TL;DR: Inspired by the superhydrophobic lotus surface in nature, special wettability has attracted a lot of interest and attention in both academia and industry as discussed by the authors, and the strategies for constructing fabric surfaces with an anti-wetting property are categorized and discussed based on the morphology of particles coated on the textile fibre.
Abstract: Inspired by the superhydrophobic lotus surface in nature, special wettability has attracted a lot of interest and attention in both academia and industry In this review, theoretical models and fabrication strategies of superhydrophobic textiles have been discussed in detail The strategies for constructing fabric surfaces with an anti-wetting property are categorized and discussed based on the morphology of particles coated on the textile fibre Such special wettability textile surfaces are demonstrated with self-cleaning, oil/water separation, self-healing, UV-blocking, photocatalytic, anti-bacterial, and flame-retardant performances Correspondingly, potential applications have been illustrated for self-cleaning, oil/water separation, asymmetric/anisotropic wetting janus fabric, microfluidic manipulation, and micro-templates for patterning In each section, representative studies are highlighted with emphasis on the special wetting ability and other relevant properties Finally, the difficulties and challenges for practical application were briefly discussed
TL;DR: A review of the recent progress of oil/water separation technologies based on filtration and absorption methods using various materials that possess surface superwetting properties is presented in this article.
Abstract: Oil/water separation is a field of high significance as it has direct practical implications for resolving the problem of industrial oily wastewater and other oil/water pollution. Therefore, the development of functional materials for efficient treatment of oil-polluted water is imperative. In this feature article, we have reviewed the recent progress of oil/water separation technologies based on filtration and absorption methods using various materials that possess surface superwetting properties. In each section, we present in detail representative work and describe the concepts, employed materials, fabrication methods, and the effects of their wetting/dewetting behaviors on oil/water separation. Finally, the challenges and future research directions of this promising research field are briefly discussed.
TL;DR: Superhydrophobicity is the tendency of a surface to repel water drops as discussed by the authors, and it is defined as the ability of the surface to resist water drops in nature.
Abstract: Superhydrophobicity is the tendency of a surface to repel water drops. A surface is qualified as a superhydrophobic surface only if the surface possesses a high apparent contact angle (>150°), low contact angle hysteresis (<10°), low sliding angle (<5°) and high stability of Cassie model state. Efforts have been made to mimic the superhydrophobicity found in nature (for example, lotus leaf), so that artificial superhydrophobic surfaces could be prepared for a variety of applications. Due to their versatile use in many applications, such as water-resistant surfaces, antifogging surfaces, anti-icing surfaces, anticorrosion surfaces etc., many methods have been developed to fabricate them. In this article, the fundamental principles of superhydrophobicity, some of the recent works in the preparation of superhydrophobic surfaces, their potential applications, and the challenges confronted in their new applications are reviewed and discussed.
350 citations
Cites background from "A review on special wettability tex..."
...This results in a slippery contact surface that increases the mobility of liquid drops favoring the easy sliding action of liquid drops.(35,36) If the Cassie–Baxter state is maintained, the drop of liquid can easily move/roll across the solid surface....
TL;DR: In this article, a comprehensive survey of the progress achieved so far in the production of super-hydrophobic materials based on cellulose and fiber networks is presented, focusing on summarizing some of the aspects that are critical to advance this evolving field of science which may provide new ideas for the developing and exploring of super hydrophobic and green-based materials.
Abstract: Superhydrophobic cellulose-based products have immense potential in many industries where plastics and other polymers with hydrophobic properties are used. Superhydrophobic cellulose-based plastic is inherently biodegradable, renewable and non-toxic. Finding a suitable replacement of plastics is highly desired since plastics has become an environmental concern. Despite its inherent hydrophilicity, cellulose has unparalleled advantages as a substrate for the production of superhydrophobic materials which has been widely used in self-cleaning, self-healing, oil and water separation, electromagnetic interference shielding, etc. This review includes a comprehensive survey of the progress achieved so far in the production of super-hydrophobic materials based on cellulose and fiber networks. The method-ologies and applications of superhydrophobic-modified cellulose and fiber networks are emphasized. Overall, presented herein is targeting on summarizing some of the aspects that are critical to advance this evolving field of science which may provide new ideas for the developing and exploring of superhydrophobic and green-based materials.
283 citations
Cites background or methods from "A review on special wettability tex..."
...Since then, research interests on super-hydrophobicity have grown tremendously, with numerous studies devoted to mimicking natural plants, animals and creatures (Li et al., 2017)....
