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    10 February 2014, Volume 35 Issue 2
    Content
    Cover and Content of Chemical Journal of Chinese Universities Vol.35 No.2(2014)
    2014, 35(2):  0-0. 
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    Review
    High Sensitivity Luminescence Nanothermometry on the Basis of Lattice Dilation of Nanocrystals
    ZHOU Ding, XU Xiaowei, LIU Min, ZHANG Hao, SUN Hongchen
    2014, 35(2):  205-214.  doi:10.7503/cjcu20131065
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    Temperature is a critical thermodynamic parameter in many biological and biotechnological processes. And its measurement is often required for both scientific research and industrial applications. However, measuring the local temperature and temperature gradient in the nanoscale regime remains an enormous challenge. Due to quantum confinement effect, semiconductor nanocrystals(NCs) show unique size-dependent optical property, which has got people’s extensive concern in the past few years and supplies a new approach towards measuring temperature in the nanoscale regime. In this review article, various NCs-based thermometers were systematically summarized with the aim to inspire the researchers engaged in this field.

    Articles: Inorganic Chemistry
    Synthesis and Characterization of Hierarchical Aluminum Free Beta Zeolite
    WENG Qiang, CHEN Pei, ZHAO Fengqi, GAO Hongxu, CHEN Xinbing, AN Zhongwei
    2014, 35(2):  215-223.  doi:10.7503/cjcu20130931
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    The influence of various parameters upon the physical state of precursor and crystallization of aluminum-free Beta zeolite were investigated in fluoride media. X-Ray diffraction(XRD) analysis showed that H2O/SiO2 molar ratio in the precursor played an important role in the viscosity of precursor and the crystallization of aluminum-free Beta zeolite. High H2O/SiO2 molar ratio(>10) was benefited to the precursor’s viscosity but inhibited the crystallization process of aluminum-free Beta zeolite. While, high crystalline aluminum-free Beta zeolite with polyhedron or sphere morphology in micrometer scale could be obtained in the presence of nucleation promoter(GeO2) and crystallization promoter such as ClO4- and PO43- at 150 ℃ for 4 d, even though H2O/SiO2 molar ratio was high to 20—30. The analysis of thermogravimetry and energy dispersive spectrometry proved that small amount of ClO4- and PO43- maybe incorporated into the channel of Beta zeolite and influenced the thermal decomposition process of template(tetraethyl ammonium cation). Further characterization for the morphology, crystalline and pore structure of the resultant aluminu-free Beta zeolite were carried out by environmental scanning electron microscope(SEM), transmission electron microscope(TEM), selected-area electron diffraction(SAED) and nitrogen adsorption-desorption isotherm. The results indicate that the obtained aluminum-free Beta zeolite is hierarchical structure, which constructed by nanoparticles or nanosheets. The mesoporous pore size is in the range of 3.4—3.8 nm.

    NaYF4∶Yb3+,Er3+ Upconverting Nanoparticles Surface Ligand Exchange in Ternary Mixture Solvent and Optical Properties
    ZHANG Qingbin, KONG Xianggui, WANG Xin, CHENG Cheng
    2014, 35(2):  224-229.  doi:10.7503/cjcu20130779
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    Hydrophobic up-converting rare-earth nanoparticles(UCNPs) were transferred from organic solvent to aqueous solution via a simple surface-ligand exchange procedure. 2-Aminoethyl dihydrogen phosphate(AEP) molecules were used to replace the original hydrophobic ligands in chloroform, ethanol and water ternary mixture solvent at ambient temperature. The ligand exchange process was confirmed by Fourier transform infrared spectra(FTIR) and thermogravimetric analysis(TG). Investigations by transmission electron microscopy(TEM), dynamic light scattering(DLS) and photoluminescence(PL) spectroscopy show no obvious variations in the morphologies, structure and luminescentproperties of the UCNPs during the ligand exchange process. The fluorescence confocal cell imaging of AEP modified hydrophilic UCNPs confirms that the hydrophilic UCNPs are suitable for potential biological labeling.

    Studies on Optical Properties and Ce Concentration of Ce∶YAG Single Crystal for WLEDs
    ZHAO Binyu, LIANG Xiaojuan, CHEN Zhaoping, XIE Cuiping, LUO Le, ZHANG Zhimin, ZHONG Jiasong, XIANG Weidong
    2014, 35(2):  230-236.  doi:10.7503/cjcu20130512
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    Ce∶YAG single crystal for white light emitting diode(WLED) was grown by Czochralski method. The structure and optical properties of samples were characterized by X-ray diffraction(XRD) and photoluminescence spectra. Ce∶YAG single crystal shows a 500—650 nm broad emission band around 526 nm(5d1 2EgГ8g→4f 1 2F7/2Г8u) under blue light of 455 nm. The excitation spectrum of Ce∶YAG single crystal is made up of 343 nm(4f 1 2F5/2Г7u→5d1 2EgГ7g) and 466 nm(4f 1 2F5/2Г7u→5d1 2EgГ8g) excitation peaks. The Stokes shift is 2448 cm-1. The Huang-Rhys parameter is 6.12. The Ce concentration of Ce∶YAG single crystal is related with colour coordinate of WLEDs made by Ce∶YAG single crystal with the red phosphor(650 nm), a best concentration range of Ce in Ce∶YAG single crystal is 0.034—0.066.

    Analytical Chemistry
    Qualitation and Quantitation for Comparative Analysis of N-glycans from Human Hepatocellular Carcinoma HepG2 and Normal Liver Cells L02 by Electrospray Ionization Mass Spectrometry
    PAN Liying, WANG Chengjian, YUAN Jiangbei, ZHANG Ying, HUANG Linjuan, WANG Zhongfu
    2014, 35(2):  237-243.  doi:10.7503/cjcu20130960
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    HepG2, a primary hepatocellular carcinoma cell line, and L02 derived from normal liver tissue, were chosen as model cell lines. In this work, the total proteins of HepG2 and L02 cells were extracted and enzymatically hydrolyzed by Peptide-N-glycosidase F(PNGase F). Then the released N-glycans were purified by microcrystalline cellulose and graphitized carbon columns. The structure of the purified N-glycans was identified by electrospray ionization mass spectrometry(ESI-MS)and MS/MS. To compare the difference of N-glycans between HepG2 and L02 cells, β-cyclodextrin was used as the internal standard to relative quantitative analysis of the N-glycans by MS. As results, 26 N-glycans are observed in both HepG2 and L02 cells. The amounts of high-mannose, sialylated, as well as fucosylated and sialylated N-glycans of HepG2 were higher than those of L02 cells. Among them, 15 kinds of N-glycans of HepG2 cells show very significant difference(p<0.01) and 1 kind of N-glycan show significant difference(p<0.05), compared to those of L02 cells. Our studies show potential in investigation of structure partterns of N-glycans expressed in hepatocellular carcinoma and in finding early biomarker in liver cancer diagnose.

