Table of Content

10 December 2009, Volume 30 Issue 12

Previous Issue    Next Issue

Contents

高等学校化学学报2009年第30卷第12期目次

2009, 30(12):  0. 

Asbtract ( )   PDF (915KB) ( )  

Related Articles | Metrics

高等学校化学学报第30卷(1~12期)学科分类目次

2009, 30(12):  0. 

Asbtract ( )   PDF (1707KB) ( )  

Related Articles | Metrics

2010年第1期目次预览

2009, 30(12):  0. 

Asbtract ( )   PDF (1033KB) ( )  

Related Articles | Metrics

Articles

Synthesis and Characterization of APTTS-Fe₃O₄ Nanoparticles for in vitro Transfection as Gene Carriers

LI Wen-Zhang, LI Jie*, TAN Ze-Ming

2009, 30(12):  2331-2336. 

Asbtract ( )   PDF (842KB) ( )  

References | Related Articles | Metrics

Fe₃O₄ magnetic nanoparticles were prepared via thermal decomposition of Fe(acac)₃ in 2-pyrrolidone. And 3-aminopropyltriethoxy-silane(APTTS) was used to modify the surface of the nanoparticles. The structure and properties of the samples were characterized by means of XRD, TEM and FTIR. The potency of adsorbing DNA and resisting DNase-I digestion of APTTS/Fe₃O₄ were analyzed via agarose gel electrophoresis. Then, APTTS/Fe₃O₄ nanoparticles were evaluated as a kind of plasmid pCMVCD carrier and transferred into human glioma cell line U251 in vitro. The mRNA and protein expression of intracellular CD gene were tested by RT-PCR, Western blot and immunofluorescent staining, respectively. The results show that all the Fe₃O₄ nanoparticles are sized 8—10 nm and have a good crystallinity. Displaying functional group of —OH, —NH, —NH₂, —C—O, —C—OH, the amino-silane modified nanoparticles had the ability of binding DNA and resisting DNase-I digestion. Though the cell transfect test, such composite nanoparticles can transfer DNA into U251 cells efficiently and get stable expression.

Synthesis, Characterization and Crystal Structure of Complex {[Cu(hmtade)][Ni(dmit)₂]}₂·4DMSO

XIE Bin*, ZHANG Xiu-Lan, ZOU Li-Ke, WANG Jun, LAI Chuan, WU Yu, ...

2009, 30(12):  2337-2343. 

Asbtract ( )   PDF (546KB) ( )  

References | Related Articles | Metrics

A new complex {[Cu(hmtade)][Ni(dmit)₂]}₂·4DMSO(1)(hmtade=5,7,7,12,14,14-hexamethyl- 1,4,8,11-tetraazacyclotetradeca-4,11-diene, dmit=4,5-dimercapto-1,3-dithiole-2-thione, DMSO=dimethyl sulfoxide) was synthesized and characterized by means of elemental analysis, Infrared, Ultraviolet-visible spectroscopy, and X-ray structure analysis. Complex 1 belongs to monoclinic system, space group P2₁/n with a=1.49952(6) nm, b=1.77229(7) nm, c=3.1275(1) nm, β=102.442(1)°, V=8.1163(5) nm³, D_c=1.558 Mg/m³, Z=8, F(000)=3944, μ(Mo Kα)=1.637 mm^-1, S=1.016, (Δ/σ)_max=0.001, and final R₁=0.0673, wR₂=0.1672[I>2σ(I)]. Two independent structural units of [Cu(hmtade)][Ni(dmit)₂] are found in an asymmetric unit along with four DMSO solvent molecules. Sulfur-bridged heterometal Cu—Ni complex is formed by one dmit ligand of [Cu(hmtade)][Ni(dmit)₂]. The copper(Ⅱ) ion is a five coordinated square pyramidal environment, with Cu—N distances in the region of 0.1949(5)—0.2007(4) nm and Cu—S distances of 0.28913(18)—0.28952(18) nm. The nickel(Ⅱ) ion which is coordinated by four sulfur atoms of two dmit ligands is in the distorted square geometry, and the Ni—S distances fall in the range of 0.21729(16)—0.21905(17) nm. The N—H…O hydrogen bonds are formed between the nitrogen atom of hmtade ligand and DMSO solvent molecule, and the dimmer is formed through intramolecular S…S and S…H short contacts. Finally, one-dimensional zigzag chain, two-dimensional and three-dimensional networks are formed via S…S, S…C or C…H short contacts.

Preparation and Ultraviolet Photoelectric Response of TiO₂ Mesoporous Thin Films

MU Rui, DAI Shu-Xi, CHENG Gang, WU Yan-Qiang, ZHANG Xing-Tang, DU Zu-Liang*

2009, 30(12):  2344-2348. 

Asbtract ( )   PDF (486KB) ( )  

References | Related Articles | Metrics

Highly orderded TiO₂ mesoporous thin films were synthesized through evaporation induced self-assembly(EISA). The as-synthesized samples were characterized by X-ray diffraction(XRD), scanning electron microscope(SEM), and transmission electron microscope(TEM). The results show that the mesoporous sample has a highly organized and nanocrystaline anatase framework with pore size of about 5 nm. The UV-Vis spectra reveal that TiO₂ mesoporous thin films have strong absorbance to UV light(λ＜380 nm). The I-V(current-voltage) properties of TiO₂ mesoporous thin films were characterized. The results show that the I-V characteristics have changed when UV light is on and off, which indicate that TiO₂ mesoporous thin films have sensitive ultraviolet photoelectric response.

Syntheses and Characterizations of a Series of Transition Metal-substituted Aluminophosphates MAPO-CHA(M=Mn, Fe,Co, Zn)

DING Hong, DUAN Fang-Zheng, CHEN Peng, LI Ji-Yang*

2009, 30(12):  2349-2353. 

Asbtract ( )   PDF (473KB) ( )  

References | Related Articles | Metrics

Open-framework metal-substituted aluminophosphates have attracted more attentions owing to their interesting structural chemistry and potential applications in catalysis, ion exchange, magnetism, and photoluminescence. A series of metal-substituted aluminophosphates MAl(PO₄)₂[(C₂H₅)₂NH₂](denoted as MAPO-CHA, M=Mn, Fe, Co, Zn) was prepared under the hydrothermal conditions. Their frameworks are analogous to zeotype CHA structure in which 50% of the aluminum sites are replaced by transitional-metal ions. These compounds show photoluminescent properties, but the emission intensities are different due to the different transitional metals. Magnetic measurements reveal that there is very weak antiferromagnetic interaction among the metal centers of MAPO-CHA(M=Mn, Fe, Co). Crystal data of MnAPO-CHA: space group R3, a=1.4003(2) nm, c=1.5236(3) nm, V=2.5873(7) nm³, Z=9.

