Table of Content

10 December 2012, Volume 33 Issue 12

Previous Issue    Next Issue

Content

Cover and Content of Chemical Journal of Chinese Universities Vol.33 No.12(2012)

2012, 33(12):  0-0. 

Asbtract ( )   PDF (16074KB) ( )  

Related Articles | Metrics



Volume Contents of Chemical Journal of Chinese Universities to Vol.33(2012)

2012, 33(12):  1-16. 

Asbtract ( )   PDF (789KB) ( )  

Related Articles | Metrics

Hydrothermal Synthesis of CdS Nanorods in NaOH Solution

YI Xiao-Feng, ZHENG Jin-Sheng, ZHAO Yi-Bing

2012, 33(12):  2597-2603.  doi:10.7503/cjcu20120776

Asbtract ( )   PDF (3673KB) ( )  

Related Articles | Metrics

CdS nanorods were synthesized via a hydrothermal route in NaOH solution and characterized by scanning electron microscopy(SEM), powder X-ray diffraction(XRD), transmission electron microscopy(TEM), high-resolution transmission electron microscopy(HRTEM) and selected area electron diffraction(SAED). The influences of NaOH concentration and hydrothermal time on morphology and crystalline structure of CdS nanorods were studied, and a probable growth mechanism was proposed. The feasibility of recycling of mother liquor was also investigated. The visible light photocatalytic activity of CdS nanorods was evaluated by photocatalytic degradation of methylene blue(MB). The experimental results showed that NaOH solution played a role of complexing agent in the growth of CdS nanorods and was the key factor in the formation of rod-like morphology. The sample obtained in optimal experimental condition was CdS nanorod with an average diameter of ca. 200 nm and a length up to ca. 4 μm. The CdS nanorods were hexagonal single-crystals with high crystallinity growing along the [001] direction, and showed good photocatalytic activity and stability under visible light.



Preparation and Characterization of High Quality CdSe Quantum Dots in Aqueous Solution

WANG Yi-Lin, YANG Kun, PAN Hua-Qiao, LIU Sheng-Yan, XU Xian-Mei, ZHOU Li-Ya

2012, 33(12):  2604-2608.  doi:10.7503/cjcu20120751

Asbtract ( )   PDF (1975KB) ( )  

Related Articles | Metrics

Using sodium selenite as selenium source and mercaptosuccinic acid(MSA) as stabilizer, high quality CdSe quantum dots(QDs) were conveniently prepared in aqueous solution. The influence of experimental conditions, including refluxing time, cadmium to selenium molar ratio and cadmium to MSA molar ratio, on the luminescent properties of the obtained CdSe QDs were systematically investigated. The obtained QDs were characterized by UV-Vis absorption spectrometry, photoluminescence(PL) spectrometry, X-ray powder diffraction(XRD) and transmission electron microscopy(TEM). The results show that the proposed method lead to the formation of cubic CdSe QDs with narrow fluorescence full width at half maximum(35 nm), high photoluminescence quantum yield(up to 21%), and a broad emission spectra tunable from 518 to 562 nm.



Synthesis of Polycarboxylic Ligand Capped Fe₃O₄ Nanoparticles with Excellent Water-dispersibility via a Ligand-exchange Approach

JIANG Ze-Quan, SONG Sheng, DOU Hong-Jing, SUN Kang, WANG Yi-Ming, HUANG Chao-Fan, WEI Zhen-Hua, QU Guan-Xiong

2012, 33(12):  2609-2616.  doi:10.7503/cjcu20120626

Asbtract ( )   PDF (3552KB) ( )  

Related Articles | Metrics

Monodispersed magnetic Fe₃O₄ nanoparticles(MNPs) capped with oleic acid(MNPs-OA) were synthesized through a thermal decomposition method. On this basis, four kinds of water-soluble Fe₃O₄ nano-particles(MNPs-CA, MNPs-SiCOOH, MNPs-BTCA and MNPs-EDTA) capped with four different polycarboxylic ligands, i.e., citric acid(CA), n-(trimethoxysilylpropyl)ethylene diamine triacetic acid(SiCOOH) trisodium salt, butane tetracarboxylic acid(BTCA) and ethylenediaminetetraacetic acid(EDTA) tetrasodium salt, were prepared via a ligand exchange approach. Among the four ligands, the BTCA and EDTA tetrasodium salt with four carboxy groups were first chosen to cap Fe₃O₄ nanoparticles. The morphology, structure, chemical composition and magnetic properties of the four water-dispersible MNPs were characterized by transmission electron microscope(TEM), X-ray diffractometer(XRD), vibrating sample magnetometer(VSM), Fourier transform infrared spectrometer(FTIR) and thermal gravimetric analyzer(TGA). The water-dispersibility and suface potential of four water-soluble MNPs in their aqueous solutions were also characterized by UV-visible spectrophotometer(UV-Vis) and Malvern Zetaszier analyzer, respectively. The results show that the resultant 15 nm Fe₃O₄ nanoparticles possess narrow size distribution and superparamagnetism. In addition, the polycarboxylic ligand capped MNPs display excellent dispersibility in their aqueous solutions. By the co-assembly of these MNPs and polyelectrolyte, we fabricated magnetic microcapsules. The microcapsules are of great potential in biomedical fields owing to the magnetic responsivity and MRI imaging capability of MNPs.



Synthesis and Antibacterial Activity of Silver-histidine Complex Doped Montmorillonite Antibacterial Agent

DUAN Shu-E, ZHAI Yun-Hui, QU Ying-Juan, MA Ming-Yang

2012, 33(12):  2617-2622.  doi:10.7503/cjcu20120460

Asbtract ( )   PDF (3869KB) ( )  

Related Articles | Metrics

A novel colorless salt-tolerant silver-histidine complex doped montmorillonite antibacterial agent(SHMMT) powder was synthesized by hydrothermal ion exchange reaction using silver-histidine complex ion [Ag(His)]⁺ as precursor. The product was characterized by inductively coupled plasma spectrometer(ICP), powder X-ray diffractometer(XRD) and thermogravimetric-differential temperature analyser(TG-DTA). The antibacterial activity of SHMMT against Pseudoalteromonas carrageenovora was examined by a modified broth dilution test and the plate counting method. The salt-tolerant and slow-releasing properties of SHMMT were tested by sea water soaking method. The results show that the amount of Ag loaded on SHMMT powder reaches 1.7 mmol/g when the molar ratio of silver to histidine equals 1: 1, which is much more than the cationic exchange capacity(cec) of Na-MMT. SHMMT powder is pile white and has high bacterial activity. After being soaked in the sea water for 45 d, the bactericidal rate of the SHMMT powder still reaches 80%.