    Independent Component Analysis Combined with On-line Infrared Spectroscopy for Researching the Synthesis Reaction Mechanism of 3,4-Bis(4'-aminofurazano-3')furoxan
    SUN Kunlun, WU Nan, YANG Huan, YANG Xiaofeng, LI Hua
    2014, 35(2):  244-249.  doi:10.7503/cjcu20130898
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    On-line infrared(IR) spectroscopy was used to monitor the synthesis process of 3,4-bis(4'-ami-nofurazano-3') furoxan(DATF). The IR spectra of components were determined by analyzing the IR data using principal component analysis(PCA) and independent component analysis(ICA). The geometric configurations of intermediates were optimized using the density functional theory(DFT) at B3LYP/6-31+G(d,p) level. Their vibrational frequencies of IR spectra were obtained on the basis of vibrational analysis. The result obtained by the chemometric resolution methods agreed well with that of quantum chemical calculation method, which demonstrated the reliability of the proposed chemometric resolution methods. The unstable intermediate was confirmed via comparing the IR spectra that calculated using B3LYP/6-31+G(d,p) and analyzed by ICA. Finally, the possible synthesis mechanism of DATF was deduced based on the analysis of the above IR spectra. The above mentioned work was expected to provide significant guidance to investigate the reaction mechanism in the future.

    Determination of Levodopa Using Biosynthesed Gold Nanoparticles/Multiwalled Carbon Nanotubes/L-Cysteine Composite Film Modified Glassy Carbon Electrode
    YUE Weichao, CAI Zhuo, JIANG Cuiwen, YE Danni
    2014, 35(2):  250-256.  doi:10.7503/cjcu20130801
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    Gold nanoparticles were bio-synthesized by the lotus leaf extract. The Au multiwalled carbon nanotubes(MWCNTs)/L-cysteine(L-Cys) composite material was prepared. The electrochemical behavior of levodopa at the modified electrode was studied. In 0.2 mol/L HAc-NaAc(pH=2.6) buffer, levodopa concentration was linear with oxidation peak current in the range of 0.6—40 and 60—120 μmol/L, and the detection limit was 5.2×10-8 mol/L(S/N=3). The results show that the Au/MWCNTs/L-Cys modified electrode has good stability and high sensitivity. It has a satisfactory result to determine the effective component of real sample with the recovery of standard addition was between 91.2%—102.5%.

    Organic Chemistry
    New Method for Synthesis of Amide Podand Extractants
    WU Yuxuan, DING Songdong, LIU Ning, HUANG Song, HUANG Huang, SU Dongping
    2014, 35(2):  257-261.  doi:10.7503/cjcu20130635
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    Amide podands are a class of very promising extractants for the treatment of high level liquid wastes from nuclear industry. With the rapid development of the spent fuel reprocessing, the current synthesis methods of amide podands have hardly kept pace with the demands of surging. Therefore, it is very essential to explore a new efficient synthesis way. In this work, three amide podand extractants, N,N,N',N'-tetraalkyl-3-oxa-pentane-1,5-diamide, where the alkyl represents butyl, isobutyl and octyl, were synthesized via a mixed anhydrides method. The synthetic route includes the following three-step reaction. Diglycolic anhydride was firstly prepared through the dehydration of diglycolic acid and then reacted with the dialkyl amine to produce mono-substituted oxa-pentaneamide using pyridine as a catalyst. Finally, in the presence of isobutyl chloroformate and 4-methylmorpholine, the amide podand extractant was obtained via the reaction of mono-substituted oxa-pentaneamide with the corresponding secondary amine. Effects of carboxyl activation time and reaction temperature on the synthesis were investigated. The obtained target compounds were characterized by 1H NMR and MS. The yields of N,N,N',N'-tetrabutyl-3-oxa-pentane-1,5-diamide, N,N,N',N'-tetraisobutyl-3-oxa-pentane-1,5-diamide and N,N,N',N'-tetraoctyl-3-oxa-pentane-1,5-diamide, were 84%, 80% and 57%, respectively. From the above, the mixed anhydrides method may be used in enlarging scale of synthesis of amide podand extractants.

    Synthesis and Herbicidal Activity of N-Arylmethyl-2-(4-arylxoyphenoxy)propionamide
    LIU Qixing, HU Aixi, WANG Xiaoguang, LEI Manxiang, OU Xiaoming, REN Yeguo, HUANG Lu, LIU Aiping
    2014, 35(2):  262-269.  doi:10.7503/cjcu20130625
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    Aryloxyphenoxypropionic acid(APP) herbicides inhibiting acetyl-CoA carboxylase(ACCase) have been identified as one of the most important herbicides. As part of continuous efforts to search for new herbicides with high efficacy, broad-spectrum activity and safety to crops, the commercialized APP herbicide metamifop was used as lead compounds for further optimization. Sixteen new N-arylmethyl 2-(4-arylxoy-phenoxy) propionamide compounds were designed and prepared by multistep synthetic procedures starting from(R)-(+)2-(4-hydroxyphenoxy) propanoic acid, and their structures were characterized by 1H NMR, 13C NMR, LC/MS, IR and elemental analysis. Steric configuration was confirmed by chiral column liquid chromatography. The bioassay results indicated that all compounds exhibited >90% activity against crabgrass(Digitaria sanguinalis L.), barnyard grass(Echinochloa crus-galliL.) and green foxtail(Setaria Viridis L.) at 2250 g/ha. Further herbicidal activity and phytotoxicit to crops results indicated that(R)-(+)-N-[(6-chloropyridin-3-yl)methyl]- 2-(4-{[3-chloro-5-(trifluoromethyl)pyridin-2-yl]oxy}phenoxy)-propanamide(2b) was more effective against Digitaria sanguinalis (IC50=15.4 g/ha) and Echinochloa crus-galli (IC50=22.8 g/ha) than metamifop(IC50=31.9 g/ha and 25.0 g/ha). In particular, compound 2b was safe to rice(Xiang zao xian 24) and more effective against Leptochloa than commercial cyhalofop-butyl. The herbicidal activity is related to steric configuration that the compounds of R configuration have more effective activity.

