Effect of the Two-Dimensional Magnetostrictive Fillers of CoFe2O4-Intercalated Graphene Oxide Sheets in 3-2 Type Poly(vinylidene fluoride)-Based Magnetoelectric Films

Abstract

In the last decade, magnetoelectric (ME) polymer films have been developed by including zero-dimensional or one-dimensional magnetostrictive fillers in a piezoelectric polymer matrix. Existing reports on ME polymer films reveal that the shape of the magnetostrictive fillers is a critical determinant of the polymeric phase conformation, strain transfer between the piezoelectric and magnetostrictive phases, and dipole alignment in the films. In this study, to investigate the effect of two-dimensional (2D) magnetostrictive fillers on piezoelectric, magnetic, and magnetoelectric responses, 3-2 type ME films were prepared using CoFe2O4-intercalated graphene oxide (CFO-i-GO) fillers and poly(vinylidene fluoride) (PVDF) polymers. The 2D fillers of CFO-i-GO were hydrothermally synthesized by CFO intercalation into the interlayers of GO sheets with different lateral sizes, which were controlled by ultrasonication treatment. It was found that the large-lateral-size GO (LGO), medium-lateral-size GO (MGO), and small-lateral-size GO (SGO) fillers in the PVDF-based ME films exhibited a lateral size effect on CFO intercalation, polymeric phase conformation, dipole alignment, and magnetoelectric responses. A maximum ME coefficient (αME) of 3.0 mV/cm∙Oe was achieved with a strong linearity (r2) of 0.9992 at an off-resonance frequency (f) of 1 kHz and applied direct current (dc) magnetic field (Hdc) of ± 1000 Oe. The 3-2 type polymer-based ME films with reliable ME responses have potential for use in high-feasibility ME devices for biomedical sensing applications.

Magnetoelectric Composites of P(VDF-TrFE)/Porous-Ni for Electrostatic Air Filters

“…Polar β-phase crystals in piezoelectric polymers are aligned along the direction of the applied electric field, which can lead to high piezoelectric outputs . In this procedure, a corona poling method was used for the effective polarization of thinly coated P­(VDF-TrFE) films on Ni foams. , The corona poling process was performed in a homemade corona poling system for 1 h at 120 °C under an applied DC voltage of 10 kV to obtain poled composites. The distance between the needle and the sample was 1 cm.…”

Current and future applications of PVDF-carbon nanomaterials in energy and sensing

“…An interesting study was published by Baek and Yang [307] who reported the application of CoFe2O4-intercalated GO as -2D magnetostriction (i.e. changing shape or dimension during magnetization) PVDF fillers.…”

High-Resolution Magnetoelectric Sensor and Low-Frequency Measurement Using Frequency Up-Conversion Technique

“…ME sensors, which are based on the magnetoelectric coupling effect, can timely transmit magnetic field signals as voltage, mediated by interfacial stress ( ) [ 3 , 22 , 23 , 24 , 25 ]. A good ME sensor should have a high ME coupling coefficient ( ); thus, large output voltage is available under a certain external magnetic field.…”