Energy-saving hydrogen production from sulfion oxidation-hybrid seawater splitting enabled by superwettable corrosion-resistant NiFe layered double hydroxide/FeNi2S4 heterostructured nanoarrays.

Electrochemical seawater splitting is a sustainable pathway towards hydrogen production independent of scarce freshwater resources. However, the high energy consumption and harmful chlorine-chemistry interference still pose major technological challenges. Herein, thermodynamically more favorable sulfion oxidation reaction (SOR) is explored to replace energy-intensive oxygen evolution reaction (OER), enabling the dramatically reduced energy consumption and the avoidance of corrosive chlorine species in electrocatalytic systems of NiFe layered double hydroxide (LDH)/FeNi2S4 grown on iron foam (IF) substrate. The resulting NiFe-LDH/FeNi2S4/IF with superwettable surfaces and favorable heterointerfaces can effectively catalyze SOR and hydrogen evolution reaction (HER), which greatly reduces the operational voltage by 1.05 V at 50 mA cm-2 compared to pure seawater splitting and achieves impressively low electricity consumption of 2.33 kW h per cubic meter of H2 at 100 mA cm-2. Significantly, benefitting from the repulsive effect of surface sulfate anions to Cl-, the NiFe-LDH/FeNi2S4/IF exhibits outstanding long-term stability for SOR-coupled chlorine-free hydrogen production with sulfion upcycling into elemental sulfur. The present study uncovers the "killing two birds with one stone" effect of SOR for energy-efficient hydrogen generation and value-added elemental sulfur recovery in seawater electrolysis without detrimental chlorine chemistry.

Superwetting Nanofluids of NiOx-Nanocrystals/CsBr Solution for Fabricating Quality NiOx-CsPbBr3 Gradient Hybrid Film in Carbon-Based Perovskite Solar Cells.

The wettability of precursor solution on substrates is the critical factor for fabricating quality film. In this work, superwetting nanofluids (NFs) of non-stoichiometric nickel oxide (NiOx) nanocrystals (NCs)-CsBr solution are first utilized to fabricate quality NiOx-CsPbBr3 hybrid film with gradient-distributed NiOx NCs in the upper part for constructing hole transport ladder in carbon-based perovskite solar cells (C-PSCs). As anticipated, the crystalline properties (improved crystalline grain diameters and reduced impurity phase) and hole extraction/transport of the NiOx-CsPbBr3 hybrid film are improved after incorporating NiOx NCs into CsPbBr3. This originates from the superb wettability of NiOx-CsBr NFs on substrates and the excellent hole-transport properties of NiOx. Consequently, the C-PSCs with the structure of FTO/SnO2/NiOx-CsPbBr3/C displays a power conversion efficiency of 10.07%, resulting in a 23.6% improvement as compared with the pristine CsPbBr3 cell. This work opens up a promising strategy to improve the absorber layer in PSCs by incorporating NCs into perovskite layers through the use of the superwettability of NFs and by composition gradient engineering.

Fluid Unidirectional Transport Induced by Structure and Ambient Elements across Porous Materials: From Principles to Applications.

Spontaneous or nonspontaneous unidirectional fluid transport across multidimension can occur under specific structural designs and ambient elements for porous materials. While existing reviews have extensively summarized unidirectional fluid transport on surfaces, there is an absence of literature summarizing fluid's unidirectional transport across porous materials. This review introduces wetting phenomena observed on natural biological surfaces or porous structures. Subsequently, it offers an overview of diverse principles and potential applications in this field, emphasizing various physical and chemical structural designs (surface energy, capillary size, topographic curvature) and ambient elements (underwater, under oil, pressure, and solar energy). Applications encompass moisture-wicking fabric, sensors, skincare, fog collection, oil-water separation, electrochemistry, liquid-based gating, and solar evaporators. Additionally, significant principles and formulas from various studies are compelled to offer readers valuable references. Simultaneously, potential advantages and challenges are critically assessed in these applications and the perspectives are presented.

Intertwisted superhydrophilic and superhydrophobic collagen fibers enabled anti-fouling high-performance separation of emulsion wastewater.

