如何获得单一导电属性的单壁碳纳米管(SWCNT),使其在各领域得到更广泛的应用,引起了科研人员越来越多的关注.琼脂糖凝胶电泳(AGE)法以其简便,低成本,可规模化等优点在分离金属型(m-)和半导体型(s-)单壁碳纳米管的诸多分离方法中体现出独特的优势.本文利用紫外-可见-近红外(UV-Vis-NIR)吸收光谱分析手段,系统研究了NaCl的添加对AGE法分离SWCNT的影响.研究发现NaCl的添加对SWCNT的分离有一定的影响:当NaCl添加量低于70 mmol.L-1时,可以提高分离后体系中s-SWCNT的相对含量;当NaCl添加量高于70mmol.L-1时,随着添加量的增加,NaCl的加入开始抑制m-SWCNT和s-SWCNT的有效分离;当NaCl添加量达到160 mmol.L-1时体系分离效率明显降低.我们推测这种影响主要是由盐的添加改变了分散剂在m-SWCNT和s-SWCNT表面的吸附结构引起的.
Plenty of attention has been paid to obtaining single-walled carbon nanotubes(SWCNT) with single conductive properties so that they can be applied in various fields.Among the separation techniques used for metallic(m-) and semiconducting(s-) single-walled carbon nanotubes,agarose gel electrophoresis(AGE) is thought to be a relatively simple and low-cost method.In this work,we used UV-visible-near infrared(UV-Vis-NIR) absorption spectroscopy to study the effect of NaCl on the separation of SWCNT by AGE.Our results show that the addition of NaCl greatly influences the separation of the SWCNT.At a NaCl concentration of less than 70 mmol.L-1,the relative content of s-SWCNT increased after separation and at a NaCl concentration of higher than 70 mmol.L-1,the separation of m-SWCNT and s-SWCNT was restrained as the concentration of NaCl increased.At a NaCl concentration of 160 mmol.L-1,the separating efficiency of the system dropped markedly.We suggest that the addition of NaCl may change the adsorption properties of the surfactant towards m-SWCNT and s-SWCNT.