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Table of Content

    10 April 2011, Volume 32 Issue 4
    Contents
    Cover and Content of Chemical Journal of Chinese Universities Vol.32 No.4(2011)
    2011, 32(4):  0. 
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    Letters
    Electrochemical Performance Matching Between LiTFSI/2-Oxazolidinone Complex Electrolyte and Various Carbon Materials with Different Pore Size and Surface Area
    CHEN Ren-Jie, ZHANG Hai-Qin, WU Feng*, XU Bin, LI Li, CHEN Shi
    2011, 32(4):  797-799. 
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    Ionic liquids based on lithium bis(trifluoromethane sulfone)imide (LiTFSI) with 2-oxazolidinone (OZO) exhibit superior physicochemical properties, such as a wide liquid-phase range and high ionic conductivity, that make them useful electrolytes in electrochemical capacitors. The configurations of ions (“free” ions, contact ion pairs and aggregates) in the electrolyte and their interactions have an important influence on the electrochemical performance of the LiTFSI-OZO system. Electrochemical double layer capacitors (EDLCs) composed of various carbon electrodes with different pore sizes and surface areas (carbon nanotubes, mesoporous activated carbons (MEACs) and microporous activated carbons) and the LiTFSI-OZO system as the electrolyte are prepared. Electrochemical performance matching of the EDLCs indicate that the one containing MEACs, which have the largest surface area and most compatible pore size of the carbon materials, possesses the highest specific capacitance of 184.6 F?g-1. This work shows that it is necessary to closely match the pore sizes of electrode materials with the ion sizes of the electrolyte system to optimize the performance of novel room temperature ionic liquids. Keywords Ionic liquid; Electrolyte; Supercapacitor; Mesoporous carbon
    Articles
    Siting and Accessibility of Lithium Cations in Zeolite Li-OFF
    Lü Xin-Chun*, ZHAO Rong, WU Tai-Liu, SUN Yao-Jun, TANG Yi
    2011, 32(4):  800-804. 
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    NH4-OFF zeolite was obtained by cations exchange of OFF zeolite.The Li-OFF zeolite with different exchange degree of Li+ cations was prepared through solid-state reaction of Li2CO3/NH4OFF system. Paramagnetic shift effect of adsorbed O2 was observed in the 7Li MAS NMR spectra of all O2 containing Li-OFF samples. By simulation of the 7Li MAS NMR spectra, it was found that Li+ cations are located in three types of cationic sites, corresponding to three simulated peaks. Li+ cations prefer the site A in the center of the channel. With the growth of exchange degree, Li+ cations appears more gradually in site B and C where need higher potential energy. As for the 100% Li+ exchanged OFF, Li+ cations occupy the three locations with a constant ratio: 54% site A, 17% site B and 29% site C, and approximately 83% of Li+ cations are accessible to O2 molecules.
    Photoluminescence Properties of Perovskite  BaZrO3∶Y Hollow Microspheres
    CHEN Juan, YE Tian-Nan, ZHAO Yong-Nan*, YU Jian-Guo, WANG Shao-Fei
    2011, 32(4):  805-808. 
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    Y doped BaZrO3 hollow nanospheres with different doping contents were hydrothermally synthesized. Y was successfully introduced into the lattice and replaced the Zr at B position of perovskite. The mean particle size varied from 180 nm to 300 nm by elevating the Y content. Pure cubic perovskite phase formed within 3% Y doping content. When excited by 410 nm laser, these hollow nanospheres emitted 503 nm light at room temperature. The PL intensity was positively related to Y doping content due to the increased oxygen vacancies that were induced by Y doping.
    Preparation and Formation Mechanism of Cuprous Oxide Microcrystals
    NING Jia-Jia, XIAO Ning-Ru, LIN Ao-Lei*
    2011, 32(4):  809-813. 
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    Hexagram-like cuprous oxide microcrystals have been synthesized by hydrothermal approach. The hexagram-like cuprous oxide microcrystals are produced by etching the six {111} facets in octahedron. The influence of reaction parameters on the shape and size of products has been discussed, the concentration of precursor has important effect on the shape of products. Only the concentration of procursor is low enough, the cuprous oxide octahedron should be formed. With increasing the concentration, the shape of products would transform to sphere. Ammonia has influence on the shape. Sodium citrate is the reduction and surfactant in the reaction. The etching on the octahedron is induced by both ammonia and sodium citrate.
    Synthesis, Structure and Surface Photo-electric Properties of a Series of Co-aip Coordination Polymers
    CONG Sheng-Mei, LIU Dong-Wei, LI Lei, JIN Jing, NIU Shu-Yun*, ZHANG Guang-Ning
    2011, 32(4):  814-821. 
