All-organic room temperature thermally switchable dielectric system

Zhao

et al. 2023

Dielectric switching materials are prospective candidates for smart electronic/electrical applications, and high dielectric switching ratios are crucial for their practical applications. However, the substantial improvement of the dielectric switching ratio is limited by the available dielectric switching mechanisms, and obtaining high dielectric switching ratios is a major challenge. Here, an unparalleled dielectric switching effect is reported in a water‐in‐oil emulsion system, caused by dual polarization synergy below the dielectric transition temperature in concert with suppression of the electrode polarization above the dielectric transition temperature. The synergistic dielectric switching effect of interfacial polarization and electrode polarization endows the emulsion with unprecedentedly high dielectric switching ratios. The highest room temperature dielectric switching ratio of this emulsion system up to 2.86 × 106 at 20 Hz, is four orders of magnitude higher than the highest switching ratio reported so far. The unparalleled high dielectric switching ratio, reliable cycle stability, good frequency adaptability, and satisfactory scalability make the inorganic salt solution/octadecane emulsions potentially excellent candidates for high‐sensitivity room‐temperature smart switching or sensing devices.

Section: Dielectric-switching Effects Caused By Dual Polarization Syn...mentioning

confidence: 99%

Section: Dielectric-switching Effects Caused By Dual Polarization Syn...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Unparalleled Dielectric‐Switching Effects Caused by Dual Polarization Synergy

Zhao

et al. 2023

Ultra‐Tough Room‐Temperature Dielectric Switching Ionic Gels with Long‐Cycle Stability

et al. 2022

As a favorable candidate for the next‐generation smart electronic devices, thermo‐responsive dielectric materials are faced with two crucial challenges: insufficient mechanical toughness and lack of the combination of promising dielectric switching properties, desired mechanical properties, and long‐cycle stability. Herein, a new scalable strategy is proposed for designing thermo‐responsive dielectric switching materials that simultaneously integrate the individual features, such as promising dielectric switching properties, outstanding mechanical properties, and great cycle stability, into one gel, based on a new dual dielectric switching mechanism induced by interfacial structure evolution. The ionic gel can readily achieve a superb combination of distinct reversible dielectric bistability, a high dielectric switching ratio above 150, a ≈15 °C wide thermal hysteresis loop, and tunable room‐temperature dielectric transition behavior, impressive high ductility, desirable high mechanical strength, record‐high stability of at least 1000 cycles. Such an all‐in‐one design enhances the adaptability to multiple application scenarios, durability, and a lifetime of the dielectric switching gels. Together with the facile fabrication process and recyclable thermoplastic system, thereby contributing to cost and energy saving, this research provides a feasible and sustainable strategy for constructing highly desirable thermo‐responsive dielectric switching materials.

Relaxation‐Induced Significant Room‐Temperature Dielectric Pulsing Effects

et al. 2023

Thermo‐responsive dielectric materials are in urgent demand owing to the rapid development of smart electronic/electrical systems. Although different types and structures of thermally responsive dielectric materials have been continuously reported, their dielectric response behaviors all originate from thermodynamic phase transitions. Herein, it is demonstrated that structural relaxation in poly(vinylidene fluoride) (PVDF), a non‐thermodynamic phase transition, can induce a significant thermal dielectric pulse at room temperature. The dielectric pulse strength of up to 6.3 × 105 at 20 Hz, with a dielectric pulsing temperature of 24 °C, is achieved from polyethylene glycol (PEG)‐PVDF coaxial nanofibrous films (PVDF@PEG), fabricated via a continuous blow spinning method. Moreover, the films exhibit excellent flexibility, adjustable strength and toughness, switchable hydrophilicity/hydrophobicity, and effective thermal management capability. The relaxation‐induced dielectric pulsing effect, outstanding multifunctionality, and simple preparation combine to promote further scalability and prospects of PVDF@PEG. In particular, the work contributes to the discovery of the relaxation‐induced dielectric response mechanism, which provides a new strategy for the generation of thermo‐responsive dielectric materials.