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...Moreover, the as-prepared fabric and sponge via the in-situ growth method followed by thiol modification possess anti-wettability towards water and can selectively absorb and filtrate oils from water with high efficiency (Li et al., 2017)....
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...From this perspective, it is essential to create liquid repellent coating with long-term durability, self-healing and non-toxicity, which is believed to be an efficient way to overcome the poor durability caused by physical and chemical damages (Li et al., 2017)....
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...of superhydrophobic surfaces have great potential applications in aircrafts, optical lenses, energy transmission system, power lines, wind turbines, and highways as well as building constructions (Li et al., 2017)....
TL;DR: In this paper, the theory and design of various superwetting states for selective oil/water separation including superhydrophobicity/superoleophilicity, super-hydrophilicity/underwater superoleophobicity, Janus wettability, and smart Wettability are discussed.
TL;DR: It is expected that the biomimetic porous materials with nanoscale interface engineering will overcome the current challenges of oil-water emulsion separation, realizing their practical applications in the near future with continuous efforts in this field.
Abstract: Oil–water separation is critical for the water treatment of oily wastewater or oil-spill accidents. The oil contamination in water not only induces severe water pollution but also threatens human beings’ health and all living species in the ecological system. To address this challenge, different nanoscale fabrication methods have been applied for endowing biomimetic porous materials, which provide a promising solution for oily-water remediation. In this review, we present the state-of-the-art developments in the rational design of materials interface with special wettability for the intelligent separation of immiscible/emulsified oil–water mixtures. A mechanistic understanding of oil–water separation is firstly described, followed by a summary of separation solutions for traditional oil–water mixtures and special oil–water emulsions enabled by self-amplified wettability due to nanostructures. Guided by the basic theory, the rational design of interfaces of various porous materials at nanoscale with special wettability towards superhydrophobicity–superoleophilicity, superhydrophilicity–superoleophobicity, and superhydrophilicity–underwater superoleophobicity is discussed in detail. Although the above nanoscale fabrication strategies are able to address most of the current challenges, intelligent superwetting materials developed to meet special oil–water separation demands and to further promote the separation efficiency are also reviewed for various special application demands. Finally, challenges and future perspectives in the development of more efficient oil–water separation materials and devices by nanoscale control are provided. It is expected that the biomimetic porous materials with nanoscale interface engineering will overcome the current challenges of oil–water emulsion separation, realizing their practical applications in the near future with continuous efforts in this field.
TL;DR: It is shown here for the first time that the interdependence between surface roughness, reduced particle adhesion and water repellency is the keystone in the self-cleaning mechanism of many biological surfaces.
Abstract: The microrelief of plant surfaces, mainly caused by epicuticular wax crystalloids, serves different purposes and often causes effective water repellency. Furthermore, the adhesion of contaminating particles is reduced. Based on experimental data carried out on microscopically smooth (Fagus sylvatica L., Gnetum gnemon L., Heliconia densiflora Verlot, Magnolia grandiflora L.) and rough water-repellent plants (Brassica oleracea L., Colocasia esculenta (L.) Schott., Mutisia decurrens Cav., Nelumbo nucifera Gaertn.), it is shown here for the first time that the interdependence between surface roughness, reduced particle adhesion and water repellency is the keystone in the self-cleaning mechanism of many biological surfaces. The plants were artificially contaminated with various particles and subsequently subjected to artificial rinsing by sprinkler or fog generator. In the case of water-repellent leaves, the particles were removed completely by water droplets that rolled off the surfaces independent of their chemical nature or size. The leaves of N. nucifera afford an impressive demonstration of this effect, which is, therefore, called the “Lotus-Effect” and which may be of great biological and technological importance.
TL;DR: In this article, a super-hydrophobic surface with both a large contact angle (CA) and a small sliding angle (α) has been constructed from carbon nanotubes.
Abstract: Super-hydrophobic surfaces, with a water contact angle (CA) greater than 150degreesC, have attracted much interest for both fundamental research and practical applications. Recent studies on lotus and rice leaves reveal that a super-hydrophobic surface with both a large CA and small sliding angle (alpha) needs the cooperation of micro- and nanostructure, and the arrangement of the microstructures on this surface can influence the way a water droplet tends to move. These results form the natural world provide a guide for constructing artificial super-hydrophobic surfaces and designing surfaces with controllable wettability. Accordingly, super-hydrophobic surfaces of polymer nanofibers and differently patterned aligned carbon nanotube (ACNT) films have been fabricated.