Investigations on Structural and Electrical Properties of KClO4 Complexed PVP Polymer Electrolyte Films

Potassium ion-conducting polymer electrolytes based on poly (vinyl pyrrolidone) (PVP) complexed with KClO₄ were prepared using a solution cast technique. These samples were characterized using X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Differential Scanning Calorimetry (DSC), and impedance spectroscopy. The complexation of the salt with polymer was confirmed by FT-IR and XRD studies. The ionic conductivity was found to increase with increasing temperature and salt concentration. The highest ionic conductivity (0.91 × 10^?5 S/cm) and low activation energy (0.29 eV) was obtained for the polymer complexed with 15 wt% KClO₄ among all the compositions.     

The conductive behavior and structural characteristics in the I+-beam-implanted layer of plasma-polymerized pyrrole film

A dense organic film was prepared by plasma polymerization of pyrrole. A 20 keV I⁺ implantation at a fluence of 1 × 10¹⁶ ions cm⁻² was used to produce a conducting surface layer due to doping. The characteristics of the implanted layer have been investigated using ion beam analysis techniques, X-ray photoelectron spectroscopy, and near-infrared to ultraviolet spectroscopy. The charge carriers transport in this implanted layer was also analyzed in the temperature region of 120 to 297 K. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 69: 1743–1751, 1998     

Evolution of the Physical Properties of FeCl3 Filled Polystyrene Films

ABSTRACT

The present work investigates the effect of various filling levels (FLs) of FeCl₃ on the structure and physical properties of polystyrene (PS) films. X-ray diffraction scans revealed two main peaks, the amorphous and the polymerization peaks. The infrared transmission spectra depicted the main PS characterizing peaks. The direct current (dc) electrical conduction was attributed to the interpolaron charge carrier hopping. The temperature dependence of dc magnetic susceptibility exhibited Curie–Weiss behavior. The positive values of the paramagnetic Curie temperature (θ_p) indicate the predominance of a ferromagnetic exchange interaction between the magnetic centers at low temperatures, whereas the negative value of θ_p at 9% FL suggests the existence of an antiferromagnetic exchange interaction. The electron spin resonance (ESR) investigations imply the presence of isolated and aggregated Fe⁺³ ions at intermediate and higher FLs, respectively, in the polymeric matrix.     

Electrical Transport Properties of Carbon Aerogels

Carbon aerogels are prepared by sol-gel polymerization and supercriticle drying. By controlling the mass ratio of reactants and the molar ratio of resorcinol to catalyst (R/C), carbon aerogels with different microstructure can be developed. Hall effect is measured by Van der Bow method. The results show that the electrical conductivity increases with increasing density of carbon aerogel, and Hall mobility at high temperature is nearly constant, while at low temperature the absolute value of Hall mobility increases linearly with decreasing temperature. The abnormal sign of Hall mobility is probably related to the microstructure of carbon aerogels, which influence the transport path of carriers.     

Characterization and Electrical Properties of Poly(aniline-co-2,4-dimethoxyaniline) Nanostructures Prepared by Interfacial Polymerization

Copolymer nanofibers of aniline and 2,4-dimethoxyaniline were chemically synthesized in various molar ratios of the comonomers by aqueous/organic phase interfacial oxidative polymerization in the presence of acid dopant. UV–visible spectroscopy, FT-IR, ¹H NMR measurements, and TGA were used to confirm the molecular structure of the doped copolymers. Morphology of synthesized copolymer nanostructures was investigated using transmission electron microscope, which indicate the formation of one-dimensional (1D) nanofibers with average diameter of 4–10 nm. The conductivity of the nanofibers increased significantly with increased proportion of aniline in the copolymer.     

丁腈橡胶导电性与温度特性的研究

对乙炔炭黑填充丁腈橡胶（ＮＢＲ）的导电性及其与温度的关系进行了研究,分析了丁腈橡胶的电阻率与乙炔炭黑（简称：ＣＢ）填充量的关系,并对环境温度变化时电阻率的变化规律提出了相应的关系式,同时对导电丁腈橡胶的通电时间与表面温度的关系进行了研究与测定。     

Electrical Conductivity and Lattice Defects in Nanocrystalline Cerium Oxide Thin Films

The results of the electrical conductivity and Raman scattering measurements of CeO₂ thin films obtained by a polymeric precursor spin-coating technique are presented. The electrical conductivity has been studied as a function of temperature and oxygen activity and correlated with the grain size. When compared with microcrystalline samples, nanocrystalline materials show enhanced electronic conductivity. The transition from extrinsic to intrinsic type of conductivity has been observed as the grain size decreases to <100 nm, which appears to be related to a decrease in the enthalpy of oxygen vacancy formation in CeO₂. Raman spectroscopy has been used to analyze the crystalline quality as a function of grain size. A direct comparison has been made between the defect concentration calculated from coherence length and nonstoichiometry determined from electrical measurements.     