Ionthermal Synthesis, Crystal Structure and Photocatalytic Properties of a Novel Hybrid Network Based on Octamolybdate

DING Yan, CHEN Hong-Li, GUO Li-Quan, FU Hai, CHEN Wei-Lin, WANG En-Bo

2012, 33(12):  2623-2627.  doi:10.7503/cjcu20120383

Asbtract ( )   PDF (1204KB) ( )  

Related Articles | Metrics

A novel hybrid network based on octamolybdate building unit, Cu₅^ⅠBBTZ₃H₂O[β-Mo^ⅤMo₇^ⅥO₂₆][1, BBTZ=1,4-bis(1,2,4-triazol-1-ylmethyl)benzene], has been synthesized under ionothermal conditions and structurally characterized by single crystal X-ray diffraction. Compound 1 is a rarely self-penetration network constructed by three dimensional(3D) poly-rings networks and (4,4) 2D layers, in which the two interpenetrating parts were united together through Cu2 and Cu1 centers. Further, the infrared(IR) spectrum, thermogravimetric(TG) analysis and photocatalytic studies were also performed to authenticate the identities of the title compound. Photocatalytic study revealed that compound 1 was active for photocatalytic H₂ evolution under UV irradiation.



X-Ray Magnetic Circular Dichroism Study on the Fe-group Magnetic Films by Electrodeposition

SUN Xiu-Yu, LI Zong-Mu, XU Fa-Qiang, CHENG Ying-Zhi, XUE Li

2012, 33(12):  2628-2632.  doi:10.7503/cjcu20111215

Asbtract ( )   PDF (2576KB) ( )  

Related Articles | Metrics

Fe-group element magnetic films were electrodeposited on single crystal GaAs(100) surface via cyclic voltammetry. The results of scanning electron microscopy(SEM) indicated that the grain sizes of the films were small and the surface of the films was very smooth. The growth relation of Fe-group films electrodeposited on GaAs surface was analyzed systematically according to the X-ray diffraction(XRD) results. The macro-scopic magnetism of the magnetic films was measured with the magneto-optic Kerr effect device. X-ray magnetic circular dichroism(XMCD) spectra of Fe-group films were obtained from X-ray absorption spectra(XAS) via synchrotron radiation circularly polarized soft X-ray. According to the sum rules, the orbital and the spin magnetic moments of the element were calculated.



Analytical Chemistry

Measurement of Complexation Stability Constant and Coordinating Number of Poly(ethylenimine) with Metals

HUANG Jia-Hua, GONG Zhen-Bin, LIN Ji-Jun, DUAN Hua-Ling

2012, 33(12):  2633-2637.  doi:10.7503/cjcu20120405

Asbtract ( )   PDF (442KB) ( )  

Related Articles | Metrics

A rapid and accurate method using polymer complexation ultra-filtration(PC-UF) technique and inductively coupled plasma mass spectrometry(ICP-MS) for the measurement of the complexation stability constant and the average coordination number of poly(ethylenimine)(PEI) groups participating in the complex formation of PEI with metal ions was proposed. The method was applied to determine the stability constant and the average coordination number of PEI and Cd²⁺ complex. Firstly the mixture of various initial concentration ratios of PEI and Cd²⁺ solution were prepared, respectively, then the mixture reacted until the complexation equilibrium reached, and at last Cd²⁺ and small components were permeated into the solution and PEI-Cd complex was hold back with centrifugal ultra-filtration kit. Then ultra-filtration followed was completed so as to decompose PEI-Cd complex and obtain Cd²⁺ species using 10 mL 3%(volume fraction) HNO₃. With the help of chemical model inferred in the study, the complexation stability constant and the average coordinating number of PEI-Cd could be calculated. Effect of pH value(pH=4.0—5.9) on the equilibrium was investigated. The results showed that the complexation stability constant and the average coordinating number of PEI-Cd became larger as pH value increases. This may due to the protonation of PEI reduces as pH values increase, then the binding ability of PEI with metals become stronger.



Heavy Metal Ions Enrichment Detection with Micro-calorimetry

WANG Li-Ping, XU Yi, ZHENG Yi-Hua

2012, 33(12):  2638-2643.  doi:10.7503/cjcu20120404

Asbtract ( )   PDF (1980KB) ( )  

Related Articles | Metrics

Enrichment effects of heavy metal ions on urease-catalyzed reaction were investigated with micro-calorimetry. The effects of heavy metal ions inject order, flow rates(0.1, 0.5 and 1 mL/min) and micro-particle diameters(0.5-0.6, 0.7-0.8 and 0.9-1.0 mm) on urease-catalyzed reactions inhibited by heavy metals were investigated experimentally based on flow injection analysis(FIA) method. Furtherly, some optimal conditions such as inject volumes of urease and heavy metal ions were also obtained. The results showed that a better thermal reaction signal could be detected for a low flow rate of 0.1 mL/min, micro-particle diameters of 0.5—0.6 mm, and urease and heavy metals inject volume are 3 and 5 mL, respectively. The inhibition effects as following: As³⁺>Cu²⁺> Cd²⁺> Pb²⁺. These results indicate that the micro-calorimetry may be a potential method to rapidly and accurately detect heavy metals when the detected heavy metal ions are enrichment appropriately.



Preparation of Chiral Ligand Exchange Chromatographic Stationary Phase by Atom Transfer Radical Polymerization for Separation of Racemates

SUN Yang, ZHANG Lei, XU Fei, GONG Bo-Lin

2012, 33(12):  2644-2650.  doi:10.7503/cjcu20120365

Asbtract ( )   PDF (1146KB) ( )  

Related Articles | Metrics

A novel stationary phase was synthesized for chiral ligand exchange chromatography(CLEC) via atom transfer radical polymerization(ATRP) method. Poly(1-acryloylpyrrolidine-2-carboxylic acid) polymer brush was grafted onto the surface of the silica by ATRP using 2-bromoisobutyryl bromide as an initiator, and the organic metal compound formed in the CuCl/2,2'-bipyridine(Bpy) system as a catalyst in water medium at room temperature. Three high-capacity chiral stationary phases obtained with different ATRP formulations were tried as chromatographic packings in CLEC. The stationary phases were characterized by means of elementary analysis and thermogravimetric analysis. The influence of the ligand grafted-density, mobile phase pH, concentration of Cu²⁺, temperature of column on the resolution of DL-amino acids by CLEC were investigated, and the optimized chromatographic conditions were selected. The thermodynamics for separatins of racemates was discussed. The results showed that the prepared columns could separate nine DL-amino acids and α-hydroxy acid with high separation factor, and high retentions. The DL-threonine, DL-tyrosine and DL-tryptophan could be simultaneously separated using the stationary phase. It could be proved that the entropy controlled the process of chiral separation.