Oil-contaminated wastewater has been one of the most concerned environmental issues. Superwetting materials-enabled remediation of oil contamination in wastewater faces the critical challenge of fouling problems due to the formation of intercepted phase. Herein, high-performance separation of emulsions wastewater was accomplished by developing collagen fibers (CFs)-derived water-oil dual-channels that were comprised of intertwisted superhydrophilic and superhydrophobic CFs. The dual-channels relied on the superhydrophilic CFs to accomplish efficient demulsifying, which played the role as water-channel to enable fast transportation of water, while the superhydrophobic CFs served as the oil-transport channel to permit oil transportation. The mutual repellency between water-channel and oil-channel was essential to guarantee the stability of established dual-channels. The unique dual-channel separation mechanism fundamentally resolved the intercepted phase-caused fouling problem frequently engaged by the superwetting materials that provided single-channel separation capability. Long-lasting (1440 min) anti-fouling separations were achieved by the superwetting CFs-derived dual-channels with separation efficiency high up to 99.99%, and more than 4-fold of stable separation flux as compared with that of superhydrophilic CFs with single-channel separation capability. Our investigations demonstrated a novel strategy by using superwetting CFs to develop water-oil dual-channels for achieving high-performance anti-fouling separation of emulsions wastewater. ENVIRONMENTAL IMPLICATION: Industrial processes discard a large amount of emulsion wastewater, which seriously imperils the aquatic ecosystem. This work demonstrated a conceptual-new strategy to achieve effective remediation of emulsion wastewater via the water-oil dual-channels established by the intertwisted superhydrophilic and superhydrophobic collagen fibers (CFs). The superhydrophilic CFs enabled efficient demulsification of emulsions and played the role of water-channel for the rapid transportation of water, while the superhydrophobic CFs worked as oil-channel to permit the efficient transportation of oil pollutants. Consequently, the long-term (1440 min) anti-fouling high-performance separation of emulsion wastewater was achieved.

Superhydrophilic Photothermal-Responsive CuO@MXene Nanofibrous Membrane with Inherent Biofouling Resistance for Treating Complex Oily Wastewater.

MXene, a recently emerged 2D material, has garnered substantial attention for a myriad of applications. Despite the growing interest, there remains a noticeable gap in exploring MXene-based membranes for the simultaneous achievement of photomodulated oil/water separation, bacterial resistance, and the removal of pollutants in the treatment of oily wastewater. In this work, we have successfully synthesized a novel multifunctional CuO@MXene-PAN nanofibrous membrane (NFM) featuring unique nanograin-like structures. Benefitting from these unique structures, the resultant membrane shows excellent superwetting properties, significantly enhancing its performance in oil/water separation. In addition, the membrane's photothermal property boosts its permeance by 40% under visible light illumination within 30 min. Furthermore, the resultant membrane shows decent dye removal efficiency in an aqueous solution, e.g., Rhodamine B (RhB), promoting efficient degradation with high reusability under visible light. Most remarkably, the resultant membrane exhibits superior anti-biofouling capability and consistently resists the adhesion of microorganisms such as cyanobacteria over a 14 day period. Thus, the combined effect of superior superwetting properties, photothermal responsivity, photocatalytic activity, and the antibacterial effect in CuO@MXene-PAN NFM contributes to the efficient treatment of intricate oily wastewater. This synergistic combination of superior properties in the membrane could be an appealing strategy for the broad development of multifunctional materials to prevent fouling during actual separation performance.

An efficient solution based on the synergistic effects of nickel foam in NiFe-LDH nanosheets for oil/water separation.

Efficient oil-water separation has always been a research hotspot in the field of environmental studies. Employing a one-step hydrothermal approach, NiFe-layered double hydroxides (LDH) nanosheets were synthesized on nickel foam substrates. The resulting NiFe-LDH/NF membrane exhibited rejection rates exceeding 99% across six diverse oil-water mixtures, concurrently demonstrating a remarkable ultra-high flux of 1.4 × 106 L·m-2·h-1. This flux value significantly surpasses those documented in existing literature, maintaining stable performance over 1000 manual filtration cycles. These breakthroughs stem from the synergistic interplay among the three-dimensional channels of the nickel foam, the nanosheets, and the hydration layer. By leveraging the pore size of the foam to enhance the functionality of the hydration layer, the conventional trade-off between permeability and selectivity was transformed into a balanced force relationship between the hydration layer and the oil phase. The operational and failure mechanisms of the hydration layer were examined using the prepared NiFe-LDH/NF membrane, validating the correlation between oil phase viscosity and density with hydration layer rupture. Additionally, an extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory was employed to investigate changes in interaction energy, further reinforcing the study's findings. This research contributes novel insights and assistance to the comprehension and application of hydration layers in other membrane studies dedicated to oil-water separation.

The antifouling mechanism and application of bio-inspired superwetting surfaces with effective antifouling performance.

