Selseleh-Zakerin Elnaz, Mirkhan Ali, Shafiee Mojtaba, Alihoseini Mohammadreza, Khani Mohammadreza, Shokri Babak, Tavassoli Seyed Hassan, Peymanfar Reza
Department of Chemical Engineering, Energy Institute of Higher Education, Saveh 39177-67746, Iran.
Department of Science, Iranian Society of Philosophers, Tehran 13187-76511, Iran.
Langmuir. 2024 Jun 11;40(23):12148-12158. doi: 10.1021/acs.langmuir.4c01046. Epub 2024 May 28.
During the past decade, ever-increasing electromagnetic pollution has excited a global concern. A sustainable resource, facile experimental scenario, fascinating reflection loss (RL), and broad efficient bandwidth are the substantial factors that intrigue researchers. This research led to the achievement of a brilliant microwave-absorbing material by treating pampas as biomass. The carbon-based microfibers attained by biowaste were treated by plasma under diverse environments to amplify their microwave-absorbing features. Moreover, a pyrolysis scenario was performed to compare the results. The reductive processes were performed by H plasma and carbonization. However, the CO plasma was performed to regulate the heteroatoms and defects. Interestingly, polystyrene (PS) was applied as a microwave-absorbing matrix. The aromatic rings existing in the absorbing medium establish electrostatic interactions, elevating interfacial polarization, and physical characteristics of PS augment the practical applications of the final product. The manipulated biomasses were characterized by Raman, X-ray diffraction, energy-dispersive spectroscopy, field emission scanning electron microscopy, and diffuse reflection spectroscopy analyses. Eventually, the microwave-absorbing features were estimated by a vector network analyzer. The plasma-treated pampas under H/Ar blended with PS gained a maximum RL of -90.65 dB at 8.79 GHz and an efficient bandwidth (RL ≤ -10 dB) of 4.24 GHz with a thickness of 3.20 mm; meanwhile, plasma treatment under CO led to a maximum RL of 97.99 dB at 14.92 GHz and an efficient bandwidth of 7.74 GHz with a 2.05 mm thickness. Particularly, the biomass plasmolyzed under Ar covered the entire X and K bands with a thickness of 2.10 mm. Notably, total shielding efficiencies of the treated bioinspired materials were up to ≈99%, desirable for practical applications.
在过去十年中，日益增加的电磁污染引发了全球关注。可持续资源、简便的实验方案、令人着迷的反射损耗（RL）以及宽广的有效带宽是吸引研究人员的重要因素。这项研究通过将蒲苇作为生物质进行处理，取得了一种出色的微波吸收材料。通过生物废料获得的碳基微纤维在不同环境下进行等离子体处理，以增强其微波吸收特性。此外，还进行了热解实验以比较结果。还原过程通过氢等离子体和碳化进行。然而，一氧化碳等离子体用于调节杂原子和缺陷。有趣的是，聚苯乙烯（PS）被用作微波吸收基体。吸收介质中存在的芳环建立了静电相互作用，提高了界面极化，并且PS的物理特性增强了最终产品的实际应用。对处理后的生物质进行了拉曼光谱、X射线衍射、能量色散光谱、场发射扫描电子显微镜和漫反射光谱分析。最终，通过矢量网络分析仪评估了微波吸收特性。在氢气/氩气混合气体中经等离子体处理并与PS混合的蒲苇，在8.79 GHz时获得了-90.65 dB的最大RL，在厚度为3.20 mm时有效带宽（RL≤-10 dB）为4.24 GHz；同时，一氧化碳等离子体处理在14.92 GHz时导致最大RL为97.99 dB，在厚度为2.05 mm时有效带宽为7.74 GHz。特别地，在氩气中进行等离子体水解的生物质在厚度为2.10 mm时覆盖了整个X和K波段。值得注意的是，处理后的仿生材料的总屏蔽效率高达约99%，适用于实际应用。
