Separation of surfactant functionalized single-walled carbon nanotubes via free solution electrophoresis method

Abstract

This work presents the application of the free solution electrophoresis method (FSE) in the metallic / semiconductive (M/S)
separation process of the surfactant functionalized single-walled carbon nanotubes (SWCNTs). The SWCNTs synthesized via laser
ablation were purified through high vacuum annealing and subsequent refluxing processes in aqua regia solution. The purified
and annealed material was divided into six batches. First three batches were dispersed in anionic surfactants: sodium dodecyl
sulfate (SDS), sodium cholate (SC) and sodium deoxycholate (DOC). The next three batches were dispersed in cationic surfactants:
cetrimonium bromide (CTAB), benzalkonium chloride (BKC) and cetylpyridinium chloride (CPC). All the prepared SWCNTs samples
were subjected to FSE separation process. The fractionated samples were recovered from control and electrode areas and annealed
in order to remove the adsorbed surfactants on carbon nanotubes (CNTs) surface. The changes of the van Hove singularities
(vHS) present in SWCNTs spectra were investigated via UV-Vis-NIR optical absorption spectroscopy (OAS).

KeywordsSWCNTs–surfactants–separation–electrophoresis