Cheng Wei, Jiao Wenling, Fei Yifan, Yang Zaihui, Zhang Xiaohua, Wu Fan, Liu Yitao, Yin Xia, Ding Bin
Engineering Research Center of Technical Textiles (Ministry of Education), Key Laboratory of Textile Science & Technology (Ministry of Education), College of Textiles and Innovation Center for Textile Science and Technology, Donghua University, Shanghai 201620, China.
Nanoscale. 2024 Jan 18;16(3):1135-1146. doi: 10.1039/d3nr04987f.
The design of three-dimensional ceramic nanofibrous materials with high-temperature insulation and flame-retardant characteristics is of significant interest due to the effectively improved mechanical properties. However, achieving a pure ceramic monolith with ultra-low density, high elasticity and toughness remains a great challenge. Herein, a low-cost, scalable strategy to fabricate ultralight and mechanically robust N-doped TiO ceramic nanofibrous sponges with a continuous stratified structure by conjugate electrospinning is reported. Remarkably, the introduction of dopamine into the precursor nanofibers is engineered, which realizes the nitrogen doping to inhibit the TiO grain growth, endowing single nanofibers with a smoother, less defective surface. Besides, the self-polymerization process of dopamine allows the construction of bonding points between nanofibers and optimizes the distribution of inorganic micelles on polymer templates. Moreover, a rotating disk receiving device under different rotating speeds is designed to obtain N-doped TiO sponges with various interlamellar spacings, further affecting the maximum compressive deformation capacity. The resulting ceramic sponges, consisting of fluffy crosslinked nanofiber layers, possess low densities of 12-45 mg cm, which can quickly recover under a large strain of 80% and have only 9.2% plastic deformation after 100 compression cycles. In addition, the sponge also exhibits a temperature-invariant superelasticity at 25-800 °C and a low heat conductivity of 0.0285 W m K, with an outstanding thermal insulation property, making it an ideal insulation material for high-temperature or harsh conditions.
由于机械性能得到有效改善,具有高温隔热和阻燃特性的三维陶瓷纳米纤维材料的设计备受关注。然而,制备具有超低密度、高弹性和韧性的纯陶瓷整体材料仍然是一个巨大的挑战。在此,报道了一种低成本、可扩展的策略,通过共轭静电纺丝制备具有连续分层结构的超轻且机械坚固的氮掺杂二氧化钛(N-doped TiO)陶瓷纳米纤维海绵。值得注意的是,将多巴胺引入前驱体纳米纤维中进行设计,实现了氮掺杂以抑制TiO晶粒生长,使单根纳米纤维表面更光滑、缺陷更少。此外,多巴胺的自聚合过程使得纳米纤维之间能够形成结合点,并优化了无机胶束在聚合物模板上的分布。而且,设计了不同转速下的旋转盘接收装置,以获得具有不同层间距的氮掺杂TiO海绵,进而影响其最大压缩变形能力。所得的陶瓷海绵由蓬松的交联纳米纤维层组成,密度低至12 - 45 mg/cm³,在80%的大应变下能快速恢复,经过100次压缩循环后塑性变形仅为9.2%。此外,该海绵在25 - 800 °C范围内还表现出温度不变的超弹性,热导率低至0.0285 W/(m·K),具有出色的隔热性能,使其成为高温或恶劣条件下的理想隔热材料。