title: Polymer binding to carbon nanotubes in aqueous dispersions: residence time on the nanotube surface as obtained by NMR diffusometry.
abstract: The binding of block copolymer Pluronic F-127 in aqueous dispersions of single- (SWCNT) and multiwalled (MWCNT) carbon nanotubes has been studied by pulsed-field-gradient (PFG) (1)H NMR spectroscopy. We show that a major fraction of polymers exist as a free species while a minor fraction is bound to the carbon nanotubes (CNT). The polymers exchange between these two states with residence times on the nanotube surface of 24 ± 5 ms for SWCNT and of 54 ± 11 ms for MWCNT. The CNT concentration in the solution was determined by improved thermal gravimetric analysis (TGA) indicating that the concentration of SWCNT dispersed by F-127 was significantly higher than that for MWCNT. For SWCNT, the area per adsorbed Pluronic F-127 molecule is estimated to be about 40 nm(2).
authors.affiliation: Division of Applied Physical Chemistry and Industrial NMR Centre, Department of Chemistry, Teknikringen 30-36, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden.
authors.forename: Anton E
authors.initials: AE
authors.lastname: Frise
authors.forename: Guilhem
authors.initials: G
authors.lastname: Pagès
authors.forename: Michael
authors.initials: M
authors.lastname: Shtein
authors.forename: Ilan
authors.initials: I
authors.lastname: Pri Bar
authors.forename: Oren
authors.initials: O
authors.lastname: Regev
authors.forename: István
authors.initials: I
authors.lastname: Furó
mesh_terms: D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D037742:Nanotubes, Carbon; D011108:Polymers / Q000737:chemistry*; D013499:Surface Properties; D014867:Water
chemical_list: D037742:Nanotubes, Carbon; D011108:Polymers; D014867:Water