导电性高聚物复合材料

导电高聚物是电子工业上使用的重要导电材料之一。它具有成本低、易加工成型、比重轻和电导率可调节等优点,现在已逐渐用来代替某些金属材料。导电高聚物分为两类。一类是在高聚物中加导电体,如加金属粉末、石墨和碳黑等,称为添加型导电高聚物;另一类是借助于高聚物本身结构因素,即通过电子或离子导电的,如高分子电荷转移复合物、共轭高分     

石墨与聚苯乙烯的纳米复合过程研究

石墨具有电导率高、化学稳定性好等优点 ,被广泛应用于聚合物 石墨复合导电材料[1～ 3] .石墨作为聚合物导电填料一般以粉末形态居多 .用粉末状石墨填料往往需要较高的填充量才能得到理想的导电性能 .石墨也可以制备成膨胀石墨 ,将它与聚合物复合 ,可以大幅度降低石墨的填充量 .如一般粉末状石墨填料与聚合物复合制备的导电材料其逾渗阀值为 1 5 %～ 2 0 % ,电导率达到 1 0 -4 ～1 0 -7Ｓ ｃｍ[4 ] ;而若采用膨胀石墨方法 ,逾渗阀值则低于 3% ,电导率可达到 1 0 -2 Ｓ ｃｍ以上[5～ 7] .Ｐａｎ等[7] 报道用膨胀石墨与聚合物复合得到纳米复合…     

尼龙6/石墨纳米导电复合材料的制备与性能

通过原位插层聚合制备了尼龙 6 /石墨纳米导电复合材料 ,其室温导电渗滤阈值为 =0 75vol% ,远远低于常规导电粒子填充的聚合物复合材料 .当石墨体积分数为 2 0vol%时 ,室温电导率可达 10 -4 S/cm .透射电镜研究表明 :由于石墨经高温膨胀后其片层被剥离导致了片状石墨粒子具有巨大的径厚比 ,经原位插层聚合其片层厚度进一步被剥离为几十个纳米 ,同时原位插层聚合使得石墨粒子能够均匀分散在尼龙 6基体中 ,因而导致了该导电复合材料的低渗滤阈值和高导电性能 .     

酚醛树脂热裂解产物的导电特性

近年来,无论是从理论方面还是从实验方面,人们对导电高分子材料的研究都不断深入,最近报道掺杂的聚乙炔电导率已高达10~5S·cm~(-1),但聚乙炔在空气中不稳定,应用受到限制。 一维石墨由于具有缩合芳香环结构,在空气中表现出很高的稳定性,日本K.Tanaka等人对一维石墨成员从理论上进行了详细讨论,认为具有多并苯骨架结构的一维石墨成员     

粉末导电填料／聚合物导电复合材料导电性与温度的关系

复合型导电高聚物电导率/温度关系大致可分为三类,即NTC、LPTC和HPTC。尤其是具有HPTC效应的材料实用价值很高。温度直接影响材料的导电性,且与导电机理、导电填料浓度等密切相关。     

纳米石墨薄片/聚吡咯复合材料的制备及导电性能

膨胀石墨经过超声处理制备了纳米石墨薄片。以其为导电填料，对甲苯磺酸为掺杂剂，FeCl₃·6H₂O为氧化剂，引发吡咯单体发生原位聚合，制备出纳米石墨薄片/聚吡咯(NanoGs/PPy)复合材料。利用红外光谱(FTIR)、扫描电镜(SEM)和透射电镜(TEM)表征了材料的组成和结构。结果表明，石墨薄片被聚吡咯完全包覆；并且以纳米级尺寸分散在聚吡咯基体中。热失重(TG)分析和电导率测试结果表明，复合材料的耐热性能和导电性能较纯聚吡咯有所提高。     

