building magnetic nanostructures from magnetic fluids

IPPTIPPT--PAS Warsaw 13.02.2008PAS Warsaw 13.02.2008

Building magnetic nanostructures from magnetic fluids

Paulo C. [email protected]

Professor of PhysicsUniversity of Brasília - Brazil


Outline

The magnetic nanoparticle synthesisNanoparticle surface coatingSuperparamagnetismComplex nanoparticulated magnetic systemsEx situ versus in situ template loading & applicationsClosing remarks


The magnetic nanoparticlesynthesis


1nm < d < 20nmmetallic ions Fe3+,

Co2+, Ni2+, …cubic ferrite nanoparticle

hydrophobic hydrophilic


JMMM 225, 37 (2001)


Nanoparticle surface coating


+CoFe2O4

TSF 515, 266 (2006)


<18% v.v.

shell

ionic

surfacted

biocompatible

Magnetic fluid

mm


Key Words

① Superparamagnetism❶ Magnetic manipulation

② Surface Aspects❷ Hydrophobicity × Hydrophilicity


Superparamagnetism


m

KV mH

)( 2HVFo

∇=rr

µχ

Superparamagnetism)(@ etemperaturblockingTT B>


Complex nanoparticulatedmagnetic systems


TM 42, 3596 (2006)

JNN 6, 2413 (2006)

JMMM 272, 2402 (2004)

INPI-001639

Fe2+ concentration

PI-0300855-0


November, 2007December, 2007


Ex situ versus in situtemplate loading &

applications


In situ Species diffusion

Fe2+

Fe2+

NaOH ( )C

Fe(OH)2

mesoporoustemplate

oxidation

nanocomposite

cycling ( )N

(200 µm )

Fe2+ concentration

Styrene-Divinylbenzene

NL 1, 105 (2001)


0 10 20 30 40 50 600

5

10

15

20

25

30 N=1 N=2 N=3 N=4 N=5 N=6

M (m

g/g)

C (mmol/L)

∆M = (∂M/∂C)∆C + (∂M/∂N)∆N

M(C,N) = A[1-exp(-αC)][1-exp(-βN)]

CM 15, 2485 (2003)


SEM-EDXPSS(a) 201, 898 (2004)


PI-0300855-0


Ex situ Nanoparticle diffusionVermiculiteMg3(Al,Si)4O10(OH)2.4H2O is an expanding clay

material with:① Mg2+ cation in the interlayer region to balance the

layer charge;② Mg2+ cation strongly hydrated separating adjacent

layers producing a shrinking and swelling clay;③ Mg2+ cation that can be exchanged with other

cation when water gets into the interlayer;④ Asbestos free availability.


Ex situ

INPI-001639


Cell Tagging


Saccharomyces

JMMM 272, 2400 (2004)

JNN 7, 1069 (2007)

Erythrocytes


HumanMelanoma

Cells

Control cell

Citrate-maghemite

DMSA-maghemite

Laurate-maghemite

n

n

n

JNN (in press)


Magnetoliposome

FS

FS

FS

FS

Liposome

LTC-liposome

Lipidic structure

PEG-Derivative

FS

FS

FSMagnetoliposome

JAP 97, 10Q906 (2005)

SKIN CANCER

THERAPY (PDT+MHT)

HRAN - Brasilia


Closing Remarks


UFU

UFRJ

USP, UNIFESP

UFG

UnB, EMBRAPA

HRAN, DNATech

FINATEC

FKBiotec

UFMS

Brazilian Nanobiomagnetism Network

Network Team

40 Professors (7 Full & 33 Associate + Assistant)

160 Students (Pos-Docs, Graduate & Undergraduate)


Brazilian NanobiomagnetismNetwork Achievements

1945-1998

1999-2008

1945-2008


Acknowledgments

END

building magnetic nanostructures from magnetic fluids

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