Preparation of Magnesium Hydroxide Whisker by Glycerol-Frequency Conversion Microwave-Hydrothermal Process

WU Jian-Song*, XIAO Ying-Kai, CHEN Lang-Yin, CHEN Xiao-Wei

2009, 30(12):  2354-2357. 

Asbtract ( )   PDF (663KB) ( )  

References | Related Articles | Metrics

The magnesium hydroxide whisker with excellent quality was synthesized by glycerol-frequency conversion microwave-hydrothermal process with MgCl₂·6H₂O and NaOH as raw materials. The phase, granularity, structure of crystal morphology of whiskers samples were characterized by X-ray diffraction(XRD), scanning electron microscop(SEM) and transmission electron microscop(TEM). The effect of glycerol-frequency conversion microwave-hydrothermal process on the crystal form, structure and dispersive capability of magnesium hydroxide whisker was investigated. The results show that high quality magnesium hydroxide whiskers with symmetrical granularity, fine crystal form and dispersibility, glabrous surface, as well as little crystal defect are obtained when 15%(volume fraction) of glycerol is added and heated at 180 ℃ for 6 h. The TEM images show that the diameters of whiskers are about 0.1-0.3 μm and the length are about 80-110 μm. The influence of glycerol and frequency conversion microwave on growth of magnesium hydroxide whiskeres was investigated primarily.

Synthesis and Electrochemical Behavior of Li-rich Cathode Materials Li[Ni_xLi_1/3-2x/3Mn_2/3-x/3]O₂(x=1/5, 1/4, 1/3) in the Lithium-ion Battery

WANG Sui-Jun, ZHAO Yu-Juan, ZHAO Chun-Song, XIA Ding-Guo*

2009, 30(12):  2358-2362. 

Asbtract ( )   PDF (728KB) ( )  

References | Related Articles | Metrics

The Li-rich cathode materials Li[Ni_xLi_1/3-2x/3Mn_2/3-x/3]O₂(x=1/5, 1/4, 1/3) were synthesized with co-precipitated metal hydroxide precursors M(OH)₂(M=Mn, Ni). The results of X-ray diffraction(XRD) and selected area electron diffraction(SAED) analysis confirmed the Li, Ni and Mn atoms are ordered in the M layer to form the superstrucutre. Images of scanning electron microscopy(SEM) show the Li-rich materials particles are about 1—3 μm, aggregated of submicron grains. Electrochemical behavior was examined by charge-discharge cycling. The Li[Ni_xLi_1/3-2x/3Mn_2/3-x/3]O₂(x=1/5, 1/4, 1/3) materials exhibited high reversible capacity of 200—240 mA·h/g and excellent cycle performance between 2.0 and 4.8 V at 10 mA/g current density.

Synthesis and Luminescence of Eu(Ⅲ) Complexes Based on 4,4′- Bis(4″,4″,4″-trifluoro -1″,3″-dioxobutyl)-biphenyl

LIU Sheng-Gui1,2*, WANG Hui-Hui1, HE Pei1, SHI Jian-Xin1, GONG Meng-Lian1

2009, 30(12):  2363-2366. 

Asbtract ( )   PDF (335KB) ( )  

References | Related Articles | Metrics

Two complexes Eu2(btb)3(H2O)4(1) and Eu2(btb)3(phen)2(2)[H2btb=4, 4′-bis(4″, 4″, 4″-trifluoro-1″,3″-dioxobutyl)-biphenyl, phen=1,10-phenanthroline] were synthesized. Their structures were characterized by elemental analysis, IR, UV and FAB-Ms. Both two complexes emit red luminescence, characteristic of the 5D0 → 7FJ (J=0—4) emission bands of Eu3+ under near UV irradiation. Monitored at 614 nm, the strongest excitation wavelength located at 395 nm, which matched to the emission light of InGaN chip. Two red conversion light-emitting diodes(LEDs) devices were fabricated by coating complex onto InGaN-based LED chip that emits 395 nm light. When the mass ratio of the red phosphor to the silicone was 1∶25, the two LEDs CIE chromaticity coordinates(complex 1: x1=0.5210, y1=0.2285; complex 2: x2=0.5835, y2=0.2857) are close to the National Television Standard Committee(NTSC) standard values for red color, the luminescence efficiency of devices are 0.65 lm/W for complex 1, 0.76 lm/W for complex 2. The results indicate that complexes Eu2(btb)3(H2O)4 and Eu2(btb)3(phen)2 can act as red components in the fabrication of white LED.

In situ Formation of Silver Nanoparticles Hosted in Mesoporous SBA-15

TIAN Dong*, YONG Guo-Ping, LIU Shao-Min

2009, 30(12):  2367-2370. 

Asbtract ( )   PDF (424KB) ( )  

References | Related Articles | Metrics

Mesoporous silicas SBA-15 with Ag nanoparticles in the channel was synthesized by one-step method with a mild reducing reagent(hexamethylenetetramine). Samples characterzation were performed by the XRD, TEM, adsorption/desorption of nitrogen. The surface areas of Ag/SBA-15 is 525 m²/g and the average pore diameter is 5.4 nm. Presence of nanoparticles of silver in mesoporous SBA-15 were confirmed by X-ray photoelectron spectroscopy(XPS), high angle X-ray diffraction(XRD) and transmission electron microscopy(TEM) confirmed the diameter of the metal nanoparticles. The content of the silver in the Ag/SBA-15 was detected by ICP-AES. The silver nanoparticles were dispersed uniformly by the in situ auto-reduction reaction with hexamethylenetetramine(HMT) as reducing reagent, and diameter of nanoparticles is found to be about 8.0 nm which is coincident with the channel diameter of SBA-15.

Leukemic Cell-enzyme-linked Immunosorbent Assay Using Interdigitated Electrodes Array with Enzymatic Silver Deposition

TAN San-Qin, WANG Guang-Ping, JIANG Jian-Hui, SHEN Guo-Li, ZHANG Rong, ...

2009, 30(12):  2371-2375. 

Asbtract ( )   PDF (311KB) ( )  

References | Related Articles | Metrics

An cell-based ELISA for cell surface antigen using interdigitated electrode array with enzymatic silver deposition was developed. Cell suspension were added to each well of a 96-well clear plate(poly-L-lysine coated).The cells were incubated with mouse-anti-human IgG, and then with HRP-conjugated horse-anti- mouse IgG. The interdigitated electrode array was added, the deposition of silver was dispersed over the microgaps and allows the microgapped interdigitated electrodes to be electrically connected, resulting in an increase in electrical conductance of interdigitated electrode array that is used to quantify the cell surface antigen.The electrical conductance signal showed correlation with cell surface antigen.Our results revealed that the electrochemical immunoassay, which was enabling the large-scale analysis of cell surface antigen, has characteristics(analyte specific, low background and low limit of detection) that provide potential for typing of acute leukemia(AL). This novel electrochemical immunoassay can also be applied in measuring the binding activity of engineering antibodies of cell surface molecules.

