Table of Content

24 March 2004, Volume 25 Issue 3

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Articles

Synthesis and Luminescence Property of a New Yellow Phosphorescent Iridium(Ⅲ) Pyrazine Complex

ZHANG Guo-Lin, LIU Ze-Hua, GUO Hai-Qing, CHUAI Yu-Tao, ZHEN Chang-Gua, ZOU De-Chun

2004, 25(3):  397-400. 

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A new iridium pyrazine complex, [Ir(dphp)₂(acac)] (dphp=2, 3 diphenylpyrazine, acac=acetylacetone), was synthesized by reaction of diphenylpyrazine with iridium trichloride hydrate. The complex was characterized by elemental analysis, ¹H NMR, and mass spectroscopy. The UV Vis absorption and photoluminescence of the complex were investigated. The complex shows strong ¹MLCT(singlet metal to ligand charge transfer) and ³MLCT(triplet metal to ligand charge transfer) absorption at 393 and 528 nm, respectively. Organic light emitting diodes(OLEDs) with a configuration of ITO/NPB(30 nm)/NPB∶8% [Ir(dphp)₂(acac)] (25 nm)/PBD(10 nm)/Alq₃(30 nm)/Mg∶Ag(mass ratio 9∶1)(130 nm) were fabricated by using this complex as the triplet emissive dopant in NPB. The diodes showed an external quantum efficiency of 13.85% at 6.5 V and brightness of 11 478 cd/m² at 10 V. The power efficiency of the device was 15.54 lm/W at 6.5 V, indicating that this complex is a promising electrophosphorescent materials.

Fabrication, Structure and Conductivity of Hybrid Organic/Inorganic Langmuir-Blodgett Films of Polyquinoline/Octadecylamine/Rare Earth-substituted Heteropolyanion

WANG Zheng, LIU Shi-Zhong, DU Zu-Liang, HU Zhen-Gang, ZHANG Hong-Jie

2004, 25(3):  401-404. 

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Three kinds of hybrid organic/inorganic Langmuir-Blodgett films are obtained by the compact organization of poly(1,2 dihydro-2,2,4-trimethyl)quinoline(abridged as PQ), octadecylamine(abridged as OA) and rare earth substituted heteropolyanions[abridged as RE(PW₁₁ )₂, RE=Ce^Ⅲ, Eu^Ⅲ, Gd ^Ⅲ] using the Langmuir-Blodgett technique. They are characterized by the π-A isotherms, the absorption spectra, the fluorescence spectra and the atomic force microscope. The scanning tunneling microscopy shows that the conductivity of the hybrid LB films is much better after heteropolyanions having been incorporated in the films.

Preparation of γ-Fe₂O₃ Nanoparticles by Solid(wet)-phase Grinding

JIANG Guo-Hua, JIANG Ji-Sen

2004, 25(3):  405-408. 

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In this paper, a new method to prepare γ Fe₂O₃ nanoparticles was described. In the presence of polyethylene glycol(PEG 400), the mixture of FeCl₃·6H₂O and NaOH was ground and the γ Fe₂O₃ nanoparticles were prepared. The product obtained was washed and dried at 60 ℃ and calcined at different temperatures for 1 h. XRD, Mssbauer Spectroscopy, TEM, TG DTA and FTIR were used to characterize the samples. The results show that after dried at 60 ℃ for 2 h, the as ground sample was transformed into poor crystalline γ Fe₂O₃ ultrafine powder. After being calcined at 450 ℃ for 1 h, the ultrafine powder became good crystalline γ Fe₂O₃ nanoparticles with particle size of 30 nm. After being calcined at 500 ℃ for 1 h, perfect crystalline γ Fe₂O₃ nanoparticles were gotten with a particle size of 40 nm.

Solvothermal Synthesis and Characterization of 1D (NH₃CH₂CH₂NH₃)AgAsS₄

LI Xue-Feng, JI Min, BAIYIN Meng-He, JIA Cui-Ying, AN Yong-Lin, WANG De-He

2004, 25(3):  409-412. 

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A one dimensional compound (NH₃CH₂CH₂NH₃)AgAsS₄ with ladder like chains was synthesized solvothermally. This compound crystallizes in the monoclinic system, space group C2/c , with a =1 358 05(8)_nm, b =0.653 31(3)_nm, c =2.277 11(9)_nm, β =106.42(3)°, Z =8. The compound comprises anionic chains formed by tetrahedral AsS₄ sharing apices with AgS₃, and organic cations are located between the chains. The hydrogen bonding of N—H…S exists in the compound, which together with electrostatic force hold the anionic chains together.

Microporous Rare Earth Coordination Polymers Constructed by a Flexible Pimelic Acid Ligand

HUANG Liang, ZHANG Li-Ping, JIN Lin-Pei

2004, 25(3):  413-417. 

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Three new rare earth coordination polymers of pimelic acid (H₂pim), [Nd(Hpim)(pim)(H₂O)] ·2H₂O(1) and [RE ₂(pim)₃(H₂O)] ·H₂O [RE=Er(2), RE=Ho(3)] , were synthesized and characterized by elemental analyses, IR spectra and X-ray crystallography. In complex 1, Nd(Ⅲ) is bridged by pimelic acid ligands to form³D microporous structure. There are two types of lattice water in complex 1. One lies in microporous structure and the other is used to form O—H…O hydrogen bond. In complex 2, Er(Ⅲ) ions are connected by pimelate ligands into a 2D microporous layer structure. Two types of O—H…O hydrogen bonds make 2D framework into 3D supramolecular structure. Single crystal X-ray diffraction analyses shows that complex 3 is isostructural to complex 2. In three complexes, different conformations for H₂pim are found, showing that coordinating characteristics of the flexible ligands are different from the rigid ligands.

Crystal Structure and Properties of Coordination Polymer; {[Co(μ-4,4′- bipy)(4,4′-bipy)₂(H₂O)₂]·(4,4′-bipy)·(H₂O)₄·(OH)₃·(Me)₄N}_n

JIN Jing, NIU Shu-Yun, YANG Zhong-Zhi, YANG Guang-Di, YE Ling

2004, 25(3):  418-420. 

