碳纳米管的液晶性取向研究

Study on Liquid Crystalline Orientation for Carbon Nanotubes

碳纳米管的液晶性研究是当今碳纳米管研究领域的全新、前沿课题,其液晶性即有序取向性。这种取向有序来自模型化碳纳米管的排斥体积效应,并外现于典型的光学双折射现象。碳纳米管的棒状各向异性深入人心,它是纳米碳管经自组织形成取向液晶性缺陷的诱因,是高度一致纳米管取向形成的源泉,若经掺杂、剪切、外场等的作用,将实现由缺陷液晶性向高度有序液晶性的期待转变。本文着重从取向形貌对液晶性碳纳米管的取向特征进行了简要综述性介绍,强调碳纳米管的本征特性。碳纳米管的大尺寸使之取向液晶性清晰可见,而其自身的高杨氏模量特性及其间强的吸引相互作用亦使之液晶性取向易于呈现展曲性、有规可循。

The research on liquid crystallinity of carbon nanotubes (CNTs) is the novel and frontier subject. The liquid crystallinity is their orientation characteristic, which is from the effects of excluded volumes for CNTs and performs the typically optical birefringence. CNTs’ rodlike anisotropy lies in promoting formations of various orienting liquid crystalline defects and the nanotube uniform alignments, and the liquid crystalline defects will be expected to transform into highly uniform orienting structures with actions of doping, shearing, external fields and so on. The paper mainly makes simple reviews about orienting characteristics for liquid crystalline CNTs by means of morphology characterization, emphasizing their inherent properties. Magni-tudes of nanotubes make them visible under certain characterization (i.e. scanning electron microscopic characterization), as well as both of their inherent high Young’s modulus and the strong attractive interaction between them make the liquid crystallinity uncommon but regular (apt to behave splaying).