Facile Removal and Collection of Oils from Water Surfaces through Superhydrophobic and Superoleophilic Sponges

The development of a convenient method for the removal (or collection) of oils and organic solvents from water surface is of great significance for water environmental protection, especially for the cleanup of oil spillage on seawater. A major challenge is the fabrication of an oil absorber with high absorption capacity, low cost, scalable fabrication, high selectivity, and excellent recyclability. In this paper, we present a simple method for the removal and collection of oils and organic solvents from the surfaces of water based on superhydrophobic and superoleophilic sponges that were fabricated by solution-immersion processes. The as-prepared sponges fast and selectively absorbed various kinds of oils up to above 13 times the sponges’ weight while completely repelling water through a combination of porous, superhydrophobic, and superoleophilic properties. More interesting, the absorbed oils were readily collected by a simple mechanical squeezing process, and the recovered sponges could be reused in oil–water separation for many cycles while still keeping high separation efficiency. The findings presented in this study might provide a fast and simple approach for the cleanup of oils and organic solvents on water surfaces

Intelligent Icephobic Surface toward Self-Deicing Capability

Superhydrophobic surfaces show attractive anti-icing properties. However, it remains a challenge for them to achieve icephobicity and ultralow ice adhesion in a humid environment, which is fundamentally attributed to the icing behavior on their hierarchical textures. Here, we address the issue by integrating a superhydrophobic copper mesh with an intelligent organogel that can secrete antifreezing agent autonomously in response to temperature. The antifreezing agent is composed of ethylene glycol and water. By autonomously secreting the antifreezing agent at subzero temperatures, the hybrid surface effectively inhibits the frosting process on the hierarchical texture of the superhydrophobic mesh. Consequently, the surface not only exhibits excellent antifrosting properties in a humid atmosphere but also repeatedly removes the ice deposited spontaneously due to ultralow ice adhesion (8 Pa). This integration of intelligent organogel paves a new and promising avenue to design superhydrophobic surfaces with excellent icephobic properties

Facile Removal and Collection of Oils from Water Surfaces through Superhydrophobic and Superoleophilic Sponges

The development of a convenient method for the removal (or collection) of oils and organic solvents from water surface is of great significance for water environmental protection, especially for the cleanup of oil spillage on seawater. A major challenge is the fabrication of an oil absorber with high absorption capacity, low cost, scalable fabrication, high selectivity, and excellent recyclability. In this paper, we present a simple method for the removal and collection of oils and organic solvents from the surfaces of water based on superhydrophobic and superoleophilic sponges that were fabricated by solution-immersion processes. The as-prepared sponges fast and selectively absorbed various kinds of oils up to above 13 times the sponges’ weight while completely repelling water through a combination of porous, superhydrophobic, and superoleophilic properties. More interesting, the absorbed oils were readily collected by a simple mechanical squeezing process, and the recovered sponges could be reused in oil–water separation for many cycles while still keeping high separation efficiency. The findings presented in this study might provide a fast and simple approach for the cleanup of oils and organic solvents on water surfaces

Intelligent Icephobic Surface toward Self-Deicing Capability

Superhydrophobic surfaces show attractive anti-icing properties. However, it remains a challenge for them to achieve icephobicity and ultralow ice adhesion in a humid environment, which is fundamentally attributed to the icing behavior on their hierarchical textures. Here, we address the issue by integrating a superhydrophobic copper mesh with an intelligent organogel that can secrete antifreezing agent autonomously in response to temperature. The antifreezing agent is composed of ethylene glycol and water. By autonomously secreting the antifreezing agent at subzero temperatures, the hybrid surface effectively inhibits the frosting process on the hierarchical texture of the superhydrophobic mesh. Consequently, the surface not only exhibits excellent antifrosting properties in a humid atmosphere but also repeatedly removes the ice deposited spontaneously due to ultralow ice adhesion (8 Pa). This integration of intelligent organogel paves a new and promising avenue to design superhydrophobic surfaces with excellent icephobic properties

Intelligent Icephobic Surface toward Self-Deicing Capability

Superhydrophobic surfaces show attractive anti-icing properties. However, it remains a challenge for them to achieve icephobicity and ultralow ice adhesion in a humid environment, which is fundamentally attributed to the icing behavior on their hierarchical textures. Here, we address the issue by integrating a superhydrophobic copper mesh with an intelligent organogel that can secrete antifreezing agent autonomously in response to temperature. The antifreezing agent is composed of ethylene glycol and water. By autonomously secreting the antifreezing agent at subzero temperatures, the hybrid surface effectively inhibits the frosting process on the hierarchical texture of the superhydrophobic mesh. Consequently, the surface not only exhibits excellent antifrosting properties in a humid atmosphere but also repeatedly removes the ice deposited spontaneously due to ultralow ice adhesion (8 Pa). This integration of intelligent organogel paves a new and promising avenue to design superhydrophobic surfaces with excellent icephobic properties

