| 초록 |
In the past few years, the demand for flexible materials such as foldable phones and wearable devices has increased. At the same time, the development of a power supply with flexibility is in progress. Dielectric capacitor, which is a kind of power supply, is used in systems that require high power for a short period of time. PVDF base polymer has ferroelectricity and flexibility, but it is used as a composite material because of its low energy storage properties. In this study, P(VDF-HFP)(co-polymer) and P(VDF-TrFE-CFE)(ter-polymer) was synthesized with ratio of 1:9, used as a matrix to improve ferroelectric properties, and 5,10,20,30,40 wt% of BNTSBT(6Bi0.5Na0.5TiO3-4Sr0.7Bi0.2TiO3) ceramic filler was added to improve energy storage properties and thermal stability. To improve the compatibility between the polymer and the ceramic, BNTSBT was coated with PDA and AuNPs, formed by UV irradiation reduction method (PVDF@PDA@BNTSBT). AuNPs formed with a thickness of 2-3 nm could have the effect of increasing EDBS and improving energy storage properties by interfering with electron migration (Coulomb-blockade effect). In addition, it was possible to increase the heat transfer efficiency due to AuNPs, which can be transferred without scattering by activating the low frequency phonon (LFP) between carbon atoms. By fabricating the PVDF@BNTSBT@AuNPs composites, enhanced energy storage properties and thermal stabilities were obtained. |
