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1.
Porous anodic alumina (PAA) was used as a template to prepare Co nanowires array from 1-ethyl-3-methylimidazolium chloride ionic liquid by direct current method. The surface morphology of porous anodic alumina template was observed by field emission-scanning tunneling microscopy (FE-SEM) before and after the electrodeposition of Co nanowires. The electrodeposition of Co nanowires was characterized by transmission electron microscopy (TEM) and X-ray powder diffraction (XRD). TEM results indicate that the Co nanowire surface is coarse and porous when aqueous solution was used as electrolyte, and the Co nanowire deposited from the ionic liquid is uniform and smooth. XRD results show that the electrodeposition of Co is a mixture of crystal and microcrystal phase.  相似文献   

2.
聚苯乙烯对酞菁铜颜料微胶囊化的研究   总被引:6,自引:0,他引:6  
张天永  周春隆 《应用化学》1999,16(2):100-98
自1954年美国首先将微胶囊化应用于无碳复写纸后[1,2],这项技术在药物、农药、食品及染料等方面已得到广泛应用[3].微胶囊(MC)直径通常是1~5000μm,构造分为囊壁和囊芯两部分[4].囊壁材料大多使用高分子材料,少数用无机物[5].有机颜料...  相似文献   

3.
用硅烷偶联剂修饰蒙脱土,制备了聚苯乙烯/蒙脱土纳米复合材料,并用XRD、FTIR、TEM和TGA等对样品进行了表征,发现硅烷偶联剂对蒙脱土表面进行了良好的修饰;苯乙烯单体在蒙脱土层间的聚合导致蒙脱土片层剥离并无规分散在聚合物基体中,片层长度为100-200nm,厚度小于10nm。  相似文献   

4.
In this article, high impact polystyrene/organo Fe‐montmorillonite (HIPS/Fe‐OMT) nanocomposites were prepared by melting intercalation. The thermal stability of HIPS/Fe‐OMT nanocomposites increased significantly compared to that of HIPS examined in thermal degradation conditions. Kinetic evaluations were performed by Kissinger, Flynn‐Wall‐Ozawa, Friedman methods and multivariate nonlinear regression. Apparent kinetic parameters for the overall degradation were determined. The results showed that the activation energy of HIPS/Fe‐OMT nanocomposites was higher than that of HIPS. A very good agreement between experimental and simulated curves was observed in dynamic conditions. Their decomposition reaction model was a single‐step process of an nth‐order reaction.  相似文献   

5.
盛玮  徐学诚 《化学学报》2011,69(12):1393-1398
通过原位悬浮聚合的方法, 以过氧化苯甲酰(BPO)做引发剂, 制备了聚苯乙烯/多壁碳纳米管(MWNT-g-PS)纳米复合材料, 复合材料在水和乙醇中均表现出良好的分散性及稳定性. 通过高倍透射电镜(HRTEM)、场发射扫描电镜(FESEM)分析, 多壁碳纳米管上包覆有1~3 nm的聚苯乙烯膜, 并分布有半径从几十纳米到几百纳米不等的聚苯乙烯微球. 通过傅立叶变换红外光谱(FTIR)、拉曼光谱(Raman spectroscopy)、X光电子能谱(XPS)和热重分析(TGA)对复合材料进行分析, 结果表明, 自由基将多壁碳纳米管表面π键打开, 形成一种新的自由基, 引发聚苯乙烯的自由基聚合, 形成了接枝聚苯乙烯/多壁碳纳米管纳米复合材料.  相似文献   

6.
Summary: Pristine FH is incorporated into a PS matrix by melt blending with and without latex precompounding of PS and FH. Direct melt blending results in microcomposites, whereas the latex‐mediated (masterbatch) technique results in PS/FH nanocomposites. The tensile creep response of the micro‐ and nanocomposites are determined in short‐term creep tests. The resistance to creep is improved with increasing dispersion of FH in the PS matrix. Master curves (creep compliance vs. time), constructed based on isothermal creep tests performed in the temperature range between 5 and 45 °C, show that the FH reinforcement affects mostly the initial creep compliance (interphase effect). On the other hand, the stable creep is matrix (bulk) dominated. It is established that the Williams‐Landel‐Ferry equation is fairly applicable to the creep results.

