共查询到19条相似文献,搜索用时 78 毫秒
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在纳米ZnO粒子存在的情况下,以吡咯单体为原料,对甲苯磺酸为掺杂剂,三氯化铁为氧化剂,采用化学氧化法制备了聚吡咯(PPy)/纳米ZnO复合物。采用扫描电子显微镜、紫外可见分光光度计和傅立叶变换红外光谱仪对复合物进行形貌观察和结构表征。分别以PPy和PPy/纳米ZnO复合物为填料,加入到聚氨酯(PUR)涂层中,再涂覆于碳钢片表面,之后浸泡在3.5%Na Cl溶液中,通过开路电位、极化曲线和交流阻抗研究涂层的防腐性能。结果表明,含有PPy/纳米ZnO复合物的PUR涂层耐腐蚀效果优于PUR/PPy涂层。 相似文献
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利用水热法合成了海胆状MnO_2,通过吡咯聚合制备了PPy@MnO_2复合结构,研究了包覆时间、包覆量对PPy@MnO_2电化学性能的影响。用PPy@MnO_2纳米复合材料作为工作电极,在1 mol/L的Na_2SO_4溶液中利用三电极体系进行了电化学性能测试。PPy@MnO_2纳米复合材料的循环伏安、恒电流充放电和电化学阻抗谱(EIS)研究表明,PPy@α-MnO_2-60纳米复合材料在吡咯与二氧化锰质量比10∶1、包覆时间6 h时电化学性能最佳,在电流密度0.5 A/g时比电容值为177.3 F/g。 相似文献
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聚3-乙酰基吡咯的合成、表征及其三阶非线性光学效应研究 总被引:1,自引:0,他引:1
以吡咯为原料,通过4步反应合成了一种大π共轭高分子———聚3 乙酰基吡咯(PAPY)。利用1HNMR、FTIR和UV-Vis-NIR对反应中间产物及聚合物PAPY进行了结构表征。热重分析表明PAPY可耐330℃的高温。通过碘掺杂和w(H2SO4)=98%的浓硫酸掺杂处理,PAPY的电导率提高了3个数量级,分别为0 86和0 28S/cm。用721型分光光度计对PAPY在可见光区的透过率进行了测量,计算结果表明,PAPY的光学禁带宽度Eg=1 435eV,属窄能隙聚合物。采用标准后向简并四波混频(DFWM)系统对PAPY的三阶非线性光学效应进行了测量。结果表明,在532nm处PAPY的三阶非线性极化率为8 6×10-10esu。 相似文献
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本论文在设计合成一系列四吡咯环状化合物的基础上,运用多种光谱手段研究周边取代对包括酞菁、三明治型酞菁、芴取代卟啉与氮杂卟啉在内的四吡咯环状化合物及其配合物的光物理性质和受355mn的光激发后所经历的光物理过程;研究不同结构因素对四毗咯环状化合物及其配合物的光物理性质的影响;用光限幅和z一扫描方法检测四吡咯环状化合物的三阶非线性光学响应,研究其三阶非线性光学性质的来源,计算衡量其光限幅性质和三阶非线性光学性质的参数,并分析其产生的原因、结构与非线性光学性质的关系和影响其强弱的因素.得到了一系列有意义的研究成果,为设计合成、制备具有更好三阶非线性光学性能的功能材料提供理论依据: 相似文献
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以吡咯单体为原料,三氯化铁为氧化剂,加入纳米二氧化铈(CeO2)粒子通过化学氧化法制备了聚吡咯(PPy)/纳米CeO2复合材料。利用扫描电子显微镜、X射线衍射仪、紫外-可见分光光度计、傅里叶变换红外光谱仪对其进行了结构表征。并将涂覆分别含聚氨酯(PU)涂层、PPy/PU复合涂层、PPy/CeO2/PU复合涂层的碳钢片,浸泡在质量分数3.5%的Na Cl溶液中,通过开路电位和极化曲线研究耐腐蚀性能。结果表明,含有PPy/CeO2/PU复合涂层的防腐效果最佳,其腐蚀电位最大,腐蚀电流密度最小,腐蚀速率最小。 相似文献
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We report the development of a novel route for the synthesis of polypyrrole/graphene (PPy/GR) composites by liquid ? liquid interfacial polymerization, where GR and the initiator were dispersed in the aqueous phase and the monomer was dissolved in the organic phase. The synthesized samples were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, ultraviolet–visible spectroscopy, Raman spectroscopy, X‐ray diffraction, thermogravimetric analysis, electrochemical and electrical conductivity measurements. Structural analysis reveals a uniform dispersion of GR sheets in the PPy matrix. The composites showed noticeable improvement in thermal stability and electrical conductivity (8.45 S cm?1) and excellent electrochemical reversibility in comparison with pure PPy. A specific capacitance of 260 F g?1 at a current density of 100 mA g?1 was achieved for the composite during the charge–discharge process. © 2013 Society of Chemical Industry 相似文献
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This article represents an analytical formulation for optical properties of absorbing metallic nanoparticles in visible region of electromagnetic spectrum based on Mie theory, in order to find a clear relationship between fundamental characteristics of nanoparticles with their spectral behavior and color coordinate in CIELAB color space. Calculations were performed on nanoparticles with various diameters (d = 50, 100, and 200 nm), as well as complex refractive index with different real (n = 1.5, 2.0, 2.5, and 3.0) and imaginary (k = 0.001 and 0.1) parts. Obtained results reveal that scattering phenomena in nanoparticles are strongly linked to the particle size parameter and complex index of refraction. The results indicate that the reflectance and lightness (L*) of nanoparticles increases as a result of increase in their size and real part of complex refractive index and decrease with increasing the imaginary part of complex refractive index. The CIELAB colorimetric system was used for analysis the color of nanoparticles. According to obtained results, all nanoparticles have greenish‐blue color, and undergo color change as a result of varying in their size and the complex refractive index. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 477–483, 2016 相似文献
