聚合物基柔性导电复合材料的制备和研究进展

柔性可穿戴电子器件的研制是未来科技发展的方向之一,柔性导电材料是可穿戴电子器件的重要支撑材料。由于聚合物具有优异的柔性,由聚合物基导电复合材料制备柔性导体是一种重要的途径和方式。文中从制备和表征方法方面归纳了聚合物基柔性导电复合材料的研究进展,重点阐述了实现柔性导体的关键因素,即聚合物优异高弹性的保持和可拉伸的稳定的导电网络的实现,详细介绍了简易地利用高弹性基体和纳米填料的直接共混法和目前应用较多的结构可拉伸导体的设计与制备,并总结了目前研究中存在的问题。     

新型定向导电橡胶的制备与性能研究

通过对金属丝进行定向排布并采用浇注成型工艺制备了具有定向导电功能的橡胶基复合材料。通过扫描电镜对材料的微观结构进行表征,并测试了材料的密度、硬度、拉伸性能、导电性能和电磁屏蔽性能。结果表明:所制备的定向导电橡胶在平行金属丝排布方向的体积电阻率为0.07Ω·cm,在多频段的电磁屏蔽效能≥80dB,同时其拉伸性能、密度与传统填充型导电橡胶相比具有一定优越性,可作为定向导电衬垫应用于一维电磁屏蔽场合。     

PTC型炭黑／聚烯烃导电复合材料加工工艺的研究

归纳了影响炭黑／聚烯烃复合材料ＰＴＣ效应的诸因素，认为归根结底取决于炭黑在聚合物的基体中的分散程度与分布状态及其随外部条件变化的结果，加工方法和工艺条件在很大程度上决定着制品性能的优劣。文中详细讨论了混合、成型及后处理方法戌相应工艺参数对复合材料导电性能的影响，更好地解这类材料的结构－加工－性能之间的关系、为制备更高性能的ＰＴＣ材料提供了科学依据。     

银基透明导电多层膜界面研究进展

由于具有较低的电阻率和成本、较好的机械加工性能、设计上的灵活性,可室温沉积等优点,银基透明导电多层膜已广泛应用于低辐射膜、强电磁屏蔽、低功耗光电子器件特别是柔性电子器件等领域.但由于材料自身的性质与制备条件的差异性,实际制备的金属/电介质(或半导体)透明导电多层膜界面处往往存在表面等离子体共振、界面导电电子散射、膜层脱...     

纤维素导电基底及其柔性电子器件的研究进展

纤维素是自然界中含量丰富且可再生、可降解的天然材料。本文综述了物理、化学、生物或相结合的技术对纤维素的影响作用及可制备的纤维素基元材料,例如纤维素纤维、纳米纤维素和纤维素分子。基于纤维素纤维,利用湿法造纸技术可以生产具有高孔隙率的纤维素纸张基底;基于纳米纤维素,利用真空抽滤或涂布等方式可制备具有低表面粗糙度及高透明度的纳米纤维素膜基底;基于纤维素分子,利用涂布或铸涂等方式可生产具有均一的表面形态及高透明度的再生纤维素膜基底。本文进一步分析了常用的导电材料(金属导电材料、聚合物导电材料及碳基导电材料等)及其与纤维素基底结合的方法(涂布、沉积、原位聚合、自组装等),进而可以制备柔韧轻质的纤维素导电基底。基于高性能的纤维素导电基底可以组装柔性电子器件,在光电转化、能量储存及电磁屏蔽等领域展现了广阔的应用前景。总之,利用天然纤维素制备柔性电子器件对于扩大纤维素的应用范围、提升纤维素的利用价值及推动柔性电子器件的进一步发展具有重要意义。      

大形变条件下的导电弹性体研究进展

近年来,智能材料发展迅速,尤其是一些柔性的电子产品、可穿戴智能设备已经渐渐普及。有别于传统电子器件,此类器件以其良好的可延展性、便携性、可穿戴性等特点,给人们的生活带来了极大的便利。然而,多数柔性电子器件仍存在形变能力差的缺点。综述了近年来导电弹性体,特别是在大形变条件下使用的导电弹性体的结构设计、控制制备与性能优化等方面的研究进展,提出了导电弹性体发展面临的困难与挑战,并展望了导电弹性体及通过其制造的柔性电子器件的应用前景。     

聚吡咯／聚硫橡胶导电复合膜的制备与表征

利用带有电活性端基的液体聚硫橡胶与吡咯单体在以三氯乙酸作增溶剂兼支持电解质的乙腈溶液中一步电化学氧化复合，制备了一类新型的聚吡咯／聚硫橡胶导电复合膜。文中讨论了电流密度，吡咯与聚硫橡胶浓度比，电解液温度等制备条件对复合膜导电性的影响，并采用傅里叶变化红外光谱，扫描电镜和热重分析等技术对复合膜进行了表征。     

