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@INPROCEEDINGS{Qdemat:891616,
author = {Qdemat, Asmaa},
title = {{M}agnetic {N}anoparticles: {F}rom {N}anoscale to
{M}esoscale},
reportid = {FZJ-2021-01627},
year = {2021},
abstract = {Magnetic nanoparticles find promising applications in
biomedicine. Examples of these applications include new
methods for cancer treatment, such as magnetic drug
targeting [1] and magnetic hyperthermia [2], or it can be
used as contrast agents or tracers in magnetic resonance
imaging [3] and magnetic particle imaging [4]. Such
applications require magnetic nanoparticles with customized
structural and magnetic properties, strongly dependent on
particle size and shape [5]. Nanoparticle's shape is of key
importance and significantly impacts their magnetic
properties for their use in several applications. The
nanoparticles' magnetic shape anisotropy can be assumed much
larger than the magnetocrystalline anisotropy and can
strongly affect magnetic moments orientation inside the
particles. Moreover, the dipolar interaction between the
nanoparticles depends on the particle shape and will
influence the structural agglomerate formation.Recent
advances in nanoparticle synthesis techniques have enabled
the synthesis of a wide variety of precisely controlled,
non-spherical particles, including cubes, cube-like shapes
[6], and ellipsoids. Nanoparticles with a shape that
deviates from a perfect cube have gained much interest and
become experimentally available because they strongly
influence the nanocubes' large-scale arrangement. Cube
Nanoparticles with rounded edges result in an anisotropic
shape known as a superellipsoid [7] or superball, which is
an asymmetric body that describes the shape that smoothly
interpolates between a sphere and a cube. To the best of my
knowledge, there's no available theoretical model for the
evaluation of SAXS data of particles with superball shape,
and only it has been approximated by spheres of different
radii [8]. Therefore, a theoretical form factor for a more
precise evaluation of the SAXS data of superball particles
has been developed, and it will be presented in our
contribution.Also, in this contribution, we will present a
combined study of magnetic field-dependent SAXS and XPCS
measurements on hematite (α-Fe2O3) nanospindles, giving
insight into the particle morphological information (length,
radius, size distribution), magnetic orientation, and
microscopic dynamics (relaxation of nanospindles). Hematite
nanospindles are receiving considerable attention due to
their unique behavior in an applied magnetic field. In
contrast to other elongated nanoparticles, they bear a
strong magnetocrystalline anisotropy and orient with their
long axis perpendicular to an applied magnetic field above
the Morin transition (TM = 263 K) [9].Moreover, we will show
in our contribution the field-dependent polarized SANS
results of different nanospheres. Additionally, SANSPOL
results with and without applied magnetic field on pure
dispersion of hematite nanospindles and for hybrid
ferrofluidic dispersion consisting of hematite nanospindles
decorated with spherical ferrite nanoparticles will be
presented. The in-situ structure formation in such hybrid
ferrofluids includes the orientational behavior of
anisotropic structures as a function of the applied magnetic
field to elucidate the correlation of superstructure
formation and ferrofluidic properties, is
studied.References[1] Mejías, R., Pérez-Yagüe, S.,
Gutiérrez, L. et al. (2011). Dimercaptosuccinic acid-coated
magnetite nanoparticles for magnetically guided in vivo
delivery of interferon gamma for cancer immunotherapy.
Biomaterials, 32(11), 2938–2952.
https://doi.org/10.1016/j.biomaterials.2011.01.008[2]
Maier-Hauff, K., Ulrich, F., Nestler, D. et al. (2011).
Efficacy and safety of intratumoral thermotherapy using
magnetic iron-oxide nanoparticles combined with external
beam radiotherapy on patients with recurrent glioblastoma
multiforme. Journal of Neuro-Oncology, 103(2), 317–324.
https://doi.org/10.1007/s11060-010-0389-0[3] Shin, T.-H.,
Choi, Y., Kim, S., $\&$ Cheon, J. (2015). Recent advances in
magnetic nanoparticle-based multi-modal imaging. Chemical
Society Reviews, 44(14), 4501–4516.
https://doi.org/10.1039/C4CS00345D[4] Khandhar, A. P.,
Ferguson, R. M., Arami, H., $\&$ Krishnan, K. M. (2013).
Monodisperse magnetite nanoparticle tracers for in vivo
magnetic particle imaging. Biomaterials, 34(15),
3837–3845.
https://doi.org/10.1016/j.biomaterials.2013.01.087[5]
Hilger, I., $\&$ Kaiser, W. A. (2012). Iron oxide-based
nanostructures for MRI and magnetic hyperthermia.
Nanomedicine, 7(9), 1443–1459.
https://doi.org/10.2217/nnm.12.112[6] Wetterskog, E., Agthe,
M., Mayence, A.et al. (2014). Precise control over shape and
size of iron oxide nanocrystals suitable for assembly into
ordered particle arrays. Science and Technology of Advanced
Materials, 15(5), 055010.
https://doi.org/10.1088/1468-6996/15/5/055010[7] Rossi, L.,
Sacanna, S., Irvine, W. T. M., Chaikin, P. M., Pine, D. J.,
$\&$ Philipse, A. P. (2011). Cubic crystals from cubic
colloids. Soft Matter, 7(9), 4139–4142.
https://doi.org/10.1039/C0SM01246G[8] Donaldson, J. G.,
Linse, P., $\&$ Kantorovich, S. S. (2017). How cube-like
must magnetic nanoparticles be to modify their
self-assembly? Nanoscale, 9(19), 6448–6462.
https://doi.org/10.1039/C7NR01245D[9] Morrish A H. (1994).
Canted Antiferromagnetism: Hematite, (Singapore: World
Scientific)},
month = {Apr},
date = {2021-04-08},
organization = {Digital Institute Seminar JCNS-2,
online event (online event), 8 Apr 2021
- 8 Apr 2021},
subtyp = {Invited},
cin = {JCNS-2 / PGI-4 / JARA-FIT},
cid = {I:(DE-Juel1)JCNS-2-20110106 / I:(DE-Juel1)PGI-4-20110106 /
$I:(DE-82)080009_20140620$},
pnm = {632 - Materials – Quantum, Complex and Functional
Materials (POF4-632) / 6G4 - Jülich Centre for Neutron
Research (JCNS) (FZJ) (POF4-6G4)},
pid = {G:(DE-HGF)POF4-632 / G:(DE-HGF)POF4-6G4},
typ = {PUB:(DE-HGF)31},
url = {https://juser.fz-juelich.de/record/891616},
}