TY  - JOUR
AU  - Yao, Yuan
AU  - Metwalli, Ezzeldin
AU  - Niedermeier, Martin A.
AU  - Opel, Matthias
AU  - Lin, Chen
AU  - Ning, Jing
AU  - Perlich, Jan
AU  - Roth, Stephan
AU  - Müller-Buschbaum, Peter
TI  - Nano- and Microstructures of Magnetic Field-Guided Maghemite Nanoparticles in Diblock Copolymer Films
JO  - ACS applied materials & interfaces
VL  - 6
IS  - 7
SN  - 1944-8252
CY  - Washington, DC
PB  - Soc.
M1  - PUBDB-2015-01005
SP  - 5244 - 5254
PY  - 2014
N1  - (c) American Chemical Society. Post referee full text in progress.
AB  - The control over the alignment of nanoparticles within a block copolymer matrix was investigated for different external magnetic fields with respect to producing well-aligned, highly oriented metal-oxide–polymer nanopatterns. Hybrid films were prepared by solution casting under a range of external magnetic fields. The nano- and microstructure of maghemite nanoparticles within poly(styrene-b-methyl methacrylate) diblock copolymer films as a function of the nanoparticle concentration was studied using optical microscopy, atomic force microscopy, scanning electron microscopy, and grazing incidence small-angle X-ray scattering. Because of a polystyrene (PS) coating, the nanoparticles are incorporated in the PS domains of the diblock copolymer morphology. At higher nanoparticle concentrations, nanoparticle aggregates perturb the block copolymer structure and accumulate at the films surface into wire-shaped stripes. These wire-shaped nanoparticle aggregates form mainly because of the competition between nanoparticle–polymer friction and magnetic dipolar interaction. The magnetic behavior of the hybrid films was probed at different temperatures for two orthogonal directions (with the line-shaped particle aggregates parallel and perpendicular to the magnetic field). The hybrid film systems show superparamagnetic behavior and remarkable shape anisotropy that render them interesting for magnetic applications.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000334572800081
C6  - pmid:24621173
DO  - DOI:10.1021/am500597t
UR  - https://bib-pubdb1.desy.de/record/206541
ER  -