Single-labeled“Turn on” Fluorescent Oligonucleotide Probe for Iodide Detection Based on T-Hg²⁺-T and Inherent Quenching Ability of G-quadruplex

ZHU Ying, LIU Pei, YANG Xiao-Hai, HE Lei-Liang, LI Qing-Zhao, WANG Qing, WANG Ke-Min, HUANG Jin, LIU Jian-Bo

2012, 33(12):  2651-2656.  doi:10.7503/cjcu20120358

Asbtract ( )   PDF (1340KB) ( )  

Related Articles | Metrics

A simple and "Turn on" type iodide anion assay method was developed, based on the inherent quenching ability of G-quadruplex and fidelity of the "thymine-Hg²⁺-thymine" binding motif. A T-rich sequence was labeled with 6-carboxyfluorescein(FAM) at its 5'-end, nearby the 3'-end was a G-rich sequence which could form G-quadruplex structure instead of traditional quenchers. Upon addition of Hg²⁺, T-rich sequence folded into a hairpin structure which led the G-quadruplex near to the FAM, and the FAM was quenched by the G-quadruplex owning to photoinduced electron transfer between the dye and the G-quadruplex. After the addition of iodide, the fluorescence of FAM recovered considering that iodide could bind with Hg²⁺. The novel method for the determination of iodide was developed in linear range of 50—500 nmol/L, with the detection limit(3σ) of 30 nmol/L. This proposed method was highly selective and other anions have no interfering effects on the determination, which was successfully applied for analysis of real samples with the recovery from 92%—109%, and the RSD<4%(n=4).



Organic Chemistry

Proton Transfer of 2-(2-Amino-3-pyridyl)-benzimidazole Under the Inclusion Interaction with Cucurbit[8]uril

YI Ping-Gui, YANG Xi-Chun, YU Xian-Yong, LIU Zheng-Jun, LIU Jin, WANG Zhao-Xu, LI Xiao-Fang

2012, 33(12):  2657-2662.  doi:10.7503/cjcu20120582

Asbtract ( )   PDF (1445KB) ( )  

Related Articles | Metrics

The inclusion interaction of 2-(2-amino-3-pyridyl)-benzimidazole(2-A3PyBI) with cucurbit[8]uril(CB8) and the effect of the interaction on the proton transfer of 2-A3PyBI were studied via fluorescence emission spectroscopy, UV absorption spectroscopy and ¹H NMR. The results show that 2-A3PyBI has a dual emission fluorescence which corresponds to its proton transfer tautomers. The fluorescence titration results at selected pH value indicate that the interaction ratio is 1:2 and the encapsulation of 2-A3PyBI into CB8 cavity enhances the excited-state intramolecular proton transfer process. The ¹H NMR titration results, which the benzene ring signal upward but no obviously change of the pyridine ring was observed in DCl/D₂O, indicate that the benzene ring of 2-A3PyBI entrapped into the CB8 cavity with the pyridine ring outside the cavity.



Synthesis of Ruthenium-phenanthroline Porphyrins Interacting with DNA

WANG Kai, LIN Xiao, WAN Xing, JIA Tao, ZHANG Xiu-Lan, ZHANG Heng, JU Xiu-Lian

2012, 33(12):  2663-2669.  doi:10.7503/cjcu20120539

Asbtract ( )   PDF (1652KB) ( )  

Related Articles | Metrics

Porphyrin compounds have important research value and significance in photodynamic therapy against tumor diseases. In this work, 5-(4-hydroxyphenyl)-10,15,20-triphenylporphyrin and ruthenium-phenanthroline derivates as starting materials, three amphiphilic ruthenium-phenanthroline porphyrins were prepared and confirmed by ¹H NMR, IR, UV-Vis, MS and elemental analysis. Through UV-visible spectro-scopy, fluorescence spectroscopy and circular dichroism, the interactions of calf thymus DNA with these porphyrins were investigated and the binding modes of them were obtained. The binding constants of Por1, Por2 and Por3 were 1.46×10⁵, 2.75×10⁵ and 5.69×10⁵ L/mol, respectively. Additionally, Por1 and Por2 showed intercalative interaction and outside groove-face binding with DNA, but Por3 interacted DNA with outside sta-cking and the electrostatic modes in presence of different DNA concentrations. The research results suggest these porphyrins are promising new photodynamic therapeutic agents.



Groups Transfer Reaction of Imidazolinium Salts as Tetrahydrofolate Model Compounds

ZHAO Yan-Qin, CHEN Jian-Xin

2012, 33(12):  2670-2675.  doi:10.7503/cjcu20120530

Asbtract ( )   PDF (1027KB) ( )  

Related Articles | Metrics

Tetrahydrofolate(THF) coenzyme is the methyl source of the methylation for many materials(including the DNA and RNA) in the living body to transfer one carbon unit for the biosynthesis and metabolism. The study on mimicking the characteristics of the THF coenzyme can contribute significantly to our understan-ding of the mechanism of action of the coenzymes themselves and provide a valuable effective reagents for groups transfer reaction for practical utility. Owing to such interests, two kinds of imidazolinium iodides 7 and 8 were prepared as the tetrahydrofolate model compounds at the oxidation level of formate, which reacting with bifunctional nucleophiles led to three or five carbon fragments be transferred completely and compound 7 reacts with monofunctional nucleophiles to afford the products transferred part of three carbon fragments. When the reaction of compound 17 as formaldehyde oxidation levels model compound of THF with amines carried out, the four carbon fragments with nitro were completely transferred. The reduction of model compound 7 was also studied. The procedure have mimicked and expanded the function of biochemical transfer of one carbon fragment of the tetrahydrofolate coenzyme and produced some new synthesis methods and reagents which can be applied to organic synthesis.



Stereoselective Construction of the Key Skeleton of Oxindole Alkaloid Humantenine

XIAO Tao, ZHOU Xuan, SONG Hao

2012, 33(12):  2676-2680.  doi:10.7503/cjcu20120494

Asbtract ( )   PDF (1095KB) ( )  

Related Articles | Metrics

Humantenine-type compounds are a group of Gelsemium alkaloids isolated from Gelsemium elegans Benth that possess complex structures and remarkable activities. In this work, the synthetic approaches of them were investigated. The key structure of Gelsemium alkaloids humantenine(13) was efficiently constructed through a region- and stereoselectivity addition of compound 11 to compound 10. A multi-step, one pot eno-loxonium cyclization cascade was used in a highly efficient way to construct, simultaneously, the tetrahydropyran ring, oxepane ring, C3 chiral carbon and C7 chiral quaternary carbon of humantenine(2). Based the above created methodology, the key skeleton(6) of oxindole alkaloid humantenine(2), humantenine N₄-oxide(3), gelseganines A(4)and gelseganines B(5) was asymmetric synthesized in 16 steps with a total yield of 1.5%. The structures of the compounds were confirmed by IR, ¹H NMR, ¹³C NMR and high resolution mass spectrometer(HRMS). Especially, we successfully synthesized hmantenine-type skeleton which indicates this method has a widely range of applications.