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A novel Co(Ⅱ) coordination polymer was hydrothermally synthesized and characterized. The crystal crystallizes in the monoclinic system, space group C_c with a =1.772 59(4)_nm, b = 1.150 00(10)_nm , c =2.452 76(11)_nm, β =92.723(3)°, V =4.994 3 nm³, Z =4, R =0.080 9, wR =0.213 4. The polymer based on [Co(μ 4,4′ bipy)(4,4′ bipy)₂((H₂O)₂]_n linear chains was cross linked by the H bond bridge of Co—OH₂…4,4′ bipy—Co and π-π stacking interaction, producing extended 2D ladder structure. The susceptibility of the polymer at variable temperature(2.0_300 K) shows a weak antiferromagnetic interaction and implies that the polymer has the tendency of spin transition. Also, the result of surface photovoltage spectroscopy(SPS) reveals that the polymer has a significant photo electronic transferring property in UV Vis regions, which correspond to π-π transition, L-M charge transfer transition(shoulder) and d-d transition of Co²⁺ion, respectively.

Quantitative Detection of the Expression Product of Tumor Suppressor Gene ING1 by Molecular Beacon Fluorescence Probe

LI Jun, WANG Ke-Min, TAN Wei-Hong, LIU Bin, GUO Qiu-Ping-TANG Zhi-Wen, LIU Ling-Feng

2004, 25(3):  421-424. 

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Three molecular beacons(MBs) were synthesized to find a suitable probe to hybridize the expression of ING1 gene, a recently identified tumor suppressor gene. The loop sequences of MB1 and MB2 are the anti sense and sense sequence of ING1, respectively. The sequence of MB3 is a piece of ssRNA sequence in tobacco mosaic virus, which has no analogy to human gene. MB1 is the most suitable probe because MB1 has the highest fluorescence enhancement after hybridizing with RNA extracted from normal cell. A simple method has been built for the quantitative analysis of ING1 mRNA from nasopharyngral carcinoma(NPC) cell lines and normal cells. The results show that the concentration of ING1 mRNA in normal cells is higher than that in tumor cells. This result is consistent to that of RT PCR detection. ING1 plasmid was delivered into living human NPC cells with liposome and the expression of ING1 by plasmid was monitored by the selected MB.

Breast Cancer Antigen Immunosensor Based on the Functional Sol-gel Film

LIANG Ru-Ping, QIU Jian-Ding, ZOU Xiao-Yong, CAI Pei-Xiang

2004, 25(3):  425-429. 

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A new type of non labeled immunosensor for the determination of breast cancer antigen(CA15 3) was made by combining sol gel with cross link techniques and utilizing glutaraldehyde(GA) to link CA15 3 antibody(Ab) on the functional sol gel film, so the sol gel/GA/Ab layer was immobilized on the surface of platinum disk electrode. Infrared spectrum(IR) and cyclic voltammetry(CV) were employed to investigate the structure and the electrochemical characteristics of the immunosensor, respectively. The linearity of CA15 3 in the range of 8—240 U/mL with a detection limit of 5 U/mL and the correlation coefficient of 0 998 are obtained. The experimental results show that the activity of the immobilized CA15 3 antibody is maintained better by this method, and the stability of the immunosensor is improved. The dependences of the potential response on pH, incubation time, sensitivity and reproducibility were studied, and the stability of the sensor was also evaluated. The immunosensor was found to be stable for about 30 days when stored in a dry state at 4 ℃. Satisfactory determination results of CA15 3 in serum samples were obtained by this method.

Determination of the Volatile Chemical Constituents of Notoptergium Incium by GC-MS and OPA or EWOP

GUO Fang-Qiu, LIANG Yi-Zeng, HUANG Lan-Fang, XU Cheng-Jian

2004, 25(3):  430-435. 

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The qualitative and quantitative determination of the chemical constituents in traditional Chinese medicines(TCMs) is an important task, which builds the foundation of the theory of pharmacological activity. The hyphenated chromatographic instruments combined with the related chemometric methods provide powerful tools for the resolution of such complex systems. The volatile chemical constituents of Notoptergium incium (NI) were analyzed by gas chromatography mass spectrometry(GC MS) and the overlapped peaks were resolved into pure chromatograms and pure spectra with iterative OPA or non iterative EWOP chemometrics resolution method. Sixty five of the 98 separated constituents in essential oil of Notoptergium incium , accounting for 92.13%, were identified and quantified by the developed method.

Development and Performance of Laser-induced Fluorescence Microfluidic Chip Analyzer

ZHOU Xiao-Mian, DAI Zhong-Peng, LIN Bing-Cheng

2004, 25(3):  436-440. 

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A laser induced fluorescence microfluidic chip system was developed. The detection system was designed according to the confocal principle. Main features of the system include the alternated emission filter in order to select many dyes, and computer controlled focusing Via 3 D micro manipulator and charge coupled device(CCD), and two curves of the current vs. time and two curves of the voltage vs. time for injection channel and separation channel displayed on the computer′s screen. The detection limit reached 6.67×10^-13 mol/L for rhodamine 6G. The linear range of detection was 4.02×10^-6 mol/L～4.02×10^-9mol/L. The high performance of the system was demonstrated by separation and detection of DNA fragments and PCR products on a home made cast molded PMMA microchip.

Studies on AOTF as the Wavelength Selector for SPR Sensor

TIAN Yuan, ZHANG Wei-Shi, SONG Da-Qian, CAO Yan-Bo, LIU Xia, ZHANG Han-Qi, XU Han-Ying

2004, 25(3):  441-444. 

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A surface plasmon resonance(SPR) experimental setup based on wavelength modulation using acousto optic tunable filter(AOTF) as the wavelength selector was described. The characteristic and performance of AOTF were introduced. Using the AOTF SPR sensor setup, alcohol, glucose and sucrose were determined. The linear ranges for the determination of alcohol, glucose and sucrose are 5%~60%(volume fraction), 0.028~0.280 mol/L, 0.014~0.140 mol/L, respectively. The mixture of glucose and sucrose was also analyzed. Some samples were analyzed with the sensor. The results obtained are in agreement with those obtained with standard method.

Preparation of Nano-scaled Magnetic Biological Probes of Fe₃O₄/Dextran/Antibody and Chromatographic Assay

HONG Xia, GUO Wei, LI Jun, LIU Yan-Mei, YANG Wen-Sheng, BAI Yubai, LI Tie-Jin , YUAN Hang, MA Lan

2004, 25(3):  445-447. 

