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10 June 2016, Volume 37 Issue 6

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Cover and Content of Chemical Journal of Chinese Universities Vol.37 No.6(2016)

2016, 37(6):  0-0. 

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Articles: Inorganic Chemistry

Template-directed Synthesis of a Novel Two-dimensional Dy(Ⅲ) Complex Containing Helical Chains Using [PMo₁₂O₄₀\begin{array}{c}{y_2}_{}\end{array}

LIU Xiaojing, TANG Weidong, ZHOU Sihui, WANG Fuxiang, LIU Ying, XIANG Mingyue, PAN Qinhe

2016, 37(6):  1025-1029.  doi:10.7503/cjcu20160141

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A new two-dimensional(2D) Dy(Ⅲ) complex, [Dy(BMBCP)(H₂O)₄][PMo₁₂O₄₀]·2.75H₂O{H₂BMBCP=1,1'-[1,4-phenylene-bis(methylene)]-bis(pyridine-4-carboxylicaicd)}, denoted as HNU-7, was hydrothermally synthesized using [PMo₁₂O₄₀]^3- as template, and characterized by single crystal X-ray diffraction, Infrared spectroscopy(IR), X-ray diffraction(XRD), inductively coupled plasa(ICP) and luminescent techniques. Interestingly, due to the electrostatic attraction between the guest ions [PMo₁₂O₄₀]^3- and N⁺ of BMBCP ligands in the host sheets, pairs of helical -Dy₂ cluster-BMBCP-Dy₂ cluster-BMBCP- chains were formed by the alternation of Dy₂ clusters and the BMBCP ligands. The left- and right-handed helical chains are linked together via Dy₂ clusters to from the infinite sheet structure with 4,4-net.



Preparation of NiO Doped Beta-Al₂O₃ Solid Electrolyte via a Low Temperature Combustion Method^†

HONG Yongfei, ZHU Chengfei, HUANG Pan, JI Guanghui

2016, 37(6):  1030-1035.  doi:10.7503/cjcu20160143

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NiO doped and Li₂O stabilized Beta-Al₂O₃ solid electrolyte was synthesized via a citrate sol-gel low temperature combustion method. Effects of the NiO content on the mechanical and electrical performances were studied by means of thermogravimetry/differential scanning calorimetry(TG/DSC), X-ray diffraction(XRD) and scanning electron microscopy(SEM). Meanwhile, the relative density, the bending strength and the electrical properties of the prepared samples were also measured. When the content(mass fraction) of NiO in Beta-Al₂O₃ solid electrolyte is 0.10%, the content of β″-Al₂O₃ phase is 88.33%, the microstructure is uniform and compact, the relative density is 99.75%, the bending strength is up to 248 MPa and the ionic conductivity can reach 0.108 S/cm at 350 ℃.



One-pot Synthesis and Antimicrobial Performance of Metallic Silver-doped Mesoporous Al₂O₃ Nanoparticles^†

CHEN Huajun, XI Xiaojing, DING Wuxiu

2016, 37(6):  1036-1041.  doi:10.7503/cjcu20160111

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Metallic sliver-doped mesoporous Al₂O₃ nanoparticles(mesoporous Ag/Al₂O₃ NPs) were synthesized via hydrothermal method using AgNO₃ and Al(NO₃)₃·9H₂O as precursors. Powder X-ray diffraction(XRD), field-emission scanning electron microscopy(FE-SEM), X-ray fluorescence(XRF), energy dispersive spectrometry(EDS) and N₂ adsorption-desorption techniques were used to characterize mesoporous Ag/Al₂O₃ NPs, and the tests of minimum inhibitory concentration(MIC) and inhibition zone were carried out to evaluate antimicrobial efficiency of mesoporous Ag/Al₂O₃ NPs. XRD analysis identified Al₂O₃ as an unique crystalline phase in mesoporous Ag/Al₂O₃ NPs, and the lattice parameters modified significantly after doping with silver, in the meantime, the FWHM of mesoporous Ag/Al₂O₃ NPs increased while the (111), (400) and (440) interplanar spacing decreased. The FE-SEM images of mesoporous Al₂O₃ NPs and mesoporous Ag/Al₂O₃ NPs illustrate the diameter of mesoporous Ag/Al₂O₃ NPs decreased while the pore diameter increased after doping with silver. The XRF and EDX spectra of mesoporous Ag/Al₂O₃ NPs confirmed that the atomic ratio of O/Al was 1.5. Insightful analyses of XRD and XRF spectra of mesoporous Ag/Al₂O₃ NPs showed that metallic silver occupied interstitial positions of Al₂O₃ lattice and interstitial solid solution was achieved. N₂ adsorption-desorption analysis illustrates the specific surface area, pore volume and average pore diameter of mesoporous Ag/Al₂O₃ NPs increased significantly after doping with silver. The MIC of mesoporous Ag/Al₂O₃ NPs was less than 80 μg/mL against Escherichia coli and Staphylococcus aureus. The diameter of inhibition zone for mesoporous Ag/Al₂O₃ NPs was 26 mm against Escherichia coli and 24 mm against Staphylococcus aureus.