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    Three Co(II) coordination polymers with the ligand of 5-aminosalicylic groups [Co2(aip)2(bipy)]n?2nH20 (1), [Co(aip)(imH)]n (2), [Co(aip)(phen)]n (3) (H2aip = 5-aminosalicylic acid, bipy = 2,2′-bipyridine, imH = imidazole, phen = 1,10-phenanthroline) were synthesized by hydrothermal method. They were characterized by X-ray single crystal diffraction, IR, UV-Vis, elemental analysis, SPS and FISPS. The structural analyses indicated that the complex (1) is 3D infinite coordination polymer; complex (2) and (3) are both 2D infinite coordination polymers, and hydrogen bonds link the complexes further connect to 3D infinite structures. There are four coordination fations of aip groups, i.e., μ3-ηo1ηo1ηo1ηo2, μ5-ηn1ηo1ηo1ηo1ηo1, μ3-ηn1ηo1ηo1, μ3-ηn1ηo1ηo1ηo1. At the same time, the surface photovoltage spectroscopy (SPS) and field-induced surface phtotvoltage spectroscopy (FISPS) were determined. The results revealed the complexes 1~3 exhibit positive surface phtotvoltage responses in the range of 300~800 nm, which indicated that the three polymers have certain photo-electric conversion properties. The influences of coordiantion enviroment and demensition for the SPS and the relationships between UV-Vis spectra and SPS were disscussed.
    Fabrication and Enhanced Photocatalytic Properties of Heterostructures SnO2/TiO2 Composite Nanofibers
    LI Yue-Jun, CAO Tie-Ping, WANG Chang-Hua, SHAO Chang-Lu*
    2011, 32(4):  822-827. 
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    Heterostructured SnO2/TiO2 composite nanofibers were prepared via (1) electrospinning fabrication of anatase nanofibers by adopting Polyvinylpyrrolidone (PVP) and n-butyl titanate as precursors and (2) hydrothermal growth of SnO2 nanostructures on anatase nanofibers substrate. The morphology and structure of SnO2/TiO2 composite nanofibers were characterized by scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD) analysis. The results showed that SnO2 nanoparticles could evenly grow on the TiO2 nanofibers surface and thus heterostructured SnO2/TiO2 composite materials were successfully obtained. By employing rhodamine B degradation as the model reaction, we found that the SnO2/TiO2 heterostructures showed enhanced photocatalytic efficiency compared with the bare TiO2 nanofibers under UV light irradiation. Last, the mechanism for the enhancement of photocatalytic activity of heterostructured nanofibers was discussed.
    Influence of Seed-layer to Orientation of TiO2 Nanorod Array and Interface State
    YUAN Zhan-Qiang, PANG Shan, CHENG Ke, LIU Bing, WANG Guang-Jun, ZHANG Xing-Tang, DU Zu-Liang
    2011, 32(4):  828-833. 
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    The single crystle TiO2 nanorod arrays gown on FTO substrate were prepared by hydrothermal method. The morphology, structure and photoelectric property were investigated with Scanning electron microscope (SEM), X-ray diffraction spectrum (XRD), ultraviolet-visible absorption spectrum (UV-Vis) and surface photovoltage spectrum (SPS) respectively. In the contraction of different arrays with different substrates we found that the FTO substrate had a decisive effect on the growth of nanorod arrays. The lattices of TiO2 seed layer and SnO2:F matched very well, which helped the epitaxial growth and the orientation of nanorod arrays. According to the Field induced surface photovoltage spectroscopy, there was a band upward bending in TiO2 nanorods at the interface of TiO2 and FTO. Introducing seed layer into the process of growth would help the orientation of array, decrease the interface state greatly and provide the potential to increase the collection efficiency of carrier.
    Preparation, Structures and Properties of Strength-enhanced Carbon Foams
    YU Li-Qiong, LI Kai, LIU Rong-Jun, LUAN Zhi-Qiang*, LIU Jiang-Ge
    2011, 32(4):  834-838. 
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    Pitch-derived carbon foam was prepared from petroleum mesophase pitch,followed by foaming, carbonization and graphitization. The obtained carbon foams were then strength-enhanced through precursor infiltration and pyrolysis(PIP) technique using polycarbosilane(PCS). Their micrographs were investigated by a scanning electron microscope(SEM)and phase identification was detected by powder X-ray diffraction(XRD). The results show that pyrolysis product of PCS was β-SiC and compressive strength of the carbon foam observably enhanced with the increase of PIP times.
    Heat and Cold Properties of Jianghuang and Yujin Based on Brain Catecholamine Metabolic Profiling
    WU Hong-Wei*, LI Hong-Mei, TANG Li-Ying, ZHANG Dong, YANG Hong-Jun, HUANG Lu-Qi*
    2011, 32(4):  839-843. 
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    Jianghuang and Yujin,as the rhizome and tuberous root of Curcuma longa L.,are used as two medicine in Traditional Chinese Medicine(TCM). It was believed Jianghuang has warm properties and Yujin has cool properties in TCM. To compare and confirm the different effect of Jianghuang and Yujin, HPLC-MS method for the quantitative determination of 7 catecholamines in brain samples was developed. And Principal Component Analysis(PCA) was processed to analyze the catecholamine metabolic profiling.The results suggest Heat-Syndrome model and Cold-Syndrome model can be distingushed by catecholamine metabolic profiling. Jianghuang and Yujin has different effect for the Heat and Cold Syndrome model based on Brain catecholamines Metabolic Profiling.
    Separation of DNA Fragments with a Broad Range of Molecular Weight by Capillary Electrophoresis with Sieving Matrix of Poly(ethylene oxide)
    LI Yu-Rong, CHEN Chang-Bao, ZHOU Jie*
    2011, 32(4):  844-850. 
