title: The removal of metallic single-walled carbon nanotubes using an aqueous two-phase system.
abstract: Here we report our findings on the removal of metallic single-walled carbon nanotubes using an aqueous two-phase system. The aqueous two-phase system contained as received carbon nanotubes, polyethylene glycol, dextran, N-methylpyrrolidone, cetyltrimethylammonium bromide, and water which phase separated into top and bottom phases. The top phase was dominated by polyethylene glycol whereas the bottom phase was dominated by dextran. The dextran-rich phase contained more semiconducting species while metallic species was more abundant in the polyethylene glycol rich-phase. It was found via Fourier-Transform Infrared Spectroscopy that cetyltrimethylammonium bromide only present in the dextran-rich phase. A selectivity mechanism is tentatively proposed and discussed.
authors.forename: Malcolm S Y
authors.initials: MS
authors.lastname: Tang
authors.forename: T J
authors.initials: TJ
authors.lastname: Whitcher
authors.forename: K H
authors.initials: KH
authors.lastname: Yeoh
authors.forename: C L
authors.initials: CL
authors.lastname: Chua
authors.forename: K L
authors.initials: KL
authors.lastname: Woon
authors.forename: P L
authors.initials: PL
authors.lastname: Show
authors.forename: Y K
authors.initials: YK
authors.lastname: Lin
authors.forename: T C
authors.initials: TC
authors.lastname: Ling