|Posted: Feb 16, 2018|
Polar bear hair inspires nanotechnology enhanced thermal textile(Nanowerk News) Inspired by the microstructure and thermal insulation function of the polar bear hair, scientists have used a freeze-spinning technique to continuously fabricate silk fibroin solution into a fiber with aligned porous microstructure.
|The textile woven with the biomimetic fibers has an excellent thermal insulation, active electroheating capacity when doped with carbon nanotubes (CNTs), good wearability and breathability, making it a promising material for thermal insulation and personal thermal management.|
|This work by researchers at Zhejiang University in China has been reported in Advanced Materials ("A Thermally Insulating Textile Inspired by Polar Bear Hair").|
|Polar bear hair with hollow core and aligned shell, and continuous and large-scale fabrication of biomimetic porous fiber. a) Photograph of a polar bear. b,c) SEM images showing the hollow core and aligned shell of a polar bear hair, respectively. d) Schematic illustration of the “freezespinning” technique, combining “directional freezing” with “solution spinning” to realize continuous and large-scale fabrication of biomimetic fibers with aligned porous structure, mimicking the polar bear hair. The silk fibroin solution extruded from a pump-controlled syringe is gradually frozen when it passes through a cold copper ring. Collected by a motor, the frozen fiber is further freeze-dried to reserve its porous structure and subsequently woven into a textile. e) Optical image showing a porous fiber collected in a roll. f,g) Optical (f) and SEM (g) images showing a woven textile of biomimetic porous fiber. The fiber diameter is around 200 µm. (© Wiley-VCH Verlag) (click on image to enlarge)|
|The team uses a freeze-spinning method to realize continuous and large-scale fabrication of fibers with aligned porous structure, mimicking polar bear hairs, which is difficult to achieve by other methods.|
|Textile woven with such biomimetic fibers shows an excellent thermal insulation property as well as good breathability and wearability.|
|In addition to passively insulate heat loss, the textile could also function as a wearable heater, when doped with electroheating materials such CNTs, to induce fast thermal response and uniform electroheating while maintaining its soft and porous nature for comfortable wearing.|
|By Michael Berger – Michael is author of two books by the Royal Society of Chemistry: Nano-Society: Pushing the Boundaries of Technology and Nanotechnology: The Future is Tiny.|
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