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    DL5000 DNA Marker (100~5000 bp) fragments were separated through no-gel sieve capillary electrophoresis on a fused silica capillary column (31.2 cm×75 μm, the effective length 21.0 cm) using Poly (ethylene oxide) as sieve matrix. The influences of Poly (ethylene oxide) concentration, pH value of running buffer, separation voltage and ethidium bromide concentration on the separation efficiency of different lengths of DNA fragments were investigated. The optimum conditions for 100~5000 bp DNA fragments were established as 0.5% Poly (ethylene oxide), pH 8.0, 3.0 μg/mL ethidium bromide and voltage of 12 kV. Under these conditions, good resolution was obtained in separating multiplex polymerase chain reaction (PCR) magnified products from sorbitol dehydrogenase gene (SDH) and ethylene receptor gene (ETR1).
    Kinetic Parameters of Interaction Between Cell Membrane and Drug by ppKCE
    XIA Zhi-Ning*, LI Li-Xian, CHEN Hua, XIONG Cai-Qiao, YANG Feng-Qing
    2011, 32(4):  851-856. 
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    Based on the theory of plug-plug kinetic capillary electrophoresis (ppKCE), the rabbit red blood cell membrane and human red blood cell membrane were used to study the kinetic parameters of the interaction between the cell membrane and drug for the first time. The rate constants of complex formation kon, the dissociation koff and the binding constant Kb between cell membrane and drugs were directly determined simultaneously. The stability of the peaks height and the migration times were studied, and the influence of pH on the kinetic parameters of the interaction between the cell membrane and drugs were examined and analyzed. It could provide a new approach for the evaluation of drug efficiency, toxicity and pharmacokinetics in vivo.
    Resonance Rayleigh Scattering, Second-order Scattering and Frequency Doubling Scattering Spectra of Ternary Mixed Ligand Complex of Hg(Ⅱ)\|famotidine and Anionic Surfactant and Their Analytical Applications
    CHEN Pei-Li, LIU Shao-Pu, LIU Zhong-Fang, HU Xiao-Li*
    2011, 32(4):  857-862. 
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    In pH 5.9 NaAc-HAc buffer medium, famotidine (FMTD) reacted with Hg (II) to form chelate cation ([Hg(FMTD)]2+), which further reacted with anionic surfactants (AS) such as sodium dodecylsulfate (SLS), sodium dodecylbenzene sulfonate (SDBS) and sodium dodecylsulphate (SDS) to form ternary mixed coordination compound([Hg(FMTD)(AS)2]). As a result, the resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering (FDS) were enhanced greatly. Their maximum wavelengths were located at 345~352 nm, 544 nm and 352 nm, respectively. The three scattering intensity (ΔI) were proportional to the FMTD concentration in a certain range and the detection limits were 3.3~3.9 ng/mL (RRS method), 14.6 ~ 16.3 ng/mL (SOS method) and 7.0 ~ 8.5 ng/mL (FDS method). Based on it, a sensitive, good selective, simple, rapid and new method had been proposed to determine FMTD. It can be applied to determine FMTD in injection, serum and urea sample. The formative mechanism of[Hg(FMTD)(AS)2] was discussed, the effects of formation of [Hg(FMTD)(AS)2] on absorption and RRS spectra were investigated, the reasons of enhancement for RRS was also discussed.
    Interaction Between N-Benzoyl\|dehydroabietylamine Derivatives with Angiotensin Ⅲ by Electrospray  Ionization Mass Spectrometry
    Lü Lin, DENG Hui-Min*, LIN Zhong-Xiang
    2011, 32(4):  863-867. 
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    The interactions between the novel N-benzoyl-dehydroabietylamine derivatives(NBDD)including N-benzoyl-dehydroabietylamine(NBD),N-o-chlorobenzoyl-benzoyl–dehydroabietyl- amine(NClBD),N-benzoyl-dehydroabietylamine-7-one(NBDO),N-o-chlorobenzoyl–dehydroabi- etylamine-7-one(NClBDO) with Angiotensin Ⅲ were investigated by electrospray ionization mass spectrometry (ESI-MS). The results showed that the four derivatives all could form non-covalent complexes with Ang Ⅲ when the derivatives mixed with Ang Ⅲ in molar ratio of NBDD:AngⅢ 1:1, 3:1,5:1, and the complexes mainly formed +2 charged ions. The MS2 of [NBDD-AngⅢ+2H]2+ and MS2 and MS3 of [(NBDD)2-AngⅢ+2H]2+ were studied.The stability of four kinds of complexes [NBDD-AngⅢ+2H]2+ and the combination mode of NBDD with Ang Ⅲ were discussed.
    Two-photon Upconversion Fluorescence Property in a Star-shaped Pyridine Chromophore
    QIAN Ying*, LIN Guo-Qiang, ZHOU Zhi-Qiang, CUI Yi-Ping
    2011, 32(4):  868-873. 
