Template-mediated self-assembly of magnetite-gold nanoparticle superstructures at the water-oil interface of AOT reverse microemulsions
- 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 AOTHypothesis: 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.…
Author details: | Rebeca Fortes MartínORCiD, Claudia Christina PrietzelGND, Joachim KoetzORCiDGND |
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DOI: | https://doi.org/10.1016/j.jcis.2020.07.079 |
ISSN: | 0021-9797 |
ISSN: | 1095-7103 |
Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/32771751 |
Title of parent work (English): | Journal of colloid and interface science |
Publisher: | Elsevier |
Place of publishing: | Amsterdam |
Publication type: | Article |
Language: | English |
Date of first publication: | 2021/07/20 |
Publication year: | 2021 |
Release date: | 2022/11/25 |
Tag: | AOT; Magnetite-gold nanoparticles; Microemulsions; Percolation; Templated self-assembly; Winsor phases |
Volume: | 581 |
Issue: | Part A |
Number of pages: | 12 |
First page: | 44 |
Last Page: | 55 |
Funding institution: | German Research FoundationGerman Research Foundation (DFG) [INST 336/64-1] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
Peer review: | Referiert |