固体氧化物燃料电池CuCoNi/SDC阳极微结构与电性能的研究

本论文采用溶胶-凝胶低温燃烧合成法制作CuxCo0.5-xNi0.5O1.75-0.5x固溶体阳极粉末,并将电解质粉末和阳极合金粉末按1:1的比例制作了CuCoNi/SDC阳极片。采用热重差热仪检测粉末的处理情况,采用x射线衍射仪(XRD)检测了粉末的成相情况。并且采用四端子法检测了不同组成阳极片的电导率值。分析了固体氧化物燃料电池CuCoNi/SDC阳极的显微结构。结果显示,用上述方法合成的粉体成相很好,阳极片的电导率和组成、温度有着极强的联系,氢气还原前后微结构有明显的变化。     

热处理对FTO薄膜结构和光电性质的影响

系统研究了在O2氛围中不同的热处理温度对FTO薄膜结构、形貌和光电性质的影响。结果表明,当退火温度较低时,样品的结晶度、可见光透过率和导电性均随退火温度的升高而升高;随着退火温度的进一步升高,样品的光电特性开始变差。当退火温度为300℃时,得到了具有最低电阻率和最高可见光透过率的样品,其室温电阻率为2.97×10-4Ωcm,可见光透过率达83%。     

Structural,Electrical and Optical Characterization of Pure and Doped Poly (Vinyl Alcohol) (PVA) Polymer Electrolyte Films

A sodium ion conducting polymer electrolyte based on Poly (Vinyl Alcohol) (PVA) complexed with Sodium Iodide (NaI) was prepared using solution cast technique. The structural properties of composite PVA polymer electrolyte films were examined by XRD. The XRD results revealed that the amorphous domains of PVA polymer matrix increased in size with the increase of NaI salt concentration. The variation in film morphology was examined by scanning electron microscopy. FT-IR spectra studies for pure PVA and complexed films revealed the vibrational changes that occurred due to the effect of dopant salt in the polymer. DC conductivity was measured in the temperature range of 303–373° K and the conductivity was found to increase with the increase of dopant concentration as well as temperature. Optical absorption studies were made in the wavelength range 200–600 nm. The absorption edge, direct band gap, and indirect band gap values were evaluated.     

石墨填充PP-HDPE复合材料的电性能研究

采用聚丙烯(PP)和高密度聚乙烯（HDPE）共混物为基体材料,以石墨为导电填料, 通过熔融共混法制备了导电复合材料。重点研究了石墨在两相基体中的分散情况以及复合体系的电学性能。扫描电镜测试结果表明:石墨粒子选择性的分散在共混物基体中,构成双渗流导电网络结构。电性能测试结果显示:在相同石墨含量下双基体体系的室温电阻率与GP/HDPE相比下降了1～4个数量级。同时,双渗流导电网络结构的存在部分消除了负温度系数（NTC）效应, 提高了热循环稳定性。     

Structural and ESR studies of Cu-doped ZnO nanostructures

Surface morphology, structural phases, and electron spin resonance (ESR) measurements were performed for Zn_1-xCu_xO nanoparticles (x = 0.00, 0.01, 0.02, 0.03, 0.04, and 0.05) synthesized by sol-gel method. The optimum annealing temperature (600°C) and weight loss was clarified using differential thermal analysis (DTA), and thermo gravimetric analysis (TG). By means of X-ray diffraction (XRD) technique, the phase of the samples was defined as single with ZnO wurtzite hexagonal structure and proofed by Rietveld analysis for Zn_0.98Cu_0.02O sample with calculating c/a rate. Spherical shape random particle distributions were observed in all scanning electron microscope (SEM) measurements. ESR measurements were conducted for all samples and g-value and ΔH (G) values were calculated and correlated from ESR measurements.     

铝阳极氧化多孔膜的离子导电性与封孔性能

研究了经逆向电解法剥离制得的铝阳采氧化多孔膜层在０．０１ｍｏｌ／ＬＫＣｌ溶液中的离子导电性。结果表明,多孔膜的离子导电性与膜的孔径大小有关。未经封孔的多孔地电解质在膜内多无阻碍作用;多孔膜经高温沸水或常温封孔剂封孔后,其离子导电性急剧减小,且经常温封孔后多摹离子导电性在一定的时间内随膜的老化时间延长而减小。对封孔后膜在电解液中的导纳值与膜在酸液中的失重量之间关系进行了讨论。     

HDPE／无烟煤导电复合材料的制备与性能研究

以氯化铜熔盐掺杂无烟煤为导电填料 ,并通过偶联剂界面处理 ,与高密度聚乙烯熔融共混 ,成功制备了HDPE/无烟煤导电复合材料 ,通过力学性能测试、扫描电镜观察、电导率测试等手段研究了其结构与性能。结果表明 :复合材料拉伸强度在填充量 2 0 %以内均高于基体树脂 ,在 10 %附近取得最大值 ;断裂伸长率有所下降 ,但仍高于10 0 % ;电阻率变化符合逾渗规律 ,在填充量为 15 %时 ,电阻率下降到 2 .2 4× 10 7Ω·cm ,达到了抗静电材料的要求     

