Development of magnetoelectric CoFe2O4 /poly(vinylidene fluoride) microspheres

• Main Authors: Gonçalves, R, Martins, P, Correia, D. M, Sencadas, V, Vilas, J. L, León, L. M, Botelho, G, Lanceros-Méndez, S
• Format: Article
• Language: English
• ISSN: 2046-2069
• DOI: 10.1039/c5ra04409j

Magnetoelectric microspheres based on piezoelectric poly(vinylidene fluoride) (PVDF) and magnetostrictive CoFe 2 O 4 (CFO), a novel morphology for polymer-based ME materials, have been developed by an electrospray process. The CFO nanoparticle content in the (3-7 μm diameter) microspheres reaches values up to 27 wt%, despite their concentration in the starting solution reaching values up to 70 wt%. Additionally, the inclusion of magnetostrictive nanoparticles into the polymer spheres has no relevant effect on the piezoelectric β-phase content ( 60%), crystallinity (40%) and the onset degradation temperature (460-465 °C) of the polymer matrix. The multiferroic microspheres show a maximum piezoelectric response | d 33 | 30 pC N −1 , leading to a magnetoelectric response of Δ| d 33 | 5 pC N −1 obtained when a 220 mT DC magnetic field was applied. It is also shown that the interface between CFO nanoparticles and PVDF (from 0 to 55%) has a strong influence on the ME response of the microspheres. The simplicity and the scalability of the processing method suggest a large application potential of this novel magnetoelectric geometry in areas such as tissue engineering, sensors and actuators. Magnetoelectric microspheres based on piezoelectric poly(vinylidene fluoride) (PVDF) and magnetostrictive CoFe 2 O 4 (CFO), a novel morphology for polymer-based ME materials, have been developed by an electrospray process.