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Polymer nano-structures with incorporated
magnetic particles mark a new class of composite
materials. Composite structures are formed from
a matrix (polymer) and magnetic filler (e.g. metal
or metal oxide or alloy). The great potential
of these composites derives from the substantial
modification of the thermal, mechanical and electrical
characteristics of polymers which results when
the polymer is combined with filler. An ordered
arrangement of nanoparticles is achieved by using
the template offered by self organization of block
copolymers. The idea is to incorporate nanoparticles
into spherical, lamellar or cylindrical microdomains
formed by micro-phase separation of the block
copolymer. The controlled incorporation of the
particles results from the presence of a hairy
polymer layer covering the magnetic particles.
The chemical design of this coating is a key feature
in the creation of the organic-inorganic composites.
[1]
On top of solid supports the polymer layers including
particles are prepared by spin-coating. The nano-structures
are created by additional preparation steps by
an interplay of dewetting, macro and micro-phase
separation. [2]
Within this self-assembly process
the polymer matrix as well as the magnetic particles
are ordered.
In case, film thickness and lamellar thickness
of the diblock copolymer are smaller than the
nanoparticles diameter, the particles are prevented
from being embedded inside the polymer superstructure.
The maghemite nanoparticles appear on the supported
diblock copolymer nanostructures. Above a critical
concentration cluster formation out of nanoparticles
is present in coexistence with isolated nanoparticles
and dominates structure creation. [3]
Long-range interface correlations are investigated
in nanocomposite films comprising diblock copolymer
matrix and magnetic nanoparticles fillers. The
roughness of the substrate is replicated on thick
composite film surfaces resulting in roughness
correlation in a wave-guide manner. No roughness
correlation is observed in thin films. [4]
The resulting structures as well as the magnetic
properties are investigated within this project.
The structural characterisation is based on real
space techniques such as atomic force microscopy
or transmission electron microscopy as well as
on scattering techniques using neutrons (FRM-II,
ILL) and synchrotron radiation (ESRF, HASYLAB).
- V.Lauter-Pasyuk, H.Lauter, G.Gordeev, P.Müller-Buschbaum,
B.P.Toperverg, W.Petry, M.Jernenkov, A.Petrenko,
V.Aksenov (2004). Physica B 350, e939.
- J.Perlich, L.Schulz, M.M.Abul Kashem, Y.-J.Cheng,
M.Memesa, J.S.Gutmann, S.V.Roth, P.Müller-Buschbaum
(2007). Langmuir 23, 10299.
- M.M.Abul Kashem, J.Perlich, L.Schulz, S.V.Roth,
W.Petry, P.Müller-Buschbaum (2007). Macromolecules
40, 5075.
- M.M.Abul Kashem, J.Perlich, L.Schulz, S.V.Roth,
P.Müller-Buschbaum (2008). Macromolecules
41, 2186-2194.
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