基于导电纤维的柔性电子器件研究进展

柔性电子器件具有优异的灵活性,实现了与服装的无缝集成,在各种实际的可穿戴应用中具有巨大的潜力。一维纤维状电子器件由于其优异的柔韧性、可编织性及舒适性成为智能可穿戴领域的研究热点。首先,综述了用于纤维状柔性电子器件的一维可拉伸电极的研究进展,然后详细介绍了高性能一维纤维状柔性电子器件制备过程中具有代表性的导电材料、制造技术及一维柔性纤维进一步应用于各类电子器件的主要制备方法,另外总结了近年来基于柔性纤维状电子器件在智能可穿戴领域的应用。最后对一维纤维基智能可穿戴电子器件的机遇和挑战进行了批判性思考。      

埃洛石纳米管及液体橡胶改性环氧复合材料性能研究

通过超声辅助机械分散技术制备了环氧/埃洛石纳米管与环氧/埃洛石纳米管/液体橡胶复合材料,借助差示扫描量热仪、拉伸测试和扫描电镜等手段研究了其固化行为、拉伸性能和断面形貌。结果表明:埃洛石纳米管及柔性橡胶在环氧树脂中呈均匀的分散状态;埃洛石纳米管使环氧树脂的拉伸强度和模量增加,断裂伸长率降低;柔性橡胶/埃洛石纳米管按比例复配可平衡环氧树脂的强度、模量和韧性。     

拉伸应变下镍包碳纤维填充导电橡胶取向及电阻响应

导电橡胶因其超高的弹性和良好的导电性而在柔性电子材料领域受到广泛关注。受载时导电填料重新排列会产生相应的电阻变化。本研究选取镍包碳纤维（Nickel coated carbon fiber,CF-Ni）填充于基胶聚二甲基硅氧烷（Polydimethylsiloxane,PDMS）中制备导电橡胶。基于MATLAB平台,观察了导电橡胶中CF-Ni纤维的静态分布,并构建了纤维取向率的计算方法;随后施加动态应变载荷,选用3D打印的样品,在拉伸应变下,对其进行了纤维在胶体中取向变化的同步观察。结果表明:CF-Ni纤维沿拉伸应变方向发生偏转,最大偏转角度可达20°; CF-Ni纤维的取向分布及拉伸应变下纤维的偏转会对导电橡胶的电学性能产生影响,在60%的应变量下,CF-Ni/PDMS表面电阻最大变化为600%。导电橡胶电阻对拉伸应变载荷的响应为CF-Ni/PDMS用于制备柔性传感器奠定了基础。      

Micromechanics modeling of the electrical conductivity of carbon nanotube (CNT)–polymer nanocomposites

A mixed micromechanics model was developed to predict the overall electrical conductivity of carbon nanotube (CNT)–polymer nanocomposites. Two electrical conductivity mechanisms, electron hopping and conductive networks, were incorporated into the model by introducing an interphase layer and considering the effective aspect ratio of CNTs. It was found that the modeling results agree well with the experimental data for both single-wall carbon nanotube and multi-wall carbon nanotube based nanocomposites. Simulation results suggest that both electron hopping and conductive networks contribute to the electrical conductivity of the nanocomposites, while conductive networks become dominant as CNT volume fraction increases. It was also indicated that the sizes of CNTs have significant effects on the percolation threshold and the overall electrical conductivity of the nanocomposites. This developed model is expected to provide a more accurate prediction on the electrical conductivity of CNT–polymer nanocomposites and useful guidelines for the design and optimization of conductive polymer nanocomposites.     

