initiation,and fast deactivation process,and in the polymerization system there are two chain transfer reactions to monomer and to macromolecules respectively.A set of polymerization reaction rate constants was obtained: k_i=(0.053) L/(mol·min),k_p=1.63 L/(mol·min),k_d=0.005 8 min^-1,k_trm=(0.052 L/(mol·min)),k_trp=0.075 L/(mol·min),k_pp=0 L/(mol·min).

Reversible and High Dye-Loading of Amphiphilic Hyperbranched Poly(sulfone-amine)s

LIU Cui-Hua, GAO Chao, ZENG Hao, YAN De-Yue

2005, 26(10):  1941-1945. 

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Three samples of core-shell amphiphilic hyperbranched poly(sulfone-amine)(HPSA) were synthesized by end-capping of hyperbranched poly(sulfone-amine) with valeryl chloride,nonanoyl chloride and palmitoyl chloride in the presence of triethylamine.They exhibit high capabilities to load water soluble dyes,such as congo red(CR),methyl orange(MO) and rose bengal(RB).It is found that the longer the terminal hydrophobic chain is,the higher the loading capability would be for the same dye.The maximum loading quantity of our hyperbranched macromolecular vessel is an order of magnitude higher than that of dendritic box for MO,and is 1—2 orders of magnitude higher than that of other hyperbranched polymers reported before for CR.For the palmitoyl-terminated HPSA,the average number of dye molecules trapped by per macromolecule achieves 41.8 of CR,19.4 of MO,and 3.0 of RB,respectively.Such high loading-capability is considered to attribute to the high water-solubility of the hyperbranched poly(sulfone-amine) core and the large polarity difference between the hydrophilic core and hydrophobic shell.Interestingly,the loaded dyes can be released from the molecular vessel by mixing its chloroform solution with pure water.The high loading capability associated with the reversible releasing property would pave the way for the molecular vessels in the application of drug transfer/delivery,selective molecular recognition and separation,nanocatalysis and nanocoating.

Studies on Synthesis of 3-(2-Cyano ethoxy)methyl- and 3-[triethylenoxy)]methyl-3'-methyloxetane and Their Copolymers

YE Lin, FENG Zeng-Guo, LI Shi-Ting, WU Feng, CHEN Shi, WANG Guo-Qing

2005, 26(10):  1946-1951. 

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The two monomers 3-(2-cyano ethoxy)methyl- and 3-[-methyl-triethyloxetane were prepared from the reaction of 3-methyl-3'-hydroxylmethyl oxetane(HMO) with acrylonitrile and triethylene glycol monomethyl ether,respectively.A novel series of copolymers were synthesized by starting from these two monomers along with BF₃·ether as the catalyst and BDO as the initiator via a cationic ring-opening copolymerization.The GPC analysis presents the number average molecular weight of the copolymers ranging from 2 756 to 5 342,and polydispersity from 1.26 to 1.83.Regarding the glass transition temperature(T_g),the DSC results imply that these copolymers would have a higher ion inductivity than pure PEO.And the TGA measurements reveal that the copolymers possess a very high heat decomposition temperature.The conductivity of the AN20 at room temperature is about 1.07×10^-5 S/cm,while at 353 K is 2.79×10^-4(S/cm),approaching the practical requirement of polymer electrolytes for lithium ion batteries.

Synthesis of Unsaturated Polyphosphoesteran Injectable Bone Tissue Engineering Scaffold Material

QIU Jin-Jun, LIU Cheng-Mei, HU Fen, GUO Xiao-Dong, ZHENG Qi-Xin

2005, 26(10):  1952-1956. 

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Unsaturated polyphosphoester(UPPE) containing unsaturated olefinic bonds in repeat units was synthesized by fumaric acid,1,2-propylene glycol and phosphorous oxytrichloride as the initiation materials.Three kinds of isomers of bis(1,2-propyleneglycol) fumarate were detected in main chain of UPPE by FTIR and NMR.The effect of reaction time on condensation polymerization reaction was investigated with GPC.High and uniform molecular weight of polymer can be obtained by extending polymerization reaction time.The molecular weight is 5 956 g/mol and the polymer dispersion degree is 1.12 after refluxing for 18 h.The temperature curve of UPPE crosslinked with N-vinyl pyrrolidone indicated that the maximum temperature is from 41.14 to 82.30 ℃,and the setting time is between 1.95 min and 10.28 min.

