聚合物纳米复合材料在介电和储能领域引起了广泛关注。然而,无机纳米粒子和聚合物之间的电学和化学性能不匹配导致界面不相容。在本研究中,将具有不同功能配体的膦酸分子引入BaTiO 3 (BT)纳米粒子的表面,以调节其表面性质并定制BT与聚(偏二氟乙烯-共-六氟丙烯)之间的主客体相互作用(P( VDF-HFP))。纳米复合材料的介电性能和电能存储能力分别通过宽带介电谱和电位移测量来记录。记录了配体长度和极性对纳米复合材料的介电性能和电能存储的影响。含有5 vol% 2,3,4,5,6-五氟苄基膦酸(PFBPA)修饰的BT的纳米复合材料在400 MV m -1时具有最高的能量密度12.8 J cm -3 ,即增强了187%比纯P(VDF-HFP)的电能储存能力。这种增强可归因于PFBPA的五氟苄基的强吸电子效应,它改变了聚合物-颗粒界面的电子性质。另一方面,PFBPA提高了纳米复合材料中主客体界面的兼容性,并减少了界面的电失配。这些结果为高性能介电纳米复合材料的设计和制备提供了新的见解。
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Tailoring the Electrical Energy Storage Capability of Dielectric Polymer Nanocomposites via Engineering of the Host–Guest Interface by Phosphonic Acids
Polymer nanocomposites have attracted broad attention in the area of dielectric and energy storage. However, the electrical and chemical performance mismatch between inorganic nanoparticles and polymer leads to interfacial incompatibility. In this study, phosphonic acid molecules with different functional ligands were introduced to the surface of BaTiO3 (BT) nanoparticles to tune their surface properties and tailor the host–guest interaction between BT and poly(vinylideneflyoride-co-hexafluroro propylene) (P(VDF-HFP)). The dielectric properties and electrical energy storage capability of the nanocomposites were recorded by broadband dielectric spectroscopy and electric displacement measurements, respectively. The influence of the ligand length and polarity on the dielectric properties and electrical energy storage of the nanocomposites was documented. The nanocomposite with 5 vol% 2,3,4,5,6-pentafluorobenzyl phosphonic acid (PFBPA)-modified BT had the highest energy density of 12.8 J cm−3 at 400 MV m−1, i.e., a 187% enhancement in the electrical energy storage capability over the pure P(VDF-HFP). This enhancement can be attributed to the strong electron-withdrawing effect of the pentafluorobenzyl group of PFBPA, which changed the electronic nature of the polymer–particle interface. On the other hand, PFBPA improves the compatibility of the host–guest interface in the nanocomposites and decreases the electrical mismatch of the interface. These results provide new insights into the design and preparation of high-performance dielectric nanocomposites.