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    The two-photon absorption and the two-photon-excited fluorescence spectra of a star-shaped pyridine chromophore, 2,5-Bis{4-{4-[N,N-bis(4-pyridylethenyl)phenylamino]styryl} phenyl}-1,3,4- oxadiazole (PyPASPO) were measured using a femtosecond Ti:sapphire laser at 800 nm. Its two-photon absorption cross-sections obtained by nonlinear transmission method were 412.5 GM in the solution of CH2Cl2 and 288.8 GM in the solution of THF. The absorption, one-photon fluorescence, fluorescence lifetime, and excitation-emission-fluorescence intensity 3D spectrum have been investigated. When pumped with 800 nm femtosecond laser irradiation, chromophore PyPASPO show strong two-photon excited green fluorescence at 571 nm in CH2Cl2 and at 525 nm in THF, respectively. In CH2Cl2 the maximum peaks of single-photon-excited fluorescence was at 532 nm and the fluorescence lifetime was 1.24 ns . The electrochemical properties was explored by cyclic voltammetry. The HOMO energy level was -5.21eV and the LUMO energy level was -2.92 eV. Enhancing the charge transfer extent has been adapted to increase the two-photon absorption and upconversion fluorescence emission of the star-shaped pyridine chromophore.
    Cyclen-based Cationic Lipids:  Design, Synthesis and  Interactions with DNA
    2011, 32(4):  874-878. 
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    The clinical success of gene therapy requires a safe and effective gene delivery system. Cationic lipids have particularly excellent potential for gene delivery applications because of their lesser immunogenic nature, ability to deliver large pieces of DNA, and ease of handling and preparation techniques. In this study, two cyclen-based amphiphilic molecules including steroid moieties were designed and synthesized, and the structures were characterized by 1H NMR, IR and HRMS. Cationic liposomes were prepared by mixing the molecules with DOPE. Agarose gel electrophoresis demonstrated that the liposomes M1 and M2 could condense plasmid DNA at N/P value of 7 and 5, respectively. The size of the formed lipoplexes were measured to be around 160~220 nm, while the zeta-potential of the lipoplexes were found to be +20~40 mV, suggesting that the synthesized cationic lipids might be of great potential as non-viral gene carrier.
    Interactions Between Polyamine-modified β-Cyclodextrins and Anionic Surfactants
    SUN Huan-Quan*, LIU Min, CAO Xu-Long, CUI Xiao-Hong, SHI Jing, GUO XIAO-Xuan, CHEN Yong, LIU Yu*
    2011, 32(4):  879-884. 
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    The binding constants between several polyamine-modified β-cyclodextrins, i.e. mono(6-amino-6-deoxy)-β-CD(NH2-β-CD), mono[6-(ethylenediamino)-6-deoxy]-β-yclodextrin(EN-β-CD), mono[6-(diethylenetriamino)-6-deoxy]-β-cyclodextrin(DETA-β-CD), mono[6-(triethylenetetraamino)- 6-deoxy]-β-cyclodextrin (TETA-β-CD) and three anionic surfactants (CnH2n+1SO3Na, n=8, 10, 12) in phosphate buffer solution (25?C, pH 7.2) and carbonic acid buffer solution (25?C, pH 10.5) were measured by the method of UV-Vis and fluorescence spectroscopy titration, in which all the hosts and guests formed 1:1 inclusion complexes. The obtained results show that the binding constants between polyamine-modified β-cyclodextrins and anion surfactants are in the region of 2.6?102 ? 4.35?104 M-1 in neutral condition, whereas in basic condition the binding would become weaker. In both of two pH conditions, the binding ability became much stronger with increasing the carbon number of anionic surfactants.
    Inhibitory Effects of Aqueous Nanoparticle Suspensions of [60]Fullerene Derivatives on Bacterial Growth
    YAO Lu, SONG Gao-Guang, HUANG Cheng, YANG Xin-Lin*
    2011, 32(4):  885-890. 
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    The biological activities of fullerene nanoparticles have received extensive attention. The antibacterial effects of two aqueous nanoparticle suspensions of [60]fullerene derivatives, a bis-methanophosphonate fullerene (BMPF) and fullerol were studied for the first time. The results showed that both nano-BMPF and nano-fullerol could dose-dependently inhibit the growth of the gram-positive bacteria S. aureus under dark condition. The 50% inhibition concentration of two nanoparticle suspensions were 9.1 μM and 4.2 μM, respectively. It was also revealed that the antibacterial activity of nano-fullerol probably did not correlate to reactive oxygen species, but superoxide anions (O2.-) might be involved in the antibacterial action of nano-BMP. In addition, both aqueous nanoparticle suspensions couldn’t inhibit the growth of the gram-negative bacteria E. coli under dark condition. These results implied that nanoparticles of both fullerene derivatives might be potentially used as antibiotics in biomedicine.
    A Natural Cyclic Peroxide Echinobithiophene A with Anti-Microbial from Echinops ritro L.
    LI Liang-Bo, REN Jie, LAI Ren, CHENG Zheng-Ming, ZHU Hua-Jie*
    2011, 32(4):  891-896. 
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    The genus Echinops(Compositae) consists of ca. 120 species in the world.  This genus is represented by 17 species mainly distributed in northwestern area of China. E. ritro L. has only been found in Xinjiang and is used as a remedy for different ailments in Uighur Pharmacopeia instead of E. grijissi Hance.  Echinobithiophene A(1),  a new peroxide bithiophene with a six-membered ring,  was isolated from the ethyl acetate fraction of Echinops ritro L., and its structure was identified by spectral analysis including 2D NMR,  and comparison of optical rotation values and chemical shifts of 13C NMR between the predicted and experimental data. Compound 1 showed significant anti-microbial activity.