钇磷钨三元杂多配合物的合成及其稀土多元渗与导电性的研究

合成了未见报道的标题配合物。通过化学分析、ICP和TG曲线确定了其化学式为K_8H_3[Y(PW_(11)O_(39))_2]·25H_2O;利用IR、UV、XRD、~(183)W-NMR、循环伏安等手段对其结构进行了表征,结果表明杂多阴离子为β_2型Keggin结构。采用稀土多元渗的方法对配合物进行了气相热扩渗,经ICP和XPS测试表明:微量的稀土元素La和Ce可以渗入到配合物的体相,并与组份元素存在键合作用。扩渗后化合物的化学式为K_8H_6YLa_(0.11)Ce_(0.18)P_2W_4~ⅤW_(18)~ⅥO_(78)·15H_2O,其晶体属单斜晶系,晶胞参数:a=6.3775nm,b=3.6771nm,c=3.7727nm,β=90.192°,V=88.47326nm~3;导电性的测试结果表明:室温时,扩渗后试样的电导率提高了约10~3倍,且热稳定范围变宽,523K时的电导率为1.33×10~(-2)S·cm~(-1),有望成为实用化的导电材料;~1H MAS NMR测试结果表明其存在三种质子,其导电机理可能是质子导电。     

染料敏化太阳能电池用聚苯胺/石墨复合对电极的制备与性能研究

引入一种具有网状结构的导电聚苯胺为催化材料,以导电石墨为填充材料,并对其共混后丝网印刷在FTO导电面上,制备了聚苯胺/石墨复合对电极.主要解决对电极催化活性和导电特性不能有效兼顾,制作工艺复杂的问题.扫描电镜(SEM)结果表示,通过二者简单的共混后,导电聚苯胺的网状结构依然存在,石墨的加入有效填充了聚苯胺之间的空隙,在不影响原来催化活性的基础上增强了对电极的导电性.利用循环伏安(CV)和电化学阻抗(EIS)对复合对电极的催化和导电特性进行研究.对该复合对电极组装成的DSSCs进行光电性能测试,结果表明,当石墨的质量分数达到10%时,基于聚苯胺/石墨复合对电极组装成DSSCs的光电转换效率达到了8.5%,为同等条件下传统Pt电极的123%.     

聚丙烯/石墨纳米复合材料的导电性能研究

磨盘碾磨固相剪切复合技术(S3C)是制备聚合物 石墨导电复合材料的有效途径,所得聚丙烯 膨胀石墨复合材料具有纳米插层复合结构,石墨纳米片层的相互搭接可形成导电网络,具有纳米间隙的石墨插层结构可形成隧道电流,从而大幅度降低复合体系的导电逾渗阈值,在低填充量实现聚合物复合材料高电导性,与熔体共混相比,导电逾渗阈值由4 .3vol%降低到0 . 5 5vol% ,在石墨含量为4 .0 1vol%时,电导率提高10个数量级.     

纳微米聚(3,4-二氧乙基噻吩)导电高分子的合成及其性能研究

在导电高分子家族中,聚(3,4-二氧乙基噻吩)(PEDOT)由于具有高的电导率、环境稳定性、透明性以及良好的成膜性等优异性能而广泛地应用于有机电致发光器件、太阳能电池、防静电、电致变色器件、传感器等领域.本论文研究了绝缘高分子聚乙二醇(PEG)和乙二醇、一缩二乙二醇等有机极性溶剂提高PEDOT/PSS(聚苯乙烯磺酸钠)电导率的机理,并通过改变稳定剂、掺杂剂等因素制备了具有不同结构和性能的PEDOT胶体颗粒以及PEDOT/PMMA(聚甲基丙烯酸酯)复合微球,取得了以下主要的创新性结果:1.通常,在导电高分子中加入绝缘高分子会降低其电导率.然而在PEDOT/PSS中加入绝缘高分子PEG,不但没有降低其电导率,反而大大提高了其电导率.PEG浓度对复合膜电导率的影响很大.其电导率最大值比PEDOT/PSS提高了两个数量级.而且,复合膜电导率最大值随PEG分子量的增加而降低,呈现良好的线性关系.     

Initiating electropolymerization on graphene sheets in graphite oxide structure

Because of its special chemical composition, graphite oxide has peculiar influences on electrochemical processes. The existence of various functional groups significantly affects electropolymerization processes and the formation of conductive polymers. Electrochemical synthesis of polyaniline (as a prototype of conductive polymers) on a paste‐based substrate of graphite oxide was investigated. In this case, the electropolymerization is significantly different from conventional cases, and the polymer is generated just during the first potential cycle. This can be attributed to the fact that graphite oxide can assist the monomer oxidation. Alternatively, electropolymerization was successfully performed inside the graphite oxide layers via electrochemical treatment of aniline‐intercalated graphite oxide in the supporting electrolyte. Although these phenomena are related to the chemical composition of graphite oxide, the graphite prepared by the reduction of graphite oxide also displayed some advantages for the electropolymerization (over natural graphite). There is an emphasis on the morphological investigations throughout this study, because novel morphologies were observed in the system under investigation. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2204–2213, 2010     

