• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Synthesis of Conductive Nanofillers/Nanofibers and Electrical Properties of their Conductive Polymer Composites.
【24h】

Synthesis of Conductive Nanofillers/Nanofibers and Electrical Properties of their Conductive Polymer Composites.

机译：导电纳米填料/纳米纤维的合成及其导电聚合物复合材料的电性能。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Thanks to their corrosion resistance, light weight, low cost, and ease of processing, electrically conducting polymer composites (CPCs) have received significant attention for the replacement of metals and inorganic materials for sensors, actuators, supercapacitors, and electromagnetic interference (EMI) shields.;In this PhD thesis, high aspect ratio conductive nanofillers namely copper nanowires (CuNWs) and multiwall carbon nanotubes (MWCNTs) were coated with polyaniline (PANi) using solution mixing and in-situ polymerization method, respectively. Transmission electron microscopy (TEM) showed a smooth polyaniline nano-coating between 5--18 nm in thickness on the nanofillers' surface. The coating thickness and; consequently, electrical conductivity was controlled and tuned by polyaniline/aniline concentration in solution. Composites with tunable conductivity may be used as chemisensors, electronic pressure sensors and switches.;Coated nanofillers demonstrated better dispersion in polystyrene (PS) and provided lower electrical percolation threshold. Dispersion of nanofillers in PS was investigated using rheological measurements and confirmed with electron micrographs and nano-scale images of CPCs. Polyaniline (PANi), when used as a coating layer, was able to attenuate electromagnetic (EM) waves via absorption and store electrical charges though pseudocapacitance mechanism. The dielectric measurements of MWCNT-PANi/PS composites showed one order of magnitude increase in real electrical permittivity compared to that of MWCNT/PS composites making them suitable for charge storage purposes.;Incorporation of PANi also brought a new insight into conductive network formation mechanism in electrospun mats where the orientation of conductive high aspect ratio nanofillers is a major problem. Conductive nanofibers of poly(vinylidene fluoride) (PVDF) filled with coated multiwall carbon nanotubes (MWCNTs) were fabricated using electrospinning. These highly oriented PVDF nanofibers exhibited high beta (beta) crystal content and enhanced piezoelectricity. Moreover, multilayer electrospun nanofibers, in which MWCNTs were located at the shell layer, were fabricated for further decrease in electrical percolation threshold.;In addition the PANi coated nanofillers, immiscible polymer blends (poly(methyl methacrylate) (PMMA) and styrene-acrylonitrile copolymer (SAN) blends) were employed to deliver lower percolation threshold via double percolation phenomenon. Conductivity measurements revealed a significant decrease in electrical percolation threshold (0.4 wt%) for PMMA70/SAN30 blends compared with MWCNT-filled SAN and PMMA (ca 0.8 wt%).
机译：凭借其耐腐蚀，重量轻，成本低和易于加工的特性，导电聚合物复合材料（CPC）在更换传感器，执行器，超级电容器和电磁干扰（EMI）屏蔽层的金属和无机材料方面引起了广泛关注在本博士论文中，分别使用溶液混合法和原位聚合法在聚苯胺（PANi）上涂覆了高长宽比的导电纳米填料，即铜纳米线（CuNWs）和多壁碳纳米管（MWCNTs）。透射电子显微镜（TEM）显示纳米填料表面上厚度介于5--18 nm之间的光滑聚苯胺纳米涂层。涂层厚度和；因此，溶液中的聚苯胺/苯胺浓度可控制和调节电导率。具有可调电导率的复合材料可用作化学传感器，电子压力传感器和开关。涂层纳米填料在聚苯乙烯（PS）中表现出更好的分散性，并提供较低的电渗漏阈值。使用流变学方法研究了纳米填料在PS中的分散性，并通过电子显微照片和CPC的纳米级图像进行了确认。聚苯胺（PANi）用作涂层时，能够通过吸收衰减电磁（EM）波并通过伪电容机制存储电荷。 MWCNT-PANi / PS复合材料的介电测量结果表明，与MWCNT / PS复合材料相比，其实际介电常数提高了一个数量级，这使其适用于电荷存储。在电纺垫中，其中导电高长径比纳米填料的取向是主要问题。使用静电纺丝制造了填充有涂层的多壁碳纳米管（MWCNT）的聚偏二氟乙烯（PVDF）的导电纳米纤维。这些高度取向的PVDF纳米纤维表现出高的beta（beta）晶体含量和增强的压电性。此外，制造了多层电纺纳米纤维，其中MWCNT位于壳层，以进一步降低电渗透阈值；此外，PANi涂层纳米填料，不混溶的聚合物共混物（聚甲基丙烯酸甲酯（PMMA）和苯乙烯-丙烯腈）共聚物（SAN）混合物）可通过双重渗透现象提供较低的渗透阈值。电导率测量显示，与MWCNT填充的SAN和PMMA（约0.8 wt％）相比，PMMA70 / SAN30共混物的电渗阈值显着降低（0.4 wt％）。

著录项

  • 作者

    Sarvi, Ali.;

  • 作者单位

    University of Calgary (Canada).;

  • 授予单位 University of Calgary (Canada).;
  • 学科 Chemical engineering.;Nanotechnology.;Electrical engineering.
  • 学位 Ph.D.
  • 年度 2014
  • 页码 238 p.
  • 总页数 238
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号