Using Annealing Treatment on Fabrication Ionic Liquid-Based PVDF Films

Abstract

In this study, a simple method to obtain pure β-phase directly from the melt process is proposed. A series of PVDF and ionic liquid (IL) was prepared by a solvent casting method with appropriate associated with the subsequent annealing treatment. IL plays a role of filler, which can create strong electrostatic interaction with PVDF matrix and directly induce β-phase crystallization on the PVDF during the melt. PVDF film sample is immersed in hot water for annealing treatment at different temperatures (25 °C to 70 °C). We found that annealing in high temperatures especially can not only increase more IL inserted into the amorphous region of polymer matrix to make more phase transformation, but also accelerate IL removal. Characteristics and performance of the PVDF films were investigated by use of FTIR, XRD, SEM, and AFM. Piezoelectric coefficient d33 as well as d31, degree of crystallinity, and sensitivity are measured in experiment to verify the performance of PVDF film.

Cross-Linked Porous Polymeric Coating without a Metal-Reflective Layer for Sub-Ambient Radiative Cooling

“…This large-scale roughness was directly read on the AFM with a root-mean-square (rms) value of 1.285 μm. 31 Recently, silver has been used as a solar reflector in most studies. However, silver is expensive, it oxidizes easily, and a high vacuum is required for its evaporation.…”

Recent Progress of Wearable Piezoelectric Nanogenerators

“…93 In addition, a simple method makes it possible to obtain a pure β-phase by preparing films of PVDF and ionic liquid using a solution casting method and subsequent annealing. 94 For an annealing temperature of 70 °C, the β-phase fraction could reach 92.4%, when the PVDF films were immersed in hot water. This implies that the ionic liquid can easily interact with PVDF chains.…”

“…Films of PVDF/barium titanate/cellulose nanocrystal composites (PVDF/BTO/CNC) were produced by Ram et al, who studied the effect of the mechanical properties of the films using BTO and CNC nanofillers . In addition, a simple method makes it possible to obtain a pure β-phase by preparing films of PVDF and ionic liquid using a solution casting method and subsequent annealing . For an annealing temperature of 70 °C, the β-phase fraction could reach 92.4%, when the PVDF films were immersed in hot water.…”

Leveraging Shape Memory Coupled Piezoelectric Properties in Melt Extruded Composite Filament Based on Polyvinylidene Fluoride and Polyurethane

“…One of the most popular adopted routes to increase β phase in PVDF is addition of fillers which brings about a transformation from (α) trans gauche conformation (TGTG / ) to (β) all trans conformation (TTTT) of PVDF. Different filler approaches like potassium sodium niobate (KNN), [ 6 ] lead zirconate titanate (PZT), [ 7 ] zinc oxide (ZnO), [ 8,9 ] Fe 3 O 4 ‐graphene oxide, [ 10 ] TiO 2 ‐Fe 3 O 4 ‐MWCNT (multi‐walled carbon nanotube), [ 11 ] calcium‐doped/cadmium‐doped ZnO, [ 12 ] calcium–aluminum‐layered double hydroxides, [ 13 ] silicon nanoparticles, [ 14 ] NaNbO 3 /RGO, [ 15 ] ionic liquids, [ 16 ] nickel–cobalt‐layered double hydroxides, [ 17 ] Li‐doped ZnO/MWCNT, [ 18 ] etc., were used to induce favorable piezoelectric phase in PVDF. It is also important to mention the growing interest to derive the best of the properties from immiscible polymeric blends, like polyurethane (PU) and PVDF.…”