Electrochemical sensing with electrodes modified with molecularly imprinted polymer films

This article summarises our work on the development of voltammetric sensors based on molecularly imprinted polymers. Several recognition elements and integration strategies were used:1.membranes electropolymerised at the electrode surface; 2.casting of polymeric membranes by drop-coating a solution of pre-formed polymer (polyphosphazene) and template in a low-boiling-point solvent on to the electrode surface; 3.preparation of composite membranes containing conductive material (graphite or carbon black), acrylic-type molecularly imprinted polymers (small particle size), and PVC as binder; and 4.in-situ polymerisation of a thin layer of acrylic imprinted polymer deposited on the electrode surface by spin coating.All the options evaluated offer the possibility of controlling electrode characteristics such as hydrophobic/hydrophilic character, permeability, or film thickness, which are essential for obtaining good sensor performance.     

Zerovalent metal polymer composites. II. Metal–polymer microdispersions

Metallization of water-soluble polymers incorporating metal-binding ligand is achieved by binding palladium ions at substoichiometric quantities, followed by reduction to polymer–zero-valent palladium complex and deposition of transition metal ions by electroless plating solutions. The polymers studied include poly[N,N,N-trimethyl-N-(m- and p-vinylbenzyl)ammonium chloride], poly-L -glutamic acid, poly-L -lysine, and a copolymer of 2-phenylhydroquinone-2-amino-phthalic acid. Noble metal polyelectrolyte solutions were directly reduced with dimethylamineborane to stable microdispersions. The reactive nickel, cobalt and copper microdispersions were coated on KODAK ESTAR filmbase. Scanning electron microscopy (SEM), ESCA, and IR were used for material characterization. Conductivity and magnetic properties were also measured. Hydrophobic materials such as graphite and fluorinated graphite were metallized in organic solvents using hydrophobic trioctylammonium–tetrachloropalladate as the activating noble metal complex. The metallized conductive graphites were evaluated for their electrochemical properties.     

In situ generation of polyaniline in poly(dimethylsiloxane) networks

Polyaniline (PANI) is one of the most studied and most stable electrically conductive polymers, with the conductive form being the navy blue emeraldine salt. However, PANI is very difficult to process and displays poor mechanical performance, which suggests improving its properties by developing composite systems. In the present approach, PANI was generated in situ in poly(dimethylsiloxane) (PDMS) networks. The color of the composites varied from brown, to blue, to greenish blue, with the blue samples being the most conductive. The chemical structures of the samples were studied using FT-IR/ATR spectroscopy, which confirmed that there was more conjugation in the more conductive samples.This paper is dedicated to Mike Owen on occasion of his winning the DeBruyn medal, the first silicon chemist to do so.     

石墨烯化聚合物:一种兼具电子和离子传输通道的三维富碳高分子能源材料

近年来,用于电化学能源存储和转化的石墨烯材料,得到了研究者们越来越多的关注。但是,这些石墨烯材料不同于严格定义的单原子碳层结构,往往具有孔洞、杂原子和化学官能团等缺陷结构。由于制备方法的不同,缺陷结构各不相同,其电化学性能也表现各异。结构分析表明,这类材料是由类似石墨烯片段的单元与聚合物链共价连接而成,使其具有石墨烯和聚合物的双重特性,我们称之为石墨烯化聚合物。由小分子通过自下而上的方法制备的多孔聚合物,也可以通过进一步热交联等方法,使其形成包含石墨烯片段单元与聚合物链的化学结构。这些材料与石墨烯衍生材料一起组成了石墨烯化聚合物的整个谱系;这个谱系涵盖了由聚合物到石墨烯的过渡区。更重要的是,这类材料特殊的结构与性质,使其成为一种兼具电子和离子传输通道的三维富碳高分子材料,非常适合作为电极材料应用于电化学能源存储和转化,这为我们深入研究储能器件中电极材料的结构与性能的相关关系提供了很好的材料平台。     

Dynamic percolation in highly oriented conductive networks formed with different carbon nanofillers

Dynamic percolation in highly oriented conductive networks formed with different carbon nanofillers is investigated during disorientation upon annealing. Conductive networks are constructed by solid-state drawing, subsequent annealing, and using fillers with different dimensions (multiwalled carbon nanotubes (MWCNTs) and carbon black (CB)) in a bicomponent tape. Interestingly, it is observed that a less entangled network work is formed by mixed filler containing CB; consequently, this result in an accelerated dynamic percolation process and reduced activation energy of such process. Three different analytical approaches have been utilized to analyze this interesting behavior. It is concluded that the dynamic percolation process in highly oriented conductive polymer composites filled with MWCNTs can indeed be accelerated by the addition of CB, since less entangled networks are formed in a hybrid filler system compared with MWCNTs alone.     

