Janus porous membrane with conical nanoneedle channel for rapid unidirectional water transport

Abstract

The pierced nanowire Janus porous membrane prepared in this study possesses piercing conical nanoneedles, which not only form a transport channel to enhance unidirectional water transport, but also reduce the energy barrier of water transport by changing the route of water transport from droplet to film.

A review on emerging developments in thermal and moisture management by membrane‐based clothing systems towards personal comfort

“…A bioinspired Janus membrane constructed from polyester as hydrophobic inner layer and nitrocellulose as superhydrophilic outer layer containing conical micropores with hydrophilic inner wall has been provided by Dai et al who reported R value of 1246%. Changing the water transport mode from drop-based to film-based along the conical hydrophilic channels made of copper nanoneedles describes the work conducted by Wang et al 107 They produced a Janus membrane made of hydrophobic poly(vinylidenefluorideco-hexafluoropropylene) (PVDF-HFP) electrospun membrane pierced by hydrophilic conical nanoneedles of a oxidized copper mesh. Reducing the energy barrier of water transport in the film-based mode compared to droplet-based mode has been stated as the reason of fast and unidirectional water transport.…”

The High Flux of Superhydrophilic-Superhydrophobic Janus Membrane of cPVA-PVDF/PMMA/GO by Layer-by-Layer Electrospinning for High Efficiency Oil-Water Separation

“…Conversely, hydrophilic nanofibers can also be electrospun onto hydrophobic fibers. When Janus membrane is produced by this method, a variety of polymers can be selected, including polyurethane (PU) [ 14 , 16 , 20 , 21 , 22 ], polyvinylidene fluoride (PVDF) [ 19 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ], polymethyl methacrylate (PMMA) [ 34 , 35 , 36 , 37 ], polylactic acid (PLA) [ 38 , 39 ], polystyrene (PS) [ 26 , 40 ], polyvinyl alcohol (PVA) [ 21 , 41 ], cellulose acetate (CA) [ 22 , 23 , 33 , 40 , 42 ], polyacrylonitrile (PAN) [ 16 , 21 , 23 , 26 , 34 , 40 , 43 , 44 , 45 ], etc. At the same time, by adding hydrophilic and hydrophobic modifiers to the electrospinning solution, its properties can also be changed.…”

Cotton nonwovens with unidirectional water-transport properties produced by atmospheric plasma deposition

“…Textiles are valuable substrates for many Janus membranes because of their porous structure (Zhao et al 2017). Such fibrous Janus membranes can be prepared as double-layer composite structures (Yang et al 2017), for example using layer-by-layer electrospinning (Gore and Kandasubramanian 2018;Wang et al 2018;Wu et al 2012), or through singlesided modification (Yang et al 2018a) using a surface treatment (Yang et al 2019b).…”