Enhanced Dielectric and Hydrophobic Properties of Poly(vinylidene fluoride-trifluoroethylene)/TiO2 Nanowire Arrays Composite Film Surface Modified by Electrospinning

Abstract

In this research, we designed a feasible method to prepare composite films with high permittivity and significantly enhanced hydrophobic performance, which showed huge potential in the electrowetting field. TiO2 nanowire arrays were prepared by a one-step hydrothermal process, and poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) was spin-coated on the nanowire arrays to form composite, the surface of which was modified by electrospinning. Due to the great orientation of TiO2 nanowires, dipoles and space charges are in ordered arrangement along the electric field, and this strongly reinforced the Maxwell–Wagner–Sillars (MWS) polarization, thus the permittivity of the composite (TiO2 nanowire length/film thickness is 0.769) reaches 53 at 1 kHz, which is nearly 3 times higher than pure P(VDF-TrFE). Meanwhile the composite film possesses low dielectric loss (0.07) and low conductivity (2.69 × 10−9 S/cm), showing good insulation. The contact angle of the composite after electrospinning (about 137°) was greatly enhanced from pure P(VDF-TrFE) spin-coated film (about 89°), which can be attributed to the microrough structure built by P(VDF-TrFE) nanofibers.

Advantages and limitations of active phase silanization in PVDF composites: Focus on electrical properties and energy harvesting potential

“…Additionally, the type of PVDF polymorph formed in the flexible film is considered an important factor that can influence the dielectric properties, especially dielectric losses, of the films 36,40,47,48 . A high dipole arrangement is expected in the films in which polar PVDF phases were formed.…”

“…Additionally, the type of PVDF polymorph formed in the flexible film is considered an important factor that can influence the dielectric properties, especially dielectric losses, of the films. 36,40,47,48 A high dipole arrangement is expected in the films in which polar PVDF phases were formed. In the samples modified by APTES, more polar β-phase was formed while in DDTES ones mostly γ-phase exists (which is also polar, but with a lower dipole moment than β-phase).…”

Progress in Microtopography Optimization of Polymers-Based Pressure/Strain Sensors

“…Via a more directional arrangement of P(VDF-TrFE) fibers, piezoelectric performance of 40 times higher than the sensitivity of PVDF-based film pressure sensors can be obtained [ 87 , 92 ].…”