    Synthesis and Crystal Structure of Stable Benzothiazole Enol
    HUO Baolong, XUE Lingwei, YANG Yunxu, YANG Chao, LI Dazhi, WANG Aizhi, YU Feifei, HU Biwei
    2014, 35(2):  270-274.  doi:10.7503/cjcu20130621
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    As an important organic functional compound, 2-methylbenzothiazole derivatives has been widely used in sensitizing dyes. In the process of sythesis of dyes, the dye intermediates could be hydrolyzed to form another substance easily. In order to determine the structure of the new substance, a dye intermediate, named 2-(2-ethoxy-1-butenyl)-1-(3-sulfopropyl)benzothiazole(3), was synthesized using 2-methyl benzothiazole and 1,3-propane sultone as the starting material, then hydrolyzed in water to form the new substance(4e), which was characterized by IR, 1H NMR, 13C NMR, MS, elemental analysis and X-ray diffraction methods. The MS spectrum showed the molecular weight of the product was 327, which was corresponding to the target compound 4e. The 13C NMR spectrum showed the chemical shift of the carbon that connected to the enol hydroxyl group was δ 194.05, and the chemical shift of the carbon that connected to the double bond was 92.52, which implied the existence of enol structure. The IR spectrum also showed the enol hydroxyl characteristic absorption peak at 1618 cm-1. X-Ray diffraction displayed the structure of the target compound intuitively. Through the characterizations of the compound, the new substance was comfirmed to be a stable enol that contained the conjugated aromatic structure.

    Synthesis of a Novel Organic Molecule for DNA Cleavage
    AN Dong, ZHAO Xiaohui, ZHOU Mi, YE Zhiwen
    2014, 35(2):  275-280.  doi:10.7503/cjcu20130565
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    The artificial nucleic acid cleaving agents have attracted extensive attention due to their potential applications in molecular biological technology and drug development. Metal-free cleaving reagents have been considered safer for their hydrolytic pathway of cleaving the P—O bond of phosphodiester in nucleic acids and have shown clinical potential. It is known that guanidinium is the arginine residue and the key functionality at the active site in staphylococcal nuclease(SNase) for DNA hydrolysis. Some small organic molecules as guanidinium derivatives have been used to cleave phosphodiester for DNA hydrolysis. We report here, according to active groups synergetic catalysis principle, the design and synthsis of a novel phosphodiester receptor 1-(N-guanidinoethyl)-4-(N-hydroxyethyl)-piperazidine hydrochloride(4) and the preliminary studies of its DNA cleavage activity. In the compound, the guanidinium group serves to recognize, bind, and electrophilically activate the anionic phosphodiester through hydrogen bonding and electrostatic interaction. The hydroxyl group works as a nucleophilic group in the transphosphorylation reaction, which is expected to be highly efficient because of the proximity effect. A “couple hardness with softness” piperazidine is designed to connect these two groups. Compound 4 was synthesized via a three-step reaction(nucleophilic substitution, hydrazinolysis and guanylation). Its structure was confirmed by 1H NMR, 13C NMR and LC-MS. The influence of pH on the cleaving of pUC 19 DNA was studied by sugar gel electrophoresis. The mechanism of cleaving DNA by the compound was proved through the free radicals quenches experiments. The way of DNA cleavage was discussed through density functional theory and theoretical investigation by Gaussian. The results indicate that with pH value of 7.2 is the optimal pH for DNA cleavage in the presence of compound 4, the phosphodiester bond of DNA would be cleaved by compound 4 via a transphosphorylation pathway through oxidation-reduction reaction. Thus, this compound may be useful as artificial nucleic acid cleaving agent and the study may be usefully applied to achieve a more effective DNA cleavage for optimizing the structure and the distance of functional group to synergistic catalytic cleavage of the phosphodiester bond. In conclusion, design and synthesis of a novel phosphodiester receptor compound 4 containing guanidinoethyl and hydroxyethyl side arms was achieved successfully. We propose to introduce more such compounds as cleaving agents of nucleic acids to be widely investigated and found to be quite efficient.

    Design, Synthesis and Biological Activity of Novel Substituted Phenyl Oxazol Based Compounds
    LIU Shaohua, LING Yun, LI Hongyue, XU Dan, YANG Xinling
    2014, 35(2):  281-285.  doi:10.7503/cjcu20130551
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    Several famous bioactive heterocycles such as oxazole, imidazolidine and thiazolidine are widely used in both pharmaceutical and pesticide industry. To find new lead compounds with favorable biological activities, a series of novel substituted phenyl oxazol based compounds containing 2-nitroaminoimidazoline or thiazolidine was designed via the method of linking active sub-structures. The target compounds were synthesized from substituted benzoic acid in three steps. Their structures were confirmed by 1H NMR and elemental analysis. The preliminary bioassay results indicated that some target compounds showed obvious inhibitory activities against Gibberella saubinetii, Rhizoctonia solani, Botrytis cinerea and Alternaria solan. Especially, compound 5q, with 62% and 86% inhibition rate against Gibberella saubinetii and Botrytis cinerea, respectively, exhibited equivalent activity to Polyoxin B with 57% and 85% inhibition rate at a concentration of 100 μg/mL. The structure-activity relationship indicated that the type and position of substituent on the benzene ring would influence the activity obviously. The halogen substituent was favorable to activity. Besides, compounds with ortho-substituent showed better activity than those with meta or para-substituent.

    Halolactonization of Alkenoic Acid Catalyzed by Ammonium Iodide
    ZHU Min, JIN Jianchang, ZHANG Hui
    2014, 35(2):  286-291.  doi:10.7503/cjcu20130535
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    A novel halolactonization of pentenoic acids was developed, which was catalyzed by hypervalent iodine species generated in situ from ammonium iodide. In this protocol, 4-pentenoic acids reacted easily with lithium bromide or lithium chloride under catalyst ammonium iodide in combination with m-chloroperbenzoic acid(mCPBA) as the terminal oxidant in CH3CN at room temperature, which provided five-membered halolactones in moderate to good yields. A new plausible reaction pathway for the reaction was hypothesized. Thus, NH4I was first oxidized to I2 and HOI with mCPBA, both of them reacted with alkenoic acid to form the iodolactone, which then was transformed into the hypervalent iodine intermediate in situ by the continuing oxidation, and finally the halolactone was provided when lithium bromide or lithium chloride was acted as nucleophile in the following intermolecular nucleophilic substitution. This method has some advantages such as mild reaction conditions, simple procedure and good yields. Furthermore, the scope of hypervalent iodine reagents in organic synthesis could be extended.