Design and Bioactivity of Novel Antimicrobial Peptides and Its Computer Simulation with Phospholipid

YU Lan-Lan, RAN Yu, BAI Xi-Xi, LI Ai-Rong, ZHU Yan-Yan, QIN Yun, QU Ling-Bo

2012, 33(12):  2681-2687.  doi:10.7503/cjcu20120476

Asbtract ( )   PDF (2165KB) ( )  

Related Articles | Metrics

Linear and cyclic peptides with two bioactive sequences and peptides with single bioactive sequence were designed and synthesized, followed by the investigation of their antibacterial activities. The results showed that the antibacterial activity sequence was linear peptides>cyclic peptides>short peptides. Especially linear peptides Linear-KT and Linear-KS showed high antibacterial activity against Gram-negative and Gram-positive bacteria. The toxicities of Linear-KT and Linear-KS against normal cell were also investigated by MTT method. Linear-KS showed low cell toxicity, which is better than the positive control Polymyxin B, implying a potential further investigation and application. The interaction between peptides and an important component of bacterial cell membrane phosphatidylglycerol(DMPG) was investigated by computer simulation. The results indicated that the binding energy between peptides and DMPG shows linear peptides>cyclic peptides>short peptides, especially Linear-KT and Linear-KS with higher binding energy. Linear peptides with two bioactive sequence provide more positively charged amino acids, which bind to negatively charged phospholipid, leading to higher binding energy and stronger antibacterial activity. Simultaneously flexible conformation and the hydroxyl group on β-C of serine and threonine in Linear-KT and Linear-KS could form more hydrogen bonds with carbonyl group in phospholipid, which further increases the binding energy. The computer simulation method provides theoretical evidence for antibacterial activity of antimicrobial peptides to some extent.



New Bibenzyl Derivative from Miao Medicine Herminium bulleyi

LIU Yu-Chen, LIU Gang, ZHANG Xian-Min, CHEN Jian-Chao, QIU Ming-Hua, QIU De-Wen

2012, 33(12):  2688-2691.  doi:10.7503/cjcu20120461

Asbtract ( )   PDF (409KB) ( )  

Related Articles | Metrics

Herminium bulleyi(Rolfe) Tang et Wang is a medicinal herb used to treat common disease such as impotent, premature ejaculation and spematorrhea by Miao in China. Despite of the widespread medicinal uses in Miao area, there is no phytochemical research on it. We had investigated its chemical consitituents for further sustainable utilization. In this work, six compounds were isolated and purification by silica gel, Sephadex LH-20 and RP-C₁₈ gel column chromatography from methyl alcohol extract of the tubers of Herminium bulleyi. Their structures were elucidated on the basis of spectroscopic evidence, particularly by two-dimensional NMR spectroscopic analysis. And they were identified as palmitic acid(1), 9,19-cyclo-9β-lanost-24-en-3-ol(2), β-sitosterol(3), glycerol monopalmitate(4), monostearin(5) and shuangshencaosu 2,2-dimethyl-5-methoxy-7-[2-(3″-hydroxyphenyl)ethyl]chromene(6). Among them, compound 6 is a new compound, the others are firstly isolated from this species.



Rapid Screening of Lipase Inhibitors from Fructus aurantii Using Lipase-immobilized Magnetic Beads Coupled with High-performance Liquid Chromatography-Mass Spectrometry

CHEN Zhui, TAO Yi, WANG Yi, WANG Yi

2012, 33(12):  2692-2696.  doi:10.7503/cjcu20120436S

Asbtract ( )   PDF (834KB) ( )  

Related Articles | Metrics

A new method for the rapidly screening of lipase inhibitors from extracts of traditional Chinese medicine using lipase-immobilized magnetic beads coupled with high-performance liquid chromatography-mass spectrometry(LC-MS) was proposed. After the lipase-immobilized magnetic beads were prepared, they were incubated with total flavonoid of Fructus aurantii to fish the ligands of lipase. Then, the eluent of magnetic beads' screening was analyzed by LC-MS. Four compounds, as naringin, hesperidin, neohesperidin and poncirin, were identified as the potential lipase inhibitors. Furthermore, the in vitro inhibitory activities against lipase of four compounds were tested. The results showed that hesperidin, neohesperidin and poncirin exhibit lipase inhibitory activities, while poncirin was firstly reported to be a lipase inhibitor. Our research showed that active compounds could be rapidly screened from extracts of traditional Chinese medicine via lipase-immobilized magnetic beads coupled with LC-MS.



Physical Chemistry

Electron Distribution and Contact Interface Transfer Process in Bilayer TiO₂ Films of Dye Sensitized Solar Cell

LIU Wei-Qing, LIANG Zhong-Guan, KOU Dong-Xing, HU Lin-Hua, DAI Song-Yuan

2012, 33(12):  2697-2702.  doi:10.7503/cjcu20120707

Asbtract ( )   PDF (1664KB) ( )  

Related Articles | Metrics

The electron accumulation and transfer process at the nano/micro-scale bilayer structure of TiO₂ film were investigated by electrochemical impedance spectroscopy(EIS). Two kinds of films with different microstructures were prepared through adding a micro-scale TiO₂ layer at the top of the nano-scale monolayer TiO₂ film. The intrinsic properties of these films, such as the capacitance distribution, the density of electronic states, the electron transportation and the solid/liquid interfacial electron transfer process, were studied detailedly. The effect of the nano/micro-scale bilayer structure of TiO₂ film on dye sensitized solar cell(DSC) was analysed. Chemical capacitance increase caused by a certain number of electrons was accumulated in micro-scale TiO₂ layer. The electron transport resistance had no significant effect when adding a micro-scale TiO₂ layer. In addition to its good performance of light scattering, the material chemical capacitor and transfer resistance should be considered in selecting and preparing materials for DSC scattering layer.



Preparation and Characterization of Fe-Ni/TiO₂ Nanotube Array Electrodes and Their Photoeletrocatalytic Activity for Dechlorination of Pentachlorophenol

TAN Jing, LI Xin-Yong, MOSES Tade, LIU Shao-Min

2012, 33(12):  2703-2707.  doi:10.7503/cjcu20120325

Asbtract ( )   PDF (1844KB) ( )  

Related Articles | Metrics

The Fe-Ni/TiO₂ nanotube array electrodes with different metal loadings were fabricated by the anodic oxidation method, followed by a dipping and electro-deposition technique. Scanning electron microscopy(SEM), X-ray photoelectron spectroscopy(XPS) and electrochemical measurements were employed to characterize the catalysts. The photoelectrocatalytic(PEC) reductive degradation of pentachloroph-enol(PCP) by the catalysts was investigated at 0.6 V bias potential in 2-propanol solution. The results indicate that the proper Fe and Ni nanoparticles depositing on the TiO₂ nanotube array electrodes could reduce the recombination probability of photoinduced electron and hole. The PEC reductive degradation efficiency of PCP over Fe-Ni/TiO₂ nanotube array electrodes with dipping and electro-deposition for 5 cycles could be above 91.35%, much faster than TiO₂ nanotube electrodes.