Coupled Electrical Conduction in Coordination Polymers: From Electrons/Ions to Mixed Charge Carriers

The coupled transport of ions and electrons is of great potential for next‐generation sensors, energy storage and conversion devices, optoelectronics, etc. Coordination polymers (CPs) intrinsically have both transport pathways for electrons and ions, however, the practical conductivities are usually low. In recent years, significant advances have been made in electronic or ionic conductive coordination polymers, which also results in progress in mixed ionic‐electronic conductive coordination polymers. Here we start from electronic and ionic conductive CPs to mixed ionic‐electronic conductive CPs. Recent advances in the design of mixed ionic‐electronic conductive CPs are summarized. In addition, devices based on mixed conduction are selected.     

Conductive mechanism of polymer/graphite conducting composites with low percolation threshold

Preparation of the conducting composites of polystyrene/expanded graphite via in situ polymerization and investigation of the conductive mechanism were carried out. They are characterized by high conductivity and a low percolation threshold. The electrical conductivity reached 10^?2 S/cm with 3.0 vol % expanded graphite content, whereas the percolation threshold was 1.0 vol %. Optical micrographs revealed the heterogeneous distribution of the graphite particles and the formation of a conductive network in the polymer matrix. A model of primary particle was proposed to interpret the conductive phenomena. The primary particle is the basic conductive unit in the composites that comprises three of the following parts: the graphite particle, the compact‐adsorbed layer, and the wrapping shell. Our model was also used to explain the experimental data in our previous studies on nylon‐6/expanded graphite composites. A low percolation threshold of conducting composites can be also explained according to the model of the primary particle. Furthermore, the theoretical line of conductivity versus primary particle content calculated from the revised Flory's theory fits the experimental data well. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 954–963, 2002     

Morphology and conduction properties of graphite‐filled immiscible PVDF/PPgMA blends

Graphite was dispersed in immiscible polyvinylidene fluoride/maleated polypropylene (PVDF/PPgMA) blends to improve electrical and thermal conductive properties by building a double‐percolation structure. The morphology of PVDF/PPgMA blends was first investigated for several compositions by selective solvent extraction, scanning electron microscopy, and dynamic mechanical thermal analysis. Blends of PVDF and PPgMA were prepared in different relative fractions, and a PVDF/PPgMA ratio of 7/3 showed a well‐co‐continuous structure. From this blend, the morphology and properties of composites with different concentrations of graphite were investigated to prepare double‐percolated structures. Graphite was observed to selectively localize in the PPgMA phase. The electrical and thermal conductive properties of graphite‐containing blends were measured, showing enhanced conductivity for the double‐percolation structures compared with single‐polymer composites containing the same graphite loadings. Copyright © 2012 John Wiley & Sons, Ltd.     

人工智能味觉系统：概念、结构与方法

本文将传统的味觉传感器、人工味觉、电子舌等研究统一纳入人工智能味觉的框架中，提出了人工智能味觉的概念、结构及方法学问题。在传统分析科学中，非特异性感应是一个极力避免的现象，而交互感应传感器阵列则是将其作为基本出发点，设计构建成一个优化的组合，使得人工智能化学感受在技术上得以实现，交互感应理论和技术也因此成为其核心概念。作为一种仿生感觉技术，人工智能味觉系统是由交互感应电极及阵列、自学习专家数据库和智能模式识别三部分构成；电位法和伏安法是两类主要的传感方法；传感器材料包括贵金属及稀土金属、类脂/聚合物、硫属玻璃、导电聚合物以及其它如碳糊、酞菁、普鲁士蓝等；主成分分析和人工神经网络是智能识别过程中主要的模式识别工具。导电聚合物修饰电化学传感器和多技术联用分析方法目前已成为人工智能味觉系统研究的两个重要发展方向。