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Dextran coated magnetic nanocomposites were prepared. A periodate oxidation method was used to further activate the magnetic dextran, forming magnetic polyaldehyde dextran, which could be conjugated to biomolecules, antibodes. The magnetic labeled nano scaled bioconjugates could be well blocked with BSA and exhibit high activity by ELISA and immunochromatographic strip assay.

Determination of Multipeptide Mixture by Using CZE Coupled with ESI-MS

LIANG Zhen, ZHANG Wei-Bing, ZHANG Yu-Kui

2004, 25(3):  448-450. 

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CZE ESI MS is one of the most sensitive detection method and one of the potential method for protomics analysis. In this work, peptide mixture was separated and detected by using CZE ESI MS, and the influence of pH value of buffer and composition of sheath liquid on CE separation and MS detection was investigated. The method allows the detection limits up to 4.2—33 pg. The result of this method is better than that of CE UV for the peptide analysis.

Chiral Resolution of Naproxen and Its Derivatives on Chiral Stationary Phase of Cellulose Tris(3,5-dimethylphenylcarbamate)-Coated Zirconia

DUN Hui-Juan, LI Yong-Min, LIU Chun-Hui, WEI Yong-Ju, CHEN Li-Ren

2004, 25(3):  451-453. 

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In this report the synthesis and characterization of chiral stationary phase of cellulose tris(3,5 dimethylphenylcarbamate) coated zirconia(CDMPC ZrO₂ CSP) was described. Direct optical resolutions of acidic racemate naproxen and its derivatives on the phase were investigated. Surface property of zirconia affects the chiral separation of naproxen greatly. Naproxen could not be eluted from the column unless an acidic modifier was present in the mobile phase. However, good chiral resolutions were obtained for its ester derivatives. The influences of loading amount of stationary phase, molecular structure of compounds, type of alcohols as the modifier and their concentration in mobile phase on chiral resolution were studied. The chiral recognition mechanism of the chiral stationary phase was discussed.

Synthesis and Characterization of a Novel Electron Acceptor——Fluoroperylene Diimide

SHI Min-Min, CHEN Hong-Zheng, SUN Jing-Zhi, YE Jian, WANG Mang

2004, 25(3):  454-457. 

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A novel electron acceptor, N,N′ diperfluorophenyl 3,4,9,10 perylenetetracarboxylic diimide (DFPP) with a good solubility and a high electron affinity was designed and prepared. Its molecular structure was characterized by FTIR and NMR measurements. As demonstrated by UV Vis, CV and ESR, the DFPP possessed much lower lowest unoccupied molecular orbital(LUMO) energy level of -4 37 eV, and the radical anion of DFPP could exist stoadily in the solution of DFPP in DMF because multiple strong electron withdrawing F atoms were introduced in the molecular structure of DFPP. Furthermore, through the simulation of the molecular conformation and the theoretical examinations of molecular interactions, the unique aggregate structure of DFPP was found; due to the disruption of the planarity of molecule structure and the increasing of intermolecular repulsion caused by the fluorination, and the radical anion of DFPP coule exist steadily in the solution of DFPP molecules stacked with the perfluorinated phenyl groups straightly above or below the perylene cores of the adjacent DFPP molecules.

Molecular Recognition Study of Some Aliphatic Chiral Enantiomers and Dyes with β-Cyclodextrin and Its Derivatives

ZHANG Qiang, LIU Yu

2004, 25(3):  458-461. 

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Spectrofluorometric and spectrophotometric titrations were performed in aqueous buffer solution at₂5 ℃ to give the complex stability constants for the stoichiometric 1∶1 inclusion complexation of β-cy-clodextrin( β-CD, 1), hydroxypropyl β cyclodextrin(HP-β-CD, 2) and 2,3,6-tri-O-methyl-β-cyclodextrin(MO-β-CD, 3) with six aliphatic chiral guests and four dyes. The molecular binding ability and selectivity of cyclodextrins 1—3 toward guests were discussed from the size/shape fit concept between hosts and guests. The results obtained indicate that hydrophobic and hydrogen bond interactions play an important role in the inclusion complexation of cyclodextrins 1—3, and the substituents introduced alter the original hydrophobicity of cavity and the molecular binding ability of β-cyclodextrin.

Low-valent Titanium Induced Reductive Cyclization of o-Nitrobenzamides and Ketones

SHI Da-Qing, WANG Ju-Xian, RONG Liang-Ce, ZHUANG Qi-Ya, HU Hong-Wen

2004, 25(3):  462-465. 

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This paper reports the reactions of o nitrobenzamides with ketones induced by titanium reagent(TiCl₄ Sm system). The results show that the low valent titanium promoted a novel reductive cyclization of o nitrobenzamides and ketones to give 1,2-dihydroquinazolin-4(3H)-ones. The products were characterized by elementary analysis, IR, ¹H NMR and X-ray single crystal diffraction. The crystal of compound 3b belongs to monoclinic system with space group P2₁/n, a =1.191 7(2)_nm, b =0.691 1(1)_nm , c =1 782 1(4)_nm, β=98.81°, V =1.455 04(5)_nm³, Z=4, D_c=1.220 g/cm³, μ =0.077 mm^-1 , F (000)=568, and final R =0.043 3 and wR =0.107 6 for reflections [ I>2σ(I) ]. In summary, a series of 1,2-dihydroquinazolin 4(3H) ones was synthesized Via reductive cyclization of o nitrobenzamides with ketones induced by the TiCl₄ Sm system. Our method possesses the advantages of easily accessible starting materials, convenient manipulation and moderate to high yield.

Preparation and Structural Characterization of a New Corn Anti-oxidative Peptide

XU Li, LI Xiang-Lu, WU Xiao-Xia, WANG Hua, HOU Rui-Zhen, HUANG Yi-Bing, ZHANG Xue-Zhong

2004, 25(3):  466-469. 

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A kind of new corn anti oxidative peptide was prepared Via protease hydrolysis of zein catalyzed by alcalase, an alkaline protease under a certain condition, followed by isolation and purification. The hydrolysis time was fixed on the basis of the dependence of antioxidative activity on hydrolysis degree. It was found that the hydrolysis for 4 h gave the highest antioxidative activity. The isolation and purification steps include ultrafiltration with a membrane of cutoff M_w 1 000, successive chromatography on Sephadex G-15, Amberlite CG-120(Na) ion exchange, Sephadex G-10 and preparative HPLC columns. The amino acid sequence of the antioxidative peptide was characterized to be Leu-Asp-Tyr-Glu by amino acid analysis and electrospray ion trap mass spectrometry. We also discussed the possible anti oxidative mechanism of the antioxidative peptide on the basis of its structure.

