(640a) Covalent Surface Modification of Carbon Coated Nanomagnets Allow Stable Dispersions in Aqueous Solutions and Specific Post-Modification
AIChE Annual Meeting
2016
2016 AIChE Annual Meeting
Particle Technology Forum
Fundamentals of Nanoparticle Coatings and Nanocoatings on Particles
Thursday, November 17, 2016 - 8:30am to 8:50am
For many applications of magnetic nanoparticles
such as for medical diagnostics, biotechnology, biomedical applications and
magnetic biosensors, stable dispersions of magnetic nanoparticles in aqueous
solutions are crucial1.
Ferromagnetic pure metallic nanoparticles possess a very high saturation
magnetization but also show a considerable tendency to agglomerate. Thus, it is
highly desirable to create a material which combines the high saturation
magnetization but still forms stable dispersions in aqueous solutions.
Here, we describe how specific covalent surface
coating can lead to the formation of a metal cobalt nanoparticle based
ferromagnetic fluid with unprecedented dispersion stability and chemical
functionality 2. More detailed, graphene-like
carbon protected metallic nanomagnets, prepared by
flame spray synthesis3, which
are covalently functionalized on the particle surface via diazonium chemistry
are shown. A block-copolymer is grown directly from the particle surface by
SI-ATRP. This block-copolymer consists of a negatively charged polymer block
that is responsible for the colloidal stability of the particles and a second
polymer block, which allows post-modification of the particles. The length of
both polymer blocks is crucial for the colloidal stability of the particles and
is studied in this work. Post-modification
of this material by introduction of azide-functionality
followed by the well-known click-reaction, allows the attachment of various
desired target molecules. These nanoparticles form stable dispersions in
various aqueous solutions, including biological relevant buffer systems.
1 A. H. Lu, E. L.
Salabas and F. Schuth, Angew. Chem.-Int.
Edit., 2007, 46, 1222.
2 C.
J. Hofer, V. Zlateski, P. R. Stoessel, D. Paunescu, E. M. Schneider, R. N.
Grass, M. Zeltner and W. J. Stark, Chem. Commun., 2015, 51, 1826.
3 R. N. Grass, E.
K. Athanassiou and W. J. Stark, Angew.
Chem.-Int. Edit., 2007, 46,
4909.