中文摘要：

利用凝胶柱色谱技术，研究者们通过两步或多步淋洗的方法实现了不同导电属性或电子结构单壁碳纳米管（SWCNTs）的分离，并提出其分离机制主要是由不同导电属性和电子结构的SWCN＂Is与凝胶填料之间作用力的差异所导致的．基于凝胶柱色谱分离技术，本文重点考察了超声时间对单壁碳纳米管单分散以及金属型／半导体型SWCNTs分离的影响．在～定的低超声功率下，适当增加超声时间有利于SWCNrs在十二烷基硫酸钠（SDS）溶液中的单分散．紫外-可见-近红外（UV-Vis—NIR）吸收光谱、拉曼（Raman）光谱和荧光（PL）光谱表征结果表明，2h的超声条件是获得高纯度的金属型以及不同直径分布的半导体型SWCNTs的最优条件．我们认为不同超声时间对SWCNTs分离的影响主要是改变了SWCNTs的单分散性和长度，调制了不同SWCNTs与凝胶之间作用力的差异，从而导致了不同SWCNTs分离结果．

英文摘要：

Recently, gel chromatography has been demonstrated as an effective method for the separation of single-walled carbon nanotubes （SWCNTs） according to their electronic type and structure. The separation of SWCNTs was thought to result from the different affinity forces between the gel and various SWCNTs. Based on this method, we investigated the effect of ultrasonic time on the dispersion and separation of metallic and semiconducting SWCNTs. At a low ultrasonic power, with the increase of ultrasonic time, better monodispersed SWCNTs in sodium dodecylsulfate （SDS） aqueous solution were obtained. The UV-visible-near infrared （UV-Vis-NIR） absorption, Raman and photoluminescence （PL） spectroscopic characterizations confirmed that under the condition of ultrasonication （2 h）, higher-purity metallic tubes and semiconducting tubes with different diameter distributions could be obtained. We believe that the control of the ultrasonication time may tune the mono-dispersity and the length of SWCNTs, which would further influence the difference in affinity forces between various SWCNTs and the gel, therefore leading to different separation results.