Study on the Target Interaction Between Mitochondria and Signal Peptide Functionalized Silica Nanoparticles

HE Xiao-Xiao, YUAN Yuan, SHI Hui, WANG Ke-Min*, HE Ding-Gen, QIN Di-Lan

2009, 30(12):  2376-2380. 

Asbtract ( )   PDF (399KB) ( )  

References | Related Articles | Metrics

The mitochondrial signal peptide functionalized fluorescent silica nanoparticles were prepared by conjugated the mitochondrial signal peptide to the nanoparticles through N-(p-maleimidophenyl) isocyanate(PMPI). The fluorescence spectrophotometer, zeta potential and TEM were used to characterize the fluorescent silica nanoparticles. The results show that the signal peptides are successfully conjugated to the surface of fluorescent silica nanoparticles, and the size of the fluorescent silica nanoparticles do not change obviously before and after modification. With the isolated nucleus as a control, the target interaction between the mitochondrial signal peptides modified fluorescent silica nanoparticles and the isolated mitochondria was investigated by flow cytometry. It was revealed that the bioactivity of the signal peptide was well remained after the conjugation with the silica nanoparticles, and the peptides could facilitate the specific recognition and binding between the silica nanoparticles and the isolated mitochondria, which put forwards a new idea for the monitoring and function controlling of the mitochondria.

Optical Detection of Immunoreaction Based on the Porous Silicon Bragg Reflector

Lü Xiao-Yi, QINGGeLe Tu, XIANG Mei, JIA Zhen-Hong*, LI Rui, ZHONG Fu-Ru, ...

2009, 30(12):  2381-2386. 

Asbtract ( )   PDF (512KB) ( )  

References | Related Articles | Metrics

Porous silicon has attracted considerable attention for sensor application due to its remarkable optical properties and the easy fabrication. In this study, an optical immunoassay was developed by the optic reflectance spectroscopy of the porous silicon Bragg reflectors. The artificial immunogen of hydroxysafflor yellow A(HSYA-BSA) and the polyclonal anti-HSYA antibodies were employed as the target and probe, respectively. HSYA is the main chemical component of the flower of the safflower, which is widely used in traditional Chinese medicine for treatment of cerebrovascular and cardiovascular diseases. First, porous silicon Bragg reflector was functionalized using oxidation and silanization. Then, the polyclonal anti-HSYA antibodies were immobilized to the porous silicon Bragg reflector surface used a crosslink method. After the antigen-antibody reaction, the reflection spectrum red shifts and the red shift of spectrum increases with the increase of HSYA-BSA concentration. It is showing the red shifts of the reflectance spectrum as function of HSYA-BSA concentrations. Control experiments were also presented with negative serum and the result suggests that the reflection spectrum red shift is due to selective antigen-antibody binding and this porous silicon Bragg reflector immunosensor possess high specificity. Compared to conventional ELISA, the procedures are label-free and detection time is reduced. Thus, this research lays a foundation of exploiting label-free porous silicon Bragg reflector immunosensor and could be further developed for component detection of safflower of a quick and accurate determination.

Label-free Electrochemical Detection of Gene Mutation with the Electrode Modified by Polyamidoamine Dendrimers and Cobalt Hexacyanoferrate

ZHU Xiang-Bin, AI Shi-Yun*, YIN Huan-Shun, SHI Wei-Jie, LIU Zhen-Zhen

2009, 30(12):  2387-2390. 

Asbtract ( )   PDF (341KB) ( )  

References | Related Articles | Metrics

Electrochemical hybridization biosensor for label-free determination of sequence-specific DNA was described. First, cobalt hexacyanoferrate films and poly (amidoamine)(PAMAM) dendrimer(generation 4.0) were modified on the glassy carbon electrode(GCE) sequentially. Then, DNA probes were successfully immobilized on the modified electrode with G4 PAMAM dendrimer acting as the coupling agent. The hybridization events were monitored by differential pulse voltammetry(DPV) measurement based on the oxidation signals of guanine without any external labels. This biosensor exhibited a superior electrochemical stability, selectivity and sensitivity in detection of the oligonucleotide sequence. Under the optimal conditions, the guanine oxidation signal was directly proportional to the mutant gene sequence concentration from 7.6×10^-11 to 3.05×10^-8 mol/L with a correlation coefficient of 0.9975 and a detection limit of 1.0×10^-11 mol/L(S/N=3).

Isolation and Structure Characterization of Polysaccharide from Morinda officinalis How

HE Chuan-Bo*, LI Lin, TANG Feng-Xia, XIONG He-Jian

2009, 30(12):  2391-2395. 

Asbtract ( )   PDF (364KB) ( )  

References | Related Articles | Metrics

Morinda officinalis How is a rare Chinese traditional herbal medicine. A water soluble polysaccharide(MOPI-3) was obtained from Morinda officinalis How, by hot water extraction, deproteination with Sevag method, precipitation with ethanol, and fractionation through DEAE-Sepharose CL-6B ion exchange chromatography. Using UV, IR, NMR, GC-MS, periodate oxidation, Smith degradation and methylation reaction, the primary structure of MOPI-3 was identified. The results show that, MOPI-3 is highly purified with average molecular weight of 35309 determined by high performance gel permeation chromatography. And it is a heteropolysaccharide composed of Ara, Gal and Glc. The backbone of MOPI-3 was linked by α-1,3-pyran-glucose and α-1,4-pyran-galactose, and the molar ratio of glucose to galactose was 5:1. There was one side chain composed by three α-1,3-furan-arabinoses linked onto C6 of glucose on backbone in each repeat unit, and the O-acetyl group was linked onto C2 of galactose.

Synthesis and Biological Activities of Xyloglucan Trisaccharides

LIU Hong-Mei, BAI Xue-Fang, DU Yu-Guang*, DU Yu-Guo

2009, 30(12):  2396-2399. 

Asbtract ( )   PDF (330KB) ( )  

References | Related Articles | Metrics

Native xyloglucan oligosaccharides are a kind of growth regulator in plant development. A xyloglucan trisaccharide: α-D-xylopyranosyl-(1,6)-β-D-glucopyranosyl-(1,4)-D-glucopyranose(1) and its derivatives were synthesized by three monosaccharide units. Glycosylation of isopropyl 2,3-di-O-acetyl-4,6-O-benzylidene-1-thio-β-D-glucopyranoside(3) as the donor with 4-methoxyphenyl 2,3,6-tri-O-benzoyl-β-D-glucopyranoside(4) gave disaccharide(5). Deprotection of 4,6-O-benzylidene of compound 5 gave 6 as disaccharide acceptor. Then coupling of isopropyl 2,3,4-tri-O-benzyl-1-thio-β-D-xylopyranoside(2) with 6 afforded α and β trisaccharides(7) and separation of compound 7 gave 8(α) and 9(β). Global deprotection of compound 8 obtained trisaccharide 1. The whole route involves five steps and the total yield is 15%. Synthetic trisaccharides were added to the culture medium to detect their effects on tobacco growth. The results show that three synthesized oligosaccharides promote the growth of tobacco at the level of 1 mg/L. These results suggest that synthesized trisaccharides may be good prospects for the application in the control of plant growth.

