title: Magnetic poly(vinylpyridine)-coated carbon nanotubes: an efficient supramolecular tool for wastewater purification.
abstract: Herein, we report the first example of a supramolecular carbon nanotube (CNT)-based magnetic depolluting agent for divalent metal ion (M(2+)) removal from aqueous solutions. In particular, magnetic multi-walled carbon nanotubes (m-MWCNTs) coated with poly(vinylpyridine) (PVPy) self-aggregate in aqueous solutions that contain divalent metal ions (such as Zn(2+), Cu(2+) and Pb(2+)) to form tight insoluble bundles in which the M(2+) ions remain trapped through pyridyl-M(2+)-pyridyl interactions. Magnetic filtration ultimately affords the efficient separation of the depolluted solution from the precipitated M(2+)-CNT agglomerates. Upon acid treatment, the supramolecular threads could be disassembled to afford the free CNT-polymer hybrid, thus allowing recycling of the depolluting agent. All materials and complexation/decomplexation steps were thoroughly characterised by using thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), transmission and scanning electron microscopy (TEM and SEM, respectively). The quantification of the M(2+) residual concentrations in water was evaluated by using inductively coupled plasma optical emission spectroscopy (ICP-OES), which showed that, depending on the metal cation, this material can remove up to 99% of the contaminant.
authors.affiliation: Department of Chemistry, University of Namur (FUNDP), Rue de Bruxelles 61, 5000 Namur, Belgium.
authors.forename: Laura
authors.initials: L
authors.lastname: Maggini
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Raquez
authors.forename: Riccardo
authors.initials: R
authors.lastname: Marega
authors.forename: Jennifer
authors.initials: J
authors.lastname: Jensen Ahrens
authors.forename: Florent
authors.initials: F
authors.lastname: Pineux
authors.forename: Franck
authors.initials: F
authors.lastname: Meyer
authors.forename: Philippe
authors.initials: P
authors.lastname: Dubois
authors.forename: Davide
authors.initials: D
authors.lastname: Bonifazi
mesh_terms: D002413:Cations, Divalent / Q000737:chemistry / Q000302:isolation & purification; D059346:Magnets / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D002413:Cations, Divalent; D037742:Nanotubes, Carbon; D011145:Polyvinyls; D062065:Wastewater; C019535:poly(4-vinylpyridine)