    Preparation of Hemoglobin-based Oxygen Carrier with Low Oxygen Affinity and Arterial Blood Pressure Responses in Rat
    YAN Kun-Ping*, HUI Wen-Li, LUO Chao, XIE Yu-Dou, PENG Ming-Li, CHEN Chao*
    2011, 32(4):  897-902. 
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    The oxygen affinity are one of important parameters of hemoglobin-based oxygen carriers(HBOCs), and are not completely understand at present. One theory considered that the low oxygen affinity are the main reason for the hypertension. In order to further research the relationship between the oxygen affinity and the hypertension, in this research, two Hemoglobin-based oxygen carriers(HBOCs) with low oxygen affinity were prepared. The raffinose were oxidized by sodium periodate (sodium periodate:raffinose=6:1, molar ratio), yielding a completely oxidized and homogeneous polyaldehyde ring-opened raffinose. It was used as the cross-linker to polymerize porcine deoxyhemoglobin, for 1 h to yield a low oxygen affinity (P50=43.1 torr) and mainly intro-molecular cross-linked 64 kDa hemoglobin(pCLHb); for 24 to yield a low oxygen affinity (P50=51.5 torr) and mean molecular weight 600 kDa polymerized hemoglobin(pPolyHb). With the two kind of HBOCs, 50% isovolemic exchange transfusion were performed in rat, the pCLHb caused an immediate and sustained hypertension but pPolyHb didn’t, and indicated hypertension are related to the 64 kDa hemoglobin and low oxygen affinity aren’t the main reason for hypertension.
    Knoevenagel Reaction of 2-Aminothiophen-4-one
    WANG Feng, LI Wen-Hong*, LI Dong, YAN Sui-Hong, XU Kang-Zhen, SUN Xiao-Hong
    2011, 32(4):  903-907. 
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    ethyl 4, 5-dihydro-4-oxo-2-(pyridin-3-ylamino) thiophene-3-carboxylate was successfully synthesized from isothiocyanate in the presence of sodium carbonate. The compound shows typical reactions of an aldehyde. Theoretical investigation was carried out. The atomic charges and natural bond orbital analyses have been discussed.
    Hydrate Formation Phase Equilibrium Model in the Porous Media Based on PC\|SAFT Equation of State
    ZENG Zhi-Yong, LI Xiao-Sen*
    2011, 32(4):  908-914. 
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    This work studies the thermodynamic model of hydrate equilibrium formation conditions in the porous media. Based on the van der Waals-Platteuw model of hydrate and Kelvin equation of capillary, a phase equilibrium computational model was built. Based on this model, the surface tension was further studied for methane and CO2 hydrate. Firstly, values of surface tension were regressed from experimental equilibrium formation conditions. It is shown that the surface tension increases with the temperature increasing and decreases with the pore radius increasing, moreover, it shows a near-line trend. Thus, the surface tension function of temperature and pore radius was proposed. Parameters of the function were optimized from experimental data with genetic algorithm. The result shows that the revised model with the correlated surface tension has a distinct improvement in the predicting the hydrate equilibrium formation conditions, average absolute deviations are 1.66% and 2.76% for methane and CO2 hydrates, respectively.
    Structural Analysis of an Active Analog of Exendin-4 in SDS Micelle Solution
    WANG Shuo, YU Jia-Yi, LI Wei, LI Fei*
    2011, 32(4):  915-919. 
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    Exendin-4 (EX-4) is a drug candidate with established potential for treatment of type II diabetes. It has been found that one of its analogs with the substitutions of both β-Asp for Glu3 and Tyr for Gln13 have a prolongation in biological half life, an increase in cell proliferation and a remarkable improvement in reducing blood sugar with respect to EX-4. In this paper, we studied the structures of both EX-4 and this EX-4 analog in SDS micelles by NMR spectroscopy. The results showed that both EX-4 and its analog adopt α-helix structures with the N-termini disordered and the C-terminal parts folded as Trp-cage in the medium, but the EX-4 analog contains more helical turns in the N-terminal region than EX-4. The extension of helix to the N-terminus may favor affinity for extracellular domain of GLP-1 receptor and accurate positioning of the crucial N-terminal residues in the transmembrane domains responsible for receptor activation.
    Theoretical Study on Electronic Structure and Photophysical Properties of Low Band Gap Dithiophene Copolymer with Different Bridging Atoms
    DUAN Yu-Ai, GENG Yun, LI Hai-Bin, YANG Guo-Chun, WU Shui-Xing, HAO Li-Zhu, LIAO Yi*, SU Zhong-Min*
    2011, 32(4):  920-926. 