Self-activated Carex Meyeriana Kunth-based Porous Carbon Prepared by Direct Carbonization and Its Electrochemical Properties^†

WANG Yun, BEN Teng, QIU Shilun

2016, 37(6):  1042-1049.  doi:10.7503/cjcu20160075

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Porous carbon material UlaC-950-HF(Ula stands for Carex meyeriana Kunth, C is short for carbo-nized, 950 is the optimized temperature, and HF is the etchant) was prepared through direct carbonization of Carex meyeriana Kunth after necessary impurity removal. The precursor self-activated in the process of pyrolysis. The electrochemical measurements of the UlaC-950-HF sample and several other carbonized biomass-based porous carbon materials were carried out. The results revealed that the capacitance of UlaC-950-HF was 113 F/g. In addition, the electrode showed excellent cycling stability as its specific capacitance decreased only by 4 F/g after 4000 voltammetry cycles, showing its potential of being applied in the supercapacitor electrode material.



Molecular Mechanism of Adhesion of Monohydrate and Dihydrate Calcium Oxalate Crystals on Injured Kidney Epithelial Cells^†

GAN Qiongzhi, SUN Xinyuan, YAO Xiuqiong, OUYANG Jianming

2016, 37(6):  1050-1058.  doi:10.7503/cjcu20160035

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Effects of cell injury on calcium oxalate monohydrate(COM) and calcium oxalate dihydrate(COD) microcrystalline adhesion and cellular response of calcium oxalate microcrystalline on African green monkey renal epithelial(Vero) cells after adhesion were evaluated. COM amd COD crystal adhesion to injured Vero cells increased oxidative damage degree, the LDH release amount, reactive oxygen species(ROS) and dead cells and decreased cell viability. The cells shrinked and apoptotic bodies appeared. COM crystals caused more serious damage to injured Vero cells than COD crystals. The results of scanning electron microscopy(SEM) showed that the adhesive capacity of injured Vero cells to COM was significantly stronger than the control group, which enhanced crystals adhesion and aggregation. Laser scanning confocal microscope showed that Vero cell injury increased the expression of crystal binding hyaluronic acid(HA) molecules which were the most important reasons for promoting microcrystalline adhesion. The microcrystalline adhesion and aggregation on cellular surface were positively correlated to cell injury degree. These findings indicated that cell injury was the leading risk factor of kidney stone formation, which may provide insights into the mechanisms of kidney stone formation from molecular and cellular levels.



DNA-binding and Anti-tumor Activities of Cobalt Corrole Complexes^†

SHI Lei, YANG Wencong, ZENG Shuying, MO Tingting, ZHANG Zhao, CAO Manli, LIU Haiyang

2016, 37(6):  1059-1068.  doi:10.7503/cjcu20160029

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10-(4-Hydroxylphenyl)-5,15-bis(pentafluorophenyl)corrolatocobalt(1-Co) and 10-(4-phenothiazine)-5,15-bis(pentafluorophenyl)corrolatocobalt(2-Co) were synthesized and characterized by NMR, HR-MS and UV-Vis spectrometries. The interactions of the two complexes with ct-DNA were studied by fluorescence, UV-Vis and circular dichroism spectrometries, viscosity measurements as well as agarose gel electrophoresis. The results suggested that complexes 1-Co and 2-Co both interact with DNA via an outside binding mode. Furthermore, the two cobalt corrole complexes can effectively cleavage DNA under irradiation. MTT experiments indicated that both complexes display low levels of dark toxicity, but have high photocytoto-xic activity against H460, HeLa and A549 cell lines. This implies complexes 1-Co and 2-Co may have potential application in photodynamic therapy(PDT) as photosensitizer. Through the observation of the nucleus morphological and the measurement of mitochondrial membrane potential, we speculated that complex 2-Co can constrain tumor cell proliferation through the oxidative damage of mitochondria possibly.



Supramolecular Design of Coordination Complexes of Zn(Ⅱ) and Vapor Adsorption for MeOH^†

WU Juan, ZHAO Bowen, HUANG Chao, CHEN Dongmei, ZHU Bixue

2016, 37(6):  1069-1074.  doi:10.7503/cjcu20150842

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By employing the N'-(2,4-dihydroxybenzylidene)-isonicotinohydrazide ligand to assemble with zinc ions in different solvents, the two metal-organic frameworks(MOFs) 1 and 2 were obtained, namely[(dhbi)₂Zn₂·8H₂O]_n(1) was obtained from the ligand assemble with Zn(ClO₄)₂·6H₂O, {[(dhbi)₂(H₂O)₂Zn₂]·4DMF]}_n(2) was obtained from the ligand assemble with Zn(NO₃)₂·6H₂O using diffusion technology of saturated vapor. Single crystal diffraction was used to characterize their structures. Thermogravimetric analysis(TG-DTA) and powder X-ray diffraction(PXRD) were used to measure their thermal stability and purity. The results of vapor adsorption for MeOH indicate that complex 1 is a kind of satisfactory microporous material, further the complex 1 shows 38.1% void volume, and the complex 2 shows 5.5% void volume according to PLATON calculations.



