Aerogels have been considered as super thermal insulators since their invention in 1931. However, applications of aerogels in textiles have been limited by their insufficient moisture permeability. Aerogel fibers are being developed to address the trade-off between thermal insulation and moisture permeability. Recently, researchers from Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences published a perspective regarding the advances of aerogel fibers on Dec 21st, 2023 in Science.
“Aerogel fibers are promising materials for next-generation thermal insulation textiles, which can outperform down and superfine fibers. For aerogel fiber-based fabrics, individual aerogel fibers can provide the best thermal insulation while the interfiber voids allow breathability. The superiority of aerogel fibers in recent textile history is reflected in the following two key aspects: processing and performance,” said corresponding author Xuetong Zhang, professor of SINANO, CAS.
Aerogel fibers can be obtained by spinning various nanoscale building blocks in a spinning dope with sol-gel transition and subsequent special drying, whereas traditional sol-gel transition is a slow and static process that is hard to couple with the fast, dynamic, and continuous spinning procedure used to make traditional textiles. These aerogel fibers are ready for use and do not require complicated postprocessing steps such as conventional yarn-spinning in textiles.
In addition to their use in textiles, aerogel fibers may be advantageous in adsorption, separation, optics, energy, and other applications.
“Specifically, the richness of nanopores in aerogel fibers could be used to entrap guest materials in these pore spaces, for example, molecules, nanoparticles, and functional liquids stabilized by capillary forces,” said first author Zhizhi Sheng, associate professor of SINANO, CAS. “We try to play with the interior nanopockets in aerogel fibers, such as the introduction of a functional liquid in aerogel fibers may provide new possibilities for carbon dioxide capture, efficient hemostasis, and energy storage and conversion.”
Despite the tremendous progress in aerogel fibers, challenges exist regarding how to develop fast-spinning technology and resolve the continuous fabrication that is necessary for mass production.
It is crucial to understand spinning thermodynamics and kinetics to decouple the mismatch between the slow sol-gel transition rate and the fast spinning rate. Additionally, although continuous spinning and batch drying have been established for aerogel fibers, a feasible strategy to bridge the two processes to realize a fully continuous process remains elusive.
“With the simultaneous advancement of materials and fabrication, aerogel fibers could have many potential applications beyond what we can expect currently,” said Professor Xuetong Zhang, “That is what we are doing and our urgent task to unravel the mysteries in aerogel fibers.”
Aerogel fibers can overcome the contradiction between thermal insulation and air permeability for personal warming. The mesopore nano-confining effect within aerogel fibers promises them broader applications beyond textiles. (Image by Zhizhi Sheng)
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