Probing and tailoring ph-dependent interactions between block copolymers and single-walled carbon nanotubes for density gradient sorting

Alexander L. Antaris, Jung Woo T. Seo, Ryan E. Brock, Jane E. Herriman, Michael J. Born, Alexander A. Green, Mark C. Hersam

Research output: Contribution to journalArticle

17 Citations (Scopus)


The method by which surfactants selectively interact with particular electronic types of single-walled carbon nanotubes (SWCNTs) and thereby enable the isolation of metallic and semiconducting species is not well understood. While density gradient ultracentrifugation (DGU) has demonstrated its potential as a powerful nanomaterial separation technique, this study utilizes DGU as an analytic tool to probe the interactions between amphiphilic block copolymers, surfactants capable of electronic type extraction, and the SWCNT surface. By modulating the pH during DGU, we find that the linear shaped Pluronic copolymers can extract either metallic or semiconducting SWCNTs at purities in excess of 99%. Furthermore, the first electronic type sorting mechanism is given by which oxygen absorption and subsequent protonation of the SWCNT surface acts to template copolymer adhesion. Detailed characterization reveals the underlying mechanism for pH-shifted DGU and is thus likely to enable future development of more efficient and facile SWCNT electronic type sorting methods.

Original languageEnglish
Pages (from-to)20103-20108
Number of pages6
JournalJournal of Physical Chemistry C
Issue number37
Publication statusPublished - Sep 20 2012


ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films

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