Preparation and Properties of Nano TiO₂-ZnO Binary Collaborative Wood^†

GAO He, LIANG Daxin, LI Jian, PANG Guangsheng, FANG Zhenxing

2016, 37(6):  1075-1081.  doi:10.7503/cjcu20150829

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Nano TiO₂/ZnO binary collaborative wood was prepared via two step method. The structure and morphology of the samples were characterized by X-ray diffraction(XRD), Fourier transform infrared spectrometer(FTIR) and scanning electron microscopy(SEM), while its antibacterial and weather resistance properties under different preparative conditions were also investigated. According to the results, nano TiO₂/ZnO binary collaborative wood shows better performance than those treated by single nanomaterial in both properties, and n-hexane treated ones are better than those treated by anhydrous ethanol or distilled water, and wood with nano oxide shows better than those with non-nano oxide.



Analytical Chemistry

Nonenzyme Sensor Based on Metal Organic Frameworks/Porphyrin/Multiwalled Carbon Nanotubes for Detection of Glucose^†

HU Yiping, SHAN Duoliang, LU Xiaoquan

2016, 37(6):  1082-1087.  doi:10.7503/cjcu20160226

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Metal-organic frameworks(MOFs) are regarded as a new type of electrochemical sensor due to its excellent properties. In this work, Co-TCPP/MWCNTs@Co-MOFs composite was prepared in a gentle method, which is a manifest of the combination of the biomimetic catalytic feature of Co-TCPP, the excellent conductivity of MWCNTs and the high density of active sites of Co-MOFs. A new glucose nonezyme sensor was also constructed, which was experimentally proved processing significant response to glucose.



Organic Chemistry

Structural Characterization of Mannatide^†

SHEN Yanhong, CHEN Linxiao, ZHANG Wenqing, XU Zhizhen, WAN Yanfei, ZHANG Li, XIA Wei

2016, 37(6):  1088-1092.  doi:10.7503/cjcu20160138

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DEAE-52 cellulose column and Sephacryl S-300 gel column were used to isolate and purify mannatide to give four homogeneous glycopeptides termed as MT1-A, MT1-B, MT2-A and MT2-B. The chemical structure of MT1-A, MT1-B and MT2-B were elucidated using monosaccharide composition analysis, methylation analysis, ¹H-nuclear magnetic resonance(¹H NMR) spectroscopy, infrared(IR) spectroscopy and amino acids analysis. It was concluded that the monosaccharide composition and connection type of sugar residues of MT1-A, MT1-B and MT2-A were the same as MT2-A reported before while the molecular weight and amino acid content of four homogeneous glycopeptides were slightly different. The ¹H NMR spectrum of MT2-A was regarded as the standard reference spectrum and the anomeric region of each spectrum(δ 4.89—5.90) was selected as the identification region. The ¹H NMR spectra of MT1-A, MT1-B, MT2-A and different batches of mannatide were compared with the standard reference spectrum, using the correlation coefficient to quantitatively calculate the similarity. The results showed that mannatide was a mixture of several kinds of homoge-neous glycopeptides with the same glycan structure but different molecular weight and amino acid content.



Design, Synthesis and in vitro Antitumor Activities of Novel Bivalent β-Carbolines^†

GUO Liang, CAO Rihui, FAN Wenxi, GAN Ziyun, MA Qin

2016, 37(6):  1093-1099.  doi:10.7503/cjcu20160103

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A series of novel bivalent β-carbolines with a spacer of three to ten methylene units between the 7-oxygen was synthesized and characterized by nuclear magnetic resonance(NMR) and mass spectrometry(MS). The antitumor activities against Bel-7402, 786-0, BGC-823, A375, 769-P and MCF7 cell lines in vitro were investigated by MTT method. The results demonstrated that compounds 4c, 4k and 4r were almost inactive against all tumor cell lines, compounds 4g and 4o displayed significant cytotoxic activities with IC₅₀ value of lower than 10 μmol/L against all tumor cell lines. Most compounds displayed good and selective cytotoxic activities against HT-29 and Blu-87 cell lines. Primary structure-activity relationships(SARs) analysis indicated that the length of the spacer affected cytotoxic activities in vitro, and 8—10 methylene units were more favorable. Moreover, n-butyl or i-butyl substituents in position-9 of β-carboline facilitated the antitumor potencies.



