Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering , Southwest Jiaotong University , Chengdu 610031 , P. R. China.
ACS Appl Mater Interfaces. 2019 Mar 27;11(12):12142-12153. doi: 10.1021/acsami.9b01122. Epub 2019 Mar 14.
Making full use of the interface modulation-induced interface polarization is an effective strategy to achieve excellent microwave absorption (MA). In this study, we develop an interfacial modulation strategy for achieving this goal in the commonly reported dielectric carbon nanotubes@polyaniline (CNTs@PANi) hybrid microwave absorber by optimizing the CNT nanocore structure. The heterogeneous interfaces from PANi and CNTs can be well regulated by longitudinal unzipping of the walls of CNTs to form 1D CNT- and 3D CNT-bridged graphene nanoribbons and 2D graphene nanoribbons. By controlling the oxidation peeling degree of CNTs, their interface area and defects are enhanced, thus producing more polarization centers to generate interfacial polarization and polarization relaxation, and also introducing more PANi loadings. Furthermore, more interface contact area can be produced between CNTs and PANi. This could induce a strong dielectric resonant and further improve the impedance matching, leading to significant enhancement of MA performance. With filler loading of only 10 wt % and a thinner coating thickness of 2.4 mm, the optimized CNTs@PANi exhibits excellent MA performance with the minimum reflection loss (RL) value of -45.7 dB at 12.0 GHz and the effective bandwidth is from 10.2 to 14.8 GHz. Meanwhile, the broadest effective bandwidth reaches 5.6 GHz, covering the range of 12.4-18.0 GHz with a thin thickness of 2.0 mm and its RL reaches -29.0 dB at 14.6 GHz. It is believed that the proposed interfacial modulation strategy can provide new opportunities for designing efficient MA absorbers.
充分利用界面调制诱导的界面极化是实现优异微波吸收（MA）的有效策略。在这项研究中，我们通过优化 CNT 纳米核结构，开发了一种界面调制策略，以在常见报道的介电碳纳米管@聚苯胺（CNTs@PANi）混合微波吸收剂中实现这一目标。通过 CNT 壁的纵向解理，可以很好地调节 PANi 和 CNT 之间的异质界面，形成 1D CNT 和 3D CNT 桥连的石墨烯纳米带和 2D 石墨烯纳米带。通过控制 CNT 的氧化剥落程度，可以增强其界面面积和缺陷，从而产生更多的极化中心，产生界面极化和极化松弛，并引入更多的 PANi 负载。此外，还可以在 CNTs 和 PANi 之间产生更多的界面接触面积。这可以产生强烈的介电共振，并进一步改善阻抗匹配，从而显著提高 MA 性能。在仅填充 10wt%的填料和 2.4mm 更薄的涂层厚度下，优化后的 CNTs@PANi 表现出优异的 MA 性能，在 12.0GHz 时最小反射损耗（RL）值为-45.7dB，有效带宽为 10.2-14.8GHz。同时，最宽的有效带宽达到 5.6GHz，覆盖范围为 12.4-18.0GHz，厚度为 2.0mm，RL 为-29.0dB，在 14.6GHz。可以相信，所提出的界面调制策略为设计高效 MA 吸收剂提供了新的机会。