Convenient Asymmetric Direct α-Phenylethynylation of β-Dicarbonyl Compounds

ZHU Min*, LI Li, SUN Na-Bo, LI He

2009, 30(12):  2400-2403. 

Asbtract ( )   PDF (270KB) ( )  

References | Related Articles | Metrics

A novel chiral alkynyliodonium salt, phenyl(phenylethynyl)iodonium(10-camphorsulfonate) was prepared by simply stirring of phenylacetylene with [hydroxyl-(((+)-10-camphorsulfonyl)oxy)iodo]benzene in CHCl₃ overnight at room temperature. The asymmetric reaction with enolate anions of β-dicarbonyl compounds was studied in t-BuOH at room temperature, which gave good yields of α-phenylethynylated products with moderate values of e.e. value. The method for asymmetric direct α-phenylethynylation of β-dicarbonyl compounds was first reported, which had some advantages such as mild reaction conditions, simple procedure and with moderate values of e.e. value. Furthermore, the scope of hypervalent iodine compounds in asymmetric organic synthesis could be extended.

Purification and Characterization of an ε-Poly-L-lysine-degrading Enzyme Isolated from Streptomyces diastatochromogenes TUST2

TAN Zhi-Lei, JIA Shi-Ru*, ZHAO Ying, YUAN Guo-Dong, CAO Wei-Feng

2009, 30(12):  2404-2408. 

Asbtract ( )   PDF (475KB) ( )  

References | Related Articles | Metrics

Streptomyces diastatochromogenes TUST2, which was isolated from Hainan province, produced the antimicrobial poly(amino acid), ε-poly-L-lysine. In this study, the ε-poly-L-lysine-degrading enzyme was purified from this strain and its properties of this enzyme were determined. Preliminary data suggested that the ε-poly-L-lysine-degrading enzyme was a cell membrane associated protein. To extract this enzyme, bacterial cells were collected and disrupted with an ultrasonic oscillator, the membrane fraction were solubilized with 1.0 mol/L NaSCN solution. The coarse enzyme extraction was subjected to Sephadex G100 column for purification. With 100 mmol/L phosphate buffer as elution solution, the fractions with the enzyme activity were collected. The purified sample was analyzed with SDS-PAGE and the subunit molecular mass of the enzyme was estimated to be about 54700. The enzyme was stable between pH 6.0 and 9.0, with a maximum at pH=7.0. The optimum temperature was 30 ℃, and no significant activity loss was observed when the enzyme was incubated at 10—50 ℃ for 30 min. The effect of different metal ions on the activity of the enzyme were also investigated, some metal ions, including Zn²⁺, Fe³⁺, and Cu²⁺, could increase the enzyme activities by 29.72%, 15.85%, and 15.08%, respectively; while some other metal ions, including Ag⁺, Hg²⁺, Co²⁺ and Mn²⁺, strongly inhibited the enzyme activity. The enzyme activity was not affected by Ca²⁺, K⁺ and Ba²⁺. Experiment results also showed that the enzyme activity increased 10% by addition of 4％Tween-80, while EDTA strongly inhibited the enzyme activity. These results suggested that the specificities of this enzyme are similar to that of the ε-poly-L-lysine-degrading enzyme from streptomyces albulus.

Characterization of Human Acrosin Active Site and Binding Modes with Its Inhibitors

ZHANG Jue, ZHENG Can-Hui, SHENG Chun-Quan, ZHOU You-Jun, ZHU Ju, Lü Jia-Guo*

2009, 30(12):  2409-2414. 

Asbtract ( )   PDF (469KB) ( )  

References | Related Articles | Metrics

Acrosin is a promising target for contraceptive agents. Based on the previous homology modeling of human acrosin, the multiple copy simultaneous search(MCSS) methodology was used to explore the active site of human acrosin. The results show that all of three subsites(P1, P2 and G) are polar zones, and P1 is crucial for inhibitors′ binding. In addition, the edge of P1 and G as well as the bottom of P2 are hydrophobic, in which several important residues form hydrogen-binding interactions and electrostatic interactions. The key residues for ligand binding confirmed by MCSS calculations were consistent with the 3D structure of human acrosin complex and the experiments of site-directed mutagenesis on the animals. On the basis of above results, six of acrosin inhibitors, were docked into the active site of the human acrosin to elucidate their binding mode and the critical residues involved in binding. Our studies provide a basis for the rational design of novel acrosin inhibitors and the discovery of novel contraceptive drugs with high potency.

Synthesis of Hydrochloride of Bis(dimethoxypropylphosphinoethyl)-ethoxyethylamine

CHU Jin-Feng*, WANG Xue-Bin

2009, 30(12):  2415-2418. 

Asbtract ( )   PDF (245KB) ( )  

References | Related Articles | Metrics

[^99mTcN(PNP5)(DTC)]⁺[PNP5: bis(dimethoxypropylphosphinoethyl)-ethoxyethylamine, DTC: dithiocarbamate] heterocomplexes can be viewed as resulting from the selective coupling of the metal fragment [^99mTcN(PNP5)]²⁺ with the bidentate dithiocarbamate π-donor ligand, and these complexes have attractive potential for myocardial perfusion imaging agents. In this article, PNP5 hydrochloride was synthesized from 2-ethoxyethylamine and 3-chloro-1-propanol through seven steps successively, in which the last two steps were the key. The structure of PNP5 hydrochloride was affirmed by IR, ¹H NMR, ¹³C NMR, ³¹P NMR, MS and Elemental analysis.

One-pot Synthesis and Biodistribution of 6-[¹⁸F]Fluoro-6-deoxy-D-glucose(6-¹⁸FDG) as Potential Glucose Transport Imaging Agent

ZHANG Zheng-Wei, QIAN Jun, XUE Fang-Ping, LIU Ping, LI Yan-Ru, GUAN Yi-Hui, ...

2009, 30(12):  2419-2423. 

Asbtract ( )   PDF (438KB) ( )  

References | Related Articles | Metrics

For the development glucose transport imaging, a radioactive glucose analogue was synthesized and evaluated. A glucose analogue, 6-[¹⁸F]fluoro-6-deoxy-D-glucose(6-¹⁸FDG), was prepared in two steps with one-pot synthesis from [¹⁸F]fluoride and tosyl-precursor. Starting with D-glucose, the D-glucose was reacted with acetone and benzaldehyde to protect hydoxy, then reacted with p-toluenesulfonyl choride(TsCl) to get the tosyl-precursor. All the intermediates were identified with NMR and MS. The total radiosysthesis spent 35 min and with 70%±5%(EOB, decay corrected, n=5), with the radiochemical purity>95%. Biodistribution of 6-¹⁸FDG was performed in mice: ¹⁸F activities in brain, liver, and heart reach the peak in 1.0 min after the injection, so reached a constant level. These results support that 6-¹⁸FDG is promising as valid tracer of glucose transport.