    Stereo Selective Synthesis and Absolute Configuration Determination of (2E,4S)-4-(t-butoxycarbonylamino)-5-[(3S)-2'-oxo-3'-pyrrolidinyl]-2-pentenoic Acid Ethyl Ester
    ZHANG Yongpo, ZHANG Yang, SUN Huailin
    2014, 35(2):  292-296.  doi:10.7503/cjcu20130465
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    (2E,4S)-4-(t-Butoxycarbonylamino)-5-[(3S)-2'-oxo-3'-pyrrolidinyl]-2-pentenoic acid ethyl ester(1) is a key intermediate widely used in drug candidate synthesis, such as the human rhinovious 3C protease inhibitor AG7088 and its related substances which are currently being developed for treatment of common cold, severe acute respiratory syndromes(SARS) and hand, foot, mouth disease(HFMD). Based on existing synthetic routes using L-glutamic acid as starting material, the optical purities of each intermediate product was rigorously examined, and the effects of reaction conditions on the optical purities of the products were studied in details. Meanwhile, racemic samples of each product were prepared from D,L-glutamic acids using the same procedures and used for comparison in high performance liquid chromatography(HPLC) analyses. Thus, new factors that could influence the optical purities of the final products were discovered, and methods for solving the problems were provided. The molecular structure of intermediate product (2S)-2-(t-butoxycarbonylamino)-3-[(3S)-2'-oxo-3'-pyrrolidinyl]propanol(5) was determined by the X-ray diffraction method, which provides direct evidence for the absolute configuration of these products.

    Ionic Liquid-functionalized Chiral salen Mn(Ⅲ) Complex for Asymmetric Oxidative Kinetic Resolution of Racemic Secondary Alcohols
    LI Chengyong, TAN Rong, ZHAO Jiangfeng, YIN Donghong
    2014, 35(2):  297-302.  doi:10.7503/cjcu20130374
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    Hydrophilic imidazolium-based ionic liquid(IL) was introduced into the framework of the chiral salen Mn(Ⅲ) complex by covalent linkage, which provided a ionic liquid-functionalized chiral salen Mn(Ⅲ) complex. Fourier transform infrared spectrometry, UV-Vis and thermal analysis results showed that the chiral salen Mn(Ⅲ) complex was modified with the IL moiety with the intact active site. The catalytic performance of IL-functionalized chiral salen Mn(Ⅲ) complex in the asymmetric oxidation kinetic resolution(OKR) of secondary alcohols was investigated. It was found that the surfactant-type complex showed higher catalytic activity than neat chiral salen Mn(Ⅲ) complex. Secondary alcohol conversion was more than 63%, enantioselective could reach 99% and separation efficiency was 18.3%. Catalyst could be facilely recovered from the reaction system for reuse 3 times by controlling solvent. The hydrophilic imidazolium-based IL was thought to improve the mass transfer associated with the aqueous reaction and stabilize the transition state, which in turns enhanced the activity and stability of the catalysts.

    Expression and Molecular Dynamics of Recombinant Ganoderma Lucidum Immunoregulatory Protein-IgG Fc(LZ8-Fc) Fusion Protein in Pichia pastoris
    HOU Yue, SUN Fei, JIN Jing, LIU Zhiyi, ZHENG Qingchuan, LIANG Chongyang
    2014, 35(2):  303-308.  doi:10.7503/cjcu20131071
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    Ganoderma lucidum immunoregulatory protein(LZ-8) was recombinant expressed in Pichia pastoris by prolonging its in vivo half-life through genetic fusion with human IgG-Fc fragment. High purify of LZ8-Fc was obtained by affinity chromatography and size-exclusion chromatography. The result of hemagglutination reaction indicated that LZ-8’s immunoregulatory activity was inhibited by IgG Fc fragment. Molecular dyna-mics simulation combined with SEC-HPLC and CD proved that LZ8-Fc assembled itself in the same way with LZ-8, dimer in natural state. All of the results suggested that LZ-8 in N-terminal affected IgG-Fc fragment in downstream, which is supposed an important issue in the recombinant expressing of fusion protein. The results will provide a solid basis for preparing and optimizing technology of fusion protein.

    Interaction of Antimalarial Components Combination from Artemisia annua L. with Bovine Serum Albumin
    WANG Manyuan, ZHANG Chao, LI Jing, LI Zhaoxia, GONG Muxin
    2014, 35(2):  309-313.  doi:10.7503/cjcu20130748
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    The interaction of arteannuin, arteannuic acid and scopoletin on the binding of artemisinin with bovine serum albumin(BSA) was investgated by fluorescent spectrometry. BSA fluorescence quenching effect was strengthened after the interaction of BSA with antimalarial components combination[AAAS, m(artemisinin)∶m(arteannuin B)∶m(arteannuic acid)∶m(scopoletin)=1∶1∶1∶1] from Artemisia annua L. compared to that of BSA with artemisinin alone, and the fluorescence quenching effect was staitc quenching. The binding constant, binding point numbers and thermodynamic parameters at three temperature levels, for example, 298, 303 and 310 K were calculated, and the results revealed that the binding of AAAS with BSA had strong electrostatic attraction and the process was a spontaneous molecular interaction procedure in which entropy was increased. Compared with artemisinin, the quenching constants and the binding constant of AAAS with BSA were also increased. These results confirmed that arteannuin, arteannuic acid and scopoletin could significantly increased the binding of artemisinin with BSA, and the interaction of AAAS with BSA might be a key factor that improved the antimalarial efficacy of artemisinin in vivo.

    Highly Efficient Preparation of Bisphenol A Glucuronide
    YANG Gang, ZHU Liangliang, LÜ Xia, WU Dachang, XIA Yangliu, MA Xiaochi, XIN Yi, HOU Jie
    2014, 35(2):  314-318.  doi:10.7503/cjcu20130613
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    Bisphenol A(BPA), an industrial chemical, has been present in many hard plastic bottles, metal-based food and beverage cans. Many governments are trying to reduce the human exposure to BPA because it is really a readily accessible toxin for human. BPA can be extensively metabolized to bisphenol A-β-O-glucuronide(BPA-G) by UDP-glucuronosyltransferases(UGTs), thus the biological activities of BPA-G should be studied intensively. However, the studies on BPA-G are very limited due to the difficulty for preparation of BPA-G. In this work, the BPA-G was prepared using BPA as the starting material and rat liver microsomes(RLM) as the enzyme source. A series of orthogonal experiments was designed and performed to determine the optimal reaction conditions for BPA glucuronidation in RLM. After incubation under the optimal reaction conditions, the conversion of BPA was higher than 98%. A unique solid-phase extraction column(SPE) packed with C18WAX was used to enrich and purify the product BPA-G with high yield. Finally, the product was identified by both ESI-MS and NMR techniques.

