原子层沉积构筑磁性金属/介电型核壳纳米结构及其吸波性能研究

Magnetic metal based nanomaterials are research focus of the microwave absorbing materials due to their favorable electromagnetic characteristics. However, magnetic metal nanoparticles are easily oxidized, subjected to corrosion and generated eddy current effect from agglomeration, and thus affect their microwave absorption performance. Constructing magnetic metal/dielectric film core-shell structure can effectively isolate and insulate magnetic metal nanoparticles from agglomeration, oxidation and corrosion. Moreover, dielectric coatings can suppress the eddy current effect, improve impedance matching, and enhance absorption. However, it is difficult to make significant progress using traditional coating methods owing to the potential limitations in coating quality, thickness control and optional materials. The developing atomic layer deposition (ALD) technology has outstanding advantages in many aspects, such as thickness control, uniformity, and the design of core-shell nanostructure. In this research project ALD will be applied to prepare magnetic metal/dielectric film core-shell structure. The effect of coating material type and thickness on the microwave absorbing property of the composite materials will be investigated. The relationship and discipline between composite material structure and electromagnetic property will also be studied. The protective layers will be deposited by ALD to study their influence on the stability of magnetic metal nanoparticles. These investigations will lead to reasonable understandings, provide theoretical basis for the design of novel microwave absorbing materials with thin coatings, light weight, broad bandwidth and strong absorption, and promote this research to make important progress.

磁性金属基纳米材料凭借良好的电磁特性成为吸波材料领域的研究热点。但是，磁性纳米金属容易被氧化腐蚀，且常因团聚产生涡流效应，影响其微波吸收效果。构筑磁性金属/介电型核壳纳米结构能有效的保护、隔离和绝缘磁性纳米颗粒，从而抑制涡流效应，改善阻抗匹配，提高吸收性能。传统方法在包覆质量、厚度控制和可选材料种类等方面都有局限性，很难再取得突破性进展。新发展的原子层沉积（ALD）在厚度控制、均匀性、纳米核壳结构设计等诸多方面具有突出的优势。因此，本项目拟利用ALD方法控制制备磁性金属/介电型核壳纳米结构，研究壳层材料种类、包覆厚度等对复合材料吸波性能的影响，探明磁性金属/介电核壳纳米材料的结构与电磁性能、吸波性能之间的关系和规律。并利用ALD制备保护层，研究其对纳米磁性金属稳定性的影响。通过这些研究得到规律性认识，为设计薄、轻、宽、强的新型吸波材料提供理论支持，促进这一研究取得突破性进展。

磁性金属基纳米材料凭借良好的电磁特性成为吸波材料领域的研究热点。但是，磁性纳米金属容易被氧化腐蚀，且常因团聚产生涡流效应，影响其微波吸收效果。构筑磁性金属/介电型核壳纳米结构能有效的保护、隔离和绝缘磁性纳米颗粒，从而抑制涡流效应，改善阻抗匹配，提高吸收性能。在本项目资金支持下，项目的各项研究内容都顺利进行，并将课题的研究对象从磁性金属/介电型核壳吸波材料的研究，扩展到碳磁复合吸波材料，以及它们在能源存储、生物传感等领域的应用，取得了许多重要的成果。例如，基于优化阻抗匹配、电磁交叉极化、界面效应等原理，设计了Ni@CNT/G、TiO2@C、ZnO@C、ZnO@Fe3O4、ZnO@Fe3O4、CoFe/C等系列具有核壳结构的高性能吸波材料。利用ALD可控生长Al2O3作为诱导层，发展了一种新的Al系水滑石的可控制备方法，在吸波、能源、生物催化等领域有着潜在应用。利用H2O和O3双氧源策略，无需任何前处理，可实现碳材料表面高效的生长NiO、Co3O4等。利用分子层沉积技术制备聚酰亚胺，结合退火处理，可实现任意材料表面包覆超薄氮掺杂碳膜。在本项目资助下，在Chemical Engineering Journal、Chemical Communication、Dalton Transactions、Sensors and Actuators B：Chemistry、Journal of Colloid and Interface Science、Materials & Design、Electrochimica Acta等国际重要SCI期刊上发表论文20余篇，项目中开发的多种核壳结构复合材料在吸波、能源存储、生物传感领域有相当的应用前景，能为批量生产提供指导。