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91.
通过在双温控的化学气相沉积炉中热解四吡啶并卟啉铁镍混合物,合成了碳包覆铁镍纳米颗粒。原料中四吡啶并卟啉铁镍的质量比为7∶3;扫描电镜和透射电镜的结果显示碳包覆铁镍纳米颗粒形貌均匀,直径为100~300 nm;能谱结果显示碳包覆铁镍纳米颗粒是由铁、镍和碳组成;拉曼光谱证明产物有大量的缺陷存在,可能是由于球状结构上的碎片引起的;此外,磁性能测试表明室温下,碳包覆铁镍纳米颗粒有很高的饱和磁化强度,为56.3 emu·g-1;而其产物的矫顽力趋近于零,呈超顺磁性,适合用于催化剂载体。 相似文献
92.
Madhusudana Reddy M. Bhojegowd Ashoka Siddaramanna Anandakumar B. Siddappa Chandrappa G. Thimmanna Mohamed A. Pasha 《中国化学》2011,29(9):1863-1868
Nanocrystalline zirconium(IV) oxide (nc‐ZrO2) possessing high surface area was synthesized by a low temperature eco‐friendly solution combustion method using a new organic fuel alanine. The powder XRD, SEM and surface area measurements were carried out for characterization of nc‐ZrO2. The powder XRD results revealed that, the nc‐ZrO2 has the pure tetragonal phase. The crystallite size calculated by Scherrer's formula and BET surface area were found to be ca. 53–57 nm and ca. 275 m2/g, respectively. SEM micrograph exhibited the macroporous nature of the powder. nc‐ZrO2 has been employed as a catalyst for the solvent‐free synthesis of 3,4‐dihydro‐ pyrimidin‐2‐ones (DHPMs) by a microwave (MW) assisted one‐pot, multicomponent Biginelli condensation reaction of araldehydes, ethylacetoacetate and urea or thiourea. DHPMs are obtained in good to excellent yields (85%–96%) under this reaction condition within short interval of time (10–20 min). 相似文献
93.
We report that nano‐emulsions can be creatively used as a morphology selective synthesis method to prepare not only nano‐grains but also nano‐fibers with high selectivity. Synthesis of the two different morphological materials was demonstrated using polyaniline synthesis as a model case. Polyaniline nano‐grains were synthesized from aniline molecules in nano‐size aqueous droplets as polymerization sites whose droplets were generated by inverse water‐in‐oil nano‐emulsion use, and polyaniline nano‐fibers were synthesized from aniline in aqueous nano‐dimensional channels as polymerization sites whose channels were generated by direct oil‐in‐water nano‐emulsion use containing high population of oil droplets. Using the approaches, we successfully synthesized nano‐fibers of 60 nm diameter with 0.5 µm length and also nano‐grains having diameter of 60–80 nm. The two different polymerization sites of nano‐scale dimension were made by changing the ratio among surfactant, aqueous aniline/HCl solution, and oil, i.e. organic solvent. We found the nano‐fibers synthesized from the channels formed by the direct oil‐in‐water nano‐emulsion have higher bulk electrical conductivity than the nano‐grains which were synthesized from the droplets formed by the inverse water‐in‐oil emulsion. We also found that the emulsion use allows us to use a room temperature synthesis unlike conventional synthesis methods which require to use ice bath temperature. Physical properties of both nano‐fibers and nano‐grains synthesized were characterized by Fourier transform infrared (FTIR), UV–Vis spectra, scanning electron microscopy (SEM), and four probes conductivity measurement. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
94.
Zhen‐Hua Wang Yong‐Lai Lu Jun Liu Zhi‐Min Dang Li‐Qun Zhang Weimin Wang 《先进技术聚合物》2011,22(12):2302-2310
In this paper, nanoalumina (Al2O3) highly filled ethylene propylene diene monomer (EPDM) composites are prepared, and the mechanical (static and dynamic) properties and thermal conductivity are investigated systemically through various characterization methods. Furthermore, influences of in situ modification (mixing operation assisted by silane at high temperature for a certain time) with the silane‐coupling agent bis‐(3‐triethoxy silylpropyl)‐tetrasulfide (Si69) and stearic acid (SA) pretreatment on the nano‐Al2O3 filled composites are as well investigated. The results indicate that nano‐Al2O3 particles can not only perform well in reinforcing EPDM, but also improve the thermal conductivity significantly. Assisted by in situ modification with Si69, the mechanical properties (especially dynamic mechanical properties) of the nano‐Al2O3 filled composites are improved obviously, without influencing the thermal conductivity. By comparing to the traditional reinforcing fillers, such as carbon black (grade N330) and silica, in situ modified nano‐Al2O3 filled composites exhibit excellent performance in mechanical (static and dynamic) properties as well as better thermal conductivity, especially lower compression heat build‐up and better fatigue resistance. In general, our work indicates that nano‐Al2O3, as the novel thermal conductive reinforcing filler, is suitable to prepare rubber products serving in dynamic conditions, with the longer expected service life. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
95.
Yu‐Fei Song De‐Liang Long Chris Ritchie Leroy Cronin 《Chemical record (New York, N.Y.)》2011,11(3):158-171
The latest advances in the area of polyoxometalate (POM)‐based inorganic/organic hybrid materials prepared by self‐assembly, covalent modification, and supramolecular interactions are presented. This Review is composed of five sections and documents the effect of organic cations on the formation of novel POMs, surfactant encapsulated POM‐based hybrids, polymeric POM/organic hybrid materials, POMs‐containing ionic crystals, and covalently functionalized POMs. In addition to their role in the charge‐balancing, of anionic POMs, the crucial role of organic cations in the formation and functionalization of POM‐based hybrid materials is discussed. DOI 10.1002/tcr.201100002 相似文献
96.
