title: Magnetically driven floating foams for the removal of oil contaminants from water.
abstract: In this study, we present a novel composite material based on commercially available polyurethane foams functionalized with colloidal superparamagnetic iron oxide nanoparticles and submicrometer polytetrafluoroethylene particles, which can efficiently separate oil from water. Untreated foam surfaces are inherently hydrophobic and oleophobic, but they can be rendered water-repellent and oil-absorbing by a solvent-free, electrostatic polytetrafluoroethylene particle deposition technique. It was found that combined functionalization of the polytetrafluoroethylene-treated foam surfaces with colloidal iron oxide nanoparticles significantly increases the speed of oil absorption. Detailed microscopic and wettability studies reveal that the combined effects of the surface morphology and of the chemistry of the functionalized foams greatly affect the oil-absorption dynamics. In particular, nanoparticle capping molecules are found to play a major role in this mechanism. In addition to the water-repellent and oil-absorbing capabilities, the functionalized foams exhibit also magnetic responsivity. Finally, due to their light weight, they float easily on water. Hence, by simply moving them around oil-polluted waters using a magnet, they can absorb the floating oil from the polluted regions, thereby purifying the water underneath. This low-cost process can easily be scaled up to clean large-area oil spills in water.
authors.affiliation: Center for Biomolecular Nanotechnologies @UNILE, Istituto Italiano di Tecnologia (IIT), via Barsanti, 73010 Arnesano (LE), Italy. paola.calcagnile@iit.it
authors.forename: Paola
authors.initials: P
authors.lastname: Calcagnile
authors.forename: Despina
authors.initials: D
authors.lastname: Fragouli
authors.forename: Ilker S
authors.initials: IS
authors.lastname: Bayer
authors.forename: George C
authors.initials: GC
authors.lastname: Anyfantis
authors.forename: Luigi
authors.initials: L
authors.lastname: Martiradonna
authors.forename: P Davide
authors.initials: PD
authors.lastname: Cozzoli
authors.forename: Roberto
authors.initials: R
authors.lastname: Cingolani
authors.forename: Athanassia
authors.initials: A
authors.lastname: Athanassiou
mesh_terms: D005740:Gases / Q000737:chemistry*; D060526:Magnetic Fields; D009821:Oils / Q000302:isolation & purification* / Q000528:radiation effects*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification* / Q000528:radiation effects; D018508:Water Purification / Q000379:methods*
chemical_list: D005740:Gases; D009821:Oils; D014874:Water Pollutants, Chemical; D014867:Water