Dual electric and magnetic responsivity of multilayered magnetite-embedded core/shell silica/titania nanoparticles with outermost silica shell†
Multilayered magnetite-embedded core/shell silica/titania (SiO2/TiO2) nanoparticles with an outermost silica shell (SiO2/TiO2@Fe3O4/SiO2) were synthesized and used to develop stimuli-responsive smart fluids. Benefiting from the incorporation of the various materials, these smart fluids demonstrated electrorheological (ER) and magnetorheological (MR) activities under applied external electric (E) and magnetic (H) fields, respectively, and electromagnetorheological (EMR) characteristics with the simultaneous application of E and H fields. The inner SiO2/TiO2 core nanoparticles, embedded Fe3O4 nanoparticles and the outer SiO2 shell served as electroresponsive, magnetoresponsive and preventative materials toward corrosion, sedimentation and aggregation. The EMR performance of these fluids depended on the direction of the applied E and H fields. Notably, a 6.6-fold enhancement in EMR activity was observed with parallel application of E and H fields compared to perpendicular direction. This study demonstrates an effective approach to precisely and spatially control the rheological/mechanical properties of dual-responsive smart fluids via both field-induced and directional control of external fields.
- This article is part of the themed collection: 2018 Journal of Materials Chemistry C HOT Papers