Electrical Properties of Gallium-Doped Zinc Oxide Films Prepared by RF Sputtering

Ga-doped polycrystalline ZnO films on glass substrates were prepared by sputtering the targets, which had been prepared by sintering disks consisting of ZnO powder and various amounts of Ga₂O₃, to investigate the effects of gallium doping and sputtering conditions on electrical properties. Optimizing the RF power density, argon gas pressure, and gallium content, transparent Ga-doped ZnO films with resistivity less than 10⁻³Ω·cm were obtained. Electron concentrations for undoped and Ga-doped ZnO films were on the order of 10¹⁸ and 10²¹/cm³, respectively. The Ga-doped ZnO films became degenerate when the electron concentration exceeded ∼ 10¹⁹/cm³, and the optical band gap increased with increasing carrier concentration because of the increase of Fermi energy in the conduction band.     

分子复合型尼龙—6合金材料的研究进展

本文概述了分子复合型尼龙－６合金材料的发展及最新研究动态，介绍了近十几年来国内外和种典型尼龙－６分子复合的制备、结构与性能、增强机理，预示了分子复合型尼龙－６合金材料的开发前景。     

微粒的导电性对复合镀层结构与性能的影响

在复合电沉积过程中辅助施加超声波搅拌,制备出Ni-Al和Ni-Al2O3两种复合镀层。借助扫描电镜、X射线衍射仪、显微硬度计和摩擦磨损试验机研究了微粒的导电性对复合镀层形貌、相结构及性能的影响。结果表明:微粒的导电性对复合镀层的形貌、相结构和显微硬度均有一定影响,但对耐磨性的影响不明显;添加惰性微粒有利于获得形貌良好、结构致密、显微硬度较高的复合镀层。     

Electrical performance of lithium ion based polymer electrolyte with polyethylene glycol and polyvinyl alcohol network

A solid polymer electrolyte based on lithium hydroxide (LiOH) added with polyethylene glycol and polyvinyl alcohol polymers was synthesized by solution casting. The structural variation with respect to loading wt% of LiOH reveals the semicrystalline property of polymer electrolyte. The differential scanning calorimetry data shows the onset of crystalline to amorphous transition, which occurs nearly to the melting peak, for higher salt content. The structural properties and cross-linking between polymer and salt were demonstrated by polarized optical microscopy. The polymer electrolytes were subjected to AC impedance analysis spectra for obtaining the ionic conductivity at different temperature. The charge carriers relax much faster for higher lithium salt concentration based polymer electrolyte and produces higher conductivity. The highest room temperature conductivity 2.63 × 10^?5 S/cm is obtained for 8 wt% loading of lithium salt based polymer electrolyte, confirming their use in preparation of ion conducting devices.     

Free Radical Scavenging and Cellular Antioxidant Properties of Astaxanthin

Astaxanthin is a coloring agent which is used as a feed additive in aquaculture nutrition. Recently, potential health benefits of astaxanthin have been discussed which may be partly related to its free radical scavenging and antioxidant properties. Our electron spin resonance (ESR) and spin trapping data suggest that synthetic astaxanthin is a potent free radical scavenger in terms of diphenylpicryl-hydrazyl (DPPH) and galvinoxyl free radicals. Furthermore, astaxanthin dose-dependently quenched singlet oxygen as determined by photon counting. In addition to free radical scavenging and singlet oxygen quenching properties, astaxanthin induced the antioxidant enzyme paroxoanase-1, enhanced glutathione concentrations and prevented lipid peroxidation in cultured hepatocytes. Present results suggest that, beyond its coloring properties, synthetic astaxanthin exhibits free radical scavenging, singlet oxygen quenching, and antioxidant activities which could probably positively affect animal and human health.     

Improvement of Mechanical and Electrical Properties of Scandia-Doped Zirconia Ceramics by Post-Sintering with Hot Isostatic Pressing

Significant improvement in the fracture strength, accompanied by an enhancement in the electrical conductivity, of zirconia polycrystals that were doped with 3–7 mol% Sc₂O₃ was obtained by sintering at 1300°C for 1 h in air, followed by hot isostatic pressing (HIP) at 196 MPa at 1300° and 1450°C for 1.5 h in an argon-gas atmosphere. Dense bodies (with an average grain size of <0.5 μm) that were doped with 3.5 mol% of Sc₂O₃ showed the highest average fracture strength up to 1770 MPa and an electrical conductivity of 0.08 S/cm at 1000°C. The present zirconia ceramics, which consisted of submicrometer-sized grains of tetragonal phases and were stabilized with 5 and 6 mol% of Sc₂O₃, exhibited high strength (1330 and 1140 MPa, respectively) and good conductivity (0.15 and 0.18 S/cm, respectively); values for both properties were greater than those previously reported. The present HIPed zirconia ceramics, which have excellent properties, are candidates for an electrolyte of planar-type solid oxide fuel cells.