Synthesis and Biological Activities of Novel 5-(Pyridine-3-yl)-1,2,4-triazole Mannich Bases and Bis-Mannich Bases Containing Piperazine Moiety^†

ZHANG Yan, WANG Baolei, ZHAN Yizhou, ZHANG Liyuan, LI Yonghong, LI Zhengming

2016, 37(6):  1100-1107.  doi:10.7503/cjcu20160042

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According to the drug design principle of active groups combination, a series of 5-(pyridine-3-yl)-1,2,4-triazole Mannich bases and bis-Mannich bases containing piperazine and fluorine moieties was designed and synthesized through the Mannich reaction of 1,2,4-triazole thiol intermediate. All the structures of new title compounds were characterized by ¹H NMR, ¹³C NMR and elemental analysis. The bioassay results showed that several compounds exhibited herbicidal activities against Brassica campestris in certain extent; compounds 2a, 2d and 2f possessed significant antifungal activities against P. piricola and were comparable with the control fungicide, triadimefon, at the concentration of 50 mg/L. Also, compounds 2a, 2b, 2d and 2i showed favorable in vitro ketol-acid reductoisomerase(KARI) inhibitory activities with inhibition rate of 51.7%—88.7% at 180 mg/L.



Physical Chemistry

Study on the Penetrating Energy of Zigzag Single-walled Carbon Nanotubes^†

ZHANG Chao, PAN Chengling, SHENG Shaoding

2016, 37(6):  1108-1114.  doi:10.7503/cjcu20160100

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The movement process and energy change of the primary knock-on atom were investigated after an energetic carbon ion colliding with single-walled carbon nanotubes via a molecular dynamics method. The relationship between the penetrating energy of the primary knock-on atom and the incident energy of the projectile carbon ion was analyzed for (2n+1,0)(n=2—9) zigzag single-walled carbon nanotubes. It was found that the penetrating energy increases linearly with the incident energy in the energy range under discussion. The linear slop was related to the nanotube diameter. The physical mechanism of linear increase was explained in detail by analyzing the time evolution of the potential energy of primary knock-on atom.



Simulation Study of the Phase Separation and Self-assembly of Nanoparticles Coated with Ligands^†

XU Fanhua, HENG Xiao, REN Jianxue, ZHOU Hengwei

2016, 37(6):  1115-1122.  doi:10.7503/cjcu20160086

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A simulation study was focused on the phase separation of binary ligands coated on the nanoparticle via the dissipative particle dynamics. After comparing with available simulation and experimental works in literatures, the results support the viewpoint that the driving force comes from the conformational entropy arisen due to a mismatch of ligand chains. A further investigation is conducted on the self-assembly of Janus or triblock Janus nanoparticles in selective solvents. The simulations show that the Janus particles tend to assemble into double-layered vesicle structure, while the triblock Janus particles can form single-layered vesicle structure. This study supplies the theoretical guideline for the design of functional vesicle material via the polymer coated nanoparticles.



Preparation of Rice Husk Carbon-based Solid Acid Catalyst for the Dehydration of Xylose to Furfural^†

LIANG Yu, CHEN Zhihao, LIANG Baoyan, HU Zhe, YANG Xiaomin, WANG Zichen

2016, 37(6):  1123-1127.  doi:10.7503/cjcu20160040

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A carbon-based solid acid catalyst, prepared by the sulfonation of rice husk carbon, was proved to be an efficient and environmental benign catalyst for the dehydration of xylose to furfural. The catalyst was characterized by Fourier transform infrared spectroscopy(FTIR), elemental analysis and Scanning Electronic Microscopy(SEM). The total acid site concentrations of the catalyst samples were obtained using standard acid-base back titration. The acid site concentration of 1.03 mmol/g was obtained when the 4.0 g of rice husk carbon was sulfonated by 15 mL of H₂SO₄ at 150 ℃ for 8 h. The effects of solvent, reaction temperature and time on the dehydration of xylose to furfural catalyzed by the rice husk carbon-based solid acid catalyst were studied. The results indicate that the yield of furfural increases gradually with the increase of reaction temperature and with the prolonger of the reaction time. The catalytic performance of the synthesized catalyst is better when using DMSO as reaction solvent than that of using water as solvent. A maximum furfural yield of 75.8% was achieved. The repeated usability and regeneration of the catalyst was investigated.