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    The excited state characteristics of two low band gap donor-accepter copolymers with different bridging atoms used in bulk heterojunction solar cells were analyzed through their absorption spectra. The charge transfer state (CT) features were investigated to distinguish their abilities of charge separations. The electronic structures and spectral properties of PSBTBT and PCPDTBT (n = 1 ~ 4) have been investigated based on density functional theory (DFT) and time-dependent density functional theory (TD-DFT). The results show that the absorption spectrum of PSBTBT is similar to that of PCPDTBT and they have similar abilities to match with the solar spectra. Meanwhile, their capabilities of charge separations for the charge transfer state (CT) are similar to each other in terms of exciton binding energy. However, when the carbon atom was replaced by the silicon atom in the main chain of the conjugated polymer, the C-Si bond is significantly longer than the C-C bond, which reduces the steric hindrance between the alkyl groups and the thiophene ring. Thus this replacement may be beneficial to the improvement of the crystallinity and increment of the carrier transport ability. These results indicate that PSBTBT may be a promising polymer material for application in polymer solar cells.
    Experimental and Theoretical Studies on Valine Cation Based Ionic Liquids
    TONG La-Ga, LI Wei*, RONG Hua, WANG Hui-Min, JIE Wei
    2011, 32(4):  927-933. 
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    Some new amino acid ionic liquids (ILs) derived from Valine (Val) were studied using both experimental and theoretical methods. First, the Val fluoborate (ValBF4), Val hydrochloride (ValCl), Val nitrate (ValNO3), paratoluenesulfonic acid Val salt (ValTsO), Val sulfate (Val2SO4), and Val phosphate (Val3PO4) were synthesized with one-step microwave synthesis method, and their physicochemical properties, including the IR spectra, melting points, thermostability and optical rotation were studied experimentally. It was found that ValBF4 and ValPO4 have potential in further application for their low melting points (less than 100oC). By using the combination of n-heptane and thiophene as model gasoline, the physical desulfurization effect of ValNO3 was investigated. Quantum chemistry calculations were also performed and the theoretical results were used as the supplementation or explanation for experimental study. Geometry optimizations on the single molecules of the Val complexes in gas phase were performed with DFT B3LYP/6-311++G** method, and the vibration frequencies of each optimized molecule were analyzed at the same level method. The binding energies between ions were calculated and the natural bond analysis was also performed. It was found that the combination of experimental and theoretical methods can help us to explore such kind of system more deeply and can provide some new idea for further design of amino acid ionic liquids.
    Electrochemical Impedance Spectroscopy Study on Effects of Temperature on the Lithiation Process of 3-Dimensional  Porous Cu6Sn5 Alloy Electrode
    FAN Xiao-Yong*, WANG Jing-Jing, LI Yan, CAO Gui-Ming, SHI Xiao-Yuan, HUANG Ling, SUN Shi-Gang*, LI Dong-Lin
    2011, 32(4):  934-938. 
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    Porous Cu was fabricated by electrodepositing using hydrogen bubbles as the dynamic template, and subsequently treated by annealing to increase the structural stability. The 3-dimentional porousCu6Sn5 alloy electrode was prepared by electrodepositing using the porous Cu as the substrate. The lithiation/delithiation potentials of 3-dimentional porousCu6Sn5 were investigated by cyclic voltammetry. The initial lithiation process of 3-dimentional porous Cu6Sn5 alloy electrode at different temperature was studied by electrochemical impedance spectroscopy. The results indicate that the Nyquist plots are composed of three regions in the main lithiation range: high frequency arc representing solid electrolyte interphase (SEI) impedance, middle frequency arc representing charge transfer impedance, and low frequency arc representing phase transformation impedance. The change principles of the electrochemical impedance versus temperature were analyzed by simulating the experimental data using appropriate equivalent circuit.
    Two-step Crystallization Synthesis and Catalytic Performance of Nano-scaled SAPO-34 Molecular Sieve
    YANG De-Xing, WANG Peng-Fei*, XU Hua-Sheng, Lü Ai-Ling, HU Jie, Lü Dai-Qing
    2011, 32(4):  939-945. 
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    In this study, nano-scaled SAPO-34 molecualr sieves with size in the range of 200~300 nm were synthesized by the two-step crystallization and H2O2 oxidation process, with pseudoboehmite, colloidal silica and H3PO4 as sources of aluminum, silicon and phosphorous and TEAOH as templates. The prepared SAPO-34 was characterized by XRD, SEM, NH3-TPD, BET and so on. The catalytic performance of the SAPO-34 on the methanol-to-olefins reactions (MTO) was carried out on a fixed bed. The results showed that the particle size of the SAPO-34 could be effectively modulated by the crystallization temperature of the two-step crystallization process. In particular, when the first and second crystallization were conducted at 130℃ and 180℃, cubic SAPO-34 with 200~300 nm size could be successfully synthesized. Compared with the micro-scaled SAPO-34 prepared by the traditional hydrothermal process, the nano-scaled SAPO-34 crystals synthesized here showed better performance in the MTO reaction and the selectivity of C2~C4 and the lifetime for one-turn could attained about 92% and 10 hours, respectively.
    Preparation of LiNi0.5Mn1.5O4 as 5 V Cathode Materials for Lithium Ion Battery and Diffusion  Performance of Li+ in the Materials
    LU Hua-Quan, WU Feng, SU Yue-Feng*, LI Ning, CHEN Shi, BAO Li-Ying
    2011, 32(4):  946-951. 
