Improving ferro- and piezo- electric properties of hydrogenized poly(vinylidene fluoride-trifluoroethylene) films by annealing at elevated temperatures

Yan

ACS Appl. Electron. Mater.

et al. 2023

The rapid development of the clean energy industry has given great impetus to energy-efficient storage and conversion technologies. Film capacitors have attracted much attention because of their higher charge and release rates, greater energy density, and extended life cycle. But the lower recharging and discharging efficiency and insulation properties pertaining to the electricity used in capacitors limit the improvement of their energy storage performance. In this paper, the addition of the linear polymer polycarbonate (PC) to polyvinylidene fluoride (PVDF) through a blending strategy and the subsequent acquisition of the high-dielectric nanofiller titanium dioxide (TiO2) to the blended matrix is expected to achieve synergistic optimization of the insulation and polarization properties, thereby enhancing the energy storage performance of the mixed media. The findings show that great storage of energy productivity (U e ≈ 11.43 J/cm3, η ≈ 57.08%) is obtained for 40 vol % PC/PVDF-x wt %-TiO2 at an optimum field strength of 450 kV/mm when the TiO2 doping amount x is 0.9 wt %. Compared with pure PVDF, its U e is improved by 2.3 times, η by 1.2 times, and E b by 1.5 times. This research presents a viable answer for applying PVDF-based high-energy-storage film capacitors.

Section: Introductionmentioning

confidence: 99%

Enhanced Energy Storage Performance of Doped Modified PC/PVDF Coblended Flexible Composite Films

Yan

ACS Appl. Electron. Mater.

et al. 2023

“…After printing, the polymer requires thermal annealing to improve its ferroelectric, piezoelectric and dielectric properties [49]. Annealing modifies the polymer microstructure and needs to be performed at 10 • C-15 • C below its melting temperature of 122 • C [34,50].…”

Section: Annealing the Eap Layermentioning

confidence: 99%

Inkjet printing P(VDF-TrFE-CTFE) actuators for large bending strains

Sekar,

Hunt

2024

Smart Mater. Struct.

Additive manufacturing of sensors and actuators together with structural materials and electronics will make it possible to fabricate innovative system designs that are overly laborious to realise with conventional methods. While printing of the structural materials and electronics are advancing fast, the additive manufacturing methods for actuators and sensors are in an earlier stage of development. This research will develop a manufacturing process for entirely inkjet printed electroactive polymer (EAP) actuators basing on the P(VDF-TrFE-CTFE) relaxor ferroelectric polymer and Ag electrodes. The process consists of (1) printing an Ag layer on a PET substrate for the bottom electrode; (2) formulating, printing and annealing a P(VDF-TrFE-CTFE) ink for the EAP layer; and (3) printing and sintering an Ag layer on the plasma-treated EAP surface to form the top electrode. Two actuator variations, addressed as DMC and KM512, are manufactured and characterized by their: (a) response to quasi-static excitation (1 Hz sine wave); (b) hysteresis behaviour; (c) actuation amplitude variation with the input voltage; and (d) frequency response. The 18 mm long actuators showed 91.4 µm (DMC, 200 Vpp) and 224 µm (KM512, 275 Vpp) deflections in response to 1 Hz sinusoidal excitation, and 1.10 mm (DMC, 113 Hz, 200 Vpp) and 1.72 mm (KM512, 114 Hz, 200 Vpp) deflections in resonant operation. It is 55% more quasi-static strain and 470% more resonant strain than in earlier fully inkjet-printed PVDF-based actuators, and comparable to similar partially inkjet-printed actuators. This is the first time that inkjet printing of all three layers of a relaxor ferroelectric actuator have been achieved.

“…It could be attributed to the fact that while the crosslinking may reduce crystallinity, the concurrent click reaction could partially restore the VDF structure damaged during the introduction of double bonds. The XRD results (Figure S10) showed that, compared to the pristine P(VDF‐CTFE‐DB), the α‐phase of the crosslinked P(VDF‐CTFE‐DB) significantly decreases at 18.2° [12,32–34] …”

Section: Figurementioning

confidence: 99%

“…The XRD results (Figure S10) showed that, compared to the pristine P(VDF-CTFE-DB), the α-phase of the crosslinked P(VDF-CTFE-DB) significantly decreases at 18.2°. [12,[32][33][34] The pristine P(VDF-CTFE-DB) film exhibited a yielding point at a strain of 28 %, with a fracture elongation exceeding 2000 % (Figure 3A), indicating its plastic behavior. However, with an increase in the amount of crosslinker, the fracture elongation of the crosslinked P(VDF-CTFE-DB) film gradually decreased, and the stress-strain curve transitioned from plastic to elastic deformation.…”

mentioning

confidence: 99%

Elastic Relaxor Ferroelectric by Thiol‐ene Click Reaction

Li,

Wang,

Gao

et al. 2024

Angewandte Chemie

As ferroelectrics hold significance and application prospects in wearable devices, the elastification of ferroelectrics becomes more and more important. Nevertheless, achieving elastic ferroelectrics requires stringent synthesis conditions, while the elastification of relaxor ferroelectric materials remains unexplored, presenting an untapped potential for utilization in energy storage and actuation for wearable electronics. The thiol‐ene click reaction offers a mild and rapid reaction platform to prepare functional polymers. Therefore, we employed this approach to obtain an elastic relaxor ferroelectric by crosslinking an intramolecular carbon‐carbon double bonds (CF=CH) polymer matrix with multiple thiol groups via a thiol‐ene click reaction. The resulting elastic relaxor ferroelectric demonstrates pronounced relaxor‐type ferroelectric behaviour. This material exhibits low modulus, excellent resilience and fatigue resistance, maintaining a stable ferroelectric response even under strains of up to 70%. This study introduces a straightforward and efficient approach for the construction of elastic relaxor ferroelectrics, thereby expanding the application possibilities in wearable electronics.