Phase Behaviour of Supramolecules Containing Methoxy-azobenzene Mesogenic Liquid Crystal Groups

BAI Bing-Lian, PANG Dong-Mei, LI Min

2005, 26(10):  1957-1959. 

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The hydrogen-bonded supramolecular complexes(F_n and 2F₆) were prepared by the complexation of carboxylic acid derivatives and 4,4'-bipyridine.The IR spectroscopic study on F_n and 2F₆ shows that they were formed through single hydrogen bonding between —COOH and pyridyl groups.F_n showed a nematic state,while no liquid crystalline behaviour was observed for 2F₆.

Preparation of Orientated Magnetite/Chitosan Nano-composite Material via In-situ Precipitation

HU Qiao-Ling, CHEN Fu-Ping, LI Bao-Qiang, SHEN Jia-Cong

2005, 26(10):  1960-1962. 

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Because of biominerals,controlled morphology and unique properties,biominerals become the idea headspring for making organic-inorganic hybrid composite with new patterns.The preferred orientation phenomena of minerals on bioorganics are frequently observed in organisms,this can make the material's performances become better,the human bone is a good example.By now,in most of the prepared nano-composites,the nano-particles dispersed randomly in polymer matrix.In this paper,magnetic/chitosan nano-composite in the magnetic environment was prepared via in-situ precipitation.From the XRD,TEM testing results,it can be concluded that nano magnetite particles arranged orderly in the chitosan matrix,the average diameter of the particles is about 11.3 nm.This provides a new method for preparing three-dimensional magnetic biomaterial,and has broad potential application to the bone repair field.

Construction of Anti-bacterial Multilayer Films via Layer-by-layer Electro Static Self-assembly of Chitosan and Heparin

YUAN Wei-Yong, JI Jian, FU Jin-Hong, SHEN Jia-Cong

2005, 26(10):  1963-1965. 

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Chitosan as an antibacterial agent and heparin as an anti-adhesive agent were alternatively deposited onto aminolyzed poly(ethylene terephthalate)(PET) to construct anti-adhesive and antibacterial multilayer films.The contact angle and UV data verified the progressive build-up of the multilayer film by alternate deposition of the polyelectrolytes.PRT experiment and in vitro antibacterial assay indicated that the multilayer-modified PET films had much better hemocompatibility and much stronger antibacterial performance than(unmodified) PET.Such an easy processing and shape-independent method to prepare an anti-adhesive and(antibacterial) surface may have a good potential for surface modification of cardiovascular devices.

Ring-opening Polymerization of ε-Caprolactone Catalyzed by Rare Earth Chloride

YANG Xiong-Fa, NI Xu-Feng, SHEN Zhi-Quan

2005, 26(10):  1966-1968. 

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Ring-opening polymerization of ε-caprolactone catalyzed by rare earth chloride dissolved in N,N-dimethylformamide and adding a small amount of propylene oxide was studied.The optimum conditions for the ring-opening polymerization of CL are as follows.In the bulk polymerization: n(DMF)/n(LaCl₃)=10,n(PO)/n(LaCl₃)=20,aging temperature: 30 ℃,aging time: 1 h,c(CL)=7.91×10^-3 mol/L,c(LaCl₃)=1.58×10^-5 mol/L,the polymerization carried out at 30 ℃ for 1 h,yield=83.3%,M_ν=1.93×10⁴.In the solution polymerization: n(DMF)/n(LaCl₃)=10,n(PO)/n(LaCl₃)=20,aging temperature: 30 ℃,aging time: 1 h,toluene as the solvent,c(CL)=4.22×10^-3 mol/L,c(LaCl₃)=8.43×10^-6 mol/L,the polymerization was carried out at 30 ℃ for 2 h,yield=62.9%,M_ν=1.21×10⁴.