    Physical Chemistry
    Theoretical Study on the Heteronuclear Metal-metal Multiple Bond Complexes Cp2MM'(μ-C8H8)
    LIU Nannan, DING Yihong, LIU Shuping
    2014, 35(2):  319-324.  doi:10.7503/cjcu20130994
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    The structure and bonding of the heteronuclear metal-metal multiple bond complexes Cp2MM'(μ-C8H8)(MM'=ScMn, TiCr, ScCo, TiFe, VMn) were theoretically studied. The calculated results shows that: (1) for the 28 ve systems, the ground-state of Cp2V2(μ-C8H8) is triplet state with V-V triple bond, the isoelectronic Cp2TiCr(μ-C8H8) is singlet state with Ti-Cr quadruple bond, and the isoelectronic species Cp2ScMn(μ-C8H8) is singlet state with Sc-Mn triple bond. (2) For the 30 valence electron systems, the ground-states of Cp2Cr2(μ-C8H8) is singlet state with Cr-Cr triple bond, the isoelectronic species Cp2VMn(μ-C8H8) is triplet state with V-Mn single bond, while the isoelectronic species Cp2ScCo(μ-C8H8) and Cp2TiFe(μ-C8H8) are singlet states with double metal-metal bond. In the triplet state of Cp2MM'(μ-C8H8), the two metal atoms are generally 17-electron configuration, while in the singlet state, the two metal atoms are generally respectively 16- and 18-electron configuration.

    Influence of Inorganic Salts on the Demulsification of Block Polyether with Seven Branches for Crude Oil Emulsion
    YUAN Jing, ZHAI Xueru, XU Guiying, TAN Yebang, ZHANG Jian
    2014, 35(2):  325-331.  doi:10.7503/cjcu20130915
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    The poly(propylene oxide)-poly(ethylene oxide) triblock polyether with seven branches(AE73) was synthesized by anionic polymerization and its demulsification for crude oil emulsion and aggregation behavior at oil/water interface were investigated in the presence of different inorganic salts. The influence mechanism of inorganic salts on the demulsification of AE73 for crude oil emulsion was studied by interfacial tension, cloud point and interfacial dilational rheology measurements. The results show that the demulsification of AE73 is enhanced in the presence of the “salting in” ions and decreased in the presence of “salting out” ions. The rate of dehydration becomes good with increasing of temperature, but the quality of dehydrated water is best at 45 ℃. This study may provide useful data for the selection and application of chemicals used in gathering and transportation of crude oil.

    Synthesis and Application of Silicon Scale Inhibitor SY-KD Under the ASP Flooding System
    CHENG Jiecheng, WANG Qingguo, ZHOU Wanfu, LI Su, CHENG Tiexin, ZHOU Guangdong
    2014, 35(2):  332-337.  doi:10.7503/cjcu20130894
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    By analyzing silica scale formation mechanism under the alkaline/surfactant/polymer(ASP) floo-ding system, we designed and synthesized a new type of scale inhibitor SY-KD. SY-KD inhibitor is a complex mixture that made by the polymer(CAABS) which is copolymerized by acrylic acid(AA) and p-methyl allyl oxybenzene sulfonate(MBS) & 2-phosphate-1,2,4-tricarboxylic acid(PBTC). The carboxyl functional groups of SY-KD can link to the orthosilicic acid molecules or its dimer acid through hydrogen bonding interactions, since the molecular chain of SY-KD’s steric effect would prevent further polymerization that the orthosilicic acid molecules or its dimer acid form silica dioxide. Laboratory experiments studies have shown that SY-KD is a good inhibitor for ASP flooding, each component of SY-KD can achieve the silicon scale inhibition ability mainly through the polymerization inhibition, the adsorption and dispersion, and the dissolution of insoluble SiO2. Field tests have shown that SY-KD scale inhibitor delays the average pump detection period of scaled wells from about 50 d to 300 d.

    Molecular Dynamics Simulation Study on the Effect of Mutant(Met108→Leu108) on Interactions Between Arabinose-binding Protein and Ligand
    FENG Xianli, LI Zhuo, ZHAO Xi, YU Hui, LIU Huiling, HUANG Xuri
    2014, 35(2):  338-343.  doi:10.7503/cjcu20130889
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    In order to understand the effect of the mutant(Met108→Leu108) of the arabinose-binding protein(ABP) on the interactions between the protein and ligand, a series of 60 ns molecular dynamics simulations for the ABP, ABP bound ARA, ABP bound GAL and their mutants was performed, respectively. The results show that the mutation(Met108→Leu108) in ABP leads to the significant change of the van der Waals interaction between residue 108 and ligand, which further causes the changes of the protein’s internal motion and interactions between the protein and ligand. The varieties in interaction between the protein and ligand make the two globular domains of wild-type and mutation-type of ABP gradually open and the ligand binding can control the open movement of the protein.

    Theoretical Investigation on the Reaction Between HRnCCH and X(X=H2O, NH3) in Gas Phase
    GAO Chenggui, LONG Zhengwen, TAN Xingfeng, LONG Bo, ZHANG Weijun, LONG Chaoyun, QIN Shuijie
    2014, 35(2):  344-350.  doi:10.7503/cjcu20130863
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    The reaction mechanisms of HRnCCH with H2O, NH3 were explored at the CCSD(T)//MP2/aug-cc-pVTZ-pp level of theory. This investigation involved the conversion between HRnCCH and HRnOH, HRnCCH and HRnNH2, and the water, water dimer, and ammonia gas molecule addition to the C≡C bond in the HRnCCH, respectively. The calculated results show that the HCCH+HRnOH is produced by the reaction of HRnCCH+H2O with an activated barrier of 54.1 kJ/mol and HCCH+HRnNH2 is yielded via the reaction of HRnCCH+NH3 with a estimated barrier of 75.2 kJ/mol. However, the formations of HRnCHC(OH)H, HRnC(OH)CH2, HRnCHC(NH2)H and HRnC(NH2)CH2 have the respective barrier of 219.6, 220.5, 174.4 and 182.4 kJ/mol. Therefore, the reactivity of HRnCCH is of quite weakness at the environments investigated herein, which indicates that HRnCCH could be existed under these conditions. In addition, the second water molecule introduced into the HRnCCH+H2O reaction leads to the remarkable reduction for the barrier of the formation of HRnCHC(OH)H to 123.2 kJ/mol, in which the second water molecule plays a strong catalytic role in the reaction of HRnCCH with water.

    Influence of Co-existing Species on Charge Transfer in Dye-sensitized TiO2 Nanocrystalline System
    CHENG Rongmin, LI Na, ZHAN Conghong
    2014, 35(2):  351-356.  doi:10.7503/cjcu20130843
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    Dye-sensitized nanocrystalline TiO2 colloidal suspensions in aqueous system were applied for H2 evolution under visible light(>390 nm). In these suspension systems, the efficiency of H2 evolution is strongly influenced by the dye-sensitizers, a ruthenium complex, (n-Bu4N)2-cis-[Ru(dcbpy)(SCN)2](N719, dcbpy=4,4'-dicarboxy-2,2'-bipyridine) and porphyrin derivatives 5,10,15,20-tetra(4-carboxyphenyl)porphyrin(TCPP) and tetra-(p-sulfonato phenyl) porphyrin(TPPS), and the combination with co-existing electron donor species, methanol(MeOH) and triethanolamine(TEOA). The analysis of fluorescence quenching and photoelectrochemical studies reveal that the charge transfer between the excited dye-sensitizers and TiO2 is strongly influenced by the surroundings, especially the concentration of co-existing donor species rather than the pH values of the surrounding solution. It is benefit for achieving higher conversion efficiency for not only the photocatalysts but also the photovoltaics using dye-sensitized of TiO2 nanoparticles.

