title: DNA-controlled partition of carbon nanotubes in polymer aqueous two-phase systems.
abstract: Sorting single-wall carbon nanotubes (SWCNTs) of different chiralities is both scientifically interesting and technologically important. Recent studies have shown that polymer aqueous two-phase extraction is a very effective way to achieve nanotube sorting. However, works published to date have demonstrated only separation of surfactant-dispersed SWCNTs, and the mechanism of chirality-dependent SWCNT partition is not well understood. Here we report a systematic study of spontaneous partition of DNA-wrapped SWCNTs in several polymer aqueous two-phase systems. We show that partition of DNA-SWCNT hybrids in a given polymer two-phase system is strongly sequence-dependent and can be further modulated by salt and polymer additives. With the proper combination of DNA sequence, polymer two-phase system, and partition modulators, as many as 15 single-chirality nanotube species have been effectively purified from a synthetic mixture. As an attempt to provide a unified partition mechanism of SWCNTs dispersed by surfactants and by DNA, we present a qualitative analysis of solvation energy for SWCNT colloids in a polymer-modified aqueous phase. Our observation and analysis highlight the sensitive dependence of the hydration energy on the spatial distribution of hydrophilic functionalities.
authors: Materials Science and Engineering Division, National Institute of Standards and Technology , 100 Bureau Drive, Gaithersburg, Maryland 20899, United States.
authors: Geyou
authors: G
authors: Ao
authors: Constantine Y
authors: CY
authors: Khripin
authors: Ming
authors: M
authors: Zheng
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D001483:Base Sequence; D004277:DNA, Single-Stranded / Q000737:chemistry*; D003911:Dextrans / Q000737:chemistry; D008969:Molecular Sequence Data; D037742:Nanotubes, Carbon / Q000737:chemistry*; D044367:Phase Transition; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011205:Povidone / Q000737:chemistry; D012666:Semiconductors; D013501:Surface-Active Agents / Q000737:chemistry; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D004277:DNA, Single-Stranded; D003911:Dextrans; D037742:Nanotubes, Carbon; D011092:Polyethylene Glycols; D011108:Polymers; D011205:Povidone; D013501:Surface-Active Agents; D000099166:Polyacrylamides; C437167:poly(ethylene glycol)diacrylate