Stretchable electrothermochromic fibers based on hierarchical porous structures with electrically conductive dual-pathways

Abstract

Stretchable color-changing fibers are urgently demanded for smart textiles/clothing due to their perfect implantability, permeability of vapor and heat, and flexibility/ stretchability. Herein, stretchable electrothermochromic fibers were fabricated with unconventional stretchable conductive fibers as core layers and thermochromic coatings as shell layers. In the stretchable conductive fibers, hierarchical porous structures with percolative one-dimensional (1D) conductive networks were constructed through phase inversion of carbon nanotube/polyurethane (CNT/PU) solutions. With the deposition of silver nanoparticles (AgNPs) on the surface of micro-pores, electrically conductive dual-pathways consisting of 0D AgNPs and 1D CNTs were formed to significantly enhance the electric conductivity and thus improve the electrothermal performance of the fibers. More importantly, because of the connective CNTs and AgNPs, such dual-pathways ensured the electron transport under the stretching state, preventing the sharp decay of conductivity and electrothermal performance. Through the continuous wet-spinning method, the stretchable conductive fibers can be easily obtained with the length up to several meters. At last, stretchable electrothermochromic fibers were prepared with two color-changing modes and implanted into textile perfectly, advancing their applications in wearable display and military adaptive camouflage of smart clothing.

摘要

可拉伸变色纤维具有良好的服装植入性、 透气透热性、 柔性和可拉伸性. 因此, 目前对于可拉伸变色纤维的研究受到广泛关注. 本文以导电纤维为芯层、 热致变色涂层为壳层, 制备了可拉伸电热致变色纤维. 通过相转换法, 在聚氨酯基体中构建了一维导电碳纳米管(CNTs)网络的分级多孔结构. 通过在微孔表面沉积银纳米颗粒(AgNPs), 使可拉伸导电纤维内形成AgNPs和CNTs的导电双路径, 从而有效提高了纤维的电导率和电热性能, 保证了电子的**常传输, 有效避免了纤维在拉伸状态下电导率的急剧衰减. 此外, 通过连续的湿法纺丝方法可制备长达几米的可拉伸导电纤维. 涂覆热致变色涂层后, 所制备的电热致变色纤维可完美地植入到织物中进行多种图案的编织, 并实现多种颜色变化, 在可穿戴显示、 自适应伪装等智能服装领域具有广阔的应用前景.