Hydroxyl Macrocyclic Polyamines Coordination Systems Interaction with DNA and Their Antitumor Activities in vitro

LIANG Feng, WEI Jun, LI Zhao-Yang, WU Cheng-Tai, ZHENG Cong-Yi, SUN Meng-Xiang

2004, 25(3):  470-473. 

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The interaction between plasmid DNA (pBR322 DNA) and Ni(Ⅱ), Ca(Ⅱ), Co(Ⅱ), Cu(Ⅱ) coordination systems of 3-hydroxyl-1,5,8-triaazacyclic amine (L1) and 3,13-dihydroxyl-1,5,8,11,15,18-hexaazacyclic amine (L2) with several molar ratios were investigated by agarose gel electrophoresis. The results suggested that M L1, M L2 and 2M L2 systems could catalyze the cleavage of supercoiled pBR322 DNA to the nicked and the linear form at the same time under near neutral conditions at 37 ℃. The efficiency of DNA cleavage decreased in the order 2M-L2>M-L2, because there was probably cooperativity between two metal ions in 2M-L2 systems which catalyzed the cleavage of DNA. The little cleavage was found under a comparable conditions by the metal ions or receptor alone. The antitumor activities of two receptors, metal ions and their metal coordination systems were all measured against BEL 7402 cell lines by using MTT assay. The metal ions have cytotoxicity to cells at 10^-3mol/L ; but when it was diluted to 10^-4mol/L, the percentage inhibition decreased sharply. On the contrary, the metal coordination systems still kept their antitumor activities even at 10^-5mol/L. Thus, these coordination systems may be useful as artificial restriction enzymes and may be usefully applied to the development of antitumor drug.

Investigations on the Adsorbents for Uremic Middle Molecular Toxins(Ⅲ)——Crosslinked Chitosan Bases Modified by Acidic Amino Acids

WANG Hong, ZHANG Ming-Ming, YANG Mei, L� Jian, YUAN Zhi, HE Bing-Lin, LIU Bin, ZHAO Cheng-Mei, SHEN Bin

2004, 25(3):  474-478. 

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Adsorbents for uremic middle molecular toxins were prepared by grafting acidic amino acids on chitosan bases. Six peptides with middle molecular weight from 500 to 5 000 were selected as the model uremic toxins accumulated in patient′s sera. The results show that these adsorbents have certain adsorption ability on the model peptides and middle molecules in patient′s at serum.

Separation and Structural Determination of Structure of a New Cembranoid Lactone from the Soft Coral of Sarcophyton sp.

MA Xiang-Quan, YAN Su-Jun, SU Jing-Yu, ZENG Long-Mei

2004, 25(3):  479-481. 

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Many cembranes, 14 membered ring diterpenoids, were reported to have antitumor and antimicrobial activities. Soft corals are rich sources of cembrenoid diterpenes. We reported cembrenoids lactones, such as sarcophinone, iso sarcophinone, sarcophine, sartrochine from the species of Sarcophyton in our earlier papers,. In continuation of our studies on the soft coral Sarcophyton , we obtained a new cembranoid lactone, named sarcophydiol(1) from a specimen of Sarcophyton sp . collected around the bay of Sanya, Hainan Island. On the basis of spectroscopic methods, its structure was determined as ( 10S^*,11S^*)₃,7,11α ,15 tetramethyl 10 β,11β dihydroxy cembr 2 E,6E,14(15)Z trien 16,1 olide(1). The bioactivities of compound 1 were under investigating.

Structrue of Liljestrandisine——a New C₁₉-Diterpenoid Alkaloid from Aconitum liljestrandii

XIE Guang-Bo, WANG Feng-Peng

2004, 25(3):  482-483. 

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Silica gel chromatography was adopted during the further study on the roots of Aconitum liljestrandii Hand Mazz and led to isolating a new C₁₉ dierpenoid alkaloid liljestrandisine(1). Its structure was established on the basis of spectral methods 2D NMR( ¹H ¹H COSY, HMQC, HMBC). Liljestrandisine was the second naturally occurring aconitine type diterpenoid alkaloid with an 16 α OH.

Surface State Studies of Nanocrystalline TiO₂ with High Dielectric Constant

RUAN Sheng-Ping, DONG Wei, WU Feng-Qing, WANG Jing, ZHANG Xin-Dong, ZHAO Mu-Yu

2004, 25(3):  484-487. 

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An appropriate amount of stearic acid was melted at 70 ℃, into which tetrabutyl titanate was added while stirring. Then the solution was cooled in cool water to form a gel. By controlling the amount of oxygen during the calcining procedure, nanocrystalline TiO₂ powder with even grain size and good dielectric properties were obtained. The surface state was analyzed by means of X-ray photoelectron spectroscopy and surface photovoltage spectroscopy. The results of experiments show that the surface structure of nanocrystalline TiO₂ is not integrate mainly due to the existence of oxygen cavities and most of the exposing atoms on the grain surface are Ti⁴⁺. The surface states of nanocrystalline materials put important influence on their dielectric properties and make the static state dielectric constant much bigger than that of bulk material.

Symmetry Breaking of Temperature Field in Spatially Distributed Systems Induced by Chemical Reaction-Diffusion-Heat Conduction Couplings

ZHANG Wen-Hua, XU Jiu-Ping, LUO Jiu-Li

2004, 25(3):  488-492. 

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Symmetry breaking of temperature field in spatially distributed pure dissipative systems induced by chemical reaction diffusion heat conduction couplings is analyzed in this paper. It is shown that this kind of self organizing processes in the temperature field is inevitable even for single component linear chemical reaction diffusion heat conduction system under a certain boundary conditions. As a prototype of temperature field in pure dissipative systems, the small spatially extended non isothermal Lindedman model, is further studied, both by analytic solution and with computer simulation. The results show that the threshold of spatio temporal symmetry breaking in the temperature field is dominated not only by the intrinsic parameters but also by the constraints forced on the system externally. An approach for bringing out, adjusting or avoiding this spatio temporal temperature pattern for utilization is then suggested.