Scheme of the change of creep compliance as a function of time for micro‐ and nanocomposites with an amorphous matrix.  相似文献   


7.
Polystyrene (PS)/clay nanocomposites were synthesized by the emulsion polymerization of styrene in the presence of sodium ion‐exchanged montmorillonite (Na+‐MMT), demonstrating that the strongly hydrophobic PS was intercalated into the hydrophilic silicate layers. The nanocomposites were examined by means of X‐ray diffraction, transmission electron microscopy, thermogravimetric analysis. The rheological properties of the PS/Na+‐MMT nanocomposites were also studied to exhibit more pronounced shear thinning behavior with increasing clay content.  相似文献   

8.
The unique optoelectronic properties and promising photovoltaic applications of organolead halide perovskites have driven the exploration of facile strategies to synthesize organometal halide perovskites and corresponding hybrid materials and devices. Currently, the preparation of CH3NH3PbBr3 perovskite nanowires, especially those with porous features, is still a great challenge. An efficient self‐template‐directed synthesis of high‐quality porous CH3NH3PbBr3 perovskite nanowires in solution at room temperature using the Pb‐containing precursor nanowires as both the sacrificial template and the Pb2+ source in the presence of CH3NH3Br and HBr is now presented. The initial formation of CH3NH3PbBr3 perovskite layers on the surface of the precursor nanowires and the following dissolution of the organic component of the latter led to the formation of mesopores and the preservation of the 1D morphology. Furthermore, the perovskite nanowires are potential materials for visible‐light photodetectors with high sensitivity and stability.  相似文献   

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10.
《中国化学会会志》2017,64(11):1354-1359
High‐purity, large‐aspect‐ratio, and well‐dispersed copper nanowires (CuNWs) with an average diameter of 45 nm and length >100 μm were successfully synthesized by reducing a Cu(II) salt with glucose, with oleylamine (OM) and oleic acid (OA) serving as dual capping agents, through hydrothermal reduction. A systematic study of the effects of the copper salt, capping agents, reductant, and temperature on the morphology of CuNWs has been conducted. Our results indicate that CuNWs with different diameters can be obtained using different copper salts. The diameter of the as‐prepared CuNWs decreases with increasing amounts of OM/OA and glucose but increases with the increasing temperature of the reaction. By adjusting the experimental parameters, we could achieve controlled synthesis of CuNWs and obtain high‐quality CuNWs with different diameters of 45, 76, 85, 90, 100, 112, 135, and 175 nm.  相似文献   

11.
A single‐step sonochemical procedure to synthesize hybrid vanadium oxide/polyaniline nanowires starting from crystalline V2O5 and aniline in aqueous medium is presented. The synthesis explores the effect of high power ultrasounds on heterogeneous solid–aqueous phases, which leads to 30 nm width wires of 5 to 10 µm in length. Monomer intercalation and oxidative polymerization within the inorganic matrix proceed simultaneously with morphological changes. The electronic conductivity of hybrid nanowires reaches 0.8 S · cm−1 at room temperature.

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13.
With the development of nanotechnology, there is a growing demand for advanced electronics based on functional nanomaterials. In this respect, owing to their unique properties, conducting polymers (CP) synthesized in the form of one‐dimensional (1D) nanostructures are of particular interest. In this feature paper, we first report one of the most powerful techniques, the hard templating synthesis, for elaborating a large number of uniform 1D CP nanotubes or nanowires with precise control over lengths and diameters. Then, recent advances in the preparation, through electrochemical template synthesis, of various multi‐segmented nanowires containing a combination of metallic and polymeric components are discussed. Hybrid metal‐CP nanowires are promising high tech materials as they exhibit enhanced performances compared to their bulk counterparts and are of direct interest for developing novel multifunctional systems for a wide range of applications. Finally, some future directions for research in the area of multi‐segmented nanowires are proposed.

