单壁碳纳米管的分离方法,科学通报,2014, 59(33), 3240
单壁碳纳米管的分离方法
刘丹, 张锦*
澳门新甫京娱乐娱城平台, 纳米化学研究中心, 北京 100871
Separation methods of single-walled carbon nanotubes
LIU Dan, ZHANG Jin*
Center for Nanochemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
摘要
单壁碳纳米管根据长度、管径、导电属性、手性和对称性的不同分为多种结构类型. 结构不同的单壁碳纳米管在光、热、电、磁等物理性质以及许多化学反应方面表现不同, 因此在应用方面有很大的差异. 为了获得结构均一的单壁碳纳米管, 人们发展了多种分离方法. 这些方法包括梯度密度离心法、共价修饰分离法、非共价修饰分离法、电泳分离法、色谱分离法、场流分离法、萃取分离法、刻蚀分离法、基于电流效应分离法、胶带法和洗涤法. 根据单壁碳纳米管的结构特征, 分离可以分为5个层次, 依次是长度、管径、导电属性、手性和对称性. 导电属性的分离是目前研究的重点, 半导体性单壁碳纳米管同时具有带隙、超小尺寸和超高载流子迁移率, 在纳电子领域有广阔的应用前景, 有望取代硅基器件引发下一代电子器件革命. 手性管和对映异构体的分离是新的发展点, 近期手性管的分离已经取得很多进展, 对映异构体的分离则处在起步阶段. 本文将从这5个层次阐述单壁碳纳米管的分离方法及其原理, 同时分析不同分离方法的优缺点.
关键词 : 单壁碳纳米管, 长度, 管径, 导电属性, 手性, 对映异构体, 分离方法
Abstract:
Single-walled carbon nanotubes (SWCNTs) can be classified into a variety of different structural types according to their length, diameter, conductive properties, chirality and symmetry. Different structural types of SWCNTs possess different physical properties, including light, heat, electronic, magnetism and reactivity. To obtain SWCNTs with homogeneous structure, numerous separation methods have been developed, including density-gradient centrifugation, covalent modification, non-covalent modification, electrophoretic separation, chromatography, field-flow fractionation, extraction, etching metallic carbon nanotubes based on the heating effect of current, tape separation and washing. According to the structural features of SWCNTs, the results of separation can be divided into five levels, followed by length, diameter, conductive properties, chirality and symmetry. [NL1] The focus of the present study is on the separation of metallic and semiconducting carbon nanotubes, because semiconducting SWCNTs that have a band gap, small size and ultra-high carrier mobility perform well in nanoelectronics and are expected to eventually replace silicon-based devices. The separation of chiral carbon nanotubes and enantiomers are new research directions; considerable progress has recently been made in separation of chiral carbon nanotubes, whereas the separation of enantiomers is in the initial stage. This article describes the separation methods for SWCNTs from the viewpoint of the five levels. The advantages and disadvantages of different separation methods are analyzed.
Key words: single-walled carbon nanotubes length diameter conductive properties chiral enantiomer separation method