Thermodynamic Stability Studies on the N-[Bis(2-pyridyl)methyl] pyridine-2-carboxamide Metal Complexes

GAO Dong-Zhao, GUO Yan-He, ZHU Shou-Rong, LIN Hua-Kuan, XU Xin-He

2004, 25(3):  493-496. 

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N [Bis(2 pyridyl)methyl]pyridine 2 carboxamide was synthesized and characterized. At₂5 ℃, I =0.1 mol/L KNO₃, the stability constants of the binary and ternary systems formed by the ligand with metal ions in ethanol aqueous solution were studied by pH titrations and the appropriate structures with respect to the titration species were proposed according to the literature and the obtained data. Furthermore we also investigated the thermodynamic stability difference between the copper and iron complexes. The results show that a good linear free energy relationship exists in the ternary systems.

Preparation and Characterization of Self-assembled Organic-Inorganic Nacre-like Nanocomposite Thin Film

ZHANG Sheng-Mao, ZHANG Jing-Wei, ZHANG Zhi-Jun, DANG Hong-Xin, LIU Wei-Min, XUE Qun-Ji

2004, 25(3):  497-500. 

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The DMCB/SiO₂ and DMTB/SiO₂ organic inorganic nanocomposite thin films were prepared by using super molecular self-assembly method on glass substrate, with the surfactant DMCB and DMTB as both the structure directing agent and the monomer to be polymerized, respectively. The as-deposited film was heated at a proper temperature and duration to allow the polymerization of the surfactant, which contributes to increasing the mechanical strength and stability of the film. The unpolymerized and polymerized films were characterized by FTIR, X-ray diffraction, and TEM. A model was also suggested to illustrate the structure of the as deposited film. The results also indicated that heat treatment of the as-deposited film led to polymerization of the organic phase and hence to increase the mechanical strength of the film. The results indicated that the films were composed of organic and inorganic layers with orderly interlaced arrangement and the distance between organic layer and inorganic layer was 3.48 nm(DMCB/SiO₂), 3.44 nm(DMTB/SiO₂) before polymerization and 2.84 nm(DMCB/SiO₂), 2.92 nm(DMTB/SiO₂) after polymerization, respectively. These films will be favourable for catalysis, optics and electronics or lubrication films.

Influence of Size of NiO on the Electrochemical Properties for SOFC Anodes

WANG Jin-Xia, JI Yuan, XU Da-Peng, HE Tian-Min, WANG Wei-Ran, ZHOU Xian-Feng, SU Wen-Hui

2004, 25(3):  501-503. 

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Nanometric NiO with a high specific surface area was synthesized by sol-gel method. NiO-YSZ anode materials were prepared by solid state reaction and their impedance spctra were measured. The analysis results show that NiO-YSZ anode materials with nanometric oxide NiO have a smaller polarization resistance R_p, higher conductivity than those with original powder NiO. The single cell with the anode of nanometric NiO-YSZ in 55% mass fraction has a higher power density and higher current density than that of the cell with the anode of original power NiO-YSZ in the same mass fraction. These demonstrate that the optimization of the anode can be obtained by increasing the three phase boundary(TPB) line among Nickel, YSZ and Hydrogen, which can be achieved by decreasing the size of the NiO.

Quantitative Identification of Nucleation and Crystal Growth Stages in Batch Crystallization from Solution

HUANG Pei, HUANG De-Chun, XU Nan-Ping, SHI Jun

2004, 25(3):  504-508. 

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For improving the precision of kinetic parameter estimation and further research of the mechanism, it was very important to identify nucleation and crystal growth stages quantitatively in the batch crystallization from solution. The dimensionless variables of K and K^* were described based on the difference of crystal number and its size contributing to the second and third moments of crystal size distribution(CSD), respectively. For a typical seeded crystallization of potassium nitrate in water reported in the literature, the simulated results showed that both K and K^* had a similar tendency and were also close during the crystallization process, and monotonously decreased in the nucleation stage and increased in the crystal growth stage. The solute concentration and transmittance were determined for an unseeded batch cooling crystallization of KNO₃-H₂O solution, and K^* was applied to identify the nucleation and crystal growth stages. It was noted that the crystal growth stage obtained by K^* agreed well with that by linear growth rate model. Compared with K simulated on the CSD and kinetic parameters, K^* could be calculated directly from relevant on line information such as solute concentration and transmittance, and therefore should be much more convenient and feasible.

Effect of Cosurfactants on Pore Size of Mesoporous Silica

HAN Shu-Hua, HOU Wan-Guo, XU Jun, LI Zheng-Min

2004, 25(3):  509-511. 

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Mesoporous silica was synthesized and templated by mixed micelles of cetyltrimethylammonium bromide(CTAB), n-pentanol or n-octylamine and nitric acid. The products were determined by small angle X-ray diffraction and N₂ gas adsorption desoption. The results show that pore size of mesoporous silica increased with increase of the molar ratio of CTAB to pentanol, while the pore size decreased with increase of the molar ratio of CTAB to n-octylamine. The reason is that micelle volume increased by addition of pentanol, resulting in the increase of the pore size of mesoporous silica, templated by the mixed micelles of CTAB, pentanol and nitric acid. However, there is bigger interaction between n-octylamin and silicate than that between CTAB and silicate in the mixed micelles of CTAB, n-octylamine and nitric acid, resulting in the decrease of the pore size of mesoporous silica.

A New Kind of Anionic Sensor Tested by Colorimetric Method

ZHOU Li-Li, ZHANG Xiao-Hong, WU Shi-Kang

2004, 25(3):  512-516. 

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The interaction and recognition between different anions and 6 kinds of intra molecular charge transfer compounds have been investigated in this paper. It is found that compounds 2, 3, 5 and 6 all possess an excellent ability to the detection of F^-anion. They also show themselves to have nice response to the H₂PO₄^-. And compound 6 has a selectivity for AcO^- over H₂PO₄^- anions. The experimental results have been discussed preliminary. And how to promote the sensitivity and the selectivity of these compounds are also discussed.

Studies on NiPMo₁₂ Catalyst for Direct Synthesis MAA from Propylene and Carbon Dioxide

WANG Da-Wen, ZHONG Shun-He

2004, 25(3):  517-521. 

