Bioinspired nanofibrils-humped Fibers with Strong Capillary for Fog Capture.

Bio-inspired nanofibrils-humped fibers (BNFs) are fabricated by using thermoplastic polyester ester elastomer (TPEE) and chitosan (CS), via combining the electrospinning technique and the fluid coating method to achieve periodic humps composed of random interlaced nanofibrils and joint composed of aligned nanofibrils, which are highly similar to the micro-/nanostructures of wetted spider silk. Especially, nanofibrils can raise the specific area of hump to capture the fog droplet effectively and transport water in channels between nanofibrils in humid conditions, and thus the fog droplets can coalesce and be high-efficiently transported into humps for water collection directionally. Such an ability of high efficient water collection is attributed to an effect of inside transportation on the outer shell of BNF. Inside transportation is induced by capillary anisotropic channels between nanofibrils from nanofibrils-joint to nanofibrils-hump. When the wetted BNF is formed, the inside transportation mode can be dominated for water collection. BNF web is also made to investigate the droplet transportation in different cross-fiber contact modes in process of water collection on large scale. This study offers an insight into design of novel materials which would be developed for some realms of applications, such as fog harvesting engineering, filtration, and others.