Magnetically induced stress birefringence in stimuli-responsive hydrogels
We report the appearance of stress birefringence induced by an external magnetic field in stimuliresponsive hydrogels containing magnetic nanoparticles (Fe3O4). The measurement of the magnetooptical Faraday effect confirmed the superparamagnetic behaviour of those nanoparticles (NPs), its magnitude...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universidad de Castilla-La Mancha |
| Repositorio: | RUIdeRA. Repositorio Institucional de la UCLM |
| OAI Identifier: | oai:ruidera.uclm.es:10578/38264 |
| Acceso en línea: | https://doi.org/10.1039/D4TC04115A https://hdl.handle.net/10578/38264 |
| Access Level: | acceso abierto |
| Palabra clave: | Stress birefringence Stimuli-responsive hydrogels Magnetic nanoparticles Magnetic field Superparamagnetic behaviour |
| Sumario: | We report the appearance of stress birefringence induced by an external magnetic field in stimuliresponsive hydrogels containing magnetic nanoparticles (Fe3O4). The measurement of the magnetooptical Faraday effect confirmed the superparamagnetic behaviour of those nanoparticles (NPs), its magnitude depending on NPs concentration. The results obtained from both magneto-optical Faraday and Voigt effects showed the magnetic field to induce a stress birefringence in the non-rigid structure of the magnetic hydrogel. The additional ellipsometric characterization of the transmitted light allowed us to fully characterize its polarization state, revealing the magnetic field direction as the optic axis of that birefringent system. These results are discussed in the frame of a local rearrangement and stretching of polymeric chains parallel to the magnetic coupling direction of NPs. Such induced alignment would break the inherent optical isotropy of the hydrogel, providing an axis of anisotropy which is responsible for turning its disordered polymeric structure into a birefringent system. |
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