Abstract

Encapsulation of magnetic nanoparticles (MNPs) of iron (II, III) oxide (Fe3O4) with a thermopolymeric shell of a crosslinked poly(2-(2-methoxyethoxy)ethyl methacrylate) P(MEO2MA) is successfully developed. Magnetic aggregates of large size, around 150–200 nm are obtained during the functionalization of the iron oxide NPs with vinyl groups by using 3-butenoic acid in the presence of a water soluble azo-initiator and a surfactant, at 70 °C. These polymerizable groups provide a covalent attachment of the P(MEO2MA) shell on the surface of the MNPs while a crosslinked network is achieved by including tetraethylene glycol dimethacrylate in the precipitation polymerization synthesis. Temperature control is used to modulate the swelling-to-collapse transition volume until a maximum of around 21:1 ratio between the expanded: shrunk states (from 364 to 144 nm in diameter) between 9 and 49 °C. The hybrid Fe3O4@P(MEO2MA) microgel exhibits a lower critical solution temperature of 21.9 °C below the corresponding value for P(MEO2MA) (bulk, 26 °C). The MEO2MA coating performance in the hybrid microgel is characterized by dynamic light scattering and transmission electron microscopy. The content of preformed MNPs [up to 30.2 (wt%) vs. microgel] was established by thermogravimetric analysis while magnetic properties by vibrating sample magnetometry.

Details

Title
Synthesis of a thermoresponsive crosslinked MEO2MA polymer coating on microclusters of iron oxide nanoparticles
Author
Lapresta-Fernández, Alejandro 1 ; Salinas-Castillo, Alfonso 1 ; Capitán-Vallvey, Luis Fermín 1 

 University of Granada, ECsens Group, Department of Analytical Chemistry, Campus Fuentenueva, Granada, Spain (GRID:grid.4489.1) (ISNI:0000 0001 2167 8994); Unit of Excellence in Chemistry Applied To Biomedicine and the Environment of the University of Granada, Granada, Spain (GRID:grid.4489.1) (ISNI:0000 0001 2167 8994) 
Pages
3947
Publication year
2021
Publication date
2021
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
3041684720
Copyright
© The Author(s) 2021. corrected publication 2024. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.