CASSCF and MS-CASPT2 Studies on an Electron-tunable,1,2-Dicyanoethylene-based Optical Molecular Switch^†

CAO Dan, LI Yuanying, SU Qingqing, WANG Bin, LIU Fengyi, WANG Wenliang

2016, 37(6):  1128-1134.  doi:10.7503/cjcu20150966

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CASSCF and MS-CASPT2 mechanistic studies were carried on the cis-trans isomerization processes of 1,2-dicyanoethylene in its neutral, cationic and anionic forms. The results confirmed the importance of electron-induction in reducing the reaction barrier, and more importantly, revealed the different nonadiabatic channels tuned by electron attachment/detachment. The S₁→S₀ decay of neutral dicyanoethylene need overcome a mild barrier(≥19.7 kJ/mol) to reach a H-migration-type, namely the S₁/S₀-CI, which is away from the C═C torsional coordinates and may slow down the speed of C═C rotation and hurt its directionality; while in cationic and anionic isomerization processes, the D₁ and D₀ PESs intersect along the rotary path, therefore, the nonadiabatic D₁→D₀ decay is barrierless, as result, the directionality of C═C rotation is maintained. The study revealed the role of electron induction in tuning the cis-trans photoisomerization, and shed light on the design of light-driven molecular rotary motors.



Preparation and Application of Molasses-based Porous Carbon Spheres for Supercapacitor Electrodes^†

HAN Xue, ZOU Bo, GU Xiaoxue, PANG Liyun, CAO Liyuan, LIU Qi, GUO Yupeng

2016, 37(6):  1135-1139.  doi:10.7503/cjcu20150874

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Porous carbon spheres for supercapacitor electrodes employing beet molasses which was a new raw material instead of conventional carbonaceous materials as precursor were produced in different ways. Porous carbons were prepared at various condition variables. The morphology, physical structure and electrochemical properties of the materials were characterized by scanning electron microscopy(SEM), nitrogen physisorption and electrochemical method. The materials had surface area of 2547 m²/g and specific capacitance of 170.5 F/g, which showed large surface area and well electrical double-layer capacitor. In a word, the problem of the use of molasses on a large scale in sugar industry may be solved. Moreover, a new way of producing porous carbons will be provided.



Catalytic Performance of Activated Carbon Supported Pt-Ni Bimetallic Catalyst for Glycerol in situ Hydrogenolysis^†

KONG Danni, JIANG Tao, ZHANG Yiying, CAO Fahai

2016, 37(6):  1140-1147.  doi:10.7503/cjcu20150857

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A series of activated carbon supported Pt-M(M=Fe, Ni, Co, Zn, Cu) bimetallic catalysts was prepared via KBH₄ reduction method for glycerol in situ hydrogenolysis to produce 1,2-propanediol. The results showed that Pt-Ni/AC catalyst with a Pt loading(mass fraction) of 2.0% and a Pt/Ni mass ratio of 1∶1 displayed excellent performance at 220 ℃ under 1.0 MPa of N₂ after 8 h reaction time, with a high selectivity of 60.5% and a conversion of 98.7%. In addition, the prepared Pt-Ni/AC had a good catalytic stability, which kept a high activity even after five cycles catalytic evaluation. The results from the characterization of catalysts by N₂ physisorption, XRD, TEM and XPS indicated that nanoparticles with an average size of ca. 2 nm were uniformly dispersed on the support. And the majority of metals in nanoparticles are present in the zerovalent metallic state. The formation of Pt-Ni phase due to the incorporation of Ni in the Pt lattice was responsible for the strong interaction between Pt and Ni metal. The catalytic performance of Pt-Ni/AC was compared with that of Pt/AC and Ni/AC, it was clearly observed that Pt could promote the aqueous phase reforming of glycerol to hydrogen, and Ni could facilitate the hydrogenolysis of glycerol. The unique perfor-mance of Pt-Ni/AC bimetallic catalysts was attribute to the the synergistic effect between Pt and Ni.



Polymer Chemistry

Preparation of Fe₃O₄ Nanoparticles and Lentiviral Vector Infected EPCs for the Improvement of Angiogenesis and MRI Tracing^†

WANG Juan, ZHOU Bing, WANG Xinxin, WU Xiujuan, LI Ting, ZHANG Wenke, LIU Kangding

2016, 37(6):  1148-1153.  doi:10.7503/cjcu20160180

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Fe₃O₄ nanoparticles(NPs) modified with sodium citrate were prepared via chemical coprecipitation method and fetal bovine serum(FBS) could improve the dispersibility of Fe₃O₄ NPs in FBS solution(volume fraction≤5%). At the temperature of 300 K, the saturation magnetization intensity of NPs reached 74.86×10^-3 A·m²/g(74.86 emu/g); MRI T2 imaging of endothelial progenitor cells(EPCs) became better after being infected by 75 μg/mL of Fe₃O₄ NPs and lentiviral vectors(LV); furthermore, EPCs could stably over express VEGF target gene. EPCs co-infected with Fe₃O₄ NPs and LV, after being injected into caudal vein of focal cerebral ischemia rats could effectively promote angiogenesis. These results indicated the modified EPCs possessed both MRI tracing and angiogenesis, and therefore had potential application value in clinical therapy of cerebral ischemia.



