Wang Zongqian, Yang Haiwei, Li Yu, Zheng Xianhong
School of Textile and Garment, Anhui Polytechnic University, Wuhu, 241000, P. R. China.
ACS Appl Mater Interfaces. 2020 Apr 1;12(13):15726-15736. doi: 10.1021/acsami.0c01330. Epub 2020 Mar 18.
Aerogel fibers with ultrahigh porosity and ultralow density are promising candidates for personal thermal management to reduce the energy waste of heating an entire room, and play important roles in reducing energy waste in general. However, aerogel fibers generally suffer from poor mechanical properties and complicated preparation processes. Herein, we demonstrate hierarchically porous and continuous silk fibroin/graphene oxide aerogel fibers (SF/GO) with high strength, excellent radiative heating performance, and thermal insulation performance through coaxial wet spinning and freeze-drying. The hollow CA/PAA fibers prepared via a coaxial wet spinning process have multiscale porous structures, which are not only beneficial for the formation of an SF/GO aerogel core, but also help to improve the mechanical strength of the aerogel fibers. Moreover, the prepared aerogel fibers show comparable porosity and mechanical properties with those of hollow CA/PAA fibers. More importantly, GO can dramatically improve the infrared radiative heating properties, and the surface temperature is increased by 2.6 °C after exposure to infrared radiation for 30 s, greatly higher than that of hollow fiber and SF aerogel fibers. Furthermore, the integration of hierarchically porous hollow fibers and SF/GO aerogels prevents thermal convection, decreases thermal conduction, and suppresses thermal radiation, rendering the SF/GO aerogel fiber with excellent thermal insulation performance. This work may shed light on the heat transfer mechanism of the microenvironment between the human body and textiles and pave the way for the fabrication of high-performance aerogel fibers used for personal thermal management.
具有超高孔隙率和超低密度的气凝胶纤维是个人热管理的理想候选材料,可减少加热整个房间所造成的能源浪费,总体上在减少能源浪费方面发挥重要作用。然而,气凝胶纤维通常机械性能较差且制备过程复杂。在此,我们通过同轴湿法纺丝和冷冻干燥展示了具有高强度、优异辐射加热性能和隔热性能的分级多孔连续丝素蛋白/氧化石墨烯气凝胶纤维(SF/GO)。通过同轴湿法纺丝工艺制备的中空CA/PAA纤维具有多尺度多孔结构,这不仅有利于SF/GO气凝胶芯的形成,还有助于提高气凝胶纤维的机械强度。此外,所制备的气凝胶纤维与中空CA/PAA纤维具有相当的孔隙率和机械性能。更重要的是,氧化石墨烯可显著改善红外辐射加热性能,在暴露于红外辐射30秒后表面温度升高2.6℃,大大高于中空纤维和SF气凝胶纤维。此外,分级多孔中空纤维与SF/GO气凝胶的结合可防止热对流、降低热传导并抑制热辐射,使SF/GO气凝胶纤维具有优异的隔热性能。这项工作可能有助于揭示人体与纺织品之间微环境的传热机制,并为用于个人热管理的高性能气凝胶纤维的制造铺平道路。