Gao Liang, Wang Linping, Hu Ben-Lin
Research Center for Advanced Interdisciplinary Sciences, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo 315201 China
College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences Beijing 100049 China.
Chem Sci. 2024 Aug 28;15(37):15432-9. doi: 10.1039/d4sc04641b.
Relaxor ferroelectrics are well-known for their high dielectric constants, low dielectric losses, and excellent electromechanical properties, making them valuable for various electronic devices. Despite recent efforts to enhance the durability of ferroelectrics through chemical cross-linking, achieving elasticity in relaxor ferroelectric materials remains a significant challenge. These materials inherently possess traits such as low crystallinity and small crystal size, while chemical crosslinking tends to diminish polymer crystallinity considerably. Thus, a key obstacle to making relaxor ferroelectric polymers elastic lies in safeguarding their crystalline regions from the effects of slight crosslinking. To tackle this issue, we selected P(VDF-CTFE-DB) with highly reactive C[double bond, length as m-dash]C double bonds as crosslinking sites, reducing the amount of cross-linking agents added and thereby lessening their impact on crystallinity. Through peroxide crosslinking, we transformed linear P(VDF-CTFE-DB) into a network structure, successfully producing a resilient relaxor ferroelectric material with maintained polarization intensity for ferroelectricity. Notably, this elastic relaxor ferroelectric was synthesized at relatively low temperatures, exhibiting a remarkable dielectric constant, superior resilience, fatigue resistance, and a stable ferroelectric response even under strains of up to 80%. Our approach paves the way for developing low-cost, high-dielectric-constant elastomers suitable for wearable electronics and related applications.
弛豫铁电体以其高介电常数、低介电损耗和优异的机电性能而闻名,这使其在各种电子设备中具有重要价值。尽管最近通过化学交联来提高铁电体耐久性的努力不断,但在弛豫铁电材料中实现弹性仍然是一项重大挑战。这些材料本身具有低结晶度和小晶体尺寸等特性,而化学交联往往会显著降低聚合物的结晶度。因此,使弛豫铁电聚合物具有弹性的一个关键障碍在于保护其结晶区域免受轻微交联的影响。为了解决这个问题,我们选择了具有高反应性C=C双键作为交联位点的P(VDF-CTFE-DB),减少交联剂的添加量,从而降低其对结晶度的影响。通过过氧化物交联,我们将线性P(VDF-CTFE-DB)转变为网络结构,成功制备出一种具有弹性的弛豫铁电材料,其铁电极化强度得以保持。值得注意的是,这种弹性弛豫铁电体是在相对较低的温度下合成的,表现出显著的介电常数、优异的弹性、抗疲劳性,甚至在高达80%的应变下仍具有稳定的铁电响应。我们的方法为开发适用于可穿戴电子设备及相关应用的低成本、高介电常数弹性体铺平了道路。