Abstract

In this work, nanocomposites consisting of TiO₂-nanorods (TiO₂-NRs) with less than 100 nm in size and poly(vinylidene fluoride) (PVDF) were prepared using a liquid-phase assisted dispersion and hot-pressing methods. At 1 kHz and 25 °C, the high dielectric permittivity of ∼66 and loss tangent of ∼0.03 can be obtained in the nanocomposite with a filler volume fraction of 0.5, which was higher than that of a neat PVDF matrix by a factor of 6. Dielectric permittivity of TiO₂-NRs/PVDF nanocomposites not only highly increased with TiO₂-NRs, but also almost independent of the frequency range of 10²–10⁶ Hz. The significant enhancement in dielectric permittivity is mainly attributed to the interfacial polarization at the interfaces of TiO₂-NRs and PVDF, and semiconducting properties of TiO₂-NRs. Among the various models used for rationalizing the dielectric behavior, the experimental dielectric data is in close agreement with EMT (n = 0.11) and Yamada models (n = 8).

摘要

在这项工作中，使用液相辅助分散和热压方法制备了由尺寸小于 100 nm的 TiO _{2 -}纳米棒 (TiO ₂ -NRs) 和聚偏二氟乙烯 (PVDF)组成的纳米复合材料。在 1 kHz 和 25 °C 下，填充体积分数为 0.5 的纳米复合材料可以获得~66 的高介电常数和~0.03 的损耗角正切，比纯 PVDF 基质高 6 倍. TiO ₂ -NRs/PVDF 纳米复合材料的介电常数不仅随 TiO ₂ -NRs显着增加，而且几乎与 10 ² –10 ⁶的频率范围无关 赫兹。在介电常数的显著增强主要归因于界面极化在TiO 2的接口₂ -NRS和PVDF，和半导体的TiO属性₂ -NRS。在用于合理化介电行为的各种模型中，实验介电数据与 EMT ( n  = 0.11) 和 Yamada 模型 ( n  = 8)非常吻合。