悬浮纳米金属丝体系电导率的蒙特卡罗模拟

利用蒙特卡罗方法研究纳米金属丝悬浮于弱导电介质中时体系的电导率．由于该导电体系与扩散体系存在一一对应关系，可将导电体系转化为扩散体系，利用扩散模型模拟体系的扩散运动，以便分析单粒子系统和多粒子系统扩散系数的变化规律．模拟结果表明．在分布于介质中的金属丝之间无相互接触的条件下，悬浮金属丝体系电导率随金属丝导电性的增加呈现常数、线形增长、常数的变化规律；金属丝浓度很低时，电导率呈常数的范围略小于理论预测；金属丝浓度很高时体系发生渗流,电导率仅与金属丝电导率有关．     

有机无机复合温差电材料的无机掺杂剂

有机导电高分子因其低的热导率在温差电方面受到广泛的关注,但低电导率限制了其发展.掺杂无机半导体或CNT等纳米材料可有效改善有机导电高分子的热电性能.以PEDOT/PSS有机高分子为代表介绍有机无机复合温差电材料的无机掺杂剂的最新进展,并展望有机无机复合温差电材料未来的发展与应用.     

聚吡咯—粘胶导电纤维的研究

本文的研究建立了一种新的导电聚吡咯成形法,首次成功地制备了聚吡咯—粘胶导电纤维,最高电导率可达:2.106×10~（-2）S/cm。在导电纤维的制备过程中,影响电导率的主要因素:作为引发剂及掺杂剂的三氯化铁溶液的浓度,作为基体材料的粘胶纤维在三氯化铁溶液中的处理时间,聚合反应时间及聚合反应温度。实验结果表明:粘胶纤维经导电性处理后,其取向度和结晶度保持不变,导电纤维的力学性能与基体聚合物基本相同。另外,本文还通过透射电镜对聚吡咯在粘胶纤维中的分布及其与电导率的关系作了较为详细的研究。     

导电聚合物聚苯胺的研究进展

聚苯胺是一种典型的导电聚合物,因其具有多样化的结构,较高的电导率,独特的掺杂机制,优异的物理性能,良好的环境稳定性,且原料廉价易得,合成方法简便等优点,而成为最具有应用前景的导电高分子材料之一.较全面地介绍了聚苯胺(PAn)的合成方法、性质及其应用.     

GEM法分析尼龙6/炭黑导电复合材料的电学性能

采用熔融共混法制备尼龙6/炭黑(carbon black,CB)导电复合材料,探讨温度对尼龙6/CB复合材料导电行为的影响.引入有效介质普适(GEM)方程分析温度对复合材料导电性能的影响,并讨论相关数学模型的适应性.研究表明:在CB含量一定的条件下,温度升高使CB在聚合物基体中形成的导电网络得到优化,电导率升高;而温度降低在一定程度上破坏了复合材料的导电网络,使电导率降低.     

MWNTs/掺溴聚苯胺复合材料导电性能研究

用化学氧化法和溴蒸气掺杂合成掺溴聚苯胺,通过机械共混制备MWNTs/PANI和MWNTs/掺溴PANI复合材料.复合材料表现出良好的导电性能,电导率达5～10 S·m~(-1),接近纯MWNTs的电导率.采用红外光谱、热重分析、紫外可见光谱、X射线粉末衍射和X射线光电子能谱研究MWNTs/掺溴PANI复合材料的导电性能和导电机理.研究表明,MWNTs和被掺杂的掺溴PANI通过π-π和p-π共轭作用形成电子转移复合物,组成了一个个独立导电单元,在复合材料的导电体系中起主要作用,随着导电单元数量增加至相互接触,形成导电网络,复合材料的电导率达到最大值.     

La0.5-xYxBa0.5CoO3系导电陶瓷导电性研究

通过对La0.5-xYxBa0.5CoO3系导电陶瓷的导电性、导电机制和微观形貌的研究,探讨了元素对该系导电陶瓷各方面性能的影响.发现稀土元素Y和La0.5Ba0.5CoO3系导电陶瓷的导电性有较大的影响.     

