Polymeric Fibers Processed Using Carbon Nanotube Seed Crystals

在这项研究中，我们建议在合适的溶剂中利用剪切流场在单个单壁碳纳米管(而不是单壁碳纳米管束)上生长扩链聚合物晶体。这种聚合物包覆的单壁碳纳米管被称为种子晶体。本研究将使用聚乙烯、聚丙烯、聚酯、尼龙6和尼龙66等柔性聚合物。这些种子晶体将从溶液中获得，并用高分辨率电子显微镜、广角X射线衍射和差示扫描量热仪进行表征。种子晶体将以熔融或溶液的形式混合在各自的聚合物中。纤维也可以通过熔融纺丝或溶液纺丝来纺制。我们的想法是使用种子晶体来促进这些聚合物中的延伸链形态，在这些聚合物中，只存在带有链折叠的半结晶形态。经过处理的纤维的结构、形态和性能将被研究。种子晶体的生长和研究将有助于从根本上理解聚合物与碳纳米管之间的相互作用。在聚合物加工中使用这种晶体将提供一系列聚合物形态，从而拓宽对结构-性能关系的理解。商品纺织纤维(如PET、尼龙和丙纶)与高性能聚合物纤维(如凯夫拉尔®和泽伦®)之间存在着显著的性能和价格差距。这项研究有可能缩小这两类纤维之间的性能差距。本研究开发的聚合物碳纳米管种子晶体还可以应用于注塑成型和挤出成型，以影响这些过程中的聚合物取向和结晶。此外，聚合物包覆的碳纳米管种子可以在电子领域得到应用，碳纳米管作为热和电的导体，聚合物作为绝缘层。

In this study we propose to grow extended chain polymer crystals on individual SWNTs (not on bundles of SWNTs) using shear flow field in an appropriate solvent. The polymer coated SWNTs are termed as ?seed crystals?. Flexible polymers such as polyethylene, polypropylene, PET, nylon 6, and nylon 66 will be used in this study. These seed crystals will be harvested from solutions and characterized by high resolution transmission electron microscopy, wide-angle X-ray diffraction, and by differential scanning calorimeter. The seed crystals will be blended in the respective polymer in melt or in solution. Fibers will also be spun by melt or solution spinning. The idea is to use seed crystals to promote extended chain morphology in those polymers, where only semi-crystalline morphology with chain folds exists. Structure, morphology, and properties of the processed fibers will be studied.Growth and study of the "seed crystals" will contribute to the fundamental understanding of interaction between polymer and the carbon nanotube. Use of such crystals in polymer processing would provide range of polymer morphologies that would broaden the structure-property relationship understanding. There is a significant performance and price gap between the commodity textile fibers such as PET, nylon, and polypropylene on one hand, and high performance polymeric fibers such as Kevlar® and Zylon® on the other. This study has the potential to close the performance gap between these two classes of fibers. Polymer-CNT seed crystals developed in this study may also find applications in injection molding and extrusion for influencing polymer orientation and crystallization in these processes. In addition polymer coated carbon nanotube seeds can find application in electronics where carbon nanotube act as conductor of heat and electricity and polymer as the insulating layer.