This work offers a strategy for combining ceramic and conductive fillers to produce composites with high dielectric properties and breakdown strength through a novel [email protected] structure. First, we successfully attached barium titanate (BT) nanoparticles to the surface of multi-walled carbon nanotubes (MWCNTs) by sol-gel method. Hyperbranched aromatic polyamide (HB-Pa) was grafted from the surface of BT-attached MWCNTs via in suit polymerization to obtain HB-Pa/BT composite-coated MWCNTs ([email protected]). After the hybrid powders were compounded with epoxy resin (EP), composites with high dielectric properties were prepared. The [email protected]/EP composite exhibited a dielectric constant of 110, a dielectric loss of 0.28 (1 kHz) and a breakdown strength of 6.7 kV/mm at 20 wt % MWCNTs content. The results indicated that we could tailor the dielectric properties of composites by adjusting the amount of BT nanoparticles on the surface of MWCNTs. In addition, HB-Pa played multiple roles in this system: (i) preventing BT nanoparticles from falling off the surface of MWCNTs; (ii) increasing the dispersibility and interaction of fillers in the polymer matrix; (iii) preventing MWCNTs from overlapping one another to form a conductive network to effectively improve the breakdown strength of composites.

这项工作提供了一种将陶瓷和导电填料结合起来以通过新颖的[电子邮件保护]结构生产具有高介电性能和击穿强度的复合材料的策略。首先，我们通过溶胶-凝胶法成功地将钛酸钡（BT）纳米粒子附着到了多壁碳纳米管（MWCNT）的表面。通过适当的聚合，从附有BT的MWCNT的表面接枝了超支化芳族聚酰胺（HB-Pa），以获得HB-Pa / BT复合涂层的MWCNT（[电子邮件保护]）。将杂化粉末与环氧树脂（EP）混合后，可制得具有高介电性能的复合材料。[受电子邮件保护] / EP复合材料在20 wt％MWCNTs含量下的介电常数为110，介电损耗为0.28（1 kHz），击穿强度为6.7 kV / mm。结果表明，我们可以通过调节MWCNTs表面上BT纳米颗粒的数量来调整复合材料的介电性能。此外，HB-Pa在该系统中起着多种作用：（i）防止BT纳米颗粒从MWCNTs的表面掉落；（ii）增加填料在聚合物基质中的分散性和相互作用；（iii）防止多壁碳纳米管彼此重叠以形成导电网络，以有效提高复合材料的击穿强度。