Monodisperse cobalt ferrite nanomagnets with uniform silica coatings

Ferro- and ferrimagnetic nanoparticles are difficult to manipulate in solution as a consequence of the formation of magnetically induced nanoparticle aggregates, which hamper the utility of these particles for applications ranging from data storage to bionanotechnology. Nonmagnetic shells that encap...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 26(2010), 22 vom: 16. Nov., Seite 17546-51
1. Verfasser: Dai, Qiu (VerfasserIn)
Weitere Verfasser: Lam, Michelle, Swanson, Sally, Yu, Rui-Hui Rachel, Milliron, Delia J, Topuria, Teya, Jubert, Pierre-Olivier, Nelson, Alshakim
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2010
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article Research Support, U.S. Gov't, Non-P.H.S. Ferric Compounds ferrite 1317-54-0 Cobalt 3G0H8C9362 Silicon Dioxide 7631-86-9
Beschreibung
Zusammenfassung:Ferro- and ferrimagnetic nanoparticles are difficult to manipulate in solution as a consequence of the formation of magnetically induced nanoparticle aggregates, which hamper the utility of these particles for applications ranging from data storage to bionanotechnology. Nonmagnetic shells that encapsulate these magnetic particles can reduce the interparticle magnetic interactions and improve the dispersibility of the nanoparticles in solution. A route to create uniform silica shells around individual cobalt ferrite nanoparticles--which uses poly(acrylic acid) to bind to the nanoparticle surface and inhibit nanoparticle aggregation prior to the addition of a silica precursor--was developed. In the absence of the poly(acrylic acid) the cobalt ferrite nanoparticles irreversibly aggregated during the silica shell formation. The thickness of the silica shell around the core-shell nanoparticles could be controlled in order to tune the interparticle magnetic coupling as well as inhibit magnetically induced nanoparticle aggregation. These ferrimagnetic core-silica shell structures form stable dispersion in polar solvents such as EtOH and water, which is critical for enabling technologies that require the assembly or derivatization of ferrimagnetic particles in solution
Beschreibung:Date Completed 04.03.2011
Date Revised 21.11.2013
published: Print-Electronic
Citation Status MEDLINE
ISSN:1520-5827
DOI:10.1021/la103042q