Studies of Interaction Between GABA and Mutant GABAaR

WEN Xia-Xia, NAN Shi-Bin, HUANG Ying, REN Tian-Rui, YAO Jian-Hua

2012, 33(12):  2708-2715.  doi:10.7503/cjcu20120319

Asbtract ( )   PDF (5150KB) ( )  

Related Articles | Metrics

Homology modeling and docking are important technologies in computer-aided drug design, which can explain the interactions between ligands and receptors. In this study, a rat γ-aminobutyric acid a-type receptor(GABAaR) model and its β205Tyr and β157Tyr mutant receptor models were built by homology modeling. The interactions between γ-aminobutyric acid(GABA) and the GABAaR and its mutants were studied by molecular docking, and the result show that the docking energy of the mutant receptors increases significantily and the biological activity of GABA decreases when Tyr changes to Phe; the docking energy becomes lower than that of the original receptor when Tyr changes to 4-F-Phe. In addition, the impact of β157Tyr mutations on the interaction between receptors and ligands is much more striking than that of β205Tyr when β157Tyr is closer to the ligand.



Preparation and Visible Light Photocatalytic Properties of Nitrogen and Carbon Co-doped TiO₂ Nanocrystalline

HARI Bala, GUO Jin-Yu, Aruna, YUAN Guang-Yu, ZHANG Zhan-Ying, LIU Zong-Rui

2012, 33(12):  2716-2721.  doi:10.7503/cjcu20120318

Asbtract ( )   PDF (1917KB) ( )  

Related Articles | Metrics

Nitrogen and carbon co-doped TiO₂ nanocrystalline(N-C-TiO₂) photocatalyst was prepared by a new method of sol-gel process using titanium n-butoxide [Ti(OC₄H₉)₄] as raw materials, acetic acid(HAc) as a modifier, and ammonium carbonate(C₂H₁₁N₃O₅) as solid substrates. The samples were characterized by thermogravimetric analysis(TGA), transmission electron microscopy(TEM), X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS) and N₂ adsorption-desorption isotherms analysis. The hydrous TiO₂ particles were deposited onto the surface of ultrafine ammonium salt particles during hydrolysis of Ti(OC₄H₉)₄. When the complex dry gel was calcined at lower temperature(300℃), the hydrous TiO₂ particles dehydrated and crystallized, and the N and C atoms diffuse into crystal lattice of TiO₂.The thermal dissociation of ammonium salt can control the particle size and inhibit the agglomeration of anatase TiO₂ in the calcining process and simultaneously enhance phase transformation from amorphous TiO₂ to anatase phase. The N-C-TiO₂ samples have smaller particle sizes, lower agglomeration and large specific surface area, which exhibit significantly higher photocatalytic activity than the P25 on the degradation of rhodamine B(RB) in water under visible light irradiation.



Preparation and Characterization of Magnetic Titanium Silicalite Molecular Sieve

WANG Dong-Qin, LI Yu, LIU Lai-Shuan, LI Jun-Ping, ZHANG Ru

2012, 33(12):  2722-2726.  doi:10.7503/cjcu20120270

Asbtract ( )   PDF (1587KB) ( )  

Related Articles | Metrics

Magnetic titanium silicalite molecular sieve(NiFe₂O₄/TS-1) particles with a core/shell structure were prepared via the process of hydrothermal synthesis and solvent vaporation method using nanosized nickelferrite with spinel structure as nuclear. The samples were characterized with Fourier transform infrared spectroscope(FTIR), vibrating sample magnetometer(VSM) scanning electron microscope(SEM), transmission electron microscope(TEM) and X-ray diffractometer(XRD). The results show that the composite particles are sphere and have an even distribution, with an average size of about 100—150 nm in diameter. The activity of the composite particles was investigated for catalysis of cyclohexanone ammoximation, the experimental results show that the conversion of cyclohexanone can reach up to 98% and the selectivity of the product is higher than 97%.



Molecular Dynamics Simulation of the Flow Behavior of Water Through Nanopipes

RAO Huan, YANG Wen-Hong, WANG Si-Miao, Kong Bin, LIU Wen-Zhi, LI Xiao-Xia, YANG Xiao-Zhen

2012, 33(12):  2727-2733.  doi:10.7503/cjcu20120261

Asbtract ( )   PDF (2442KB) ( )  

Related Articles | Metrics

Molecular dynamics was adopted to simulate the flow behavior of water through nanopores at atomistic level. Effects of the pressure difference, the diameter and the length of nanopipes to the flux of fluid were validated according to Hagen-Poiseuille(HP) equation with diameter of the nanopipe between 2 nm and 2.8 nm. Further investigation found that thereis the end effect to the flow behavior of fluid and the end effect depends on the nanopipe length and more significant for shorter nanopipes. In order to understand the flow behavior of real nanopores, we proposed four different nanopipe models possessing variational diameters along the pipe, which consists of two different diameter pipes and finally result in different fluxes. The behavior of fluid through the diameter variational nanopipes was elementarily discussed with a binary pipe model, which was put forward in the present study.



Improving the Accuracy of Low Level Quantum Chemical Calculation for Absorption Energies Based on Least Squares Support Vector Machine

GAO Ting, HAN Bo, LI Hui, LI Hong-Zhi, LV Ying-Hua, SU Zhong-Min

2012, 33(12):  2734-2738.  doi:10.7503/cjcu20120231

Asbtract ( )   PDF (1144KB) ( )  

References | Related Articles | Metrics

Least squares support vector machine(LS-SVM) was introduced to improve the calculation accuracy of low level density functional theory. As a demonstration, this approach combined low level quantum mechanical calculation with LS-SVM correction has been applied to evaluate the absorption energies of 160 organic molecules. After LS-SVM correction, the root mean square(RMS) deviations of the calculated absorption energies reduce from 0.95 and 0.46 eV to 0.16 and 0.15 eV for B3LYP/STO-3G and ZINDO methods, respectively. The LS-SVM correction may be a potential better method to predict high accurate absorption energies comparing with quantum chemical calculations when time and resource are limited or it is hard to achieve high accurate results by either quantum chemical calculation or measurement. This method provides a new means for accurately and quickly predicting of the molecular properties in quantum chemistry study.