    Preparation and Photocatalytic Efficiency of Fe3O4/TiO2 Nanocomposite Fibers Modified with Ag Nanoparticles
    , WANG Xiaohui, LI Xiaotian
    2014, 35(2):  357-361.  doi:10.7503/cjcu20130798
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    Fe3O4/TiO2 nanofibers were prepared via electrospinning technique. Then, the samples were modified with Ag nanoparticles by hydrothermal method to obtain the composite fibers with strong magnetism and excellent photocatalytic efficiency. XRD, SEM, TEM and UV-Vis adsorption spectra were used to characterize and analyze the structure and morphology. The photocatalytic efficiency was tested under ultraviolet light irradiation using Rh B degradation as the model reaction. The results showed that TiO2 in all samples were anatases and Ag nanoparticles were scattered on the magnetic TiO2 fiber surface averagely. The UV-Vis spectra showed that TiO2 photoadsoption ability enhanced and the adsorption range were shifted to the visible light region. After modification with Ag nanoparticles, the photocatalytic efficiency of Rh B degradation rate can reach 99.5% under 40 min UV light irradiation. The new material with strong magnetism can be separated easily and cyclically used by adding the magnetic field.

    Structure and Electrochemical Properties of Li-rich Li2+4xMn0.6+2xNi0.6-6xCr0.8O4 Spinel Prepared by Hydrothermal Method
    ZHAO Lifang, ZHANG Qian, HE Shici, LIU Weiwei, YANG Yusheng, ZHENG Junwei, PAN Qinmin, LI Decheng
    2014, 35(2):  362-367.  doi:10.7503/cjcu20130599
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    A series of cathode materials, Li2+4xMn0.6+2xNi0.6-6xCr0.8O4(x=1/30, 1/20, 1/15, 1/12), was prepared via hydrothermal method, and their composition, structure and electrochemical properties were investigated using X-ray diffraction(XRD), inductively coupled plasma-atomic emission spectrometry(ICP-AES), scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS), Fourier transform infrared spectrometry(FTIR), Raman spectrometry and charge-discharge tests. XRD measurements combining with ICP results reveal that the obtained samples are Li-rich type spinel structure. Moreover, XPS results suggest that the valence for Cr is +3 for x=1/15 and 1/12 and no Cr6+ exist. As to their electrochemical properties, it is found that these materials have a high-voltage plateau near 4.7 V and a low-voltage near 2.7 V. With the increase of x value, both charge and discharge capacities of the samples increase. The sample with x=1/12 shows a good cyclic performance as well as good rate capability.

    Multifunctional Zinc Oxide-coated Mesh for Oil/Water Separation and Pollutant Degradation
    LU Fei, CHEN Yuning, LIU Na, CAO Yingze, FENG Lin
    2014, 35(2):  368-371.  doi:10.7503/cjcu20130596
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    With an operation of low-temperature hydrothermal treatment, a steel mesh was coated with hexagon-shaped nanorods of zinc oxide. The as-prepared mesh shows good wettability of underwater superoleophobicity to the droplet of 1,2-dichloroethane, making it possible for the use in oil/water separation. Mixture of water with various kinds of oil such as gasoline, diesel and petroleum ether can be separated rapidly with a high separation efficiency of 98%.The mesh could suffer an oil pressure of 1.4 kPa, with the oil thickness of 21 cm. Depending on the UV-response property of zinc oxide, the mesh can also be used in the degradation of methylene blue, which makes it a multifunctional material for water treatment.

    Research on Extracellular Electron Transfer of Acidithiobacillus Ferrooxidans
    LIANG Fangyuan, WU Ranran, CAO Changli, ZHENG Yue, YANG Zhaohui, ZHAO Feng
    2014, 35(2):  372-376.  doi:10.7503/cjcu20130578
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    Extracellular electron transfer of Acidithiobacillus ferrooxidans(At. f) was investigated using cyclic voltammetry and chronoamperometry. Compared with cyclic voltammograms with ferrous ion or sulfur as electron donors, At. f has the extracellular electron transfer capability, and the reduction peak is produced by At. f under the condition of a constant potential -0.4 V, adding ferrous ion to the system could improve extracellular electron transfer. The current produced/changed under aerobic condition is more than one order of magnitude than under anaerobic condition. It illustrates that At. f has the stronger electrochemical activity under aerobic condition. In addition, surface characteristics of At. f were analyzed using X-ray diffraction, Fourier transform infrared spectra and scanning electron microscopy. These results could provide a basis for improving metal leaching rate.

    Enhanced the Performance of Photoelectrochemical Oxidation of Water over BiVO4 Film Electrodes by Electrochemical Reduction Pretreatment
    LI Haili, ZHU Hongqiao, CAO Fahe, LENG Wenhua
    2014, 35(2):  377-383.  doi:10.7503/cjcu20130537
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    BiVO4 thin film electrodes were pretreated by electrochemical reduction(ER) in acid aqueous solutions(pH=2), and its impact on the performance of photoelectrochemical oxidation of water was tested. The results show that this treatment enhances the photoelectrochemical oxidation of water over the BiVO4 thin film electrodes and the treated electrodes have a good photoelectrochemical stability. The untreated and ER treated electrode films were characterized by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectroscopy, photoluminescence, electrochemical impedance spectroscopy, Mott-Schottky measurements, etc. From a physical chemistry perspective, the ER pretreatment resulted an increase of the roughness of the electrode with increasing in surface area by a factor of 1.4; no detectable change in crystalline but a slightly red-shift in the V—O symmetric stretching; a decrease in binding energy for the surface Bi, V and O; partly reduction of Bi3+ with an increase in the atom ratio of Bi/V on the surface. From the view of photoelectrochemistry, due to ER treatment, the flatband potential for the electrode was negatively shifted, the charge-transfer rate of photocarriers at the electrode/solution interface was accelerated while the surface recombination rate was decreased. These changes and the increased surface area are the main reasons for the enhanced photoelectrochemical performance.

