TY  - JOUR
A1  - Fortes Martín, Rebeca
A1  - Prietzel, Claudia Christina
A1  - Koetz, Joachim
T1  - Template-mediated self-assembly of magnetite-gold nanoparticle superstructures at the water-oil interface of AOT reverse microemulsions
JF  - Journal of colloid and interface science
N2  - Hypothesis: Bimetallic magnetite-gold nanostructures are interesting candidates to combine and enhance individual properties of each metal element in catalytic and analytical applications. Microemulsions have been employed in templated synthesis of nanoparticles, and their combination with different types of nanoparticles can further mediate interactions at the water-oil interface, providing new forms of hybrid nanostructures. 

Experiments: Reverse water-in-oil microemulsions of droplet sizes below 50 nm were prepared from ternary mixtures of Aerosol-OT (AOT) as surfactant, incorporating 4 nm sized superparamagnetic nanoparticles (MNPs) to the hexane-pentanol oil phase and 5 nmsized polyethyleneimine-stabilized gold nanoparticles (Au(PEI)-NPs) to the water phase. The resulting isotropic L-2 phase, Winsor phases and organized nanostructures were investigated using conductometry, calorimetry, UV-Vis spectroscopy, cryoSEM and HRTEM. 

Findings: Droplet-droplet interactions, morphology and surfactant film properties of AOT microemulsions could be modulated in different ways by the presence of the different nanoparticles from each liquid phase. Additionally, phase separation into Winsor phases allows the formation upon solvent evaporation of films with bimetallic heterostructures on the micrometer scale. This demonstrates a new way of nanoparticle templated assembly at liquid interfaces by assisted interactions between microemulsions and nanoparticles, as a promising strategy to obtain thin films of small, isotropic nanoparticles with hierarchical ordering.
KW  - AOT
KW  - Magnetite-gold nanoparticles
KW  - Microemulsions
KW  - Percolation
KW  - Templated self-assembly
KW  - Winsor phases
Y1  - 2021
U6  - https://doi.org/10.1016/j.jcis.2020.07.079
SN  - 0021-9797
SN  - 1095-7103
VL  - 581
IS  - Part A
SP  - 44
EP  - 55
PB  - Elsevier
CY  - Amsterdam
ER  -