Theoretical Studies on Small Sn/Pb Single-doped Al₄ Cluster

GAO Si-Meng, HE Hai-Peng, DING Yi-Hong

2012, 33(12):  2739-2745.  doi:10.7503/cjcu20120223

Asbtract ( )   PDF (3723KB) ( )  

Related Articles | Metrics

At the CCSD(T)/aug-cc-pVTZ&CEP-121G//B3LYP/6-311+G(d)&LANL2DZ level, the structures and stabilities of XAl₄(X=Sn, Pb) were investigated. The results show that different from XAl₄(X=Si, Ge), the ground state structures of SnAl₄ and PbAl₄ are planar tetra-coordinate Al in stead of a planar tetra-coordinate Sn/Pb structure. In addition, the stabilities of non-planar three-coordinate structure of SnAl₄/PbAl₄ are also better than that of ptX(X=Sn,Pb)



Synthesis and Catalytic Properties of Ordered Mesoporous Amino-group Functionalized Mesopolymers as Solid Base Catalysts

MU Li, ZHANG Long, WU Xiu-Li

2012, 33(12):  2746-2749.  doi:10.7503/cjcu20120214

Asbtract ( )   PDF (1403KB) ( )  

Related Articles | Metrics

A series of amine- or diamine-functionalized mesopolymers with cubic mesostructures has been prepared by two-step chemical modification procedures involving chloromethylation and a subsequent amination reaction of the FDU-16 mesoporous resol materials. The sample was carefully investigated by various techniques such as X-ray diffraction(XRD), N₂ adsorption-desorption, transmission electron microscopy(TEM) and infrared spectrometry(IR). Characterization results suggested that the mesostructure of the sample was retained during the chloromethylation and amination. The amino-group functionalized mesopolymer materials prove to be efficient heterogeneous base catalysts in Knoevenagel condensation.



Synthesis and Characterization of MgFe₂O₄@(TF-LDHs) Magnetic Nanocomposites

XU Jie, ZHAO Man, HOU Wan-Guo

2012, 33(12):  2750-2756.  doi:10.7503/cjcu20120188

Asbtract ( )   PDF (1817KB) ( )  

Related Articles | Metrics

Using magnesium ferrite(MgFe₂O₄)as magnetic substrates, a series of MgFe₂O₄@(TF-LDHs) nanocomposites possessing a core-shell structure with a tegafur(TF) intercalated Zn-Al layered double hydro-xides(LDHs) shell coated onto the surface of magnetic MgFe₂O₄ core was assembled via a one step coprecipitation method. The chemical composition, crystal structure, magnetic property, arrangements of tegafur within interlayer and drug release behavior of the magnetic nanocomposite were investigated systematically. The results show that MgFe₂O₄@(TF-LDHs) nanocomposites have a paramagnetism and the saturation magnetization are enhanced with increasing the magnetic substrates content. Tegafur molecules are arranged as a bilayer with the long axis slightly tilting to the LDHs layers. The release kinetics of tegafur from MgFe₂O₄@(TF-LDHs) nanocomposites was investigated in pH=7.2 and pH=4.8 buffer solutions. It was found that the release process might fit the pseudo-second-order release kinetics and the release mechanism was Fick diffusion. The in vitro drug release from the nanocomposites is remarkably lower than that from the corresponding physical mixture and the release rate reduce gradually with increasing the content of magnetic substrate or under an external magnetic field, showing that the MgFe₂O₄@(drug-LDHs) is a potential magnetic targeting drug delivery-controlled-release system.



Theoretical Study of the Electronic Spectral Property of Firefly Oxyluciferin Analogues

LI Zuo-Sheng, ZOU Lu-Yi, REN Ai-Min, FENG Ji-Kang

2012, 33(12):  2757-2764.  doi:10.7503/cjcu20120153

Asbtract ( )   PDF (3741KB) ( )  

Related Articles | Metrics

A series of firefly oxyluciferin analogues were designed, in which the N and S atoms of benzothiazole of firefly oxyluciferin were substituted by other atoms. In aqueous solution and virtual protein environment, the absorption and emission spectrum were calculated by TD B3LYP/6-31+G(d). The results of the calculation indicate that the absorption spectra of complexes with the O atom at X₁-site show more blue-shift than that with the S atom, while the spectra of complexes in which the S atom is replaced by the N atom show red-shift. The six complexes have similar orbital distributions and the overlapping volume between HOMO and LUMO is high. That benefits to the maintain of high fluorescence efficiency. Deprotonation can enhance the π orbital component of benzene fragment and make emission spectra shift to red. Thus electronic transition probability can be improved. Replaced by different atoms at X₁ and X₂ sites, the emission spectra can be adjusted to move to long wave up to 44 nm and move to short wave up to 41 nm(in virtual protein environment). The emission wavelength range of the six complexes is wide. So they can be used in biological imaging as new potential chemical luminescent material.



Interactions Between Sodium p-Perfluorononenyloxy Benzene Sulfonate and Alkyl Quaternary Ammonium Salts

YANG Bai-Qin, LU Guo-Chao, XING Hang, ZHOU Hong-Tao, GAO An-Tao, XIAO Jin-Xin

2012, 33(12):  2765-2770.  doi:10.7503/cjcu20120103

Asbtract ( )   PDF (707KB) ( )  

Related Articles | Metrics

p-Perfluorononenyloxy benzene sulfonate(C₉F₁₇OC₆H₄SO₃Na, OBS) a low-cost fluorinated surfactant. However, its surface activity is poor. In this work, OBS was mixed with different cationic hydrogenated surfactants, namely C_nNR[C_nH_2n+1N(CH₃)₃Br(C_nNM, n=8, 10) and C_nH_2n+1N(CH₂CH₃)₃Br(C_nNE, n=8, 10, 12)]. The effects of the molar ratio of OBS to C_nNR, the hydrophobic chain length and the headgroup size of C_nNR(R=M or E) on the critical micelle concentration(cmc), the minimum surface tension(γ_cmc), the maximum surface amount adsorbed(Γ_tm) and the limited surface area per molecule(A_min) for the mixtures of the cationic-anionic hydrogenated-fluorinated surfactants were investigated. The results showed that, after mixed with C_nNR, both the cmc and γ_cmc of the system were greatly lowered, i.e. the efficiency was totally enhanced. The OBS-C₈NE surfactant mixtures with molar ratio of 1:1 showed the best surface activity, i.e. the lowest cmc and γ_cmc, compared with the OBS-C₈NE mixtures with other molar ratios. Meanwhile, when the molar ratio was apart from equimolarity, the cmc of OBS-excess systems were smaller than that of C₈NE-excess systems, but the γ_cmc was not found to be significantly changed. Compared with single surfactant systems, the Γ_tm for the mixtures of OBS-C₈NE was significantly increased and the A_min was significantly decreased. When OBS was mixed with C_nNE with different alkyl chain length, the sequence of cmc for the mixtures was C₈NE>C₁₀NE>C₁₂NE. It suggested that the increase of hydrophobic chain length of C_nNE would induce the decrease of cmc of the mixtures. When the headgroup size of C_nNR(n=8, 10) in the mixture was changed from —triethylammonium to —trimethylammonium, no significant change of the surface activity was found for the mixtures.



Polymer Chemistry

Fabrication and PBG Modification of Gradient Colloidal Photonic Crystal

CHEN Jun-Bo, HUANG He, ZHANG Gang

2012, 33(12):  2771-2778.  doi:10.7503/cjcu20120581

Asbtract ( )   PDF (4554KB) ( )  

Related Articles | Metrics

Colloidal photonic crystals with controllable layers were fabricated by improved convective self-assembly method, and isotropic O₂ plasma etching was used to construct gradient structure. The gradient(along the surface normal) could be controlled by plasma treatment, leading to a wider tuning range of the stop band compared with colloidal photonic crystals without gradient. The photonic band gap(PBG) of the gradient colloidal photonic crystal was modified through controllable deposition of gold and amorphous silicon. Furthermore, a fluorescent molecule(Rhodamine B) was penetrated into the interstice of gradient colloidal crystals, and it exhibited an 8.6-fold enhancement of fluorescence emission. According to the tunable optical property of gradient colloidal photonic crystals(GCPCs), they could be used in fields such as photonics, catalysis and life science.