    Enthaplic Pairwise Self-associations of Nicotinamide and Isonicotinamide in Aqueous KCl Solutions by Microcalorimetry
    JIA Zhaopeng, HU Xingen, FANG Guoyong
    2014, 35(2):  384-388.  doi:10.7503/cjcu20130388
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    Dilution enthalpies of nicotinamide and isonicotinamide in pure water and aqueous KCl solutions of various molality(m=0—0.3 mol/kg) were determined at 298.15 K by isothermal titration microcalorimetry(ITC). The corresponding values of enthalpic pairwise self-association coefficient(hxx) were evaluated accor-ding to the McMillan-Mayer theory. From the point of view of solute-solute and solute-solvent interactions, the equilibrium between hydrophobic and hydrophilic interactions of the two pyridinecarboxamides was discussed. It is found that both of the hxx values of the two isomers are all largely negtive, and decrease rapidly with increasing molalities of KCl at its higher concentrations. It is concluded that both of them are characterized by prevailing hydrophilic-hydrophilic interaction, and that the π-electronic conjugation between aromatic pyridyl ring and carbonyl of amide group makes resonance structure molecule of the para-isomer be more hydrophilic due to charge separation. The results also indicate that the contribution from π-π packing between pyridyl rings can be neglected nearly, and that the increase of ionic strength I favors hydrophilic-hydrophilic interaction greatly since both of the hxx absolute values of the two amides increase gradually with the increasing mola-lity of KCl in solutions.

    Polymer Chemistry
    Preparation and Performance of POMs/PS/PVA Electrospinning Fiber Membranes
    LI Tingting, LIU Ce, ZHANG Zhiming, AN Libao, YANG Cuihuan
    2014, 35(2):  389-395.  doi:10.7503/cjcu20130913
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    POMs(phosphomolybdic acid)/PS(polystyrene)/PVA(polyvinyl alcohol) composite fibers were prepared by electrospinning, which were molded into a membrane. The structure and morphology of the composite fibers were characterized, by infrared(IR) spectroscopy, scanning electron microscopy(SEM) and energy dispersive X-ray(EDX) spectroscopy. The photocatalytic performance and mechanical properties of the composite fibers membranes were also tested. The results show that the Keggin structure of POMs in the composite fiber was not destroyed. When the mass ratio of PS and PVA was 1∶1, the composite fibers got the best morphology, smooth surface and smaller diameter along with uniform distribution. The diameter of composite fibers decreased with the increase of POMs content. UV test showed that the POMs immobilized on composite fiber membranes displayed higher photocatalytic activity than that of the direct use. Around 98% of methyl orange was degraded after 25 min irradiation. The composite fiber membrane was easy to recycle and reuse. After using 5 times repeatedly, the photocatalytic activity of the composite fiber membranes was not significantly reduced. The composite fiber membranes were very few breakages. The composite fiber membranes strength increased first and then decreased with the POMs content increased. The toughness increased with the increase of PVA content but the toughness decreased with the increasing of the POMs content.

    Latent Curing Activity of Dimethylaminoethoxy Hetero-oxy Borane for Epoxy Resin
    GAO Yubin, LIU Shumei, ZHAO Jianqing, JIANG Zhijie, YUAN Yanchao
    2014, 35(2):  396-401.  doi:10.7503/cjcu20130826
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    2-(2-Dimethylaminoethoxy)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane(PDB), 2-(2-dimethylaminoethoxy)-5,5-dimethyl-1,3,2-dioxaborinan(NDB) and 2-(2-dimethylaminoethoxy)-1,3,2-benzodioxaborole(CDB) with five-membered ring or six-membered ring contained intramolecular nitrogen boron coordinate bond(N→B), which hydrolytic stability was determined by exposure observation method. Differential scanning calorimetry, oven curing experiments, gelation time experiment and infrared spectroscopy(FTIR) were used to investigate their effect on the curing activity and latent property of E51 epoxy resins. The apparent activation energy associated with curing reaction(Ea) was calculated by Ozawa-Avrami method. The electron density of boron atom and the degree of N→B complexation in dimethylaminoethoxy hetero-oxy borane were influenced by the conjugative effect of phenyl ring, the donor effect of alkoxy and the steric hindrance effect. The conjugative effect of phenyl ring decreased the electron density of boron atom and strengthened the complexation degree of N→B of CDB, which induced a lower hydrolytic stability and curing activity on E51 than NDB and PDB with the donor effect of alkoxy substitution. A higher shielding effect of six-membered ring on boron atom caused a higher hydrolytic stability and curing activity than five-membered ring while a lower curing activity exhibited good latent performance for E51. The degree of conversion of one-pot E51-PDB epoxy resin[aE(t)] after depositing 3 months at room temperature was 0.22.

    Preparation and Microwave Absorption Performance of Polyaniline/CoFe2O4 Nano-composite by Coordination-oxidative Polymerization-hydrothermal Method
    JIANG Junjun, YANG Chunming, WANG Hongbo, LIU Xiaohua, LI Longhao
    2014, 35(2):  402-408.  doi:10.7503/cjcu20130804
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    Polyaniline/CoFe2O4 binary nano-composites were prepared by coordination-oxidative polymerization-hydrothermal method, and doped by sulfosalicylic acid. The influence of reactants ratio and concentration of doping acid on electromagnetic properties of resulting composites was investigated. The micrographs, structure and electromagnetic properties of polyaniline/CoFe2O4 composites were characterized by TEM, XRD, FTIR and electromagnetic measurements. The results indicate that the prepared composite show a multi-level structure in which CoFe2O4 is cube-shaped with an average particle size less than 20 nm. The optimal experimental results were as follows: the conductivity of the composite is about 0.43 S/cm when the content of CoFe2O4 in composite is 8.86%(mass fraction). When the thickness of PAn/CoFe2O4 composite is at 2 mm, a maximum reflection loss of -16.71 dB at 16.01 GHz is observed with a bandwidth of 4.68 GHz above -10 dB loss; and when the thickness of PAn/CoFe2O4 composite is at 3.2 mm, a maximum reflection loss of -51.81 dB at 9.23 GHz is observed with a bandwidth of 3.69 GHz above -10 dB loss. The nanocomposite exhibits excellent microwave absorbing capacity.

    Synthesis and Third-order Nonlinear Optical Properties of Indiumphthalocyanine-functionalized Four-arm Star Polymethylmethacrylate
    SHEN Liyuan, WU Yanying, LIU Dajun, HE Xingquan
    2014, 35(2):  409-414.  doi:10.7503/cjcu20130689
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    Using tetra-kis(2-chloropropionamido) indium(Ⅲ) phthalocyanine chloride [InClPc(NHCOCHClCH3)4] as initiator, a novel four-arm star polymethylmethacrylate(PMMA-InClPc) with an indium chloride phthalocyanine core was synthesized by atom transfer radical polymerization(ATRP) method. PMMA-InClPc structure was characterized by Fourier transform infrared(FTIR) spectroscopy, ultraviolet-visible(UV-Vis) spectroscopy and hydrogen nuclear magnetic resonance spectroscopy(1H NMR) techniques. The molecular weight and molecular weight distribution of polymer sample were measured by gel permeation chromatograph(GPC). Polymerization reaction kinetics of the synthesized polymer was also studied by GPC. The results show that polymerization process follows a first-order reaction kinetics. The third order nonlinear optical properties were measured by the Z-scan technique at 532 nm using a frequency-doubled Q-switching Nd∶YAG laser pulse with pulse width of 21 ps. When the molecular weight of polymer is 2902, the third-order nonlinear polarizability χ(3) reaches the maximum value, which is 7.216×10-10 esu by calculation. These results display that the synthesized PMMA-InClPc polymer has potential nonlinear optical applications.

