柔性超常电磁介质构筑与宽频弱负介电性能调控

Metacomposites are usually fabricated by conventional methods and possess novel electromagnetic properties especially including negative permittivity behavior, which have great potential in the field of electronic devices, microwave absorption and sub-wavelength image, etc. In this proposal, the low-dimensional nanosized carbon materials are selected as functional fillers distributed in flexible membranous matrix to achieve flexible metacomposites with weakly negative permittivity in broad band. The effects of chemical composition, microstructure and processing parameters on weakly negative permittivity and frequency dispersion are attempted to reveal taking advantage of experiments, model fittings and electromagnetic simulation computations. The influence of elastic deformation on weakly negative permittivity will be further explored and clarified in detail. This proposal can effectively overcome the difficulties that the values of negative permittivity derived from metal or conductive polymers are too large with obvious frequency dispersion phenomenon. Meanwhile, it can provide theoretical support for flexible metacomposites and promote their practical applications in the field of flexible electronic devices and wearable equipment, etc.

利用复合材料工艺技术构筑而成的超常电磁介质，具有负介电常等诸多新奇的电磁特性，在电子器件、微波吸收和亚波长成像等领域具有广阔应用前景。本项目选用低维纳米碳材料作为导电功能相，分布在柔性薄膜基体中，构筑具有宽频弱负介电性能的柔性超常电磁介质。以实验研究为主，结合模型拟合和仿真计算等研究手段，建立材料化学组成、微观结构和制备工艺与弱负介电性能之间的内在联系，阐明负介电常数频散行为的产生机理和调控机制，探明柔性超常电磁介质的弹性形变对弱负介电性能的影响机制，进而实现对宽频弱负介电性能的优化设计。本项目的实施可以解决金属或导电高分子材料负介电常数的数值太大，且伴随着强烈频散现象的难题，同时为超常电磁介质在柔性电子器件和可穿戴设备等领域提供理论依据。

以负介电常数、负磁导率为主要性能特点的超常电磁介质，也称超材料，具有与常规材料迥异的奇特电磁性能，在电子器件、微波吸收和亚波长成像等领域具有重要的应用前景。如何获得数值和频率可调控的弱负介电性能，成为超常电磁介质研究与应用中亟待解决的关键科学问题。如果将超常电磁特性与柔性结构相结合，制备出一种具有可调控弱负介电性能的柔性超常电磁介质，将会在柔性电子器件和可穿戴设备等领域具有广阔应用前景。据此，本项目提出选用低维纳米碳材料作为功能相，将其表面改性后分布在高分子薄膜基体中，制备出具有宽频弱负介电性能的柔性超常电磁介质。通过对材料微观结构与化学组成的设计与剪裁对负介电常数频段和数值的调控，实现了具有宽频弱负介电性能的柔性超常电磁介质。通过对柔性超常电磁介质施加一定压力使其发生弹性形变，研究了弹性形变对柔性超常电磁介质弱负介电性能的影响规律。利用逾渗理论、自由电子气理论、等效电路等理论探究了弱负介电产生机理与调控机制，明确了柔性超常电磁介质中弹性形变对弱负介电性能的影响机制。本项目的顺利实施为柔性超常电磁介质的可控制备与宽频弱负介电性能调控提供了理论依据与技术支持，在柔性电子器件、可穿戴设备和传感等领域具有重要应用价值。以第一/通讯作者身份在Acta Materialia、Composites Science and Technology、Journal of Physical Chemistry C等期刊上发表SCI收录论文23篇，其中5篇论文入选ESI高被引论文(含2篇ESI热点论文)，1篇论文入选《Acta Materialia》期刊“2018年至今被引用次数最高的25篇论文”；以第一发明人，授权发明专利3项；在研期间，项目负责人入选第六届中国科协青年人才托举工程和上海市晨光计划人才激励计划。