Superparamagnetic Colloids: Controlled Synthesis and Niche Applications


  • These two groups contributed equally to this review article. The work at UW has been supported in part by a DARPA-DURINT subcontract from Harvard University and a fellowship from the David and Lucile Packard Foundation. Y. X. is an Alfred P. Sloan Research Fellow and a Camille Dreyfus Teacher Scholar. U. J. was partially supported by a postdoctoral fellowship from the Korea Science and Engineering Foundation (KOSEF). Part of the research at UW was performed at the Nanotech User Facility, a member of the National Nanotechnology Infrastructure Network (NNIN) funded by the NSF. The work at UR has been supported in part by the NSF (CAREER Award, DMR-0449849 and SGER, CTS-0417722), ACS-PRF (42446-G10), the Environmental Protection Agency (EPA-STAR R831722), and the Department of Energy (DE-FC03-92SF19460) through LLE.


The aim of this article is to provide a comprehensive review of current research activities that center on superparamagnetic colloids. We begin with an overview of synthetic strategies that have been developed for generating both nanoscale and mesoscale superparamagnetic colloids, with a focus on those systems that can be prepared as monodisperse samples and in relatively large quantities. We then discuss a variety of techniques that have been exploited for modifying surface properties, as well as for controlling the assembly and patterning of these magnetically active colloids. Towards the end, we highlight a range of innovative applications enabled by the unique combination of superparamagnetism and colloidal suspension. We conclude this review article with personal remarks and perspectives on the directions toward which future research in this area might be directed.