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    5 V cathode material LiNi0.5M1.5O4 was synthesized via an oxalate co-precipitation method, and the relationship between the structure, morphology and the electrochemical performance of the material were investigated. The results show that the sample synthesized at 900 ℃ has the best electrochemical performance, and its reversible capacity reaches 133.0 mAh?g-1. After 30 cycles, this LiNi0.5Mn1.5O4 sample maintains a discharge capacity of 132.2 mAh?g-1 with a capacity retention rate of 99.4%. The chemical diffusion coefficient of Li-ion in LiNi0.5M1.5O4 cathode material was measured by potentiostatic intermittent titration technique (PITT). It’s found that at the different voltage point of the discharge process, the change of Li content and the redox couple is also different, thus the chemical diffusion coefficient of Li-ion is various, it ranges in 10e-10 cm2?s-1~10e-11 cm2?s-1.
    Effect of Draw Ratio on the Morphology, Orientation and Properties of Biphenyl\|type Polyimide Fibers
    ZHANG Chun-Ling, QIU Xue-Peng*, XUE Yan-Hu, GAO Lian-Xun, DING Meng-Xian, JI Xiang-Ling*
    2011, 32(4):  952-956. 
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    Abstract Novel biphenyl-containing polyimide (PI) solution based on pyromellitic dianhydride (PMDA)/3,3’,4,4’-biphenyl-tetracarboxylic dianhydride (BPDA)/o-tolidine(OTOL) were synthesized via co-polymerization. Its PI fibers are produced through dry-jet wet-spinning technique. These fibers are characterized with field emission scanning electron microscopy (FESEM), wide-angle X-ray diffraction (WAXD), fiber mechanical property tester, dynamic mechanical analyzer (DMA), thermogravimetric analyzer (TGA). Particularly, effects of draw ratio on morphology, orientation, mechanical properties and thermal properties of PI fibers are discussed. PI fibers have smooth surface, relatively uniform diameter, and skin-core structure in cross-section. The diameter and filament of PI fibers decrease and the degree of orientation increases with draw ratio. Crystallinity of these fibers is very low. The tensile strength and tensile modulus of the PI fibers can reach 2.95 GPa and100.0 GPa when draw ratio is 2.8. Generally, 10% weight loss of these PI fibers corresponds to temperatures above 580oC and it indicates that these fibers possess excellent thermal stability under nitrogen atmosphere Two relaxations above room temperature can be found in DMA curves. The glass transition temperature (Tg) of PI fibers is above 340 oC.
    Hepatic-targeting Microcapsules Construction by Layer-by-layer Self-assembly of Lactose-branched Polyelectrolyte
    GAO Xia, ZHANG Fu, CHEN Zhi-Chun, LIN Xian-Fu
    2011, 32(4):  957-963. 
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    Hepatic-targeting microcapsules were constructed by Layer-by-layer self-assembly of poly(allylamine hydrochloride) (PAH) and chemo-enzymatic synthesized poly(vinyl lactose ester-co-sodium p-styrenesulfonate) (PLESS) containing lactose branches. Alternate deposition of PAH and PLESS was carried out on different solid surfaces such as quartz slides and CaCO3 microparticles. The self-assembly nature of the novel polyelectrolytes was investigated in detail by varying polyelectrolytes concentration, ionic strength, and counteranion types. The assembly process and structure of multilayers were characterized by UV-vis. Hollow capsules were formed after the removal of CaCO3 templates and observed by TEM. The potential targetability of the system was proved in vitro by PNA lectin recognition. Furthermore biocompatibility of the polyelectrolytes was tested by MTT assay.
    Synthesis and Properties of Novel Polyglycerol Hydrogels Containing L-Lactic Acid Groups
    YANG Xiao-Gang*, LIU Li-Jian*, LIAO Li-Qiong
    2011, 32(4):  964-970. 
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    Novel pH-sensitive polyglycerol hydrogels were designed and synthesized through the reaction of epichlorohydrin (ECH) with L-lactic acid (LLA) in the presence of sodium hydroxide (NaOH), and cetyltrimethylammonium bromide (CTAB) as a phase transfer catalyst (PTC) at room temperature, followed by hydrolysis, polymerization and cross-linking reactions. The resultant gel was characterized by carbon nuclear magnetic resonance spectroscopy and X-ray photoelectron spectroscopy, and it was found that incorporated LLA was bound to polyglycerol network as a pendant acidic substituent by the hydroxyl group of LLA (PGL gel). The PGL hydrogels with different LLA contents and equilibrium swelling ratios were prepared by changing the feed ratios of materials. The results determined by chemical titration showed that under the applied conditions the efficiency of introducing the carboxyl group into polyglycerol network was ca. 86% and the amount of LLA in the hydrogel reached to ca. 17 wt%. The swelling behavior of the hydrogels in different mediums was investigated, and the results showed that the hydrogels are pH-, and ionic strength-responsive. The hydrogels also have the reversible swelling/deswelling properties and exhibites modulated release of drug in response to the environment pH.
    Influence of Stretching on Crystallization Behavior of Poly(L-lactic acid)
    XING Qian, ZHANG Xiu-Qin, LUO Fa-Liang, LIU Guo-Ming, WANG Du-Jin*
    2011, 32(4):  971-977. 