基于空间限域强制组装法制备短切碳纤维-碳纳米管/聚二甲基硅氧烷导电复合材料性能

采用空间限域强制组装（SCFNA）法制备短切碳纤维-碳纳米管/聚二甲基硅氧烷（SCF-CNTs/PDMS）导电复合材料,研究SCFNA方法制备SCF-CNTs/PDMS复合材料对断面形态变化、导电性能和力学性能的影响。结果表明,通过SCFNA制备的SCF-CNTs/PDMS导电复合材料得到了密实有效的导电网络,由于缩短了导电填料之间的距离,实现了在低浓度填料下增大复合材料的导电性能和力学性能。在填料总量不变的前提下,SCF/PDMS复合材料中添加少量的CNTs,SCF与CNTs之间能形成较好的协同作用。并发现SCF质量分数为8wt%、CNTs质量分数为2wt%的SCF-CNTs/PDMS复合材料与SCF质量分数为10wt%的SCF/PDMS复合材料相比,其导电性能提高了33%,力学性能提高了144%;在SCF/PDMS复合材料中添加较多的CNTs,由于CNTs之间发生团聚现象,SCF-CNTs/PDMS复合材料的导电性能和力学性能均有所下降。SCF质量分数为5wt%、CNTs质量分数为5wt%的SCF-CNTs/PDMS复合材料随着密炼转速由40 r/min逐步增加到80 r/min,CNTs团聚现象有所改善,但是由于扭矩的增大,SCF受到的剪切作用力增大,SCF大部分被搅碎,在导电复合材料中,SCF起主要连接导电网络的作用。因此,SCF质量分数为5wt%、CNTs质量分数为5wt%的SCF-CNTs/PDMS复合材料导电性能反而随着密炼转速的提高而降低。      

Carbon nanotubes for electronics manufacturing and packaging:from growth to integration

Carbon nanotubes (CNTs) possess excellent electrical, thermal and mechanical properties. They are light in weight yet stronger than most of the other materials. They can be made both highly conductive and semi-conductive. They can be made from nano-sized small catalyst particles and extend to tens of millimeters long. Since CNTs emerged as a hot topic in the early 1990s, numerous research efforts have been spent on the study of the various properties of this new material. CNTs have been proposed as alternative materials of potential excellence in a lot of applications such as electronics, chemical sensors, mechanical sensors/actuators and composite materials, etc. This paper reviews the use of CNTs particularly in electronics manufacturing and packaging
field. The progresses of three most important applications, including CNT-based thermal interface materials, CNT-based interconnections and CNT-based cooling devices are reviewed. The growth and post-growth processing of CNTs for specific applications are introduced and the tailoring of CNTs properties, i.e., electrical resistivity, thermal  conductivity and strength, etc., is discussed with regard to specific application requirement. As the semiconductor industry is still driven by the need of getting smaller and faster, CNTs and the related composite systems as emerging new materials are likely to provide the solution to the future challenges as we make more and more complex electronics devices and systems.     

碳纳米管复合亚麻纤维柔性传感材料的制备

导电的碳纳米管(CNTs)与不导电的亚麻纤维(CEL)相结合,可以得到柔性导电复合材料。拉伸或弯曲该材料对其导电性能影响很大。根据电阻变化率(ΔR/R₀)可以敏锐地检测到材料形状的变化,因此CNTs/CEL复合材料适用于柔性传感器。用NaOH/尿素水体系处理亚麻纤维,得到CEL浆,再与不同浓度的CNTs悬浊液混合、抽滤、干燥,制得了CNTs/CEL复合材料。用XRD、FTIR和SEM分析了CNTs/CEL复合材料的结构形态。将CNTs/CEL复合材料制成形变传感器,用拉伸导电性能测试了拉伸对传感器导电性能的影响;将传感器应用到手指关节上,用电阻变化监测了手指弯曲时传感器的形变敏感性。结果发现,随着拉伸应变的增加,CNTs/CEL传感器的电阻变化率ΔR/R₀逐渐增大,50%应变下,ΔR/R₀达到980以上,能灵敏地感知到形状的变化;随着手指关节弯曲程度的增加,CNTs/CEL传感器电阻随之增大,手指最大程度弯曲时,CNTs/CEL传感器电阻可以达到12000 Ω以上,而且重复性良好。      

Electrical conductive CNT-PVA/PC nanocomposites with high tensile elongation

Electrically conductive CNT reinforced polycarbonate matrix nanocomposites with high strain-to-failure were fabricated by inserting polyvinylalcohol as a surface modifier through a melt blending process. The addition of PVA by coating the CNT through a simple ball milling process before melt blending with a polycarbonate matrix resulted in an increased percolation limit as compared to that prepared using uncoated CNTs, while the electrical conductivity was maintained at a similar level of 2 x 10(-2) S/cm. However, tensile elongation was considerably improved by the addition of PVA and remained at 81% even though 5 wt% of the CNTs were added for electrical conductivity, while elongation dropped to 25% when the CNTs were not coated with PVA. The addition of PVA induces homogeneous dispersion of CNTs during the melt blending process and can enhance both electrical conductivity and mechanical durability.     