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NiPMo₁₂ catalyst was prepared by using the reaction of MPA and nickel nitrate. The chemical composition, molecular structure, chemisorption character and reaction behaviour were studied by different techniques including inductively coupled plasma atomic emission spectroscopy, X-ray diffraction, thermogravimetric analysis, infrared spectrum analysis, extend X-ray absorption fine structure, temperature programmed desorption and microreactor, respectively. At 350 ℃, the catalyst still remained the original Keggin structure of MPA. The experimental results show that CO₂ chemisorbs at bridging oxygen of Ni—O—Mo (Lewis base site) and Ni²⁺ (Lewis acid site) to form bridged adsorption Ni(Ⅱ)←O—(CO)—(O^-—Ni) , and propylene chemisorbs on the surface of catalyst to form three adsorption states, and the main reaction products of CO₂ with propylene on the catalysts are MAA and β-butenic acid, with propylene conversion of 2.6%, MAA selectivity of 96%, at the reaction temperature of 290 ℃ and 1 MPa. MAA and β-butenic acid were synthesized by the route of hydrogen transfer and carbon-insert.

Prediction and Simulation on Interaction Between HIV-1 Envelope Protein gp 120 and Heparin

YAN Zuo-Wei, HU Yuan-Dong, LI Song, JIANG Tao

2004, 25(3):  522-525. 

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Molecular simulation software are used to investigate the interaction between HIV-1 envelope protein gp 120 and heparin. Monosaccharide, disaccharide and trisaccharide of heparin are used as the probe molecules to make a global search around protein gp 120. After statistics analysis, we found the most favorable binding domain on gp 120 to heparin, and got two binding model which could be used to interpret the phenomenon that heparin could inhibit HIV-1 in vitro very well by docking heparin hexasaccharide to the binding domain.

Theoretical Studies on Several TPA Materials with Three Different π Electron Centers

YANG Li, REN Ai-Min, FENG Ji-Kang, LIU Xiao-Juan, ZHOU Xin

2004, 25(3):  526-530. 

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Using density functional theory and ZINDO method, the two-photon absorption(TPA) cross section( δ ) and nonlinear third-order optical hyperpolarizabilities( γ ) of several TPA materials with three different π electron centers(diphenylacetylene, stilbene and azobenzene) were theoretically investigated. On the basis of correct geometry and UV-Vis spectrum, the position and strength of the one-photon absoorption(OPA) and two-photon(TPA) were studied and compared systematically.

Solid-State High-Resolution ¹³C NMR Studies on Interfacial Interaction of PEO/Nano-SiO₂ Composites

YAO Ye-Feng, YANG Guang, CHEN Qun

2004, 25(3):  531-534. 

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A series of nano SiO₂/PEO composites with different compositions were prepared and studied by solid-state high-resolution NMR spectroscopy. The ¹H spin-spin relaxation time( t₂) of PEO in the composites was measured Via ¹H→ 13^C cross polarization. It is found that with the increase of nano-SiO₂ content, the crystallinity of PEO decreases greatly while the mobility of PEO chains in the noncrystalline region of PEO decreases dramatically. A model was suggested to describe the interfacial structure of the nano SiO₂/PEO composites based on the single exponential relaxation characteristic of the ¹H t₂ decay curve. Via ¹H→ ²⁹Sicross-polarization the dynamics of the hydroxyls lying on the surface of nano SiO₂ particles was also studied. The obtained result strongly suggests that at room temperature there exists an equilibrium of forming and breaking of the hydrogen bonds between the surface hydroxyl group and the ether oxygen.

Theoretical Investigation of Cyclooxide Isomers of Armchair Single-walled Carbon Nanotubes

ZHANG Chong, LI Rui-Fang, WANG Gui-Chang, SHANG Zhen-Feng, PAN Yin-Ming, CAI Zun-Sheng, ZHAO Xue-Zhuang

2004, 25(3):  535-538. 

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The geometries of Armchair single walled carbon nanotubes with different lengths and diameters, i.e . (3,3)/C₄₂ H₁₂ , (4,4)/C₅₆ H₁₆ , (5,5)/C₇₀ H₂₀ and (6,6)/C₈₄ H₂₄ were optimized by Gaussian 94 programme, and so did their cyclooxide isomers. The results showed that there were four isomers found for shorter and enlarged carbon nanotubes, which were named as Sloppy closed(S-closed), Sloppy-open(S-open), Horizontal closed(H-closed) and Horizontal open(H-open) isomers; and there were only three of them (without H-closed isomer) were found for longer and slimmer carbon nanotubes. After frequency analysis, there were no negative frequencies found for them, which indicated that these isomers were all stable ones. At the same time, we investigated the heat of formation( H_f), ionization potentials, distort energies, electron affinities energies and the energy gap of HOMO-LUMO of these carbon nanotubes and their corresponding cyclooxide isomers, and also discussed the relationship between the stability and these parameters. In addition, we explored sp² rehybridization of carbon atoms and strain force of these nanotubes using POAV programme.

Hydrogen-bonding Interaction in Water/Methanol Mixed Solvent and Theoretical Studies on Solubility of Polymer Chain

GONG Zhen, LI Xiang-Yuan, LI Ze-Rong

2004, 25(3):  539-542. 

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Theoretical study on the structure of hydrogen bond was carried out by using density functional theory. Geometries were optimized at B3LYP/6-31G^* and single point calculations were performed at B3LYP/6-31+G^* level. Stabilization energy was obtained by taking basis set superposition error correction into account. After the investigation of various minimum-energy geometries, single-ring structures of water pentamer and water hexamer were found most stable in liquid water. The calculations show that these single-ring structures have no imaginary frequency. Adding the methanol molecules to the ring like water cluster, geometries of water-methanol complexes were optimized. No imaginary frequencies were found in these structures. A significant and novel feature revealed firstly in this work is the perfect double hydrogen bond between methanol molecules and the ring-like water complexes. In water and methanol solvent, the polymer chain, PNIPAM, can form hydrogen bond with solvent molecules. It can stretch to coil shape and be soluble. But when the two solvents are mixed, water and methanol molecules will form stable comlexes because of strong double-hydrogen bonding. The active point of hydrogen bonds of mixed solvent will be shielded; and the solvent becomes non-polar. So, the polymer chain will overlap immediately because of the formation of intra molecular hydrogen bonds and consequently perform a coil-to-globule transition.