Coexistence of ferromagnetism and metallic conductivity in a molecule-based layered compound

Crystal engineering--the planning and construction of crystalline supramolecular architectures from modular building blocks--permits the rational design of functional molecular materials that exhibit technologically useful behaviour such as conductivity and superconductivity, ferromagnetism and nonlinear optical properties. Because the presence of two cooperative properties in the same crystal lattice might result in new physical phenomena and novel applications, a particularly attractive goal is the design of molecular materials with two properties that are difficult or impossible to combine in a conventional inorganic solid with a continuous lattice. A promising strategy for creating this type of 'bi-functionality' targets hybrid organic/inorganic crystals comprising two functional sub-lattices exhibiting distinct properties. In this way, the organic pi-electron donor bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) and its derivatives, which form the basis of most known molecular conductors and superconductors, have been combined with molecular magnetic anions, yielding predominantly materials with conventional semiconducting or conducting properties, but also systems that are both superconducting and paramagnetic. But interesting bulk magnetic properties fail to develop, owing to the discrete nature of the inorganic anions. Another strategy for achieving cooperative magnetism involves insertion of functional bulky cations into a polymeric magnetic anion, such as the bimetallic oxalato complex [MnIICrIII(C2O4)3]-, but only insoluble powders have been obtained in most cases. Here we report the synthesis of single crystals formed by infinite sheets of this magnetic coordination polymer interleaved with layers of conducting BEDT-TTF cations, and show that this molecule-based compound displays ferromagnetism and metallic conductivity.     

聚苯胺的化学合成、结构及导电性能

导电聚苯胺是结构和性能最稳定的导电高分子材料，有较广泛的应用前景。本实验用化学氧化合成方法，较系统地研究了氧化剂种类、用量、介质酸的浓度以及聚合反应温度等因素对苯胺聚合反应及产物性能的影响；找出了最适宜的合成反应条件和特殊的后处理工艺，并合成出了电导率高达３０．６５Ｓ／ｃｍ，收率达１２７．８％的高性能导电聚苯胺     

Light-induced conversion of an insulating refractory oxide into a persistent electronic conductor

Materials that are good electrical conductors are not in general optically transparent, yet a combination of high conductivity and transparency is desirable for many emerging opto-electronic applications. To this end, various transparent oxides composed of transition or post-transition metals (such as indium tin oxide) are rendered electrically conducting by ion doping. But such an approach does not work for the abundant transparent oxides of the main-group metals. Here we demonstrate a process by which the transparent insulating oxide 12CaO x 7Al(2)O(3) (refs 7-13) can be converted into an electrical conductor. H(-) ions are incorporated into the subnanometre-sized cages of the oxide by a thermal treatment in a hydrogen atmosphere; subsequent irradiation of the material with ultraviolet light results in a conductive state that persists after irradiation ceases. The photo-activated material exhibits moderate electrical conductivity (approximately 0.3 S cm(-1)) at room temperature, with visible light absorption losses of only one per cent for 200-nm-thick films. We suggest that this concept can be applied to other main-group metal oxides, for the direct optical writing of conducting wires in insulating transparent media and the formation of a high-density optical memory.     

聚吡咯-聚酯透明导电复合膜的研究(Ⅱ)电导率及其与温度的关系

作者在以前工作的基础上,对聚吡咯-聚酯透明导电复合膜的电导率及其与温度的关系进行了实验研究,应用渗流理论解释了复合膜的导电特性。实验结果表明,复合膜与非晶态半导体具有相同的电导率-温度变化规律。     

A review on hybridization modification of graphene and its polymer nanocomposites

Recently,graphene has attracted numerous interests from both fundamental and applied fields due to its excellent mechanical,thermal,electrical conductivity and other novel properties.This review gives an overview of recent progress on hybridization modifications of graphene with carbon nanomaterials.Some example applications of graphene-based nanohybrids in polymer composites,optical and conducting materials,high performance electrolyte materials and as well as other functional materials are summarized and discussed.     

STUDY ON POLYPYRROLE-VISCOSE CONDUCTING FIBER

The conductivity of Polypyrrole-viscose conducting fiber prepared with author's method can be shown up to as high as 2.106x10~(-2) S/cm. The main factors influencing the conductivity are the concentration of FeCl_3 used as dopant and initiator, the treatment time of viscose fiber as base material in FeCl_3 solution, temperature and polymerization time. It is found that the orientation and crystallization degree of viscose fiber keep constant before and after conducting treatment and the mechanical properties of conducting fiber is the same as that of base material. In addition, the distribution of polypyrrole in viscose fiber, and its effect on the conductivity were investigated in details by TEM.     

稀土元素对La_(0.5)Ba_(0.5)CoO_3系导电陶瓷导电性影响的研究

通过对La0 .5-xCexCoO3 系导电陶瓷的导电性、导电机制和微观形貌的研究 ,探讨了Ce元素对该系导电陶瓷各方面性能的影响 .     