Self-assembled Structures and Structural Transition of Dimethyl Isophthalate-Functionalized Janus Dendrimers on HOPG Investigated with STM

ZHANG Xu, FENG Yu, FAN Qing-Hua*, WAN Li-Jun*

2009, 30(12):  2424-2428. 

Asbtract ( )   PDF (561KB) ( )  

References | Related Articles | Metrics

Self-assembled structures of three dimethyl isophthalate-functionalized Janus dendrimers G₁G₂COOCH₃, G₀G₃COOCH₃, and G₁G₃COOCH₃ were investigated with scanning tunneling microscopy(STM) on HOPG. It was found that G₁G₂COOCH₃, G₀G₃COOCH₃, G₁G₃COOCH₃ assembled into ordered, partial ordered, and disordered structures, respectively. After heated to 60—80 ℃, regular dendrimer dimers could be found on HOPG, resulting in close-packed ordered structures instead of the previous disordered structures. The results show that with the increase of the molecule generation, molecules are bound down onto surface due to the enhanced intermolecular and molecule-substrate interactions. The self-assembly is dependent on the dynamic process, leading to disordered structures. However, when heated, the mobility of dendrimer molecules on surface could be improved. Structural transformation from disordered structures to thermodynamically stable dimeric structures could be observed by STM on G₀G₃COOCH₃ and G₁G₃COOCH₃ adlayers.

Gas-phase Aldol Condensation of Acetone over Mg-Al Oxides Prepared by Co-precipitation Methods

MA Chun-Xiang, LIU Gang, ZHU Wan-Chun, WANG Li-Xia, LI Yu-Fei, ZHANG Wen-Xiang,

2009, 30(12):  2429-2433. 

Asbtract ( )   PDF (424KB) ( )  

References | Related Articles | Metrics

Mg-Al oxide catalysts were prepared by co-precipitation method, used ammonia as the precipitating agent. The catalytic performances of these materials were investigated in the gas-phase Aldol condensation of acetone to isophorone. The structure and surface properties of the catalysts were characterized by means of XRD, XPS, ICP, TG-DTA and TPD. The Mg_1.0AlO catalyst prepared by back-titration shows relatively high activity and stability, the conversion of acetone maintains at 65% even after 85 h at 573 K. The co-existence of a certain amount of weak basic centers and strong basic centers on the surface Mg-Al oxides may play an important role for improving the activity and stability of these catalysts.

Theoretical Investigation on the Changes of Structures and Properties Caused by the Different Link Form in Bicarbazoles

WANG Hui-Ping, BAI Fu-Quan, ZHENG Qing-Chuan, ZHAO Zeng-Xia, ZHANG Hong-Xing*

2009, 30(12):  2434-2438. 

Asbtract ( )   PDF (322KB) ( )  

References | Related Articles | Metrics

Density functional theory(DFT) and configuration interaction with single excitations(CIS) method were used to optimize the ground state and excited state structures of carbazole and 14 bicarbazole isomers on the 6-31G(d,p) basis set level, respectively. On the base of the geometry structures, the absorption and emission wavelengths and charge transfer characters were calculated with the time-dependent DFT(TD-DFT) method on the same basis set level. In this paper, we discussed the relationship between different molecular structures and properties, detailedly, the calculated data are in agreement with the reported corresponding experimental results. On the base of the varied frontier molecular orbital energies, ionization potentials(IP), electron affinities(EA) and reorganization energies(λ) for bicabazoles, the dissimilar applications are studied all round. The studies can provide some help in designing and synthesizing more and greater molecular materials.

EXAFS Studies of pH Effects on Adsorption and Microscopic Strutures of Zn(Ⅱ) onto TiO₂

GAO Shuang, CHEN Hao, HE Guang-Zhi, PAN Gang*

2009, 30(12):  2439-2444. 

Asbtract ( )   PDF (568KB) ( )  

References | Related Articles | Metrics

Microscopic structures and thermodynamic characteristics of Zn(Ⅱ) adsorbed onto anatase TiO₂ at different pH were studied using extended X-ray absorption fine structure(EXAFS) spectroscopy. Macroscopic adsorption-desorption experiments indicated that as pH increased from 5.8 to 6.8, the adsorption capacity coefficient(K_F) increased from 1.345 L/g to 15.385 L/g, while the adsorption irreversibility coefficient(TⅡ) decreased from 0.43 to 0.23. EXAFS spectra results showed that Zn(Ⅱ) was adsorbed onto the solid surface in a mixed form of octahedral and tetrahedral hydrous Zn(Ⅱ) ions, which were linked to TiO₂ surface by sharing O atoms. Both the bond length and the coordination number of the first Zn—O coordination sphere decreased as pH increased. Analysis of the second Zn—Ti coordination sphere indicated two Zn—Ti atomic distances: R₁=0.319—0.334 nm and R₂=0.366—0.378 nm, referring to bidentate(stronger adsorption site) and monodentate(weaker adsorption site) complexation respectively. The number of stronger adsorption sites(CN1) decreased while the number of weaker adsorption sites(CN2) increased remarkably with increasing pH, resulting in a drop of CN1/CN2 from 2.12 to 0.89. EXAFS results revealed that the macroscopic adsorption phenomena were directly related to the changes in microscopic adsorption structures of Zn(Ⅱ) on the surface of TiO₂ under different pH conditions.

Theoretical Study for DNA and RNA on Their Stability Difference

FENG Feng, YU Jian-Guo*, FANG Wei-Hai

2009, 30(12):  2445-2451. 

Asbtract ( )   PDF (471KB) ( )  

References | Related Articles | Metrics

The semi-empirical method RM1_BH, was employed to explore the reasons and nature of the intrinsic stability of the RNA and DNA duplexes. RM1_BH is based on the convenient RM1 and modified to deal with the weak interactions between molecules, especially for the hydrogen bonding between biological systems, and embedded to our software module SimuCal_SE. And the calculations were processed using our software package SimuPac 1.0, with the linear scale algorithm to treat large molecular systems. The calculations in this study include 4 different sets of base pairs appeared in both DNA and RNA. By our calculations, the hydrogen bonding interaction energy of r(A\5U) is little bit larger than that of d(A\5T). When including more base pairs, the hydrogen bonding energies of RNA become much larger than DNA. Arrangements of purine and pyrimidine in RNA and DNA have contributions for the stabilities of both RNA and DNA. The calculation results in this study support and agree with the experimental results and conclutions.

