RESUMO
Monodisperse superparamagnetic Fe(3)O(4)/polymethyl methacrylate (PMMA) composite nanospheres with high saturation magnetization were successfully prepared by a facile novel miniemulsion polymerization method. The ferrofluid, MMA monomer and surfactants were co-sonicated and emulsified to form stable miniemulsion for polymerization. The samples were characterized by DLS, TEM, FTIR, XRD, TGA and VSM. The diameter of the Fe(3)O(4)/PMMA composite nanospheres by DLS was close to 90 nm with corresponding polydispersity index (PDI) as small as 0.099, which indicated that the nanospheres have excellent homogeneity in aqueous medium. The TEM results implied that the Fe(3)O(4)/PMMA composite nanospheres had a perfect core-shell structure with about 3 nm thin PMMA shells, and the core was composed of many homogeneous and closely packed Fe(3)O(4) nanoparticles. VSM and TGA showed that the Fe(3)O(4)/PMMA composite nanospheres with at least 65% high magnetite content were superparamagnetic, and the saturation magnetization was as high as around 39 emu g(-1) (total mass), which was only decreased by 17% compared with the initial bare Fe(3)O(4) nanoparticles.
Assuntos
Compostos Férricos/química , Nanocompostos/química , Nanosferas/química , Nanotecnologia/métodos , Polimetil Metacrilato/química , Compostos Férricos/síntese química , Magnetismo , Nanocompostos/ultraestrutura , Nanosferas/ultraestrutura , Polimerização , Polimetil Metacrilato/síntese químicaRESUMO
Tea polyphenol serves as an environmentally friendly ligand-exchange molecule to synthesize multifunctional metal-doped superparamagnetic iron oxide nanoparticles via a catechol-metal coordination interaction. The resultant particles not only exhibit excellent hydrophilicity and protein adsorption resistance, but also are applicable as magnetic resonance/fluorescent dual-imaging probes due to their high T2 relaxivity, autofluorescence and large cellular uptake.
Assuntos
Química Verde , Nanopartículas/química , Nanotecnologia/métodos , Polifenóis/química , Chá/química , Adsorção , Materiais Biocompatíveis/química , Meios de Contraste/química , Compostos Férricos/química , Células HeLa , Humanos , Ligantes , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Nanopartículas Metálicas/química , Metais/química , Microscopia de Fluorescência , Óptica e Fotônica , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
A new kind of nanorattle, composed of a Fe(3)O(4)/polymethyl methacrylate (PMMA) composite nanospherical core and mesoporous SiO(2) shell, has been successfully synthesized with the combination of a modified stöber method and a dual-template strategy, followed by alcohol dialysis. The nanorattles showed high efficiency in protein adsorption and separation.