Facile Removal and Collection of Oils from Water Surfaces through Superhydrophobic and Superoleophilic Sponges

The development of a convenient method for the removal (or collection) of oils and organic solvents from water surface is of great significance for water environmental protection, especially for the cleanup of oil spillage on seawater. A major challenge is the fabrication of an oil absorber with high absorption capacity, low cost, scalable fabrication, high selectivity, and excellent recyclability. In this paper, we present a simple method for the removal and collection of oils and organic solvents from the surfaces of water based on superhydrophobic and superoleophilic sponges that were fabricated by solution-immersion processes. The as-prepared sponges fast and selectively absorbed various kinds of oils up to above 13 times the sponges’ weight while completely repelling water through a combination of porous, superhydrophobic, and superoleophilic properties. More interesting, the absorbed oils were readily collected by a simple mechanical squeezing process, and the recovered sponges could be reused in oil–water separation for many cycles while still keeping high separation efficiency. The findings presented in this study might provide a fast and simple approach for the cleanup of oils and organic solvents on water surfaces

Juncus Pith: A Versatile Material for Automatic and Continuous Separation of Various Oil–Water Mixtures

It is extremely important to develop a facile and versatile strategy for effectively separating various oil–water mixtures. Here we report that the pith of juncus (which is also known as common rushes) can serve as a versatile material for oil–water separation. Under the action of capillary force and gravity, a piece of pith automatically and continuously separates not only immiscible oil–water mixtures but also surfactant-stabilized water-in-oil emulsions with high selectivity and desirable flux. The separation strategy is cost-effective and energy-efficient because it avoids the switch of wettability, the input of additional energy, and the use of low-surface-energy chemicals or special equipment. The unique capability of the pith is mainly attributed to the presence of three-dimensionally (3D) reticular texture with highly hydrophobic and superoleophilic properties. Owing to its easy availability and high effectiveness, juncus might be a promising material aiming for oil–water separation, water treatment, and purification of solvent or fuel, and so on

Remote Manipulation of a Microdroplet in Water by Near-Infrared Laser

Facile manipulation of a tiny liquid droplet is an important but challenging issue for many miniaturized chemical and biological systems. Here we report that a microdroplet can be readily and remotely manipulated in aqueous environments under ambient conditions. The droplet is encapsulated with photothermal nanoparticles to form a liquid marble, and subsequently irradiated with a near-infrared (NIR) laser. The marble is able to ascend, shuttle, horizontally move, and even suspend in water by simply controlling the laser irradiation. Moreover, filling and draining of the marble can also be conducted on the water surface for the first time. This facile manipulation strategy does not use complicated nanostructures or sophisticated equipment, so it has potential applications for channel-free microfluidics, smart microreators, microengines, microrobots, and so on

Remote Manipulation of a Microdroplet in Water by Near-Infrared Laser

Facile manipulation of a tiny liquid droplet is an important but challenging issue for many miniaturized chemical and biological systems. Here we report that a microdroplet can be readily and remotely manipulated in aqueous environments under ambient conditions. The droplet is encapsulated with photothermal nanoparticles to form a liquid marble, and subsequently irradiated with a near-infrared (NIR) laser. The marble is able to ascend, shuttle, horizontally move, and even suspend in water by simply controlling the laser irradiation. Moreover, filling and draining of the marble can also be conducted on the water surface for the first time. This facile manipulation strategy does not use complicated nanostructures or sophisticated equipment, so it has potential applications for channel-free microfluidics, smart microreators, microengines, microrobots, and so on

Ultrafast Fabrication of a Robust Superwetting Coating

Superwetting surface has attracted extensive attention because of its wide potential applications. However, its application is still restricted by its complex fabrication, time-consuming preparation, high cost, and poor mechanical or chemical stability. Herein, it only took ∼14 min to fabricate a robust superwetting coating via a successively spraying and pressing process. The resulting coating exhibited excellent mechanical stability, good anticorrosion, and chemical durability by pressing various micro-/nanoparticles such as montmorillonite (MMT), sepiolite (SEP), or TiO2 nanoparticles into the epoxy-based coating. Besides the self-cleaning and wettability switch performance, the “E44 + TiO2” coating exhibited good separation performance for an oil–water mixture and emulsion. This strategy provides a simple and ultrafast route to fabricate a robust superwetting surface with multifunctions, which extend the range of the superwetting surface in practical applications