Polymer-coated ferromagnetic colloids from well-defined macromolecular surfactants and assembly into nanoparticle chains

Bryan D. Korth, Pei Keng, Inbo Shim, Steven E. Bowles, Chuanbing Tang, Tomasz Kowalewski, Kenneth W. Nebesny, Dong-Chul Pyun

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Abstract

A novel synthetic route to polymer-coated ferromagnetic colloids of metallic cobalt has been developed. Well-defined end-functional polystyrenes were synthesized using controlled radical polymerization and used as surfactants in the thermolysis of dicobaltoctacarbonyl to afford uniform ferromagnetic nanoparticles. The presence of the polymer shell enabled prolonged colloidal stability of dispersions in a wide range of organic solvents and formed glassy encapsulating coatings around ferromagnetic cores in the solid state. These polymer-coated colloids assembled into robust, micron-sized nanoparticle chains when cast onto supporting surfaces due to dipolar associations of magnetic cores. Hierarchical assemblies were also prepared by blending polystyrene-coated cobalt colloids with larger silica beads.

Original languageEnglish (US)
Pages (from-to)6562-6563
Number of pages2
JournalJournal of the American Chemical Society
Volume128
Issue number20
DOIs
Publication statusPublished - May 24 2006

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ASJC Scopus subject areas

  • Chemistry(all)

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