Surface Hydrophilic Modification of Poly(ether ether ketone) and Immobilization of Collagen^†

SUN Hui, YU Qingsong, YANG Biao, XU Guozhi

2016, 37(6):  1154-1160.  doi:10.7503/cjcu20160120

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Surface modification of poly(ether ether ketone)(PEEK) was performed to increase the surface wettability. Acrylamide(AAm) was grafted on the surface of PEEK film by ultraviolet grafting to improve the hydrophilicity through the introduction of hydrophilic groups. Then, glutaraldehyde was used to immobilize collagen and hydrolyzed collagen on surface of the material. Fluorescein-labelled collagen was also used to verify the immobilization. The surfaces of PEEK film before and after modification were characterized by contact angle meter, scanning electron microscope, fluorescence spectrophotometer and X-ray photoelectron spectrometer. The results show that the surface morphology and the hydrophilicity are changed significantly after surface modification. Polyacrylamide grated on PEEK has a density of as high as 50.9 μg/cm². PEEK-g-PAAm becomes hydrophilic with a decreased water contact angle of (22±3)°. Surface immobilized with hydrolyzed collagen labeled with fluorescein isothiocyanate exhibits strong fluorescence effect. Modified films immobilized with collagen showed nitrogen peak, which was not observed for unmodified PEEK film in X-ray photoelectron spectroscopy, indicating the successful immobilization of collagen. The concentration of collagen immobilized on PEEK was determined to be 10.2 μg/cm².



Preparation and Thermoelectric Properties of Composites Based on Polythiophene Derivatives with Donor-acceptor Structure^†

LIANG Ansheng, LI Junjie, PAN Chengjun, WANG Lei

2016, 37(6):  1161-1167.  doi:10.7503/cjcu20160110

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Poly{(3-methylthiophene-2,5-diyl)[p-(nitro)benzylidene](3-methylthiophenylene quinodime-thane-2,5-diyl)}(PMTNBQ) with low bandgap was synthesized and its thermoelectric properties were investigated. PMTNBQ/graphite(G) composites were prepared by mixing in solution followed by mechanical ball milling and cold pressing. The thermoelectric properties of the composites were investigated as a function of the graphite to polymer ratios. The highest value of ZT(5.36×10^-3) was obtained for the PMTNBQ/G composite containing 90%(mass fraction) of G. This work suggests that the thermoelectric properties of polymer-inorganic composites can be improved by synthesizing polymers with low band gap.



Synthesis of a New Cyanoacrylate Monomer and Its Application in Fluorescence Imaging in vivo^†

ZHANG Tao, TANG Yongjia, XU Liang, LIU Keliang

2016, 37(6):  1168-1174.  doi:10.7503/cjcu20160079

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A new cyanoacrylate monomer with fluorescein isothiocyanate(FITC) labeling was synthesized. It could copolymerize with any other cyanoacrylate monomers and result in copolymer being able to produce fluorescence. Well fluorescence imaging could be got when the copolymer was embedded in subcutaneous tissue of Sprague-Dawley(SD) mice. We also discussed the degradation pattern of polycyanoacrylate by monitoring the fluorescence intensity with time. The synthesis was started with anthracene /cyanoacrylate acid adduct and 6-(4,4'-dimethoxytriphenylmethyl)-amino-1-hexanol. After deprotection of 4,4'-dimethoxytriphenylmethyl group from intermediate anthracene/6-(4,4'-dimethoxytriphenylmethyl)-amino-1-hexanol cyanoacrylate adduct, FITC was labeled onto the amino group. The target product was finally got by reduction of the ethylenic bond. Structure of intermediates and target compound were identified by ¹H NMR and MS spectroscopy. Both the monomer and polymer could be observed fluorescence around 525 nm wavelength by an exciting light at 488 nm.



Rheological and Structural Characterization of Pectin Polysaccharides from Citrus Pulp^†

ZHI Zijian, ZOU Mingming, LI Shan, CHEN Jianle, YE Xingqian, CHEN Shiguo

2016, 37(6):  1175-1181.  doi:10.7503/cjcu20160066

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Raw pectin from citrus pulp was prepared with diluted acid extraction and ethanol precipitation. Its rheological behavior was assessed under different thermal treatments at different concentrations. Three polysaccharides, named P-0, P-1 and P-2, were isolated by anion-exchange chromatography on a diethyl-aminoethyl(DEAE) cellulose-52 column at 0, 0.1, 0.3 mol/L NaCl eluent, respectively. Their structural features were elucidated by determination of their molecular weight, sugar analyses, esterification degree analyses, Fourier transform infrared(FTIR) and ¹H nuclear magnetic resonance(¹H NMR) spectra. The results indicated that citrus pulp pectin was the typical shearing thinning non-newtonian fluid. The molecular weights of P-0, P-1 and P-2 were 752410, 286320, 131380, respectively. They belonged to the kind of acid polycose, which was abundant in uronic acid and low-esterified pectin with partial acetylesterification. P-0, P-1 and P-2 were mainly made up of rhammogalacturonan-Ⅰ(RG-Ⅰ) structure and their monosaccharides compositions were mostly glucuronate, galactose, arabinose, rhamnose and fucose at different ratio. FTIR and NMR spectra implied that P-0, P-1 and P-2 owned pyranose rings and exhibited both α- and β-glycosidic bonds.