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《Ceramics International》2019,45(11):14376-14383
Zero-dimensional cadmium sulfide (CdS) nanoparticles with small size (∼50 nm) were grafted on the two-dimensional reduced graphene oxide (RGO) nanosheet via a facile hydrothermal method without any surfactant to synthesize CdS@RGO nanocomposites in this paper. The structural analysis confirms the strong attachment and interaction between CdS and RGO in CdS@RGO photocatalyst, which leads to a higher photocatalytic efficiency (95.3%) with superior anti-corrosion stability (almost no change of efficiency over three repeated experiments) to that of pure CdS in visible light. The unique hybrid nanostructure of CdS@RGO can effectively prevent the self-corrosion of CdS and facilitate the separation of electron-hole pairs. Consequently, these outstanding photocatalytic performances of CdS@RGO endow it with a promising prospect for the degradation of organic pollutants and this work can be extended to other graphene-based inorganic semiconductor composites. 相似文献
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Schottky barriers of the type Au/polypyrrole/Al (or In) were made in sandwich configuration. The conductivity of polypyrrole was tuned to be on the order of 10−3 ohm−1 cm−1 by its electrodeposition from a novel ambient temperature ternary eutectic melt consisting of acetamide, urea, and ammonium nitrate. The rectification characteristics were obtained from the current–voltage and capacitance–voltage measurements at room temperature. The analysis of data using thermionic emission theory gave improved values for the junction parameters of ideality factor, reverse saturation current, rectification ratio, and barrier potential when compared to the previously reported values for this polymer. Between Al and In metals used for the junction formation, the diode formed with Al metal is found to show better performance. The energy gap and work function of polypyrrole were also estimated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2127–2135, 2001 相似文献
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Jian‐Mei Lu Shun‐Jun Ji Nai‐Yong Chen Zhen‐Rong Sun Xiu‐Lin Zhu Wei‐Ping Shi Zu‐Geng Wang 《应用聚合物科学杂志》2003,89(10):2611-2617
Polymerization of benzoguanamine (BGA) and 2,4‐tolylenediisocyanate (TDI), BGA–TDI polycondensation polyurea (PU), and pyromellitic dianhydride (PMDA) in solid phase under microwave radiation was studied. In the system of TDI and BGA, the effect of microwave radiation time, the composition and concentration of monomer, the temperature, and the concentration of catalyst on the third‐order optical nonlinearities of polymer were discussed. In the system of PU and PMDA, the effect of imidization degree on third‐order optical nonlinearities was also discussed. The results showed that the prepared polymer had high third‐order nonlinear optical coefficients (PU: χ(3) = 1.174 × 10?13 esu) and fast time responses (24 ps); simultaneously, the third‐order optical nonlinearities of polymer were improved greatly by microwave radiation. The results also showed that third‐order optical nonlinearities were affected not only by the length of the polycondensate chain but also by the molecular structure, which was explained and confirmed by the computation of the AM1 semiempirical method and UV‐visible absorption spectrum. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2611–2617, 2003 相似文献