A Study of (BN)_n Fullerene and BN Mono-layer Nanotubes by Graphic Theory

KE Hong-Wei, ZHANG Qian-Er

2004, 25(3):  543-546. 

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The stabilities of (BN)₁₂ , (BN)₁₆ and BN nanotubes was studied by graphic theory and density functional theory(DFT). The results of the two methods both show that BN nanostructures are more stable than the same structure of C. So it is significant that BN nanostructures are studied qualitatively by graphic theory.

Surface Modification Induced Surper-hydrophobicity of Well-aligned ZnO Nanorod Array Film

GUO Min, DIAO Peng, CAI Sheng-Min, LIU Zhong-Fan

2004, 25(3):  547-549. 

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Well-oriented ZnO nanorod array films were prepared by a low cost and low temperature hydrothermal approach. The wettability of the films were studied. The films treated with octadecanethiol(ODT) possess super hydrophobic properties. The static contact angle for water of the ODT modified films is 155.3°±2.3°, and the advancing and receding angles are 156.5°±1.9° and 150.3°±2.8°, respectively. It is believed that the super-hydrophobic property of the ZnO nanorod array films is mainly caused by the nanostructures of the films and the modification of ODT adsorption layer on ZnO surfaces.

Studies on the Interaction Between Cu Nanoparticles and ZnO Nanoparticles with EPR and XPS

WANG Zhen-Lü, WU Tong-Hao, YU Jian-Feng, ZHU Wan-Chun, YANG Piao-Ping, JING Shu-Bo, WANG Guo-Jia

2004, 25(3):  550-552. 

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The mixtures of Cu nanoparticles and ZnO nanoparticles were obtained with some physical methods, such as grinding and ultrasionic dispersion and characterized by EPR and XPS. The EPR results showed that no signal could be observed in the Cu EPR spectrum and only a signal g=1.961 appeared in the ZnO spectrum before they were mixed. After they were mixed, a special signal that could be attributed to Cu²⁺ was observed in the spectrum. The XPS results showed that the values of the kinetic energy of ZnL₃M₄₅M₄₅ and O_1s changed in the XPS spectrum of the mixture, indicating that Zn valance decreased. We could also find that a new O species appeared in the mixture. These results showed that there was some interaction between Cu nanoparticles and ZnO nanoparticle, and the model would be Cu—O—Zn.

Preparation of 2-Quinolinethiol Capped Gold Nanoparticles and Its Electrochemical Properties

LI Di, LI Jing-Hong

2004, 25(3):  553-555. 

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2-Quinolinethiol was employed as one stabilizer to produce 8—10 nm gold nanoparticles. UV-Vis spectrum confirmed the surface plasmon absorbance and in comparison with alkanethiolate-gold nanoparticles with the same size, the blue shift in absorbance peak was interpreted as the free electron transferred from N to gold core. Cyclic voltammograms proved that the reduction potential of 2-quinolinethiol was not altered as it assembled onto gold nanoparticles, however there appeared an obvious hysteresis in oxidation current, which was attributed to the oxidation ability of quinoline reduction product.

A New Method for Synthesis of DAR·2HCl and Its Polymerization with Terephthalic Acid

ZHANG Chun-Yan, SHI Zi-Xing, ZHU Zi-Kang, XU Ji-Ping

2004, 25(3):  556-559. 

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A new method for synthesizing 4,6-diaminoresorcinol dihydrochloride(DAR·2HCl) was adopted by three steps, which will give DAR·2HCl without involving any nitro or halo compound but in high yields and high regioselectivity. In the first step, the resorcinol was reacted with acetic anhydride to give the 4,6-diacylresorcinol, then followed by the oximation of 4,6-diacylresorcinol to form the dioxime with the addition of hydroxylamine hydrochloride, finally, the dioxime was subject to producing DAR·2HCl by Beckmann rearrangement in the presence of polyphosphoric acid . The structures of these two intermediates and the final product(DAR·2HCl) were characterized and confirmed by FTIR, MS, elemental analysis, ¹H NMR and 13^C NMR etc ., the results show that all the products are very pure. Meanwhile, the salt of 4,6 diaminoresorcinol/terephthlate(TPA) was prepared with DAR·2HCl and terepthalic acid. By using TPA salt as the starting monomer, polybenzoxazole(PBO) with a high molecular weight was obtained in the polyphosphoric acid. The structure and thermal property of PBO were characterized by means of FTIR, solid state 13^C NMR and TGA.

Investigation on Colloidal Crystals Fabricated by Rapid Self-assembly of Monodispersed Cross-linked Carboxy-modified Polymer Microspheres

CHEN Zhi-Min, CHEN Xin, ZHANG Kai, CUI Tie-Yu, CUI Zhan-Chen, YANG Bai

2004, 25(3):  560-564. 

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By means of vertical deposit method on several kinds of substrates, mondispersed cross-linked-carboxy modified polymer microspheres were self assembled into colloidal crystals rapidly in the temperature range of 20_70 ℃. The colloidal crystals fabricated by the polymer microspheres with different diameters show different stop-bands due to the Bragg diffraction. The relationship between the stop-band of colloidal crystals and the diameters of polymer microspheres were investigated by using UV-Vis spectra. Experiments had proved that the stop band red-shefted with increasing the diameters of the polymer microspheres, while blue-shifted with the increasing of the incidence angle. It was studied that the effects of pH value and other factors on the self-assembly of these polymer microspheres by SEM and AFM. We found that the polymer microspheres could form colloidal crystals in a broad range of pH value from³.0 to 13.0, which was mainly based on the fact that the microspheres can change their surface properties by turning carboxy groups to their corresponding ions at different pH values. The property of these microspheres could manipulate the interactions among themselves in the self-assembly procedure, leading to the above results.

Synthesis and Characterization of the Crosslinkable PMMA and PS Types of Polymers with High Thermal Stability for Nonlinear Optics

WANG Yao, FU Na, CHUAI Xiao-Hong, L� Chang-Li, CUI Zhan-Chen, ZHANG Da-Ming, YI Mao-Bin, LIU Shi-Yong, YANG Bai

2004, 25(3):  565-569. 

