基于超长弹性金属纳米线双导电网络结构的透明柔性导电材料

As one of the key components of next-generation electronics, flexible transparent electrodes (FTEs) have become the most attractive subject in materials science and engineering. However, it remains a significant challenge to realize the balance between transparency, flexibility and conductivity. To overcome the difficulty, a novel strategy is put forward to construct a double-conductive networks (DCNs) based on very-long elastic metal nanowires (VLEMNs) followed by incorporated with transparent elastic matrix to fabricate high-performance FTEs. In this project, electrospinning and chemical deposition are combined to prepare the VLEMNs-based DCNs. The elastic nanofibers consisted of ultrafine gold nanowires (AuNWs) and silver (Ag) nanoparticles serve as the first conductive network and the very-long siver nanowires (AgNWs) coated on elastic nanofibers serve as the second conductive network. The formation mechanism of VLEMNs-based DCNs with different microstructures will be investigated to provide evidence for the structural control of AuNWs-SBS-Ag/PDMS. The relation between structures and properties of the VLEMNs will be constructed and the deformation mechanism of the two conductive networks under the external strain will be specified. As a result, novel strategies to FTEs with high conductivity, flexilibility as well as transparency will be proposed for their applications in flexible displays and wearable electronics.

透明柔性导电材料作为新一代电子器件的重要组成部分，是研究的热点。如何实现透明、柔性和导电的均衡是至今未能解决的难题。为克服这一困难，本项目提出了构筑超长弹性金属纳米线双导电网络结构的新思路，并将其与透明的弹性基体结合，制备新型透明柔性电极。结合静电纺丝和化学沉积法制备超长弹性金属纳米线双导电网络结构，以含超细金纳米线（AuNWs）和银纳米颗粒（Ag）的复合弹性纳米纤维为第一导电网络，弹性纳米纤维表面沉积的银纳米线为第二导电网络；建立超长弹性金属纳米线微观结构的形成机理和控制原则；研究超长弹性金属纳米线结构与性能的关系，明确两个导电通路在外力作用下的形变机理，探索兼具导电率、柔韧性和透光率的透明柔性导电电极的制备新方法，为其在柔性显示器、可穿戴电子设备中的应用奠定基础。

本项目利用静电纺丝法和离子溅射制备超长弹性金属纳米线双导电网络，在超长大尺寸AuNW导电网络上旋涂小尺寸的AgNW导电网络，制备出了一种高可拉伸、高灵敏、高透光的应变传感器。低应变下，主要是AgNW网络的断裂提供灵敏性，高应变下，平行于拉伸方向AuNWs的断裂是电阻增加的主要原因，与此同时，垂直于拉伸方向的AuNWs仍能保持完整，两种网络的协同作用不仅赋予材料优异的光电性能（86%，25Ω/sq），而且实现了大应变范围内高的灵敏度（最大可拉伸90%，70%应变下灵敏度系数高达2370），为兼具导电率、柔韧性和透光率的透明柔性导电电极的制备提供了新的方法。在此基础上拓展，以超长弹性纳米纤维为骨架，引入新颖独特的微米或纳米结构，显著增强复合材料的形变能力和功能特性，获得了多种性能优异的可拉伸导电材料和柔性传感材料，在隐形可穿戴传感器、透明和可拉伸电极中有巨大的应用价值。