    In situ Synthesis of Silver Nanoparticles on Fabric Attached with Chitosan
    PENG Junjun, ZHANG Xin, WU Yiming, LIU Honglin, RAN Jianhua, LI Ming, YANG Feng
    2014, 35(2):  415-420.  doi:10.7503/cjcu20130678
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    Cotton and polyester fabrics modified with silver nanoparticles were synthesized in situ through the reaction of absorption and reduction of chitosan which was attached on the surface of respective fibers. The obtained nanosilver fabrics were characterized by scanning electronic microseopy(SEM), energy dispersive X-ray(EDX) microscopysis, X-ray diffraction(XRD) and reflectance spectrum, and the influence of the concentration of silver ion and chitosan solution on the nanosilver fabrics was investigated. The antibacterial performances of the prepared nanosilver fabrics towards E. coil and S. aureus were detected. The results indicated that silver nanoparticles were uniformly formed on the surface of cotton and polyester fabrics attahced with chitosan, without any reductant addition. The crystalline size of the silver nanoparticels was about 5—10 nm. The prepared nanosilver cotton and polyester fabrics exhibited good antibacterial activity and antibacterial durability.

    Arrested Coalescence of Droplets in PBD/PDMS Blends
    ZOU Zhiming, LI Zhanwei, FU Cuiliu, SUN Zhaoyan, AN Lijia
    2014, 35(2):  421-426.  doi:10.7503/cjcu20130674
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    We investigated the effect of silica nanoparticle loading, dispersed phase fraction and shear rate on the arrested coalescence in immiscible blends of polybutadiene/polydimethylsiloxane(PBD/PDMS) under simple shear flow by an online optical-shear system. It was found that the size and regularity of the non-spherical PBD droplets resulted from arrested coalescence were determined by SiO2 nanoparticles loading, dispersed phase fraction and shear rate. At low SiO2 nanoparticle loading or high dispersed phase fractions, the coalescence of PBD droplets induced at low shear rate can be arrested by the nanoparticles at the interface, leading to the formation of large and irregular droplets. Increasing SiO2 nanoparticles loading, decreasing dispersed phase fraction or increasing shear rate can greatly decrease the size of the PBD droplets and improve their regularity. The results should be closely related to SiO2 nanoparticles coverage at the interface of the PBD droplets.

    Preparation and Properties of Surface Modified Nano-Ni Particles with n-Hexadecylphosphonic and Its Composites
    SHANG Guangyuan, LI Ming
    2014, 35(2):  427-432.  doi:10.7503/cjcu20130631
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    Through the modification of nano-Ni particles with n-hexadecylphosphonic acid(HDPA) as surface modifier, Ni/HDPA hybrid particles were prepared. Composite of polypropylene(PP) and Ni/HDPA was prepared by solution blending. The dispersion of Ni in PP, the compatibility and stability of Ni and PP, the dielectric performance of composite were discussed. The X-ray photoelectron spectroscopy(XPS), X-ray diffraction(XRD) and transmission electron microscope(TEM) results showed the surface morphology of Ni/HDPA, while the fracture surface morphology and the dielectric properties of composite were demonstrated by scanning electron microscope(SEM) and the dielectric spectrum analysis system. It is found that a coverage layer, which is 2—4 nm thick, of n-hexadecylphosphonic can be formed on the surface of nano-Ni. In the presence of the coverage layer, nano-Ni was changed from hydrophilicity into lipophilicity, in results of which the Ni/HDPA disperses well in the PP matrix. At the Ni/HDPA volume fraction of 40%, permittivity of composite can be as high as 10 times of pure PP.

    Synthesis and Properties of Fluorinated Poly(arylene ether sulfone)s with Sulfonated Pentiptycene Pendants as Proton Exchange Membranes
    GONG Feixiang, QI Yonghong, XUE Qunxiang
    2014, 35(2):  433-439.  doi:10.7503/cjcu20130605
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    Two series of poly(aryl ether sulfone)s[SPES-x-PPD(10F) and SPES-x-PPD(4F)] containing sulfonated pentiptycene groups were synthesized through nucleophilic aromatic substitution polycondensation using pentiptycene-6,13-diol, decafluorobiphenyl, 4,4'-(hexafluoroisopropylidene)diphenol, and 3,3',4,4'-tetrafluorodiphenyl sulfone, followed by postsulfonation with chlorosulfonic acid. The structures of polymers were characterized by 1H NMR spectra. These ionomers generally show high thermal stability. The correspon-ding membranes generally show good mechanical properties, excellent dimensional changes, good oxidative stability and high proton conductivity under high temperature and low humidity. Transmission electron microscopic photos reveal that the microphase separated structures of SPES-x-PPD(10F) and SPES-x-PPD(4F) membranes are improved greatly after fluorine atoms introducing. Meanwhile, the hydrophilic domain enlarged when the contents of fluorine atoms in polymer backbone increased. This is just the main reason of high conductivity for these membranes.

    Dissipative Particle Dynamics Simulation of the Phase Behavior of T-shaped Ternary Amphiphiles Possessing Long Rod-like Mesogens
    LIU Xiaohan, GUO Hongxia
    2014, 35(2):  440-448.  doi:10.7503/cjcu20130583
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    Using dissipative particle dynamics simulations, a phase diagram in terms of temperature and lateral chain length was established, related structural parameters and the effective volume fraction of lateral chains fL related to each mesophase were calculated.The experimentally observed pentagonal, hexagonal columnar phase and the lamellar phase where rods are stacked with in-plane order are firstly reproduced. The results show that the phase sequence and structures in the diagram of T-shaped ternary amphiphilies with long rod-like mesogens agree well with previous reports, the effective volume fraction of lateral chains fL related to each mesophase is also quantitatively consistent with the experimental value. These combined results demonstrate that the coarse graining model in our simulation reflects essential structural features of T-shaped real mo-lecules like molecular topology, excluded volume effects, tendency to phase separation, the length-to-width ratio of rod liquid crystal unit and the spatial effects of lateral chains, and they also confirm the fact that the size of lateral chains plays an important role in affecting the self-assembled structures of nonlinear systems and the distribution of each constituent.