Self-assembly and field-responsive optical diffractions of superparamagnetic colloids

Superparamagnetic Fe(3)O(4) colloids with highly charged surfaces have been assembled into ordered structures in water in response to external magnetic fields. The colloids form chainlike structures with regular interparticle spacings of a few hundred nanometers along the direction of the external f...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 24(2008), 7 vom: 01. Apr., Seite 3671-80
1. Verfasser: Ge, Jianping (VerfasserIn)
Weitere Verfasser: Hu, Yongxing, Zhang, Tierui, Huynh, Tuan, Yin, Yadong
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2008
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article
Beschreibung
Zusammenfassung:Superparamagnetic Fe(3)O(4) colloids with highly charged surfaces have been assembled into ordered structures in water in response to external magnetic fields. The colloids form chainlike structures with regular interparticle spacings of a few hundred nanometers along the direction of the external field so that the system strongly diffracts visible light. The balance between attractive (in this case, magnetic) and repulsive (electrostatic) forces dictates interparticle spacing and therefore optical properties. By changing the relative strength of these two forces, one can tune the peak diffraction wavelength over the entire visible spectrum. We were able to optimize the diffraction intensity and the tuning range through studying their dependence on variables such as the size distribution and concentration of the Fe(3)O(4) colloids or ionic strength of the solutions. The fast, reversible response and the feasibility for miniaturization impart these photonic materials great potential in applications such as optoelectronic devices, sensors, and color displays
Beschreibung:Date Completed 05.05.2008
Date Revised 25.03.2008
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1520-5827
DOI:10.1021/la7039493