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21.
This study describes the preparation of polypyrrole (PPy)/multiwalled carbon nanotube (MWNT) composites by in situ chemical oxidative polymerization. Various ratios of MWNTs, which served as hard templates, were first dispersed in aqueous solutions with the surfactant cetyltrimethylammonium bromide to form micelle/MWNT templates and overcome the difficulty of MWNTs dispersing into insoluble solutions of pyrrole monomer, and PPy was then synthesized via in situ chemical oxidative polymerization on the surface of the templates. Raman spectroscopy, Fourier transform infrared (FTIR), field‐emission scanning electron microscopy (FESEM), and high‐resolution transmission electron microscopy (HRTEM) were used to characterize the structure and morphology of the fabricated composites. Structural analysis using FESEM and HRTEM showed that the PPy/MWNT composites were core (MWNT)–shell (PPy) tubular structures. Raman and FTIR spectra of the composites were almost identical to those of PPy, supporting the idea that MWNTs served as the core in the formation of a coaxial nanostructure for the composites. The conductivities of these PPy/MWNT composites were about 150% higher than those of PPy without MWNTs. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1413–1418, 2006 相似文献
22.
The electrochemical behavior of gatifloxacin (GTFX) and its interaction with natural calf thymus DNA (ctDNA) is investigated by differential pulse voltammetry (DPV) on a carbon paraffined electrode. According to the suggested electrochemical equation, a binding constant of 1.7058 x 10(5) (mol L(-1))(-1) and binding sizes s = 3.09 (base pairs) of GTFX with ctDNA are obtained by nonlinear fit analysis of electrochemical data. The results demonstrate that GTFX has the properties of an intercalative binder. 相似文献
23.
Ju-Chun Huang Chien Hong Cheng Shyang Roeng Sheen Zhi Ling Lee Chien Ming Lei Maw Kuen Wu 《中国化学会会志》1996,43(2):139-143
The synthesis of bulk Y2Ba4Cu7O15-δ superconductor at atmospheric oxygen pressure via solid state sintering is reported. Temperature ranging from 860 to 890 °C as well as time interval over 2 to 15 days were used to investigate the formation of the Y2Ba4Cu7O15-δ phase. A time-temperature profile characterizing the conditions for the preparation of Y2Ba4Cu7O15-δ phase suggests the optimal condition to be sintering at 890 °C for over 10 days. Detailed results of X-ray diffraction, electrical resistivity, iodometric titration and magnetization measurements are described. 相似文献
24.
YU Ming XU Qiang School of Materials Science Engineering East China University of Science Technology Shanghai China 《Chinese Journal of Reactive Polymers》2006,(1)
1. INTRODUCTIONThese years, HCFC-141b may be the most used blowing agent for its useful properties. But, because of its high global warming effect leading to the destruction of the ozone layer, production of HCFC141b has been forbidden. However, there are… 相似文献
25.
Zong Ming LUO 《中国化学快报》1990,1(3):229-230
In pH2.0-3.0,niobium(V)forms molybdonlobic acid with sodiummolybdate.A spectrophotometric method has been developed for the deter-mination of niobium based on the formation of ion-associate compound ofmolybdoniobate with Butyl Rhodamine B in aqueous solution in the presenceof polyvinyl alcohol and 0.4-0.7 mol/L H_2SO_4.The maximum absorption ofion-associate compound exhioits at 85 nm and the molar absorptivity is7.5×1.0~5 L.mol~(-1).cm~(-1)for niobium.The new method has been applied tothe determination of microamounts niobium in silicate rock,when niobiumcontent is at the level of 8×10~(-3)%,with the relative standard deviationof about 3%. 相似文献
26.
Ming Z. Gao 《Tetrahedron letters》2004,45(29):5649-5652
The novel structures of sulfur-containing chiral bis(oxazoline) compounds which have been synthesized have been determined by X-ray crystal diffraction analyses. A high enantioselectivity (ee >99%) in the asymmetric cyclopropanation of diphenylethene with diazoester using the bis(oxazoline)-Ru(II) catalyst was obtained. 相似文献
27.
A novel and efficient ionic liquid supported synthesis of oligosaccharides with a general protocol of coupling and purification is described. The method represents an attractive alternative to the classical solid- and fluorous-phase synthesis strategies and combines the advantage of performing homogeneous chemistry on a relatively large scale while avoiding large excesses of reagents. 相似文献
28.
In this study, the determination of 4-Bromoaniline (4-BA) in green algae Chlamydomonas reinhardtii (C. reinhardtii) was investigated by applying continuous-flow microextraction (CFME) combined with high-performance liquid chromatography
(HPLC). Continuous-flow microextraction was conducted in a homemade glass chamber, i.e. the sample solution flowed through
a constant volume drop of solvent in the chamber at a constant flow rate. The effects of different factors on extraction efficiencies
were also investigated and these factors included the kind of extraction solvent, solvent drop volume, sample flow rate, extraction
time and addition amount of salt. Under the optimum extraction conditions (extraction solvent, carbon tetrachloride; solvent
drop volume, 3.5 μL; sample flow rate, 1.0 mL min−1; extraction time, 10 min; no addition of salt), the calibration plot was set up by plotting peak area against a series of
4-Bromoaniline concentrations (0.01–10 μg mL−1) in aqueous solution. The correlation coefficient (r) was 0.9990. The limit of detection (LOD) was 0.6 ng mL−1. The precision of this method was obtained by successive five time analyses of 100-ng mL−1 standard solution of 4-Bromoaniline, and the relative standard deviation (RSD) was 3.5%. The concentration factor was calculated
by the ratio of peak area of the analyte obtained after and before extraction and found to be 10.6. 4-Bromoaniline residues
in Chlamydomonas. reinhardtii cells and tap water samples were satisfactorily analyzed according to the method described above. 相似文献
29.
Min Ming Tang 《Journal of Mathematical Analysis and Applications》1977,57(2):368-381
In this paper we study the behavior of solutions of some quasilinear parabolic equations of the form as t → ∞. In particular, the solutions of these equations will decay to zero as t → ∞ in the L∞ norm. 相似文献
30.
A novel immune algorithm for resolution and quantitative determination of the components in overlapping chromatograms was proposed by imitating biological immune systems. The algorithm takes an overlapping chromatogram as its input and subtracts the chromatograms of standard samples from the input by iteration of a network. When the residual does not change, the network will converge and chromatographic information of the components in overlapping chromatogram will be obtained. Both simulated and experimental data sets were investigated by the method. Results showed that both resolved results and recoveries of quantitative determination are satisfactory. Comparing with conventional least-square method, the immune algorithm is fast in calculation. 相似文献