Strategies for Preparing Continuous Ultraflexible and Ultrastrong Poly(Vinyl Alcohol) Aerogel Fibers with Excellent Thermal Insulation

Aerogel fibers are thermally insulating and can be woven, so they are expected to form a new generation of smart textiles that can efficiently reduce heat consumption. However, producing continuous aerogel fibers that have the necessary strength and toughness to be woven remains a great challenge. Herein, with the aid of freeze-thaw treatment of poly(vinyl alcohol) (PVA) solution and freeze-spinning technology, continuous PVA aerogel fibers with an aligned porous morphology are prepared in a large-scale. Freeze-thaw treatment greatly contributes to improving the spinnability of the spinning dope of aerogel fibers, which leads to the formation of the continuous fibers. Remarkably, through this process the aerogel fibers achieve ultraflexible and ultrastrong features, which results in excellent weaving ability, as well as attractive mechanical properties that benefit from the cross-linking of PVA molecular chains with the aligned porous structure. More importantly, a textile woven with the special porous structure aerogel fibers shows extraordinary thermal insulation (thermal conductivity as low as 0.026 W m(-1) K-1) and infrared stealth. This study illustrates a promising direction for the design of next generation, wearable, intelligent materials that have great potential for personal thermal management applications.