Temperature dependence of electrical conductivity in double-wall and multi-wall carbon nanotube/polyester nanocomposites

The aim of this study is to investigate temperature dependence of electrical conductivity of carbon nanotube (CNT)/polyester nanocomposites from room temperature to 77 K using four-point probe test method. To produce nanocomposites, various types and amounts of CNTs (0.1, 0.3 and 0.5 wt.%) were dispersed via 3-roll mill technique within a specially formulized resin blend of thermoset polyesters. CNTs used in the study include multi walled carbon nanotubes (MWCNT) and double-walled carbon nanotubes (DWCNT) with and without amine functional groups (–NH₂). It was observed that the incorporation of carbon nanotubes into resin blend yields electrically percolating networks and electrical conductivity of the resulting nanocomposites increases with increasing amount of nanotubes. However, nanocomposites containing amino functionalized carbon nanotubes exhibit relatively lower electrical conductivity compared to those with non-functionalized carbon nanotubes. To get better interpretation of the mechanism leading to conductive network via CNTs with and without amine functional groups, the experimental results were fitted to fluctuation-induced tunneling through the barriers between the metallic regions model. It was found that the results are in good agreement with prediction of proposed model.     

耐高温聚酰亚胺导电复合材料的性能

采用涂膜法制备了以碳纳米管(CNTs)、乙炔黑和石墨粉为导电填料的聚酰亚胺(PI)导电复合材料,研究了其电学性能、力学性能和粘接性能。结果显示,PI/CNTs导电复合材料有较好的综合性能。     

The electrical properties of polymer nanocomposites with carbon nanotube fillers

The electrical properties of polymer nanocomposites containing a small amount of carbon nanotube (CNT) are remarkably superior to those of conventional electronic composites. Based on three-dimensional (3D) statistical percolation and 3D resistor network modeling, the electrical properties of CNT nanocomposites, at and after percolation, were successfully predicted in this work. The numerical analysis was also extended to investigate the effects of the aspect ratio, the electrical conductivity, the aggregation and the shape of CNTs on the electrical properties of the nanocomposites. A simple empirical model was also established based on present numerical simulations to predict the electrical conductivity in several electronic composites with various fillers. This investigation further highlighted the importance of theoretical and numerical analyses in the exploration of basic physical phenomena, such as percolation and conductivity in novel nanocomposites.     

Carbon nanotubes based high temperature vulcanized silicone rubber nanocomposite with excellent elasticity and electrical properties

In the present study, we have fabricated a series of high temperature vulcanized silicone rubber (HTVSR)/carbon nanotubes (CNTs) nanocomposites with different CNT contents. The CNTs were pretreated by the chitosan salt before being incorporated into the HTVSR. The nanocomposites were then characterized in terms of morphological, thermal, mechanical and electrical properties. It was found that the chitosan salt pretreated CNTs dispersed uniformly within the HTVSR matrix, improving the thermal and mechanical properties of the HTVSR. The nanocomposites could remain conductive without losing inherent properties after 100 times of repeated stretching/release cycles by 100%, 200%, and even 300%. Moreover, the nanocomposites had good response to the compressed pressures. The results obtained from this study indicate that the fabricated nanocomposites are potential to be used in many electrical fields such as the conductive elastomer or the pressure sensor.     

基于界面相互作用构建纳米纤维素-羧基化碳纳米管-石墨/聚吡咯柔性电极复合材料

以纳米纤维素(CNF)、羧基化碳纳米管(CNTs—COOH)、铅笔石墨(PGr)、聚吡咯(PPy)为原料,通过真空抽滤、涂覆、氧化聚合等方法,同时基于氢键界面相互作用的原理,制备出具有石墨层结构的CNF-CNTs—COOH-PGr/PPy柔性电极复合材料。结果表明,CNF-CNTs—COOH-PGr/PPy柔性电极复合材料在平直、折叠和拉伸时不会断裂,展现出较强的力学性能,其拉伸强度达到28.90 MPa。亲水性CNF与CNTs—COOH构筑的多孔结构增强了离子和电子的扩散路径。PGr的加入有效增加了CNF-CNTs—COOH-PGr/PPy柔性电极复合材料的导电路径,赋予其优良的导电性能。氧化聚合后得到的CNF-CNTs—COOH-PGr/PPy柔性电极复合材料的电导率达到5.403 S·cm?1。在1 mol·L?1 H₂SO₄溶液中,0.5 A·g?1电流密度下,CNF-CNTs—COOH-PGr/PPy柔性电极复合材料具有521 F·g?1的高比电容量,且经过1 500次充放电循环后,其电容保持率高达68%。基于柔性电极优良的力学性能、电化学性能和导电性能,CNF-CNTs—COOH-PGr/PPy柔性电极复合材料具备成为柔性储能器件电极材料的基本特性。