TY  - JOUR
A1  - Fortes Martín, Rebeca
A1  - Thünemann, Andreas F.
A1  - Stockmann, Jörg M.
A1  - Radnik, Jörg
A1  - Koetz, Joachim
T1  - From nanoparticle heteroclusters to filament networks by self-assembly at the water-oil interface of reverse microemulsions
JF  - Langmuir : the ACS journal of surfaces and colloids / American Chemical Society
N2  - Surface self-assembly of spherical nanoparticles of sizes below 10 nm into hierarchical heterostructures is under arising development despite the inherent difficulties of obtaining complex ordering patterns on a larger scale. Due to template-mediated interactions between oil-dispersible superparamagnetic nanoparticles (MNPs) and polyethylenimine- stabilized gold nanoparticles (Au(PEI)NPs) at the water-oil interface of microemulsions, complex nanostructured films can be formed. Characterization of the reverse microemulsion phase by UV-vis absorption revealed the formation of heteroclusters from Winsor type II phases (WPII) using Aerosol-OT (AOT) as the surfactant. SAXS measurements verify the mechanism of initial nanoparticle clustering in defined dimensions. XPS suggested an influence of AOT at the MNP surface. Further, cryo-SEM and TEM visualization demonstrated the elongation of the reverse microemulsions into cylindrical, wormlike structures, which subsequently build up larger nanoparticle superstructure arrangements. Such WPII phases are thus proven to be a new form of soft template, mediating the self-assembly of different nanoparticles in hierarchical network-like filaments over a substrate during solvent evaporation.
KW  - Emulsions
KW  - Liquids
KW  - Nanoparticles
KW  - Water
KW  - X-ray scattering
Y1  - 2021
U6  - https://doi.org/10.1021/acs.langmuir.1c01348
SN  - 0743-7463
VL  - 37
IS  - 29
SP  - 8876
EP  - 8885
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Kunnus, Kristjan
A1  - Schreck, Simon
A1  - Föhlisch, Alexander
T1  - Free-electron laser based resonant inelastic X-ray scattering on molecules and liquids
JF  - Journal of electron spectroscopy and related phenomena : the international journal on theoretical and experimental aspects of electron spectroscopy
N2  - The unprecedented beam properties of free-electron laser based X-ray sources enable novel resonant inelastic X-ray scattering (RIXS) experiments. Femtosecond time-resolved RIXS can be used to follow charge, spin and structural dynamics of dilute solute molecules in solution. Ultrashort X-ray pulses allow probing of highly radiation sensitive states of matter such as the metastable phase of supercooled liquid water. Nonlinear X-ray probes like amplified spontaneous emission and stimulated resonant X-ray scattering provide an enhanced selectivity and sensitivity as well as a path to control radiation damage and increase the photon yields in RIXS experiments. (C) 2015 Elsevier B.V. All rights reserved.
KW  - Free-electron laser
KW  - RIXS
KW  - Pump-probe
KW  - Nonlinear X-ray spectroscopy
KW  - Molecules
KW  - Liquids
Y1  - 2015
U6  - https://doi.org/10.1016/j.elspec.2015.08.012
SN  - 0368-2048
SN  - 1873-2526
VL  - 204
SP  - 345
EP  - 355
PB  - Elsevier
CY  - Amsterdam
ER  -