Abstract:
Ti-series oxide ceramics in the form of aerogels, such as TiO2, SrTiO3, BaTiO3, and CaCu3Ti4O12, hold tremendous potential as functional materials owing to their excellent optical, dielectric, and catalytic properties. Unfortunately, these inorganic aerogels are usually brittle and prone to pulverization owing to weak inter-particulate interactions, resulting in restricted application performance and serious health risks. Herein, a novel strategy is reported to synthesize an elastic form of an aerogel-like, highly porous structure, in which activity-switchable Ti-series oxide sols transform from the metastable state to the active state during electrospinning, resulting in condensation and solidification at the whipping stage to obtain curled nanofibers. These curled nanofibers are further entangled when flying in the air to form a physically interlocked, elastic network mimicking the microstructure of high-elasticity hydrogels. This strategy provides a library of Ti-series oxide nanofiber sponges with unprecedented stretchability, compressibility, and bendability, possessing extensive opportunities for greener, safer, and broader applications as integrated or wearable functional devices. As a proof-of-concept demonstration, a new, elastic form of TiO2, composed of both \"white\" and \"black\" TiO2 nanofiber sponges, is constructed as spontaneous air-conditioning textiles in smart clothing, buildings, and vehicles, with unique bidirectional regulation of radiative cooling in summer and solar heating in winter.
摘要:
气凝胶形式的Ti系列氧化物陶瓷,如TiO2,SrTiO3,BaTiO3和CaCu3Ti4O12,由于其优异的光学性能,作为功能材料具有巨大的潜力,电介质,和催化性能。不幸的是,这些无机气凝胶通常是脆性的,并且由于弱的颗粒间相互作用而易于粉碎,导致应用程序性能受限和严重的健康风险。在这里,我们报告了一种合成弹性形式的气凝胶的新策略,高度多孔的结构,其中活性可切换的Ti系列氧化物溶胶在静电纺丝过程中从亚稳态转变为活性状态,导致在搅打阶段冷凝和固化,以获得卷曲的纳米纤维。这些卷曲的纳米纤维在空气中飞行时进一步缠结,形成物理互锁,弹性网络模拟高弹性水凝胶的微观结构。该策略提供了具有前所未有的拉伸性的Ti系列氧化物纳米纤维海绵库,可压缩性,和可弯曲性,拥有更环保的广泛机会,更安全,以及作为集成或可穿戴功能设备的更广泛的应用。作为概念验证演示,一个新的,弹性形式的TiO2,由“白色”和“黑色”TiO2纳米纤维海绵组成,被构造为智能服装中的自发空调纺织品,建筑物,和车辆,具有独特的夏季辐射冷却和冬季太阳能加热的双向调节。本文受版权保护。保留所有权利。