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    The crystallization ability of poly(L-lactic acid) (PLLA) is greatly improved by stretching at high temperature. The influence of stretching under different temperatures on the crystallization behavior of PLLA has been investigated by the combinational investigation of FTIR, DSC, and XRD. It was found that stretching can remarkably improve the crystallization rate and crystallinity of PLLA films. Stretched at a draw ratio of 3, PLLA forms α-form crystals rapidly in the range of 90-95 oC. Further improving the draw ratio, the crystallinity remains almost constant. With increasing the stretching temperature up to 105 oC, the PLLA films cannot crystallize under stretching. Contrary to the unstretched PLLA film, the stretched PLLA films gradually crystallize during the heating process, indicating that pre-stretching can change the crystallization behavior of PLLA.
    Preparation of Composite Porous Resin by γ-Al2O3 Foaming and Its Characterization of Humidity-controlling and Formaldehyde Adsorption
    YANG Hai-Liang, PENG Zhi-Qin, ZHANG Jing, CAO Xiao-Ye, CHEN Cai-Hui, ZHOU Yang, ZHAO Feng, HU Zhi-Wen*
    2011, 32(4):  978-983. 
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    As intelligent humidity control materials, porous resins have more advantages, such as high moisture content and fast absorption-desorption rate than traditional porous silica gels. A composite porous resin was prepared via a foaming method in this study, in which aluminum hydroxide was decomposed into activated alumina and water vapor was released simultaneously at high temperature. The morphology and pore structure of the composite porous resins were characterized by Thermogravimetry (TG), Scanning Electron Microscopy (SEM), X-Ray Diffractomer (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Nitrogen adsorption. Humidity control capability and saturation moisture content of the composite porous resins were tested under high humidity and low humidity conditions. Humidity control performance at various temperatures and trace formaldehyde adsorption ability at 25℃ of the composite porous resins were investigated particularly. The results show that porous structure was successfully formed in the resin. The composite porous resin has good performances on humidity control and formaldehyde adsorption. Through controlling the pore parameters of the resin by changing preparation processes, we could adjust the humidity-controlling range of the resin between 50% and 60% RH in 4h free from the influence of temperature, and the formaldehyde adsorption content of the resin was about 5.55 ppm/g. The composite porous resin could be applied as intelligent humidity control material and create a clean micro-environment for cultural relic conservation.
    Pervaporation Properties and Characterization of Poly( vinyl alcohol)/Cellulose Nanocrystal Composite Membranes
    BAI Lu, ZHANG Li-Ping*, QU Ping, GAO Yuan, QIN Zhu, SUN Su-Qin
    2011, 32(4):  984-989. 
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    Poly( vinyl alcohol) (PVA)/cellulose nanocrystal (NCC) composite membranes were used in the pervaporation separation of water-ethanol feed mixtures, and characterized by fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetric(DSC) and thermogravimetry (TG). Atomic force microscope (AFM) was used to characterize the cellulose nanocrystal. The characterization results demonstrated that cellulose nanocrystal (NCC) displayed slender rods and dispersed homogeneously within the PVA matrix, which could be assigned to the hydrogen bonds formed between PVA and NCC. The DSC and TG analysis demonstrated that the nanocomposite membranes exhibited a increase in melting temperature and higher thermal resistance. The nanocomposite membranes had good pervaporation properties. Among all the prepared membranes, PVA/NCC nanocomposite membrane containing 2 wt% NCC exhibited the best separation factor, whose averaged separation factor was 347 for 90wt% aqueous solution of ethanol at 80 ℃ and 24% higher than that of crosslinked PVA membrane.
    Layer-by-Layer Assembled Microgel Films Containing Silver Nanoparticles as Antimicrobial Coatings on Plastics
    LIU Feng, WANG Xu, YE Kai-Qi, QIU Ling-Ying, SHEN Jia-Cong*
    2011, 32(4):  990-994. 
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    Antimicrobial coatings on hydrophobic plastic surfaces were directly fabricated by layer-by-layer deposition of cross-linked poly(allylamine hydrochloride) and dextran microgels containing silver nanoparticles (Ag@PAH-D) with poly(sodium 4-styrenesulfonate) (PSS). The as-prepared Ag@PAH-D/PSS microgel films are effective in prohibiting the growth of Escherichia coli. The antimicrobial activity of the coatings can be easily controlled by tailoring the number of coating deposition cycles. The antimicrobial coatings of Ag@PAH-D/PSS microgel films are stable and have satisfactory adhesion to the underlying plastic substrates, which guarantee the long-term application of the coatings.
    Mixed Solvent Induced Dewetting of Polystyrene Thin Film
    TONG Shu-Yuan, XU Lin, SHI Tong-Fei*, AN Li-Jia
    2011, 32(4):  995-1000. 
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    An experimental method for reproducible results has been used to investigate dewetting behavior of thin film of mixed-solvent-laden polymer. The variation of the mixed solvent (acetone and water) in the composition enables the films to exhibit different dewetting behavior, such as the process of holes growth, from the unstable growth process to the stable growth process, the mechanism of holes growth, from the nucleation growth to the replacement of solvent, and the dewetting dynamics.