Shen Ying, Wang Lanlan, Liu Feng, Liu Huizhong, Li Dawei, Liu Qingsheng, Deng Bingyao
Key Laboratory of Eco-Textiles (Ministry of Education), Nonwoven Technology Laboratory, Jiangnan University, Wuxi 214122, China.
ACS Appl Mater Interfaces. 2020 Nov 25;12(47):53104-53114. doi: 10.1021/acsami.0c15751. Epub 2020 Nov 11.
Owing to the hierarchically three-dimensional (3D) network, ultralow density, and high porosity, nanofiber-based aerogels (NFAs) have drawn great attention recently. However, precise control of the porous structure and mechanical properties of NFAs, which have been proved to be extremely essential to the applications, still remains a major challenge. Herein, electrospun polyimide (PI) nanofibers were utilized as building blocks to construct NFAs through the solid-templating technique. The porous structure of PI nanofiber-based aerogels (PI-NFAs) could be adjusted by changing the processing parameters. By further welding the adjacent nanofibers at the contact sites with solvent vapor, high-resilience PI-NFAs were successfully prepared with comparable or higher recoverable, under compression, folding and torsion relative to other NFAs. The welded PI-NFAs showed ultralow density (minimum of 0.96 mg/cm), high porosity (maximum of 99.93%), and tunable hierarchical structure. Therefore, this study brought a new perspective on the simple preparation of high-resilience nanofiber-based aerogels with tunable porous structures.
由于具有分层三维（3D）网络、超低密度和高孔隙率，基于纳米纤维的气凝胶（NFA）最近受到了极大关注。然而，对NFA的多孔结构和机械性能进行精确控制，已被证明对其应用极为关键，但这仍然是一个重大挑战。在此，静电纺聚酰亚胺（PI）纳米纤维被用作构建单元，通过固体模板技术构建NFA。基于PI纳米纤维的气凝胶（PI-NFA）的多孔结构可以通过改变加工参数来调节。通过用溶剂蒸汽在接触位点进一步焊接相邻的纳米纤维，成功制备了具有高弹性的PI-NFA，其在压缩、折叠和扭转下的可恢复性与其他NFA相当或更高。焊接后的PI-NFA表现出超低密度（最低0.96 mg/cm）、高孔隙率（最高99.93%）和可调的分层结构。因此，本研究为简单制备具有可调多孔结构的高弹性纳米纤维基气凝胶带来了新的视角。
