Oriented polyvinylidene fluoride–trifluoroethylene (P(VDF–TrFE)) films by Langmuir–Blodgett deposition: a synchrotron X-ray diffraction study

Abstract

Langmuir-Blodgett films of polyvinylidene fluoride trifluoroethylene - P(VDF-TrFE)-copolymers possess substantially improved electrocaloric and pyroelectric properties, when compared with conventionally spin-cast films. In order to rationalize this, we prepared single-layered films of P(VDF-TrFE) (70 : 30) using both deposition techniques. Grazing incidence wide-angle X-ray scattering (GIWAXS), reveals that Langmuir-Blodgett deposited films have a higher concentration of the ferroelectric β-phase crystals, and that these films are highly oriented with respect to the substrate. Based on these observations, we suggest alternative means of deposition, which may substantially enhance the electrocaloric effect in P(VDF-TrFE) films. This development has significant implications for the potential use of P(VDF-TrFE) in solid-state refrigeration.

The tuning of crystallization behavior of ferroelectric poly(vinylidene fluoride‐co‐trifluoroethylene)

“…This can bring more charge due to the dipole shift 105 . Controlling the orientation of molecular chains parallel to the substrate direction can increase the out‐of‐plane polarizability, which is also an effective way to increase the pyroelectric properties 221 …”

Environmentally Friendly Printable Piezoelectric Inks and Their Application in the Development of All-Printed Touch Screens

“…Further, the glass transition temperature, T g , is around −26 °C and the melting temperature, T m , at 147 °C. 13−15 Several processing techniques have been used for the preparation of PVDF-TrFE films including solvent-casting, 16 electrospinning, 17 Langmuir−Blodgett, 18 spin-coating, 19 or screen-printing, 20 among others. Piezoelectric PVDF-TrFE has been used for several applications, such as medical ultrasound transducers, 21 energy harvesting, 22 MEMS resonators, 23 battery separator, 24 sensors and actuators, 25 and tissue engineering applications.…”