Effect of Layer-by-layer Films of Natural Polymers on Drug Release of Magnetic Poly(lactic acid) Microspheres

FU Yu, YANG Min, LI Yan, ZHONG Chong-Bin, JIAO Yong-Hua, LIN Ao-Lei

2012, 33(12):  2779-2783.  doi:10.7503/cjcu20120534

Asbtract ( )   PDF (1452KB) ( )  

Related Articles | Metrics

Polylactic acid(PLA) microsphere is an ideal drug carrier with high tolerance to the human body and the capability of carrying a wide range of drugs. However, the burst release of drug from the drug-loaded microspheres limit its effective application. Constructing a barrier layer at the surface of microspheres is an effective way to control the burst release of drug. A barrier layer consisting of natural polymer chitosan and sodium alginate was constructed by employing the layer-by-layer assembly technology. Furthermore, the effect of the layer on the drug release from magnetic PLA microsphere was investigated. The experimental results demonstrated that the barrier layer could effectively restrain the burst release of model drug, thus delaying the drug release. The magnetic drug delivery system constructed in this study is a promising magnetic targeted drug delivery system which allows the sustained release of drug and has high biocompatibility.



Synthesis of 8-Anilino-1-naphthalenesulfonic Titanium Complex and Ethylene-norbornene Copolymerization

ZHANG Hao, ZHANG He-Xin, CAI Xiao-Ping, HAO Xiu-Feng, ZHANG Xue-Quan

2012, 33(12):  2784-2788.  doi:10.7503/cjcu20120301

Asbtract ( )   PDF (869KB) ( )  

Related Articles | Metrics

The synthesized novel 8-anilino-1-naphthalenesulfonic titanium complex was used as catalyst for ethylene and norbornene copolymerization. The polymerization behavior of synthesized titanium complex was typically studied by varying various parameters, types of cocatalyst, concentration of norbornene, Al/Ti molar ratio, polymerization temperature and pressure. The resulting copolymers were characterized by ¹³C NMR, DSC and GPC. It was found that when methylaluminoxane(MAO) was used as cocatalyst, the catalytic activity was higher than that of triethyl aluminum(TEA) as cocatalyst under the same condition, and the copolymerization reaction mechanism was addition polymerization. In addition, the GPC curves of the copolymers showed a unimodal with a relatively narrow molecular weight distribution(M_w/M_n≈3). The incorporation ratio of the norbornene linear increased with the increase of norbornene feed ratio, while the melting point of the resulting copolymer was decreased with the norbornene feed ratio.



Effects of Talcum Powder(Talc) and Compounding Sequence on the Morphology and Mechanical Properties of PA6/PP/MAPP Blend

WANG Li, LING Xue-Liang, GUO Zhao-Xia, YU Jian

2012, 33(12):  2789-2794.  doi:10.7503/cjcu20120181

Asbtract ( )   PDF (2929KB) ( )  

Related Articles | Metrics

Talcum Powder(Talc) filled polyamide 6(PA6)/polypropylene(PP)/maleic anhydride grafted polypropylene(MAPP) blends were prepared by extrusion and subsequent injection molding. Effects of Talc and compounding sequence(one-step compounding and PA6 masterbatch method) on the morphology and mechanical properties of PA6/PP/MAPP blends were investigated. Field emission scanning microscopy shows that branched fibrils of PP phase oriented along the injection flow direction are formed in the core of specimen for Talc filled blends, instead of spherical dispersed PP domains for unfilled blend. And the sample prepared by masterbatch approach possesses finer morphology than the sample prepared by one-step compounding. The distribution of Talc in PA6 and PP phases was determined by selectively dissolving PA6 phase and thermogravimetric analysis of PP phase. Talc is selectively distributed in PA6 phase. The masterbatch method yields better dispersion state of Talc than the one-step compounding method. The tensile property, flexural property, impact property, heat distortion temperature and dynamic mechanical property of the materials were tested. The addition of Talc can greatly increase the flexural modulus, heat distortion temperature and dynamic storage modulus of PA6/PP/MAPP blend and the sample prepared by masterbatch approach outperforms the sample prepared by one-step compounding.



Synthesis of a New Acetyl-meglumine Resin and Its Adsorption Properties of Boron

WANG Nan, WEI Rong-Qing, CAO Fei-Ting, LIU Xiao-Ning

2012, 33(12):  2795-2800.  doi:10.7503/cjcu20120157

Asbtract ( )   PDF (1119KB) ( )  

Related Articles | Metrics

A new acetyl-meglumine resin which contains α-acetyl-amine and orth-dihydroxy was directly synthesized by the reaction of chloroacetylated polystyrene resin(PS-Acyl-Cl) with meglumine. The boron adsorption behavior of the acetyl-meglumine resin was studied by varying different parameters, such as the pH value, temperature, the initial concentration of boron and the adsorption time. The experimental results showed that the adsorption behavior of the resin obeyed the Langmuir model equation within the range of experimental condition. And the maximum adsorption capacity could be up to 28.1 mg/g. The adsorption capacity of the acetyl-meglumine resin for boron was superior to the Boron Specific Resin that was synthesized by chloromethyl polystyrene resin. The high adsorption capacity showed that α-acetyl-amine and orth-dihydroxy had synergic adsorption of boron. It was found that the resin maintained the high capacity at pH=6.0 and the effect of temperature on resin adsorption was little. The resin desorption rate was more than 96%. After repeating 5 times, adsorption capacity for boron basically unchanged. The kinetics studies show that the dominant procedure of the adsorption is liquid film diffusion-controlled mechanism.



Preparation and Characterization of Photoresponsive Organic-inorganic Hybrid Molecularly Imprinted Polymers

GAO Chao, YANG Yu-Zhu, ZHANG Guang-Bo, PENG Jing-Dong, TANG Qian, GONG Cheng-Bin

2012, 33(12):  2801-2808.  doi:10.7503/cjcu20120140

Asbtract ( )   PDF (2340KB) ( )  

Related Articles | Metrics

A photoresponsive functional azobenzene monomer containing silica was prepared by covalent imprinting for 2,4-dicholrophenoxyacetic acid(2,4-D) via oxidation-coupling reaction, acetylation and esterification reaction using commercially available p-nitrophenol, 2,4-dicholrophenoxyacetic acid and 3-chloropropyltriethoxysilane as the starting materials. Photoresponsive organic-inorganic hybrid molecular imprinted polymer(OIHMIP) for 2,4-D was prepared by sol-gel method. The photoresponsive properties, absorption abilities, selective recognition and photoregulated control the release and uptake of target molecule of OIHMIP were also studied. As characterized by atomic force microscope, the morphology of OIHMIP is sphere and the diameter of the spheres ranges in 150—200 nm. The experimental results show that OIHMIP has a high adsorption capacity and good selective recognition for 2,4-D, and reversible uptake and release of 2,4-D upon alternate irradiation at 365 and 440 nm, respectively.