Badaloni E Barbarino M Cabri W D'Acquarica I Forte M Gasparrini F Giorgi F Pierini M Simone P Ursini O Villani C 《Journal of chromatography. A》2011,1218(25):3862-3875
New monolithic HPLC columns were prepared by γ-radiation-triggered polymerization of hexyl methacrylate and ethylene glycol dimethacrylate monomers in the presence of porogenic solvents. Polymerization was carried out directly within capillary (250-200 μm I.D.) and nano (100-75 μm I.D.) fused-silica tubes yielding highly efficient columns for cap(nano)-LC applications. The columns were applied in the complete separation of core (H2A, H2B, H3, and H4) and linker (H1) histones under gradient elution with UV and/or electrospray ionization (ESI) ion trap mass spectrometry (MS) detections. Large selectivity towards H1, H2A-1, H2A-2, H2B, H3-1, H3-2 and H4 histones and complete separation were obtained within 8 min time windows, using fast gradients and very high linear flow velocities, up to 11 mm/s for high throughput applications. The method developed was the basis of a simple and efficient protocol for the evaluation of post-translational modifications (PTMs) of histones from NCI-H460 human non-small-cell lung cancer (NSCLC) and HCT-116 human colorectal carcinoma cells. The study was extended to monitoring the level of histone acetylation after inhibition of Histone DeACetylase (HDAC) enzymes with suberoylanilide hydroxamic acid (SAHA), the first HDAC inhibitor approved by the FDA for cancer therapy. Attractive features of our cap(nano)-LC/MS approach are the short analysis time, the minute amount of sample required to complete the whole procedure and the stability of the polymethacrylate-based columns. A lab-made software package ClustMass was ad hoc developed and used to elaborate deconvoluted mass spectral data (aligning, averaging, clustering) and calculate the potency of HDAC inhibitors, expressed through a Relative half maximal Inhibitory Concentration parameter, namely R_IC(50) and an averaged acetylation degree. 相似文献
97.
Nano-scale nickel hydroxide was prepared by precipitate transformation method in the paper. Effect of rinse pH on the agglomeration degree and electrochemical performance of nano-scale Ni (OH)2 was investigated. The measurement results of XRD and TEM indicate that the prepared nano-scale Ni (OH)2 is β (II)-phase, the grain size is in the rang of 10 ~ 50nm, and rinse pH exerts a great influence on the agglomeration degree of nano-scale Ni(OH) 2.The agglomeration of material becomes very obvious when rinse pH = 11, and the density of nano-scale Ni(OH)2 is enhanced obviously. Cyclic voltammetry(CV) and simulate cells experiment show that nano-scale Ni(OH)2 with suitable agglomeration degree have better electrochemical CV performance than those with ideal disperse Ni (OH)2and micron Ni(OH)2, and its proton diffusion coefficient is also the highest. It can elevate the discharge potential platform and prolongs discharge time, so the utilization ratio of Ni (OH)2 is raised.`` 相似文献
98.
N. Kuanchertchoo S. Kulprathipanja P. Aungkavattana D. Atong K. Hemra T. Rirksomboon S. Wongkasemjit 《应用有机金属化学》2006,20(11):775-783
Nano‐sized Na A zeolite was successfully synthesized via the sol–gel process and microwave techniques. The synthesis parameters, such as hydroxide ion concentration, seed amount, as well as heating time and temperature, were studied to obtain the most uniform and very small sized NaA zeolite using the composition of SiO2:Al2O3:xNa2O:410H2O; 3 ≤ x ≤ 6. It was found that hydroxide ion concentration affects the crystal size and heating time, whereas a higher amount of seed provides smaller sized NaA zeolite. The zeolite product can be synthesized using a higher temperature for a shorter time or lower temperature for a longer time. The best conditions for synthesizing the smallest size, 0.1–0.2 µm, and the most homogeneous NaA zeolite is to use the composition of SiO2:Al2O3:3Na2O:410H2O and 3 wt% crystal seed at 80 °C microwave heating for 6 h. The synthesized NaA zeolite was characterized using XRD and SEM. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
99.
NiMn2O4纳米粉体的相变过程和晶粒生长行为研究 总被引:1,自引:0,他引:1
王疆瑛 《新疆大学学报(理工版)》1998,15(2):49-51
采用溶胶凝胶法(Sol-Gel)制备NiMn2O4纳米粉体.用X射线衍射(XRD)法,热分析仪研究NiMn2O4纳米粉体的相变过程.用X射线衍射线线宽法,透射电子显微镜(TEM)研究晶粒长大行为.研究结果表明:热处理温度小于670°C,存在非晶晶化过程和向NiMn2O4尖晶石主晶相转变等相变过程,晶粒尺寸缓慢增大,热处理温度在于670°C,粉体的相结构为NiMn2O4尖晶石相.晶粒尺寸较快增长.相变过程严重影响了晶粒长大行为. 相似文献
100.
M.?L.?Di?VonaEmail author M.?Trombetta S.?Dirè P.?Egger C.?D’Ottavi S.?Licoccia 《Journal of Sol-Gel Science and Technology》2005,35(2):151-157
Diphenylsilanediol (DPDO) reacts with triethoxysilane (TREOS) in anhydrous conditions and in the presence of pyridine, to form complex mixtures of linear and cyclic condensation products which were identified by 29Si NMR and ATR/FTIR spectroscopies. The distribution of products can be varied by modifying the reaction conditions. Spectroscopic analysis allowed to identify the optimal reagents ratio and concentration for the production of hetero-condensation products minimizing the number of residual –OH groups whose presence would affect the performance of optical waveguides based on the synthesised nano building blocks. 相似文献