Directional water-transfer through fabrics induced by asymmetric wettability

et al. 2016

Adv Materials Inter

Self Cite

Fabrics with automatic one‐way water transport ability are highly desirable for applications in daily life, industry, health, and defense. However, most of the studies on one‐way water transport fabrics only report the qualitative water transport results. The lack of quantitative measure makes it hard to assess the directional transport quality. Here, it is proved that a hydrophilic fabric after being electrosprayed with a thin layer of hydrophobic coating on one side shows one‐way water transport ability. By using moisture management tester, the water transport property is qualitatively characterized and the effect of hydrophobic fabric layer thickness on one‐way water transport feature is examined. The hydrophobic fabric layer thickness is found to play a key role in deciding the one‐way transport ability. When a plain woven fabric with an overall thickness of 420 μm and average pore size of 33 μm is used as fabric substrate, a hydrophobic fabric layer thickness between 22 and 62 μm allows the treated fabric to show a one‐way droplet transport feature. A one‐way transport index as high as 861 can be attained. The one‐way water transport is durable enough to withstand repeated washing. This novel fabric may be useful for development of “smart” textiles for various applications.

Section: Resultsmentioning

confidence: 99%

Directional Water Transport Fabrics with Durable Ultra‐High One‐Way Transport Capacity

Zeng

et al. 2016

Adv Materials Inter

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“…Wang et al8 in our group reported directional water transport effect on fabrics through the formation of a wettability gradient from superhydrophobicity to hydrophilicity across the fabric thickness. When water was dropped on the superhydrophobic side, it penetrated through the fabric rapidly and spread on hydrophilic area.…”

mentioning

confidence: 85%

“…In this case, electrospinning was used to prepare hydrophilic and hydrophobic nanofibres and deposit into a dual-layer fibrous membrane. All the works reported to date, however, have been confined to transport of liquid water81011. Thin porous media with directional transport ability to oil fluids have not demonstrated in the research literature.…”

mentioning

confidence: 99%

Superphobicity/philicity Janus Fabrics with Switchable, Spontaneous, Directional Transport Ability to Water and Oil Fluids

Niu

et al. 2013

Sci Rep

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155

Herein we demonstrate that switchable, spontaneous, directional-transport ability to both water and oil fluids can be created on fabric materials through wet-chemistry coating and successive UV irradiation treatment. When the fabric showed directional transport to a liquid, it prevented liquids of higher surface tension from penetration, but allowed liquids of lower surface tension to permeate, from either side. The directional transport ability can be switched from one fluid to another simply by heating the fabric at an elevated temperature and then re-irradiating the fabric with UV light for required period of time. By attaching liquid drops vertically upwards to a horizontally-laid fabric, we further demonstrated that this novel directional fluid transport was an automatic process driven by surface property alone, irrespective of gravity's effect. This novel fabric may be useful for development of “smart” textiles and functional membranes for various applications.

“…Such a "smart" property has been reported mainly on open solid surfaces, 1−6 single filaments, 7−13 and thin porous materials. 14 −19 On open solid surfaces, one-way fluid transport is often driven by opposite wettability in the adjacent areas. A typical example is a Stenocara Beetle's back, which contains an array of hydrophilic bumps on a hydrophobic surface.…”

Section: ■ Introductionmentioning

confidence: 99%

Selective, Spontaneous One-Way Oil-Transport Fabrics and Their Novel Use for Gauging Liquid Surface Tension

ACS Appl. Mater. Interfaces

Yang

et al. 2015

Self Cite

Thin porous materials that can spontaneously transport oil fluids just in a single direction have great potential for making energy-saving functional membranes. However, there is little data for the preparation and functionalities of this smart material. Here, we report a novel method to prepare one-way oil-transport fabrics and their application in detecting liquid surface tension. This functional fabric was prepared by a two-step coating process to apply flowerlike ZnO nanorods, fluorinated decyl polyhedral oligomeric silsesquioxanes, and hydrolyzed fluorinated alkylsilane on a fabric substrate. Upon one-sided UV irradiation, the coated fabric shows a one-way transport feature that allows oil fluid transport automatically from the unirradiated side to the UV-irradiated surface, but it stops fluid transport in the opposite direction. The fabric still maintains high superhydrophobicity after UV treatment. The one-way fluid transport takes place only for the oil fluids with a specific surface tension value, and the fluid selectivity is dependent on the UV treatment time. Changing the UV irradiation time from 6 to 30 h broadened the one-way transport for fluids with surface tension from around 22.3 mN/m to a range of 22.3-56.7 mN/m. We further proved that this selective one-way oil transport can be used to estimate the surface tension of a liquid simply by observing its transport feature on a series of fabrics with different one-way oil-transport selectivities. To our knowledge, this is the first example to use one-way fluid-transport materials for testing the liquid surface tension. It may open up further theoretical studies and the development of novel fluid sensors.