Electronic Properties of Codoped Spinel Silicon Nitride with C and As by DFT Method

ZHANG Yu-Fen, CHENG Xiu-Feng, ZHAO Xian*

2009, 30(12):  2452-2454. 

Asbtract ( )   PDF (314KB) ( )  

References | Related Articles | Metrics

Density functional calculations were performed to investigate the electronic properties of codoped spinel silicon nitride with C and As. When very low concentrations of Si was replaced by C at the tetrahedral sites, together with the doping of substitutional As impurity in spinel silicon nitride, the band-gap could be adjusted, and an insulator-to-metal transition would occur at the C/Si ratio ~0.063 and As/N ratio ~0.047. Seen from the DOS spectra, it is clearly observed that the TDOS increases at the valence band maximum. Finally, some possible examinations and potential applications for the large band-gap reduction are discussed.

Dissipative Particle Dynamics Simulation of Physical Gelation Behavior of P123(PEO₂₀-PPO₇₀-PEO₂₀) Block Copolymer Aqueous Solution

ZHAO Ying, XIE Yu, LU Zhong-Yuan*, SUN Chia-Chung

2009, 30(12):  2455-2459. 

Asbtract ( )   PDF (360KB) ( )  

References | Related Articles | Metrics

Dissipative particle dynamics(DPD) method was used to study the physical gelation behavior of P123(PEO₂₀-PPO₇₀-PEO₂₀) block copolymer aqueous solution at room temperature. P123 in aqueous solution forms spherical micelles at lower volume fractions(2%—10%). When the volume fraction of P123 is increased to 20%, cylindrical micelles are formed. The gels with three dimensional network structures are observed when the volume fraction of P123 are 30% and 40%. These simulation results are consistent with the experiments. We find that dissipative particle dynamics simulation method is an important and suitable method to study physical gelation behaviour.

Density Functiond Theory Study on Decomposition Reaction of Organic Uranyl Acetate in Gas Phase

YU Li-An, HU Bin, LUO Ming-Biao*, ZHANG Xie, CHEN Huan-Wen

2009, 30(12):  2460-2463. 

Asbtract ( )   PDF (315KB) ( )  

References | Related Articles | Metrics

A quantum chemical model was established for theoretical studies by employing the widely used density functional theory(DFT), the selected hybrid functional TPSSh in combination with TZVP basis set and an effective core potential(ECP) for uranium atom. As a test calculation, the structure of a complex UO₂(CO₃)₃^4- was optimized with the above-mentioned TPSSh/TZVP(ECP) method, it was found that the calculated results(bond distances) are in good agreement with the experimental data. Then, we investigated the decomposition reaction of the anion UO₂(CH₃COO)₃^- with this method. The results indicate that the uranyl(+5) radical specie is the most stable state in the gas phase. The two decomposition reactions of the species(CH₃COO)UO₂CH₃^- and CH₃UO₂OH^- with water were also simulated with the above-mentioned method and the obtained results agree well with the mass spectroscopy data.

Theoretical Study on the Sandwich-like Compounds Containing the Planar Tetracoordinate Carbon Unit CAl₂Si₂

HE Hai-Peng, YANG Li-Ming, DING Yi-Hong*

2009, 30(12):  2464-2468. 

Asbtract ( )   PDF (585KB) ( )  

References | Related Articles | Metrics

One of the focuses of molecular science is the theoretical and experimental investigations on the pentatomic planar coordinated carbon(ptC) molecules. This paper for the first time reported the design of sandwich-like compounds based on a Si-containing ptC unit CAl₂Si₂. We found that due to the strong fusion interaction between CAl₂Si₂ decks, the assembly of CAl₂Si₂ with the alkali and alkaline earth metals(M=Li, Na, K, Be, Mg, Ca)in form of the traditional “homo-deckered sandwich” scheme to form [(CAl₂Si₂)M(CAl₂Si₂)]^q+ is unstable. Instead, our recently proposed “hetero-decked sandwich” scheme can be effectively applied to CAl₂Si₂ to form [CpM(CAl₂Si₂)]^q+). Both the “hetero-decked sandwich” and the ionic interaction play important roles in the assembly and stabilization of CAl₂Si₂. During the assembly, the electronic and structural features of CAl₂Si₂ are well kept. Thus, the ptC molecule CAl₂Si₂ can act as a “building block” to construct large-scale compounds that contain planar coordinated carbon centers.

Electrochemical Behavior of Nitromethane on Cu Disk Electrode in Ionic Liquid BMImBF₄

MA Chun-An*, WANG Xiao-Juan, LI Guo-Hua, QIAN Xiao-Feng

2009, 30(12):  2469-2472. 

Asbtract ( )   PDF (347KB) ( )  

References | Related Articles | Metrics

The electrochemical behavior of nitromethane were studied by cyclic voltammetry and in situ FTIR technique in the room temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluorobrate(BMImBF₄) on a copper disk electrode. The influences of temperature and scan rate on the electrochemical characteristics of nitromethane were also investigated. Results show that the electroreduction of nitromethane in BMImBF₄ is an irreversible process, which is controlled by diffusion. Finally nitromethane is reduced into trans-dimer of nitrosomethane in BMImBF₄.

Theoretical Study on Adsorption of CO on Novel Pt-doped BN Nanotube

LI Xi-Mao, TIAN Wei Quan*, HUANG Xu-Ri*, SUN Chia-Chung, JIANG Lei

2009, 30(12):  2473-2477. 

Asbtract ( )   PDF (366KB) ( )  

References | Related Articles | Metrics

Novel Pt-substitution doped(5,5) single-walled BN nanotubes(BNNTs) were studied with density functional theory(DFT). The Pt atom protrudes to the exterior of the sidewall of BNNT, thus improves the reactivity of BNNT and favors attack from approaching molecules. The smaller energy gap between the highest occupied molecular orbital and lowest unoccupied molecular orbital for the Pt-doped BNNTs implies enhanced conductivity with respect to that of the pristine BNNT. The DFT predictions suggest a strong affinity of the Pt atom in BNNT towards CO molecules. Up to two CO can be chemically adsorbed on the Pt site of BNNT.

Chelate Regulatory ζ-potentials of Montmorilloniteand Its Adsorption Capacity for Cr(Ⅲ)

YE Ling*, ZHANG Jing-Yang

2009, 30(12):  2478-2483. 