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In this paper, the thermal stability of poly[(DR1M)-co-(MMA)] and poly[(DR1M)-co-(St)] have been evidently improved by copolymerizing with epoxy GMA through sealed-tube reactive method. The two regular crosslinkable PMMA and PS types of nonlinear optical(NLO) polymers with a high yield were acquired. The two types of polymers, to which side chains containing NLO chromophores(DR1) were covalently attached, were of high thermal stability for nonlinear optics. Studied with DSC and TGA, it can be concluded that the glass transition temperatures of the two polymers, 398 and 397 K, respectively, approximately increased 30—50 K compared with that before crosslinked. Besides, the decomposition temperatures(at 5% mass loss) of the polymers were 552 and 546 K, respectively. The second-order nonlinearity of the polymers was measured with the simple reflection technique at 1.3 μm wavelengths. The values of electro-optic coefficient( r₃₃) of the two types of polymers after crosslinking were 12.50, 8.60 pm/V respectively and they were both stabilized around 75% of their initial values after 100 h at room temperature. The above results confirmed that the thermal stability of copolymers was improved significantly, which is due to the opening and crosslinking of the epoxy group in the copolymers.

Studies on the Preparation of Sm(AA)₃/NBR Composites by in situ Reaction Method and Their Fluorescent Properties

LIU Li, ZHANG Xiu-Juan, JIN Ri-Guang, YANG Cheng, HE Lei, ZHANG Wan, ZHANG Li-Qun

2004, 25(3):  570-574. 

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Two methods were used to prepare the Sm(AA)₃/NBR composites. The photographs of SEM and TEM indicated that in situ reaction not only reduced the sizes of the particles but also made them well dispersed. The fluorescent results showed that there were two emission peaks at 379 nm(⁴D_1/2, ⁶P_7/2→ ⁶H_5/2) and 418 nm( ⁴L_15/2, ⁴G_1/2→ ⁶H_5/2) when the composites were excited by a 260 nm excitation. The emission peaks are similar to those of the free samarium ion at 374 nm and 390 nm, which belong to the emission of the central ion. The fluorescent intensity of the composites prepared by in situ reaction method is much stronger than those made by other methods. Moreover, the fluorescent intensity of these composites will be enhanced with the increase of the content of the rare earth element until the rare earth element content reaches 30%(mass fraction).

Multilayer Assembly Based on Concanavalin-Glycoprotein Specific Interaction and Its Application to the Preparation of Glucose Biosensors

SHI Li-Xin, LU Ying-Xi, ZHANG Jing, LIU Jun-Qiu, SHEN Jia-Cong

2004, 25(3):  575-579. 

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The multilayers were constructed by the strong lection glycoprotein specific interaction and were used in the preparation of glucose biosensors. The results showed that the glucose oxidase with glucose residues and hydrogen peroxidase without glucose residues could be assembled into multilayers. The thickness of multiplayer films increased linearly with the increase of the layers. The morphology was investigated, and the relationship between film structure and function was discussed. The study on electrochemistry of gold electrode of lectin enzyme multiplayer shows that the enzyme in multilayers remains the catalytic activity.

Surface Architecture of PMMA-g-SPEO and Its Effects on Protein Adsorption

JI Jian, SHEN Jia-Cong

2004, 25(3):  580-584. 

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To investigate the effects of SPEO surface architecture onto protein adsorption, a “loop-like” SPEO(surface A) and a “tail-like” SPEO(surface B), which had almost the same surface composition, were constructed Via a special thermal treatment. The contact angle on the Surface A/water interface decreased rapidly with increasing of the water hydration time. After longer water incubation, it presented a hydrophilic interface and impart significant resistant to both albumin and fibrinogen adsorption. But it is non selective for the albumin. By contrast, the contact angle on the Surface B/water interface decreased little with water hydration. It presented a hydrophobic interface, which exhibits a very low fibrinogen adsorption while adsorbing a high level of albumin. The results proved that surface B may keep a “tail-like” SPEO in aqueous solution and it is possible to get a glycocalyx mimic surface, in which a hydrophobic matrix was covered by a layer of flexible hydrophilic PEO and then by hydrophobic signal molecules. The theoretical analysis of the SPEO surface architecture onto protein adsorption was also explored preliminarily.

Syntheses and Characterization of Poly(olefin-co-ester)s

ZHAO Xian-Liang, LIU Jing-Yu, LI Yue-Sheng

2004, 25(3):  585-588. 

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A series of copoly(olefin-co-ester)s were synthesized and characterized by starting from cyclooctene, cyclooctadiene or nobornene with ethanediol di(10-undecenoate) Via metathesis copolymerization and hydrogenation reaction. The yield, molecular weight, polar comonomer content and melting temperature of the poly(olefin-ester)s can be controlled by the change of polymerization reaction condition. Two step procedure is preferable to prepare high molecular weight poly(olefin-ester)s with a high polar monomer content and a high melting temperature.

Refining of Polyacrylonitrile Nanofiber

YANG Qing-Biao, WANG Ce, HONG You-Liang, LI Zhen-Yu, ZHAO Yi-Yang, QIU Shi-Lun, Wei-Yen

2004, 25(3):  589-591. 

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Preparation of polyacrylonitrile(PAN) nanofibers Via electrospinning was reported in the literature, in which diameter of the nanofibers ranged from 500 to 1 000 nm. We investigated the effect of processing parameters, such as solvent types, solution mass fraction, spinning angle, and molecular weight on morphology and diameter of the PAN nanofiber in detail. The results showed that ultrafine PAN nanofiber with an average diameter of 20 nm could be obtained by adjusting the electrospinning parameters.

Synthesis of Parent Aniline Hexamer via One-step Method and Its UV-Vis Spectral Study

CHEN Liang, YU You-Hai, MAO Hua-Ping, LU Xiao-Feng, ZHANG Wan-Jin

2004, 25(3):  592-594. 

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The parent aniline hexamer was synthesized in the emeraldine base(EB) oxidation state through one step oxidative coupling reaction using parent aniline trimer in the leucoemeraldine oxidation state. The hexamer in the EB state was reduced by phenylhydrazine in ethanol and was characterized by IR, ¹H NMR , MALDI-TOF-MS and elemental analysis. The chemical oxidation process of the hexamer was studied by UV-Vis spectra. It was found that the hexamer was oxidized to its EB form and then to the pernigraniline oxidation state.