Transcript Magnetomicelles - Department of Chemistry

Magnetomicelles:
Nanostructures from Magnetic
Nanoparticles and CrossLinked
Amphiphilic Block Copolymers
Olivier Nguon
Worth Reading Paper: October 2005
UW CHEM 7530*/750
February 14th, 2006
References
 NANOLETTERS
 2005, Vol. 5, No. 10, 1987-91
 Byeong-Su Kim, Jiao-Ming Qiu, Jian-Ping
Wang, and T. Andrew Taton*
 Department of Chemistry and Department of
Electrical and Computer Engineering,
 University of Minnesota, 207 Pleasant Street SE,
Minneapolis, Minnesota 55455
Magnetomicelles
Cross-linked, amphiphilic block-copolymer
(micelles)
Encapsulate superparamagnetic iron oxide
nanoparticles (magnetic)
Interests: magnetic particles
Carriers for magnetic drug targeting
Tags for biomolecular sensors
Biomolecule separation and purification
In vivo imaging
Stability and surface functionality of
magnetic nanostructures
Synthesis
Nanoparticles γ-Fe203:
 Thermal decomposition of
Fe(CO)5 in hydrocarbon
solvent
 Further oxidation using
(CH3)3NO
TEM image of 10.9 nm
γ-Fe2O3 nanoparticles
Synthesis (next)
Amphiphilic block copolymer:
poly(styrene250-block-acrylic acid13)
Or PS250-b-PAA13
Atom-transfer radical polymerization1
Dissolved in DMF
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1. Kang, Y.; Taton, T. A. Angew. Chem., Int. Ed. 2005, 44, 409-412.
Synthesis (next)
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Nanoparticles in THF
Added to polymer in DMF in defined ratio
Water added gradually to desolvate
Cross-linker added: 2,2’-(ethylenedioxy)bis(ethylamine)
Experimental procedure for magnetomicelles preparation
Control of properties
Average number of encapsulated particles per micelle
(Nave):
 Controlled by varying relative concentrations of
nanoparticles and polymer
 Increased particle concentration  Increased numbers
of nanoparticles incorporated
Encapsulation tests
Aqueous HCl (pH 2), a known etchant for
iron oxide
TEM analysis: particles not affected
Suspensions stable to a variety of
biological buffer (wide pH range pH 2-11)
Achievements and limitation
 Encapsulation of magnetic nanoparticles within
amphiphilic block-copolymer micelles
 Control of magnetic properties by varying the
relative concentrations of the magnetic
nanoparticles
 Hydrophilic shell can be functionalized
chemically
 Not able to encapsulate one single particule
Future developments
Other inorganic nanostructure materials
Different shapes
Biotechnological, micro- and
nanomaterials applications
Thank You !!
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