Asymmetric wicking and reduced evaporation time of droplets penetrating a thin double-layered porous material

Abstract

We study numerically and experimentally the penetration and evaporation dynamics of droplets wicking into a thin double-layered porous material with order-of-magnitude difference in the physical properties between the layers. We show that such double-layered porous materials can be used to create highly asymmetrical wicking properties, preventing liquid droplets wicking from one surface to the other, while allowing wicking in the reverse direction. In addition, these double-layered porous materials are shown to reduce the evaporation time of droplets penetrating into the porous material, compared with a single-layered porous material of equal thickness and physical properties similar to either of the layers.

Droplet evaporation on porous fabric materials

“…Additionally, in sportswear industry, moisture control through absorption and evaporation is crucial in managing the external fluids and inner body sweat that inevitably come in contact with the fabric, offering protection and comfort to athletes 32 , 33 . To achieve breathability and waterproofing, appropriate textiles such as multilayered textiles are being developed 34 – 36 . Furthermore, the study of droplet evaporation in fabric materials, such as protective fabric masks, can enlighten the interaction of mucoidal viral droplets with complex porous networks, resulting in a better perception on their efficiency and handling 37 .…”

Structural design of a double-layered porous hydrogel for effective mass transport

“…The capillary flow through multi-layered porous layers, such as packed beds of particles or absorbent materials, has been widely investigated experimentally and theoretically. [9][10][11][12][13][14][15] Reyssat et al, studied the imbibition of a wetting fluid into layers of packed beads 13 and Shou et al, studied the geometry induced asymmetric capillary flow to obtain the optimal geometry for fastest flow absorption. 10,11 However, little attention has been paid to the mass transport through multilayered porous structure by chemical potential difference.…”