Synthesis and Self-assembly of Thermoplastic Elastomer Poly(ε-decalactone)-Poly(L-lactide)-PEG with Rare Earth Catalyst^†

WANG Xiaoqing, LING Jun, SHEN Zhiquan

2016, 37(6):  1182-1188.  doi:10.7503/cjcu20160064

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Three triblock copolymers PLLA-PDL-PLLA with different compositions were synthesized by lanthanum tris(2,6-di-tert-butyl-4-methylphenolate) [La(OAr)₃] as the catalyst and 1,4-butanediol(BDO) as the initiator via a “one-pot two steps” block copolymerization strategy without PDL puriflcation. With biobased L-lysine diisocyanate(LDI) as the chain-extender, triblock copolymers were successively chain extended with biocompatible PEG6000 to produce multiblock copolymers. In tensile tests, the elongation at break of multiblock copolymers was up to 1200%, and they were good thermoplastic elastomers with an excellent mechanical property. In addition, the amphiphilic copolymers self-assembled into micelles in aqueous solution with a low critical micelle concentration(cmc) value of 4×10^-3 mg/mL.



Rheological Properties of GuHCl/Type Ⅰ Collagen Dispersions^†

BU Honghong, JIAO Yanni, LAN Wenjun, ZHUANG Xiaoli, DAI Xiaonan, LI Tianduo

2016, 37(6):  1189-1195.  doi:10.7503/cjcu20160063

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Collagen was extracted from the outer skin of pig using a pepsin digestion method. The isolated collagen was characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE), Fourier transform infrared spectroscopy(FTIR) and ultraviolet(UV). According to the electrophoretic pattern, the isolated collagen consisted of two different α-chains(α₁, α₂) and one β-chain, indicating type Ⅰ collagen. FTIR and UV results confirmed the presence of triple helical structure in the collagen molecule. The rheological properties of GuHCl/type Ⅰ collagen dispersions were investigated as a function of guanidine hydrochloride(GuHCl) concentration and action time. The results of flow curves indicated that the pseudoplastic flow behavior of GuHCl/collagen dispersions gradually close to the Newtonian fluid with the increase of GuHCl concentration in the range of 0—6.0 mol/L and action time in the range of 6—48 h. The linear oscillatory shear, steady shear and thixotropic loop experiments were performed to investigate thixotropic behavior of the GuHCl/collagen dispersions. It was found that the thixotropic type of GuHCl/collagen dispersions transformed from positive thixotropy to complex thixotropy and then to negative thixotropy with the increase of GuHCl concentration. The thixotropic type of collagen dispersion transformed from complex thixotropy to negative thixotropy with the increase of action time of 1.0 mol/L GuHCl. It should be note that the complex thixotropy in GuHCl/collagen dispersions has not been reported in the similar systems so far. And we tentatively discussed this novel discovery on the basis of the interactions between GuHCl molecule and collagen. Meanwhile, this work would be helpful to deeply understand the mechanism of thixotropy.



Simulation on the Static and Dynamic Properties of Linear, Comb-like and Star-like Polymers^†

PAN Kai, ZHU Youliang, FU Cuiliu, HUANG Yineng, SUN Zhaoyan

2016, 37(6):  1196-1201.  doi:10.7503/cjcu20160059

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We studied the static and dynamic properties of linear, comb-like and star-like polymers by means of molecular dynamics method. We found star-like polymers had the smallest size, and linear polymers had the largest size at the same chain length. Changing the chain topologies from linear to comb-like and star-like will lead to the great dependence of the scaling relationship of radius of gyration on both the degree of polymerization and the number of side chains or the arms. For star polymers, the increase of the number of arms results inthe decrease of the radius of gyration and increase of the diffusion coefficients. Moreover, the scaling relationship for radius of gyrations for star polymers and comb polymer is also obtained. These results may help people understand the physical insight of the topological structure dependence on the static and dynamic properties of polymer chains.



