title: Magnetic hydrogels with supracolloidal structures prepared by suspension polymerization stabilized by Fe(2)O(3) nanoparticles.
abstract: Magnetic hydrogels with supracolloidal structures were fabricated by suspension polymerization of N-isopropylacrylamide (NIPAm) and/or acrylamide (Am) stabilized by Fe(2)O(3) nanoparticles. Fe(2)O(3) nanoparticles can self-assemble at liquid-liquid interfaces to form stable water in oil Pickering emulsion droplets. Monomers dissolved in suspended aqueous droplets were subsequently polymerized at 60 degrees C. When NIPAm was homopolymerized the PNIPAm produced deposited from the interior water phase onto the interface to form Fe(2)O(3)/PNIPAm nanocomposite shells because of its hydrophobicity at the reaction temperature. Magnetic and thermosensitive hollow microcapsules were obtained. When Am was homopolymerized magnetic core-shell microcapsules with PAm hydrogel cores and Fe(2)O(3) nanoparticle shells were obtained. When NIPAm and Am were co-polymerized, magnetic hydrogel microcapsules with two kinds of supracolloidal structures were obtained varying with the NIPAm/Am ratio. These microcapsule beads may find applications as delivery vehicles for biomolecules, drugs, cosmetics, food supplements and living cells. Suspension polymerization based on Pickering emulsion droplets opens up a new route to synthesize a variety of hybrid hydrogels with supracolloidal structures.
authors.affiliation: Research Institute of Materials Science, South China University of Technology, Guangzhou 510640, China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Liu
authors.forename: Chaoyang
authors.initials: C
authors.lastname: Wang
authors.forename: Quanxing
authors.initials: Q
authors.lastname: Gao
authors.forename: Xinxing
authors.initials: X
authors.lastname: Liu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Tong
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D003102:Colloids / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D006358:Hot Temperature; D020100:Hydrogels / Q000737:chemistry*; D008280:Magnetics; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry*; D018613:Microscopy, Confocal / Q000379:methods; D008855:Microscopy, Electron, Scanning / Q000379:methods; D053758:Nanoparticles / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D013696:Temperature
chemical_list: D001672:Biocompatible Materials; D003102:Colloids; D005290:Ferric Compounds; D020100:Hydrogels; D011108:Polymers; C000499:ferric oxide