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CHARACTERIZATION OF REGENERATED CELLULOSE MEMBRANES HYDROLYZED FROM CELLULOSE ACETATE

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Chinese Journal of Polymer Science 2002年第4期20卷 369-375页

作者： Yun Chen Xiao-peng Xiong Guang Yang Li-na Zhang Sen-lin Lei Hui Liang Electron Microscope Lab of Medical School, wuhan university wuhan 430072. china college of chemistry and molecular sciences, wuhan university, wuhan 430072. china wuhan Univ Coll Chem & Mol Sci Wuhan 430072 Peoples R China wuhan Univ Sch Med Electron Microscope Lab Wuhan 430072 Peoples R China

A series of cellulose acetate membranes were prepared by using formamide as additive, and then were hydrolyzed in 4 wt% aqueous NaOH solution for 8 h to obtain regenerated cellulose membranes. The dependence of degree of substitution, structure, porous properties, solubility and thermal stability on hydrolysis time was studied by chemical titration, Fourier transform infrared spectroscopy, scanning electron microscopy, wide-angle X-ray diffraction, and differential scanning calorimetry, respectively. The results indicated that the pore size of the regenerated cellulose membranes was slightly smaller than that of cellulose acetate membrane, while solvent-resistance, crystallinity and thermostability were significantly improved. This work provides a simple way to prepare the porous cellulose membranes, which not only kept the good pore characteristics of cellulose acetate membranes, but also possessed solvent-resistance, high crystallinity and thermostability. Therefore, the application range of cellulose acetate membranes can be expanded.

关键词： hydrolysis cellulose acetate thermal stability regenerated cellulose membrane pore size solvent-resistance SEM

Electrochemical Studies of Glutathione Monolayer Assembled on A Polycrystalline Gold Electrode

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wuhan university Journal of Natural sciences 2002年第1期7卷 102-106页

作者： Fang Cheng, Zhou Xing-yao  college of chemistry and molecular sciences, wuhan university, wuhan 430072. Hubei, china wuhan university College of Chemistry and Molecular Sciences Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

The glutathione (GSH) monolayer and complex monolayer of GSH-metallic ion on polycrystalline gold electrode were studied by using K3Fe(CN)6 as the redox probe. As for the GSH monolayer, it was found that the metallic ions could open the ion-gate in the monolayer dramatically in the order La3+> Pb2+>>Ba2+>Ca2+ whereas Zn2+ ion closed the ion-gate. The complexes of GSH-metallic ions were capable of self-assembling the different kind of monolayer. All the differences were related to the structural configuration of the anchored GSH molecule, which changed with different metallic ions or pH.

关键词： glutatione monolayer complex voltammetry and ac impedance

SOLUTION PROPERTIES OF ANTITUMOR CARBOXYMETHYLATED DERIVATIVES OF α-(1→3)-D-GLUCAN FROM GANODERMA LUCIDUM

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Chinese Journal of Polymer Science 2001年第3期19卷 283-289页

作者： Li-na Zhang Mei Zhang Jing-hua Chen Fan-bo Zeng Department of chemistry wuhan university, wuhan 430072. china Pharmacy college, Tongji Medical university, wuhan 430072. china wuhan Univ Dept Chem Wuhan 430072 Peoples R China Tongji Med Univ Coll Pharm Wuhan 430072 Peoples R China

Fractions of a water insoluble α-(1→3)-D-glucan (GL) extracted from Ganoderma lucidum were carboxy-methylated (CM) to obtain water-soluble carboxymethylated derivatives (CM-GL) having a degree of substitution (DS) of0.38～0.51. Weight-average molecular weight M_w and intrinsic viscosity [η] of the samples CM-GL were measured by gelpermeation chromatography combined with laser light scattering (GPC-LLS) and viscometry. The CM-GL exhibits a stifferchain in aqueous solution at 25℃ than the original glucan, The antitumor activities against Ehrlich ascites carcinoma (EAC,5×10~6) of the carboxymethylated derivatives from the α-glucan and curdlan, a β-glucan, are significantly higher than thoseof the original glucans. The effects of the relatively low molecular weight, expanded chains and better water-solubility of theCM-GL on the enhancement of antitumor activity could not be neglected. The chain stiffness decreased speedily withincrease of temperature from 40 to 60℃ or NaOH concentration from 0.1 to 0.4 in the solution, respectively, and the changeof the chain stiffness is reversible.

