Sorption properties of modified single-walled carbon nanotubes

Single walled carbon nanotubes (SWNTs), with high carboxylic acid content, were chemically modified in order to develop hydrophilic and organophilic analogues. The hydrophilic SWNTs were prepared by wrapping a water–soluble polymer, namely poly (sodium 4-styrene sulfonate) (PSSNa) around the pristine SWNTs, while the organophilic SWNTs were developed by forming amide bonds with oleylamine (C18H37N). The modification of carbon nanotubes was studied through IR spectroscopy. Moreover, the sorption properties of pristine and modified carbon nanotubes were studied by using adsorbates, which differ in polarity (i.e. water, ethanol and n-hexane). Based on these measurements it is concluded that the sorption behaviour of the SWNTs has been completely modified after the treatment, since the hydrophilic and organophilic carbon nanotubes reveal enhanced selectivity of water and n-hexane respectively.