The Removal of Metallic Single-Walled Carbon Nanotubes Using an Aqueous Two-Phase System

• Main Authors: Tang, M.S.Y., Whitcher, T.J., Yeoh, K.H., Chua, C.L., Woon, K.L., Show, P.L., Lin, Y.K., Ling, T.C.
• Format: Article
• Published: American Scientific Publishers 2014
• Subjects: Q Science (General)
• Online Access: http://eprints.um.edu.my/12984/; http://www.ingentaconnect.com/content/asp/jnn/2014/00000014/00000005/art00017?token=00541da5e1e0c70eca9e1573d257025704423796c244034422c20797c4e75477e4324576b642738bed8c; http://dx.doi.org/10.1166/jnn.2014.8680

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.