关键词： Solution properties Antitumor activity Carboxymethylated derivative α-D-glucan Ganoderma lucidum

Infrared Spectroscopic and Theoretical Studies on Cobalt(Ⅱ) Complex of Maleinitriledithiolate and 4, 4′-Dimethyl-2, 2′-bipyridine

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wuhan university Journal of Natural sciences 2002年第1期7卷 87-96页

作者： Peng Zheng-he, Cai Ping, Fang Chen-jie, Wen Li-li college of chemistry and molecular sciences, wuhan university, wuhan 430072. Hubei, china college of chemistry and molecular sciences Wuhan University Wuhan Hubei China

The complete experimental IR spectra and vibrational analysis of the title complex Co(mnt)(dmbpy) were reported in this paper. The results show that the complex molecule has a planar geometry belonging to point group C 2v and ground electronic state with spin quartet. A new method for analyzing vibrational spectra of complicated molecule is established. The essential of this method is to point out main fixed points and pivotal vibrational units in assignment for each fundamental band. Two new symbols η (heaving along the specified direction) and M (midpoint of a bond or unit) were defined for describing the vibrational modes accurately.

关键词： Cobalt(Ⅱ) complex infrared spectrum new method to analyze vibrational spectra quantum chemical calculation

Immunomagnetic assay combined with CdSe/ZnS amplification of chemiluminescence for the detection of abscisic acid

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Science china chemistry 2011年第8期54卷 1298-1303页

作者： ZHOU GuoHua, WANG Ping, YUAN Ju, QIU Ting & HE ZhiKe Key Laboratory of Analytical chemistry for Biology and Medicine, Ministry of Education college of chemistry and molecular sciences, wuhan university, wuhan 430072. china 1. Key Laboratory of Analytical chemistry for Biology and Medicine Ministry of Education college of chemistry and molecular sciences Wuhan University Wuhan 430072 China

Abscisic acid (ABA) is an important plant hormone. It plays a key role in regulating plant responses to abiotic stress and in controlling seed germination, growth, and stomatal aperture. A rapid, sensitive analytical method for the ABA detection is urgently required for further investigation of ABA signaling. In this work, an immunomagnetic assay combined with CdSe/ZnS amplification of chemiluminescence has been developed for the detection of ABA. The result could be read out in 30 min at least, with the simplified procedure of immunomagnetic assay. Under the optimized condition, a linear range from 1 pM to 10 nM was obtained. An unexpected result induced by the dose hook effect was discussed. This method provided the high selectivity for ABA over other components that might be contained in real samples.

关键词： abscisic acid immunomagnetic assay chemiluminescence CdSe/ZnS

Preparation and Characterization of Chitosan/Carboxymethylated Konjac Glucomannan Blend Films

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wuhan university Journal of Natural sciences 2002年第1期7卷 107-112页

作者： Zheng Hua 1 , Du Yu-min 2 1. Department of Chemical Engineering, wuhan university of Technology, wuhan 430070, Hubei, china 2. college of chemistry and molecular sciences, wuhan university, wuhan 430072. Hubei, china wuhan university of Technology Department of Chemical Engineering Wuhan Hubei China (GRID:grid.162110.5) (ISNI:***) wuhan university College of Chemistry and Molecular Sciences Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

