Waste heterocyclic aramid fiber (HAF) retains the same or similar properties as the original fiber. It will be a waste of resources if these waste HAFs cannot be handled sensibly and efficiently. Based on the above background, in this paper, discarded HAFs are recycled for the preparation of heterocyclic aramid nanofiber aerogel membrane (HANFAM) at greatly reduced cost. The strategy started from the chemical exfoliation of discarded HAFs, which were converted into HANFAM through the bladed coating followed by the freeze-drying techniques. The prepared HANFAMs have tunable and ultra-low dielectric constants and low dielectric loss, with the dielectric constant range of 1.31–1.47 and the dielectric loss range of 0.0026–0.0073 at 1 MHz, which are much lower than other reported aerogel materials. Therefore, it can be used as an important substrate to secure high-speed circuit transmission in integrated electronic devices. In addition, the obtained HANFAMs exhibit a high initial thermal decomposition temperature of 514 °C and a low thermal conductivity of 28.87–40.73 mW/(m·K). This work provides a new perspective on the fabrication of HANFAMs with ultra-low dielectric and excellent thermal insulation based on upcycled waste HAFs.

中文翻译：

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基于升级回收废杂环芳纶纤维的具有超低介电常数和优异隔热性能的杂环芳纶纳米纤维气凝胶膜


废弃杂环芳纶纤维 （HAF） 保留与原始纤维相同或相似的性能。如果不能明智有效地处理这些废弃 HAF，那将是一种资源浪费。基于上述背景，本文以极低的成本回收废弃的 HAF 用于制备杂环芳纶纳米纤维气凝胶膜 （HANFAM）。该策略从废弃 HAF 的化学剥离开始，通过刀片涂层转化为 HANFAM，然后是冷冻干燥技术。制备的 HANFAM 具有可调谐和超低介电常数和低介电损耗，在 1 MHz 时的介电常数范围为 1.31-1.47，介电损耗范围为 0.0026-0.0073，远低于其他已报道的气凝胶材料。因此，它可以用作确保集成电子设备中高速电路传输的重要衬底。此外，所获得的 HANFAM 表现出 514 °C 的高初始热分解温度和 28.87–40.73 mW/（m·K） 的低热导率。这项工作为基于升级回收的废弃 HAF 制造具有超低介电和出色隔热性的 HANFAM 提供了新的视角。