Preparation and Wave-absorbing Performance of PANI/Fe₃O₄/CB Hollow Structured Composites^†

GUO Yajun, ZHANG Long, HOU Jieqiong, MA Yongbo, QIU Hu, ZHANG Wenjuan, DU Xueyan

2016, 37(6):  1202-1207.  doi:10.7503/cjcu20150965

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Polyaniline(PANI)/Fe₃O₄/carbon black(CB) microspheres with hollow-structure were synthesized through the method of interfacial polymerization and Pickering emulsion polymerization. The morphology, electromagnetic properties, and microwave absorbing properties of these materials were characterized. The results showed that the average diameter of these microspheres was about 2.0 μm. The magnetic loss within 2—4 GHz and within 4—18 GHz of these materials were mainly attributed to natural resonance and exchange resonance and to eddy current loss, respectively. In the measurement frequency range of 2—18 GHz, the microspheres with hollow-structure’s minimum reflection loss(RL) shifted to low frequency with the increase of coating layer thickness. As the coating layer thickness increased to 5.0 mm, two peaks occurred, which respectively located in C band(4—8 GHz) and Ku band(12—18 GHz). It was believed that PANI/Fe₃O₄/CB could be a potential electromagnetic wave absorbing materialin C and Ku bands.



Preparation of Superhydrophilic and Underwater Superoleophobic PVDF-g-PAA Porous Membranes and Their Oil-water Separation Performance^†

GAO Hong, DUAN Yueqin, YUAN Zhihao

2016, 37(6):  1208-1215.  doi:10.7503/cjcu20150961

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Traditional polymer membranes used for treating emulsified oil/water mixtures always suffer from low flux, membrane damage and separation efficiency decline, which limit its further application. Here we fabricated a superhydrophilic and underwater superoleophobic poly(vinylidene fluoride)-grafed-poly(acrylic acid)[PVDF-g-PAA] membrane by salt-induced phase inversion method, the saturated sodium chloride solution was used as coagulation bath. In order to improve membrane performance polyvinylprrolidone(PVP) was added as porogen to improve internal structure of the membrane. The result showed that when the content of PVP was 5% the PVDF-g-PAA membrane could be used to separate both simple oil/water mixture and oil in water emulsion, the separation efficiency of oil in water emulsion still reaches 91% after several times and the flux maintained at 444 L/(m² · h) or more. Also the membrane exhibits an excellent antifouling property and is easily recycled for long-term use. The outstanding performance of the membrane and the efficient, energy and cost-effective preparation process highlight its potential for practical applications.



Effects of Glass Fiber on Electrical Conductivities of Multiwalled Carbon Nanotube-filled Polymer/Thermoplastic Polyurethane Blends

ZHANG Boyuan, GUO Zhaoxia, YU Jian

2016, 37(6):  1216-1223.  doi:10.7503/cjcu20150939

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The effects of epoxy-functionalized glass fiber(GF) on the electrical conductivities of polypropylene(PP)/thermoplastic polyurethane(TPU)/multiwalled carbon nanotube(MWCNT), poly(methyl methacrylate)(PMMA)/TPU/MWCNT and poly(lactic acid) (PLA)/TPU/MWCNT composites were investigated. The electrical resistivities of polymer/MWCNT composites increase with the addition of TPU due to the selective location of MWCNTs in the TPU phase. After the addition of GF, the electrical resistivities of polymer/TPU/MWCNTs composites are significantly reduced by up to 13 orders of magnitude, indicating that the addition of GF is a universal and effective method to improve the electrical conductivities of MWCNTs-filled polymer blends with TPU as the dispersed phase. The mechanism for resistivity reduction of GF-filled system is mainly the formation of TPU coated GF structure which serves as long conductive rod with high aspect ratio, facilitating the construction of conductive paths, although the effective concentration of the conductive species increases because of the volume-exclusion effect of GF. It is found that the contents of GF and MWCNTs are important factors affecting the electrical conductivities of the composites.



Preparation and Characterization of UV Curable Hyperbranched Polyurethane Acrylate with Adjustable Double Bond^†

XU Zhaohua, CHEN Chan, SUN Ning, LI Heng, LI Yibiao

2016, 37(6):  1224-1228.  doi:10.7503/cjcu20150878

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The hyperbranched polyurethane with six hydroxyl-terminated groups(HBPU-OH) was synthesized by glycerol as the core and diethanolamine(DEOA), isophorone diisocyanate(IPDI) as the branched monomer. Through further reacting with the half adduct of isocyanate-hydroxyethyl acrylate(IPDI-HEA), the obtained HBPU-OH was transformed into the UV-curable hyperbranched polyurethane acrylate(HBPUA), where the number of acrylic double bonds is adjustable. The Fourier transform infrared spectroscopy(FTIR) and nuclear magnetic resonance spectroscopy(¹³C NMR) were used to analyze the molecular structure of HBPUA and HBPU-OH. The results show that HBPUA was successfully synthesized. The differential scanning calorimeter(DSC) analyses indicate that displays the temperature of glass transition(T_g=67.8 ℃) of HBPUA is lower than the T_g(110.0 ℃) of HBPU-OH can be attributed to the introducing of hydroxyethyl acrylate. Furthermore, the thermal gravimetric analysis(TG) results show that both of the HBPU-OH and HBPUA have similar three-stage decomposition process.