title: Superparamagnetic-oil-filled nanocapsules of a ternary graft copolymer.
abstract: Stearic and oleic acid-coated Fe3O4 nanoparticles were dispersed in decahydronaphthalene (DN). This oil phase was dispersed in water using ternary graft copolymer poly(glycidyl methacrylate)-graft-[polystyrene-ran-(methoxy polyethylene glycol)-ran-poly(2-cinnamoyloxyethyl methacrylate)] or PGMA-g-(PS-r-MPEG-r-PCEMA) to yield capsules. The walls of these capsules were composed of PCEMA chains that were soluble in neither water nor DN, and the DN-soluble PS chains stretched into the droplet phase and the water-soluble MPEG chains extended into the aqueous phase. Structurally stable capsules were prepared by photolyzing the capsules with UV light to cross-link the PCEMA layer. Both the magnetite particles and the magnetite-containing capsules were superparamagnetic. The sizes of the capsules increased as they were loaded with more magnetite nanoparticles, reaching a maximal loading of ~0.5 mg of ligated magnetite nanoparticles per mg of copolymer. But the radii of the capsules were always <100 nm. Thus, a novel nanomaterial--superparamagnetic-oil-filled polymer nanocapsules--was prepared. The more heavily loaded capsules were readily captured by a magnet and could be redispersed via shaking. Although the cross-linked capsules survived this capturing and redispersing treatment many times, the un-cross-linked capsules ruptured after four cycles. These results suggest the potential to tailor-make capsules with tunable wall stability for magnetically controlled release applications.
authors.affiliation: Guangzhou Institute of Chemistry and ‡Key Laboratory of Cellulose Lignocellulosics Chemistry, Chinese Academy of Sciences , Guangzhou, PR China 510650.
authors.forename: Lei
authors.initials: L
authors.lastname: Miao
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Shudong
authors.initials: S
authors.lastname: Lin
authors.forename: Jiwen
authors.initials: J
authors.lastname: Hu
authors.forename: Guojun
authors.initials: G
authors.lastname: Liu
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Tu
authors.forename: Chengmin
authors.initials: C
authors.lastname: Hou
authors.forename: Fei
authors.initials: F
authors.lastname: Li
authors.forename: Meilong
authors.initials: M
authors.lastname: Hu
authors.forename: Hongsheng
authors.initials: H
authors.lastname: Luo
mesh_terms: D058185:Magnetite Nanoparticles / Q000737:chemistry*; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry; D009821:Oils / Q000737:chemistry*; D019301:Oleic Acid / Q000737:chemistry; D010316:Particle Size; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D013229:Stearic Acids / Q000737:chemistry; D013499:Surface Properties
chemical_list: D058185:Magnetite Nanoparticles; D009281:Naphthalenes; D009821:Oils; D011108:Polymers; D013229:Stearic Acids; D019301:Oleic Acid; C031183:stearic acid; C007229:decalin