新型聚二茂铁基席夫碱及其盐的合成与性能

以二茂铁甲醛和对苯二胺为原料在中性条件下合成了小分子二茂铁基席夫碱,利用Friedel—Crafts反应合成了新型导电聚二茂铁基席夫碱,然后用二价金属盐（ZnCl2、CoCl2、SnCl2）对其进行了掺杂,得到了导电聚合物配体,用IR、^1H NMR对产物结构进行了表征,并测试了产物的电导率和磁性能．实验结果表明：未掺杂前本征态电导率在10^-8～10^-9 S·cm^-1范围内,经金属盐掺杂后,电导率可提高4～5个数量级,暗示了它们可用作有机半导体材料;同时钴金属配合物的磁性测试发现其具有S型特征磁滞回线,其磁饱和强度为0．612emu／g,剩余磁场强度为0．0257emu／g,矫顽力为130 Oe,表明聚合席夫碱的钻配合物是一种有机软铁磁体．     

液晶聚氨酯/Al2O3/环氧树脂复合材料电性能的研究

采用机械共混及模压成型工艺将Al2O3粉体,液晶聚氨酯(DLCP)与环氧树脂(E-51)共混制备了EP/DLCP/Al2O3复合材料.对复合材料的制备工艺、Al2O3粒子表面修饰以及Al2O3含量对材料热稳定性、导电性能、导热性能及热膨胀进行了研究.结果表明:导热系数、介电常数及热稳定性随Al2O3含量的增加而增大;介电损耗、线膨胀系数随Al2O3含量的增加而减小.同时,液晶聚氨酯(DLCP)网格的存在,可降低材料的内耗,提高材料的玻璃化转变温度(Tg).当DLCP加入量为5wt%时,复合材料的玻璃化转变温度比纯树脂提高了10-30℃,复合材料的电性能得到了增强.     

聚苯胺/涤纶导电复合纤维的制备

先将涤纶纤维在苯胺溶液中预浸泡,然后进行处理,再将纤维置于氧化剂的酸溶液中使苯胺在纤维上氧化聚合,同时进行掺杂制得聚苯胺/涤纶导电复合纤维。讨论了苯胺单体含量、掺杂酸浓度、氧化剂浓度、反应温度及时间对纤维导电性能的影响。实验表明,采用此法制得的导电纤维具有较高的聚苯胺含量和优良的导电性能,电导率达10~(-2)S/cm数量级。     

聚氨酯／LiCF3SO3电解质体系的导电机理

利用FT-Raman、FT-IR和复数阻抗谱,对聚氧化乙烯聚氨酯/LiCF3SO3固体电解质样品中离子在聚合物电解质中的导电机理进行了研究,发现导电离子以自由离子、离子对和聚集体的形式存在于体系中,离子状态随盐浓度不同发生变化,自由离子比率随温度的上升而下降;对离子的存在状态与电导率之间的关系进行了研究,发现体系的电导率随自由离子的比率上升而变大;初步探讨了离子在体系中的导电机理;对Nernst-Einstein公式在聚合物电解质体系的应用做了校正,建立了合理的自由离子浓度和电导率的关系。     

设置导热片对固定床反应器操作的影响

本文以苯催化氧化为工作反应,研究了管式固定床反应器中设置金属铝片作为惰性导热片对反应器操作的影响。实验表明:导热片的设置,提高了床层有效热导,使床层热点位置移前,并提高热点前的床层温度;在相似的操作范围内,产品收率提高2%;进料浓度可提高20%。同时,扩大了操作多态区,提高了反应器操作稳定性,改善了反应器的操作弹性。     

溶剂和酸处理对聚吡咯膜电性能的影响

在大气氛围中,采用电化学沉积的方法在钽电极表面合导电聚吡咯膜,实验发现,机械拓磨促进了电极表面缺陷位置的增加,有利于聚吡咯膜的形成,从对支撑电 液老化机理的探讨出发,讨论了溶剂组分对聚吡咯膜电气性能的影响,由于吡咯单位的质子化作用是导致支撑电解液老化的根本原因,因此采用亲核性强的１,２－丙二醇碳酸酯（ＰＣ）和亲核性稍弱的乙腈（ＡＮ）混合溶剂配制支撑电解液,既可以合成出具有较高电导率的吡咯膜,又可以