Effects of NaCl on the Separation of Single-Walled Carbon Nanotubes by Agarose Gel Electrophoresis

 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 systemdropped markedly. We suggest that the addition of NaCl may change the adsorption properties of the surfactant towards m-SWCNT and s-SWCNT