Synthesis and Characterization of Tumor-acidity-sensitive Poly(L-lysine)-doxorubicin Conjugates

ZHANG Jian-Cheng, DING Jian-Xun, XIAO Chun-Sheng, HE Chao-Liang, ZHUANG Xiu-Li, YANG Ya-Nan, CHEN Xue-Si

2012, 33(12):  2809-2815.  doi:10.7503/cjcu20120137

Asbtract ( )   PDF (1972KB) ( )  

Related Articles | Metrics

Succinic anhydride(SA) and cis-aconitic anhydride(CA) were used to modify doxorubicin(DOX), obtaining acid-insensitive SA-DOX(SAD) and acid-sensitive CA-DOX(CAD), respectively. SAD or CAD, and carboxyl group terminated monomethoxyl poly(ethylene glycol)(mPEG-COOH) were conjugated onto poly(L-lysine)(PLL), yielding acid-insensitive PLL-g-mPEG/SAD and acid-sensitive PLL-g-mPEG/CAD, respectively. The chemical structures of PLL-DOX conjugates were characterized by ¹H NMR and FTIR. The drug conjugating content was determined with UV-Vis spectrophotometer. Dynamic laser scattering(DLS) measurements revealed that the amphiphilic PLL-DOX conjugates could self-assemble into nanoparticles in phosphate buffer(PB) at pH=7.4. In vitro release profiles revealed that the DOX release from PLL-g-mPEG/CAD could be accelerated at acid conditions(pH=5.3 and 6.8), while that from PLL-g-mPEG/SAD was slow at all test pH(5.3, 6.8 and 7.4). The acid-sensitive DOX release from PLL-g-mPEG/CAD conjugates ensured higher concentration of free DOX in tumor and more pronounced antitumor efficacy. In vitro methyl thiazolyl tetrazolium assay demonstrated that PLL-g-mPEG/CAD had enhanced tumor proliferation inhibition activity comparing with acid-insensitive PLL-g-mPEG/SAD. Therefore, PLL-g-mPEG/CAD conjugates might be further developed as potential smart antitumor drugs with controlled DOX release.



Synthesis and Responsive Behavior of Amphiphilic PS-b-PEG Diblock Copolymer Brushes

YANG Mu-Quan, MAO Jun, DONG Zhi-Xin, WANG Da-Peng, JI Xiang-Ling

2012, 33(12):  2816-2821.  doi:10.7503/cjcu20120114

Asbtract ( )   PDF (2569KB) ( )  

Related Articles | Metrics

Polystyrene-b-polyethylene glycol(PS-b-PEG) diblock copolymer brushes on a silicon wafer were synthesized via the combination of atom transfer radical polymerization(ATRP) and Click chemistry reaction. The ATRP initiator was grafted to silicon wafer. Then, polystyrene was grafted to the substrates through ATRP technique. After azidation with NaN₃, the Si/SiO₂/PS-Br brushes were transformed to Si/SiO₂/PS-N₃ with azide groups at the ends. The synthesis of PS-b-PEG brushes was then achieved via the click reaction of the obtained Si/SiO₂/PS-N₃ and an excess of alkynyl-PEG. The chemical compositions and the surface properties of the as-prepared PS-b-PEG brushes were detected via X-ray photoelectron spectroscopy(XPS), atomic force microscopy(AFM), ellipsometry, and water contact angle techniques. The responsive behavior of diblock copolymer brushes treated under different solvents was also discussed.



Preparation and Properties of Starch/Poly(vinyl alcohol) Film Plasticized by Magnesium Nitrate Hexahydrate

JIANG Ting, JIANG Xian-Cai, ZHANG Xiao-Fei, DAI Hua, ZHANG Xi

2012, 33(12):  2822-2826.  doi:10.7503/cjcu20120057

Asbtract ( )   PDF (1678KB) ( )  

Related Articles | Metrics

The plasticized starch/poly(vinyl alcohol)(PVA) film was prepared by casting method using magnesium nitrate hexahydrate [Mg(NO₃)₂·6H₂O] as the plasticizer. The micro morphologies of pure starch/PVA and Mg(NO₃)₂·6H₂O plasticized starch/PVA film were observed by scanning electron microscope(SEM). The interaction between Mg(NO₃)₂·6H₂O and starch/PVA molecule was investigated by Fourier transform infrared(FTIR). The crystallinity and thermal properties were measured by X-ray diffraction measurement(XRD) and thermogravimetric analysis(TGA). The mechanical properties were measured by tensile testing and dynamic mechanical analysis(DMA). It was found that Mg(NO₃)₂·6H₂O could form some interaction with starch and PVA molecules. The addition of Mg(NO₃)₂·6H₂O could improve the miscibility of starch and PVA. The XRD results showed that Mg(NO₃)₂·6H₂O could destroy the crystals of starch and PVA. The TGA results showed that the thermal stability of starch/PVA decreased with the addition of Mg(NO₃)₂·6H₂O. Tensile testing showed that Mg(NO₃)₂·6H₂O was highly effective in modifying the mechanical properties of starch/PVA film, making the elongation at break of starch/PVA film largely increased from 8% of pure starch/PVA film to 514% with 60%Mg(NO₃)₂·6H₂O.



Preparation and Bioactivities of Electrospun PBS Nanofiber Membrane and Hybrid PBS Nanofiber Membrane of Sustained Release Growth Factors in Platelet

SUN Shu-Fen, LI Nan-Nan, LIU Min, LIU Yi-Cong, ZHANG Ying-Chao, ZHOU Yan-Min

2012, 33(12):  2827-2832.  doi:10.7503/cjcu20120006

Asbtract ( )   PDF (5719KB) ( )  

Related Articles | Metrics

Poly(butylene succinate)(PBS) nanofiber membrane and hybrid nanofiber membrane of PBS and platelet-rich plasma(PRP) were prepared by electrospinning. The properties and bioactivities of scaffold materials were evaluated by means of scanning electron microscope(SEM), methyl thiazolyl tetrazolium(MTT), fluorescent staining and laser scanning co-focal microscope, hemolytic properties of materials and enzyme-linked immunosorbent assay(ELISA). The experiment results show that nanofiber membranes can accelerate the proliferation of human osteosarcoma MG63 cells line. Also, in vitro the growth factors in the scaffold material display a sustained release with the scaffold degrading after the initial burst release. In addition, hemolytic rate of scaffold material is 0.1475%(<5%), which meets the demand of hemolytic rate of medial materials.