  相似文献   


14.
《Analytical letters》2012,45(13):2562-2573
Abstract

A sensing system for uracil was constituted by using lanthanum hydroxide nanowires (LNW) as a modifier to obtain LNW modified carbon paste electrode (LNW/CPE) and by introducing copper(II) ion into supporting electrolyte to transform electroinactive uracil to electroactive uracil‐Cu(II) complex. The voltammetric behaviors of uracil in the presence of Cu(II) ion at LNW/CPE were investigated. A reduction peak of the uracil‐Cu(II) complex at ?0.18 V was the two‐electron reduction of Cu(II) ion in the uracil‐Cu(II) complex; while a new oxidation peak at 0.22 V was the one‐electron oxidation of the uracil‐Cu(I) complex. Additionally, the voltammetric responses of all the complexes at LNW/CPE were more sensitive than that at carbon and multiwall carbon nanotube paste electrodes, which resulted from both the large surface effect of LNW and the chemical coordination of uracil with La(III) ion in LNW. With the sensitive oxidation peak of the uracil‐Cu(I) complex at LNW/CPE, a linear range of 4.0×10?9?3.0×10?8 mol/l for uracil was obtained along with a detection limit of 2.0×10?10 mol/l. The proposed system was evaluated by the determination of uracil derivatives, anticancer drug 5‐flurouracil, in pharmaceutical preparations.  相似文献   

15.
以阳极氧化铝膜 (AAO)作模板 ,制备聚苯胺 (PANI)纳米管和PANI纳米管列阵 ;同时利用溶胶_凝胶法制备ZnO_PANI同轴纳米线和同轴纳米线列阵 .PANI纳米管和ZnO_PANI同轴纳米线的形貌通过透射电子显微镜表征 .PANI纳米管的外径约 3 0nm ,内径约 1 0nm ;ZnO_PANI同轴纳米线直径约 60nm .实验发现 ,较之ZnO纳米线 ,同轴AAO模板中纳米线列阵的可见光发射谱带兰移 ,强度显著增强 ,这可能和PANI链上的NH基团与表面Zn2 +离子之间的相互作用有关 ,以及由于ZnO纳米微粒在PANI上富集、PANI的光生载流子部分转移给ZnO微粒所致 .实验还发现分散在NaOH溶液中的同轴纳米线 ,其可见光发射谱带比AAO模板中同轴纳米线的谱带兰移更甚  相似文献   

16.
贾法龙  刘娟  张礼知 《化学学报》2017,75(6):602-607
阿特拉津是一种持久性含氯有机污染物,难以生物降解,因此有必要开发高效技术清除环境中残留的阿特拉津.近来纳米铁材料的发展为降解阿特拉津提供了一种可供选择的新方法,但降解过程中纳米铁活性逐渐减弱的问题仍需改进.本论文研究了铜离子(Cu2+)存在条件下Fe@Fe2O3纳米线活化分子氧降解阿特拉津的过程,并探讨了Cu2+的作用机理.研究结果表明,少量Cu2+的存在就可以显著促使Fe@Fe2O3生成溶解态Fe(Ⅱ),从而有助于分子氧活化并产生更多·OH等活性氧物种.在降解过程中,阿特拉津首先被氧化,进而发生脱氯上羟基反应、侧链氧化以及脱侧链反应.  相似文献   

17.
The reduction of the diameter of Bi nanowires below 10 nm has been an important target because of the theoretical prediction with regard to significant enhancement in thermoelectric performance by size reduction. In this study, we have demonstrated the usefulness of mesoporous silica with tunable pore size as a template for the preparation of thin Bi nanowires with diameters below 10 nm. Bi was deposited within the templates through a liquid phase deposition using hexane and 1,1,3,3‐tetramethyldisiloxane as a solvent and reducing agent, respectively. Bundles of thin Bi nanowires with non‐crystalline frameworks were successfully obtained after the template removal. The diameter was precisely controlled between about 6 nm and 9 nm. The judicious choices of mesoporous silica and deposition conditions are critical for the successful preparation. The reliable formation of such thin Bi nanowires reported here opens up exciting new possibilities.  相似文献   

18.
Ultrathin nanostructures are attractive for diverse applications owing to their unique properties compared to their bulk materials. Transition‐metal chalcogenides are promising electrocatalysts, yet it remains difficult to make ultrathin structures (sub‐2 nm), and the realization of their chemical doping is even more challenging. Herein we describe a soft‐template mediated colloidal synthesis of Fe‐doped NiSe2 ultrathin nanowires (UNWs) with diameter down to 1.7 nm. The synergistic interplay between oleylamine and 1‐dodecanethiol is crucial to yield these UNWs. The in situ formed amorphous hydroxide layers that is confined to the surface of the ultrathin scaffolds enable efficient oxygen evolution electrocatalysis. The UNWs exhibit a very low overpotential of 268 mV at 10 mA cm?2 in 0.1 m KOH, as well as remarkable long‐term stability, representing one of the most efficient noble‐metal‐free catalysts.  相似文献   

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