In order to improve the mechanical and water swelling properties of the chitosan (CS) film, a series of transparent films were prepared by blending 2%(weight) chitosan acetic acid solution with 1.5%(weight) carboxymethylated konjac glucomannan (CMKGM) aqueous solution according to predetermined ratio and drying at 30°C. The morphological structure, miscibility, thermal stability, mechanical properies, and swelling capacity of the blend films were studied by infrared (IR), X-ray diffraction (XRD), differential thermal analysis (DTA), scanning electron micrograph (SEM), and measurements of the mechanical properties and swelling properties. The results demonstrated that there was strong interaction and good miscibility between CS and CMKGM resulted from intermolecular hydrogen bonding and electrostatic force. The mechanical properties in dry state and wet state, thermostability, and water swelling properties of the blend films were obviously improved. The best values of the tensile strength in the dry and wet state achieved 89 MPa and 49 MPa, respectively, when the CMKGM content was 30%(weight). The CS/ CMKGM blend films provided promising biomedical applications.

关键词： Key words chitosan carboxymethylated konjac glucomannan blend films structure characterization

Chitosan-Pectin Synergistic Interaction and Gelation

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wuhan university Journal of Natural sciences 2001年第4期6卷 826-830页

作者： He Dong bao, Shi Yi, Zhan Dong feng, Fong Feng college of chemistry and molecular Science, wuhan university, wuhan 430072. china wuhan university College of Chemistry and Molecular Science Wuhan China (GRID:grid.49470.3e) (ISNI:***)

Mixed gels of chitosan-pectin were prepared by varying the ratio of constituents in the presence of NaCl. Mixed gel at 3%of total polysaccharide concentration with addtion of 12%NaCl showed a synergistic maximum when the ratio of chitosan to pectin was 60: 40. The effect of the polysaccharide concentration, the preparation temperature (T p), the time of incubation, balk salt concentration, the molecular weight and the degree of deacetylation of chitosan on gelation have been studied. Interaction mechanism between molecules of both polysaccharides was investigated by FT-IR spectrometry.

关键词： chitosan pectin synergistic interaction gelation

The Electrochemical Properties of Thionine Adsorbed Monolayer on Gold Electrode

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wuhan university Journal of Natural sciences 2001年第4期6卷 846-850页

作者： Fang Cheng, Liu Yue lin, Zhou Xing yao  college of chemistry and molecular Science, wuhan university, wuhan 430072. china wuhan university College of Chemistry and Molecular Science Wuhan China (GRID:grid.49470.3e) (ISNI:***)

A gold electrode modified with adsorbed thionine monolayer was investigated with ac impedance and cyclic voltammetry method. It was found there were some different redox properties for the adsorbed thionine depended on the different potential scanning rate. At the slower potential scanning rate (10 mV? s?1), the dimer of thionine appeared and possessed the catalytic activity for the oxidation of ascorbic acid. The underpotential deposition (UPD) and the bulk deposition of Cu2+ were also employed to investigate the monolayer of adsorbed thionine.

关键词： Key words thionine monolayer ac impedance voltammetry

The Characteristic of Electrochemical Oxidation of Aniline on SnO_2/Ti Electrode

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wuhan university Journal of Natural sciences 2001年第4期6卷 836-840页

作者： Wang Yu ling, Cai Nai cai , Huo Yao dong, Chen Hao college of chemistry and molecular Science, wuhan university, wuhan 430072. china wuhan university College of Chemistry and Molecular Science Wuhan China (GRID:grid.49470.3e) (ISNI:***)

The characteristic of electrochemical oxidation of aniline on SnO 2/Ti electrode is studied. The results indicate that SnO 2/Ti electrode doped F plays a wonderful role in the oxidation of aniline comparing with Pt electrode. The kinetics factors that influence the oxidation rate of aniline on the SnO 2/Ti electrode are determined by the dissolving of the film on the electrode. The dissolving of the film consisted of intermediate products on the electrode is the slow step. The effects of aniline concentration, pH in aniline solution and the current density( i )on the rate of aniline oxidation, the complexity of intermediate products and the basic category of the intermediate products consisted of the film are introduced.

关键词： electrochemical oxidation SnO 2/Ti aniline