Crystallization Behavior of Single or Pauci Chain Congeries of Isotactic Polystyrene

XIN Yan, YU Ying, He Yong, ZHANG Yu, FAN Zhong-Yong

2005, 26(10):  1969-1971. 

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Single- and a few-chain aggregates of isotactic polystyrene(i-PS) were prepared by the freeze-drying procedure from dilute solutions with the concentration from 1×10^-3 to 2×10^-5 g/mL.It was found that the melting point of crystals was gradually shifted to lower temperatures as the solution concentration decreased by the differential scanning calorimetry(DSC).As a result, the thickness of the lamellas of bulk samples and the samples prepared by the freeze-drying procedure from 2×10^-5 g/mL solution decreased from 19.3 nm to 12.6 nm,respectively.The half crystallization time(t₁/2) of samples by freezing-dried from 1×10^-4 g/mL solution was about 36 s,it was merely a tenth of the period of the bulk sample annealed at 468.3 K.In addition,the growth rate of spherulite(dr/dt) of the samples prepared from 2×10^-5 g/mL solution was more faster than ones of the bulk samples annealed at 478.3 K.All these should be attributed to the samples with less entanglement prepared by freeze-drying procedure from dilute solution.A preliminary study on the crystallization of the samples indicates that entanglements has a pronounced effect on crystallization behavior of polymer.

Studies on Lamellar of Polyethylene Crystal from the Melt with High Resolution Transmission Electron Microscopy

YIN Li, CHEN Jian-Feng, YAN Shi-Feng, LIU Lei-Jing, ZHOU En-Le

2005, 26(10):  1972-1974. 

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The high resolution transmission electron micrographs(HRTEM) of lamellar crystal of polyethylene(PE) obtained from the melt were successfully obtained by using high resolution electron microscopy,although PE is a relatively irradiation sensitive polymer.The HRTEM images with a clear one-dimensional structure(reported) here were recorded in a transmission electron microscope(TEM) operated at 200 kV.The spacing(between) the fringes was found to be 0.37 nm,which is close to the d-spacing of(200) plane. Micrographs image were processed by using optical filtering methods to improve the signal-to-noise ratio.

A Study of Ultraviolet Irradiation Functionalization of LLDPE and Its Modification of PA66

WU Shi-Shan, RAN Qian-Ping, LUO Yan-Ling, SHEN Jian

2005, 26(10):  1975-1977. 

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The oxygen-contained groups such as C—O,C—OH,CO,C(O)O and C(O)OH are introduced onto the molecular chains of linear low density polyethylene(LLDPE) through ultraviolet irradiation at environmental temperature of 70 ℃ in air without adding any additives.The concentration of these groups increases with the iucrease of irradiation time.The gel appears in irradiated LLDPE,the gel content increases with the iucrease of irradiation time.The melt flow index decreases and reach minimum when the irradiation time is 24 h,and then increase.The interfacial adhesion between irradiated LLDPE and polyamide 66(PA66) and the mechanical properties of the PA66/irradiated LLDPE(80/20) blends are improved owing to the oxygen-contained polar groups introduced.Compared with those of PA66/LLDPE(80/20) blends,the tensile strength,Young's modulus,bending strength and notch impact strength of PA66/irradiated LLDPE(80/20) blends for 24 h are increased from 48.3,908,64.8 MPa and 31 J/m[PA66/LLDPE(80/20)blend] to 62.0,984,83.1 MPa and 85 J/m,respectively.

Preparation of Hollow Silica Nanospheres via Surface-initiated Atom Transfer Radical Polymerization Using Polymer Latex as Templates

CHEN Yi-Wang, NIE Hua-Rong, CHEN Lie, KANG En-Tang

2005, 26(10):  1978-1980. 

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Hollow silica nanospheres were synthesized by silyl functionalized poly(vinyl benzyl chloride)(PVBC) latex nanoparticles via surface-initiated atom transfer radical polymerization(ATRP) of 3-(trimethoxysilyl)propyl methacrylate(TMSPM),followed by polycondensation with tetraethoxysi-lane(TEOS) in the ethanol-ammonia and removal of the PVBC cores by thermal decomposition.Transmission electron microscopy(TEM) were used to characterize the intermediate products and the hollow nanospheres.