Asbtract ( )   PDF (457KB) ( )  

References | Related Articles | Metrics

Use of montmorillonite as sorbents to remove toxic heavy metals from aqueous solutions was increa-singly paid attention. In order to improve the soption ability of montmorillonite, various polyoxy cations(Zr⁴⁺, Al³⁺, Si⁴⁺, Ti⁴⁺) , surfasctants(quaternary ammonium cations) and acid activation were widely used to alter the surface properties . In fact, soption ability of montmorillonite depends on electrokinetic behavior of colloid suspension. The values of ζ-potential have a prominent effect on its adsorptive affinity for metal cations. Therefore, the main attempts in this work are focused on ζ-potential of montmorillonite , and the relationships between montmorillonite ζ-potential and adsorption capacity for Cr(Ⅲ). Various chelates were utilized to regulate montmorillonite ζ-potential in order to find a effective method which could improve the adsorption capacity of montmorillonite for Cr(Ⅲ). The results show that the adsorption capacity is ζ-potential-dependent, and increased greatly with its negative value increasing. The ζ-potentials of montmorillonite modified by chelates were changed evidently, and took place reversal from negative to positive after modified by 1,10-phenanthroline chelates. The effect of cation exchange adsorption depended on absolute values of ζ-potential, which before adsorption must be higher than that after adsorption. It was also found that modified montmorillonite showed higher adsorption capacity with more difference values of ∣ζ∣-potential between before and after adsorption. The adsorption quantity of Cr(Ⅲ) on montmorillonite could be double when ζ-potential was regulated by 1,10-phenanthroline chelates. Therefore, the cation exchange adsorption capacity of montmorillonite, which ζ-potential regulated by chelates, could be improved greatly.

Letters

Investigation of the Properties of CeO₂-ZrO₂-Al₂O₃ Prepared by Co-precipitation

LI Hong-Mei, ZHOU Ju-Fa, ZHU Qing-Chao, ZENG Shao-Hua, WEI Zhen-Ling, ...

2009, 30(12):  2484-2486. 

Asbtract ( )   PDF (265KB) ( )  

References | Related Articles | Metrics

CeO₂-based oxygen materials were prepared with co-precipitation method and characterized via Brunauer-Emmet Teller(BET) method, X-ray diffraction(XRD) and temperature-programmed reduction(H₂-TPR). This paper revealed that three CeO₂-based oxygen storage materials are all forming homogeneous solid solution. Among the samples, CeO₂-ZrO₂-Al₂O₃(CZA) has the best textural properties and excellent thermal stability. The specific surface area and pore volume of aged CZA are 90 m²/g and 0.29 mL/g. We proposed a viewpoint: Al³⁺ might insert among the interspace of fluorite structure or highly dispersal in solid solutions.

Articles

Composite Nanospheres of PAA/silica Controlled by Anionic Polymer

LI Li-Ying, WANG Jin-Gui, CHEN Tie-Hong*

2009, 30(12):  2487-2490. 

Asbtract ( )   PDF (612KB) ( )  

References | Related Articles | Metrics

The anionic polymer, poly(acrylic acid)(PAA), was used to synthesize composite nanospheres of PAA/silica with 3-aminopropyltrimethoxysilane(APMS) and tetraethyl orthosilicate(TEOS) as silica source. In the synthesis, the assembly of PAA, APMS and TEOS follows the mechanism of the anionic surfactant templated mesoporous silica(AMS) through a S^-N⁺-I^- pathway, where S stands for the anionic PAA, I stands for inorganic precursors(TEOS) and N stands for co-structure-directing agent(APMS). The results of SEM, TEM, TG and FTIR show that the average size of composite nanospheres of PAA/silica is 80 nm. Furthermore, it was proved that addition of organic solvent such as THF could tune the size of the composite spheres.

Adhesion and Proliferation of Osteoblast on the Amidation Surface of Polylactide Film

TIAN Ye, WANG Ying-Jun, ZHOU Chang-Ren*, ZENG Qing-Hui, TAN Guo-Xing

2009, 30(12):  2491-2495. 

Asbtract ( )   PDF (467KB) ( )  

References | Related Articles | Metrics

Acrylic amide(AAm) was polymerized onto polylactide(PLA) film via UV irradiation to achieve amidation surface, furthermore the adhesion and proliferation of osteoblast on this surface was investigated. The results show that the hydrophilicity of PLA film is improved by introduction amido: the contact angle decreases from 78° to 56° and the free energy increases from 42.7 mJ/m² to 51.4 mJ/m². Compared with the control, osteoblast spread out more filopodia after 3 d incubation on amidation surface, and it entered cell division phase more quickly, which indicated that the surface amidation could promote the cell′s adhesion and proliferation on the PLA film.

Synthesis and Properties of Styrene-N-phenylmaleimide-maleic Anhydride Tercopolymer

HU Yi-Min, DONG Jian-Ting, FAN Zhong-Yong*, SUN Meng

2009, 30(12):  2496-2501. 

Asbtract ( )   PDF (470KB) ( )  

References | Related Articles | Metrics

Styrene-N-phenylmaleimide-maleic anhydride copolymers were synthesized by means of one-shot process with ditertbutyl peroxyphthalate as an initiator. The composition of N-phenylma leimide in copolymers is modified from 48% to 63% in the mass fraction by various monomer molar ratio. The structures and characteristic of the terpolymers were charactered via FTIR, ¹H NMR, ¹³C NMR, GPC, DSC and TGA, respectively. The mass fraction of the N-phenylmaleimide in terpolymers calculated from FOX equation was in agreement with the ¹H NMR results. DSC results show that the glass transition temperature of terpolymers increases from 202 ℃ to 215 ℃ with various compositions of chain segments. TGA results prove that the thermal decomposition temperature of samples at 5% mass loss with the N-phenylmaleimide in terpolymers more than 48% was higher than 363 ℃. Therefore, the Styrene-N-phenylmaleimide-maleic anhydride tercopolymer applies as an excellent heat-resistant agent to polymer materials.

Saccharified Thermoresponsive Modification of Polystyrene and Its Effect on Cell Behavior

HE Xiao-Ling, DONG You-Yu, NIE Ping-Ping, FENG Xia, CHEN Li*

2009, 30(12):  2502-2507. 

Asbtract ( )   PDF (461KB) ( )  

References | Related Articles | Metrics

Poly(N-isopropylacrylamide) and acrylic acid were grafted onto tissue culture polystyrene(TCPS) by UV irradiation, followed by immobilization of the monoamine terminated lactobionic(L-NH₂) to acrylic acid carboxyls. The compositions of modified surfaces were characterized by ATR-FTIR and XPS. The morphologies were observed via AFM. Results from drop contact angle measurement indicate that the modified surfaces show hydrophobic/hydrophilic property alterations in response to temperature. Adhesion and detachment of hepatic tumor cells(HepG-2) were examined on virgin surface and modified surfaces. Immobilization of L-NH₂ facilitated HepG-2 cells adhesion on saccharified thermoresponsive surface. Moreover, HepG-2 cells cultured on modified surfaces can be recovered non-invasively by decreasing temperature.

Synthesis, Characterization and Protein Drug Release of Temperature-Sensitive PCL-PEG-PCL Hydrogel

MIAO Bo-Long, MA Gui-Lei, SONG Cun-Xian*

2009, 30(12):  2508-2513. 

