Enhanced electrocaloric strength in P(VDF-TrFE-CFE) by decreasing the crystalline size
Enhanced electrocaloric strength in P(VDF-TrFE-CFE) by decreasing the crystalline size
复制标题
通过减小晶体尺寸增强 P(VDF-TrFE-CFE) 的电热强度
DOI：
10.1016/j.jmat.2019.04.001
复制
发表时间：
2019-09-01
影响因子：
9.4
通讯作者：
Shen, Yang
中科院分区：
文献类型：
--
作者：
Qian, Jianfeng;Jiang, Jianyong;Shen, Yang
通过在外加电场（E）下调制偶极熵，可以在介电材料中实现可逆的温度变化（Δ T），这被称为电热（EC）效应。在所有的电致变色材料中，铁电体LiFeP（VDF-TrFE-CFE）由于其大的电致变色效应和优良的上级热稳定性而被认为是最有前途的电致变色材料之一。然而，低EC强度限制了三元共聚物在实际冷却装置中的应用。本工作采用淬火和低温退火的热处理方法，制备了结晶尺寸明显减小的三元共聚物，并研究了它们的电致变色性能。与普通共聚物相比，具有较小结晶尺寸的三元共聚物表现出显著增强的EC强度。较好的EC性能可能主要归因于偶极子取向的较低能量势垒，这在低电场下引起较高的极化。这项工作强调了EC聚合物的宏观性能的结晶尺寸的关键作用。(C)2019中国陶瓷学会由爱思唯尔公司制作和主持
Through the modulation of the dipolar entropy under an applied electric field (E), a reversible temperature change (Delta T) could be achieved in a dielectric material, which is known as the electrocaloric (EC) effect. Among all EC materials, ferroelectric terpolymer P(VDF-TrFE-CFE) has been regarded as one of the most promising EC materials owing to its large EC effect and superior thermal stability. Yet, the low EC strength limits the application of terpolymers in realistic cooling devices. In this work, using the thermal treatment of quenching and low-temperature annealing, the terpolymers with significantly decreased crystalline size are prepared with their EC performances investigated. Compared to the normal ones, the terpolymers with smaller crystalline size exhibit substantially enhanced EC strength. The better EC performance may be mainly attributed to the lower energy barriers for dipole orientation, which gives rise to higher polarization at low electric fields. This work emphasizes the critical role of crystalline size on the macroscopic properties of EC polymers. (C) 2019 The Chinese Ceramic Society. Production and hosting by Elsevier B.V.