1. Stimuli-responsive assembly of iron oxide nanoparticles into magnetic flexible filaments
- Author
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Grein-Iankovski, Aline, Graillot, Alain, Loh, Watson, and Berret, Jean-Francois
- Subjects
Condensed Matter - Materials Science - Abstract
The combination of multiple functionalities in a single material is an appealing strategy for the de-velopment of smart materials with unique features. In this work, we present the preparation of thermoresponsive magnetic nanoparticles and their one-dimensional assembly into transient micro-filaments. The material is based on 9.4 nm iron oxide nanoparticles grafted with poly(N-n-propylacrylamide) via multiphosphonic acid anchoring sites. The hybrid nanoparticles present a low critical solution temperature (LCST) transition between 21 {\deg}C and 28 {\deg}C, depending on the pH and the ionic strength. When heated above the LCST in defined conditions, the nanoparticles ag-gregate and respond to an external magnetic field. An intrinsic characteristic of the thermorespon-sive particles is an asymmetric transition between cooling and heating cycles, that was favorably exploited to build one-dimensional permanent microstructures, such as magnetic microfilaments and cilia. In summary, we present the development of a nanoplatform responsive to multiple stimu-li, including temperature, magnetic field, pH and ionic strength and its transformation into magneti-cally active microfilaments that could find potential applications in remotely controlled devices., Comment: 18 pages, 8 figures
- Published
- 2021
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