Asbtract ( )   PDF (531KB) ( )  

References | Related Articles | Metrics

The effect of PEG and PCL composition of thermosensitive PCL-PEG-PCL hydrogels on Sol-gel transition temperature and release rate of bovine serum albumin(BSA) were investigated. A series of thermosensitive PCL-PEG-PCL triblock copolymers with different PEG and PCL block lengths were synthesized via ring-opening polymerization of ε-CL using PEG1500/PEG1000 as the initiator and Sn(Oct)₂ as the catalyst. Their composition, structure, and molecular weight were characterized via ¹H NMR and GPC techniques. The Sol-gel transition temperature was determined with the test tube inverting method. TEM, ¹H NMR, and fluorescence probe technique were employed to identify formation of micelles of the triblock copolymers in aqueous solution. BSA was used as a model protein drug. Hydrogels of these PCL-PEG-PCL triblock copolymers loaded with BSA were prepared for in vitro release study, and BSA concentration in the released sample was determined with microBCA method. The effect of PCL and PEG block lengths on Sol-gel transition temperature and release rate of BSA was also discussed. The results obtained indicated that the Sol-gel transition temperature of copolymers was related to block lengths of PCL and PEG, increasing the PCL length at a fixed PEG central block led to a lower transition temperature at a given copolymer concentration, while with the enhancement of the PEG length at a similar hydrophobic PCL length, the transition temperature increases. And the protein release rate was independent of the hydrophobic PCL length, whereas the longer PEG length, the lower protein release rate.

Molecular Recognition Characteristics of Quercetin′s Metal-complexing Imprinted Polymer

FAN Pei-Min, WANG Bing*

2009, 30(12):  2514-2520. 

Asbtract ( )   PDF (676KB) ( )  

References | Related Articles | Metrics

Using Zn(Ⅱ)-quercetin complex as template, a metal-complexing template polymer was prepared in methanol by molecular imprinting technique. The coordination mode and complex molar ratio between quercetin and Zn(Ⅱ) were studied in differential UV absorption spectrometry, and the ternary complexation of quercetin, Zn(Ⅱ) and 4-vinylpyridine was verified by similar methods. The molecularly imprinted polymers(MIPs) prepared were analyzed via infrared spectra, and it showed that MIPs had the necessary characteristics of the structure. In order to optimize the reaction ratio of MIPs, the effect of functional monomer and cross-linking agent dosage on the binding capacity of MIPs was studied with equilibrium binding experiments. The selective binding experiments for substrates indicated that compared with quercetin′s (rutin and naringenin), Zn(Ⅱ)-quercetin template polymer exhibited significant adsorption selectivity for Zn(Ⅱ)-quercetin complex. The separation factors were 3.21 and 1.91 respectively.

Poly(α,L-glutamic acid) Microspheres for Oral Insulin Delivery

HAN Ya-Dong, XIA Jia-Liang, HE Pan, TIAN Hua-Yu, CHEN Xue-Si*, JING Xia-Bin

2009, 30(12):  2521-2524. 

Asbtract ( )   PDF (516KB) ( )  

References | Related Articles | Metrics

Insulin-loaded poly(α,L-glutamic acid) microspheres for oral delivery were prepared by anhydrous emulsion system. The microspheres had diameters of 5—20 μm, and drug loading of 5%—9%. The microspheres had good pH sensitive release behavior. In gastric simulated fluid about 5% of insulin was released from microspheres after 2 h, while in intestinal simulated fluid over 90% of insulin released. The effect of polymer molecular weight, theoretical drug loading and polymer solution concentration to the microsphere release profile were investigated.

Synthesis and Characterization of Liquid Polycarbosilane-derived Polyaluminocarbosilane

YANG Jing-Ming, YANG Lu-Jiao, YU Yu-Xi, CHENG Xuan, ZHANG Ying*

2009, 30(12):  2525-2529. 

Asbtract ( )   PDF (483KB) ( )  

References | Related Articles | Metrics

Polyaluminocarbosilanes(PACS) with different Al contents were synthesized by reacting liquid polycarbosilane(LPCS) with aluminum acetylacetonate[Al(AcAc)₃]. Compared with those reported in literatures, this route is considered to be more convenient and safer since no circulating reflux is needed. It was shown that the composition and structure of LPCS heated and kept at the synthesis temperature of PACS remained fairly stable. The chemical elemental analysis results of PACS indicated that through this route the Al contents were almost fully introduced into PACS from Al(AcAc)₃, and with the increasing of Al contents, the O contents also increased. Furthermore, the formation of AlO₄, AlO₅ and AlO₆ was confirmed by ²⁷Al MAS NMR results. On the base of the structure analysis it was suggested that LPCS reacted with Al(AcAc)₃ by consuming Si—H bonds. Then Si—O—Al crosslinking bonds were formed, leading to the increases of the number average molecular weight and the polydispersion index in molecular weight with the increase of Al contents in PACS.

Improvement of Heat Stability of PLA/Fiber Composite by Radiation Induced Cross-linking

DENG Peng-Yang*, LIU Mei-Hua, ZHENG Xiao-Wei, LIU Nan-An, DONG Li-Song

2009, 30(12):  2530-2533. 

Asbtract ( )   PDF (290KB) ( )  

References | Related Articles | Metrics

A series of PLA/fiber composites containing triallyl isocyanurate(TAIC) were prepared with melt blending. In order to induce radiation crosslinking, composites were irradiated by γ-rays under N₂. Experimental results of heat distortion temperature(HDT) demonstrated that the HDT of composites were enhanced after crosslinking. Especially when the mass fraction of fiber exceeded 20%, the HDT of composites increased from 60 ℃ to 120 ℃ even at very low absorbed dose. The improvement of HDT was related with the fiber content instead of the fiber type. The gelation experiment and FTIR results indicated that the complicated crosslinking structure was formed after radiation. And such structure caused the significant improvement of HDT.

Letters

Preparation of Organic-inorganic Hybrid Materials Based on a Hydroxyl-containing Polyethersulfone

CHEN Wen-Hui, LIU Bai-Jun, YANG Yan-Hua, YUE Xi-Gui, JING Li-Wei, ...

2009, 30(12):  2534-2536. 

Asbtract ( )   PDF (453KB) ( )  

References | Related Articles | Metrics

A novel aromatic polyethersulfone bearing a(3-methoxy)phenyl group(PPES-OMe) was synthesized via an aromatic nucleophilic substitution reaction. A hydroxyl-containing polyethersulfone(PPES-OH) was successfully obtained via a demethylation reaction of PPES-OMe. A series of nano-hybrid materials could be prepared with sol-gel method and FTIR results suggested the chemical bond formed between the hydroxyl group of PPES-OH and TEOS. Nano-size SiO₂ particles were observed to disperse uniformly in the polyethersulfone matrix by SEM. It was found that all the films based on these materials were flexible.