With the rapid development of industries, the issue of pollution on Earth has become increasingly severe. This has led to the deterioration of various surfaces, rendering them ineffective for their intended purposes. Examples of such surfaces include oil rigs, seawater intakes, and more. A variety of functional surface techniques have been created to address these issues, including superwetting surfaces, antifouling coatings, nano-polymer composite materials, etc. They primarily exploit the membrane's surface properties and hydration layer to improve the antifouling property. In recent years, biomimetic superwetting surfaces with non-toxic and environmental characteristics have garnered massive attention, greatly aiding in solving the problem of pollution. In this work, a detailed presentation of antifouling superwetting materials was made, including superhydrophobic surface, superhydrophilic surface, and superhydrophilic/underwater superoleophobic surface, along with the antifouling mechanisms. Then, the applications of the superwetting antifouling materials in antifouling domain were addressed in depth.

A comprehensive review on state-of-the-art antifouling super(wetting and anti-wetting) membranes for oily wastewater treatment.

One of the most dangerous types of pollution to the environment is oily wastewater, which is produced from a number of industrial sources and can cause damage to the environment, people, and creatures. To overcome this issue, membrane technology as an advanced method has been considered for treating oily wastewater due to its stability, high removal efficiency, and simplicity in scaling up. Membrane fouling, or the accumulation of oil droplets at or within the membrane pores, compromises the efficiency of membrane separation and water flux. In the last decade, the fabrication of membranes with specific wettability to reduce fouling has received much consideration. The purpose of this article is to offer a literature overview of all fabricated anti-fouling super(wetting and anti-wetting) membranes for applicable membrane processes for the separation of immiscible and emulsified oil/water mixtures. In this review, we first explain membrane fouling and discuss methods for preventing it. Afterwards, in all membrane separation processes, including pressure-driven, gravity-driven, and thermal-driven, membranes based on the form and density of oil are categorized as oil-removing or water-removing with special wettability, and then their wettability modification with different materials is particularly discussed. Finally, the prospect of anti-fouling membrane fabrication in the future is presented.

Hierarchical Ni-Mn LDHs@CuC2O4 Nanosheet Arrays-Modified Copper Mesh: A Dual-Functional Material for Enhancing Oil/Water Separation and Supercapacitors.

The pursuit of superhydrophilic materials with hierarchical structures has garnered significant attention across diverse application domains. In this study, we have successfully crafted Ni-Mn LDHs@CuC2O4 nanosheet arrays on a copper mesh (CM) through a synergistic process involving chemical oxidation and hydrothermal deposition. Initially, CuC2O4 nanosheets were synthesized on the copper mesh, closely followed by the growth of Ni-Mn LDHs nanosheets, culminating in the establishment of a multi-tiered surface architecture with exceptional superhydrophilicity and remarkable underwater superoleophobicity. The resultant Ni-Mn LDHs@CuC2O4 CM membrane showcased an unparalleled amalgamation of traits, including superhydrophilicity, underwater superoleophobicity, and the ability to harness photocatalytic forces for self-cleaning actions, making it an advanced oil-water separation membrane. The membrane's performance was impressive, manifesting in a remarkable water flux range (70 kL·m-2·h-1) and an efficient oil separation capability for both oil/water mixture and surfactant-stabilized emulsions (below 60 ppm). Moreover, the innate superhydrophilic characteristics of the membrane rendered it a prime candidate for deployment as a supercapacitor cathode material. Evidenced by a capacitance of 5080 mF·cm-2 at a current density of 6 mA cm-2 in a 6 M KOH electrolyte, the membrane's potential extended beyond oil-water separation. This work not only introduces a cutting-edge oil-water separation membrane and supercapacitor electrode but also offers a promising blueprint for the deliberate engineering of hierarchical structure arrays to cater to a spectrum of related applications.

Superhydrophilic and Superaerophobic Ru-Loaded NiCo Bimetallic Hydroxide Achieves Efficient Hydrogen Evolution over All pH Ranges.

Realizing an effective, binder-free, and super-wetting electrocatalyst for the hydrogen evolution reaction (HER) at full pH is essential for the creation of clean hydrogen. In this study, the Ru-loaded NiCo bimetallic hydroxide (Ru@NiCo-BH) catalyst was prepared by spontaneous redox reaction. The chemical interaction between Ru NPs and NiCo-BH by the Ru-O-M (M=Ni, Co) interface bond, the electron-rich Ru active site, and the multi-channel nickel foam carrier make the superhydrophilic and superaerophobic surface advantageous for mass transfer in the HER process. Therefore, Ru@NiCo-BH has remarkable HER activity, with low overpotential of 29, 68 and 80 mV, a 10 mA cm-2 current density can be obtained in alkaline, neutral and acidic electrolytes respectively. This work provides a reference for the rational development of universal electrocatalysts for hydrogen evolution in the all pH ranges through simple design strategies.

3D Hierarchical-Architectured Nanoarray Electrode for Boosted and Sustained Urea Electro-Oxidation.

Exploring active and durable Ni-based materials with optimized electronic and architectural engineering to promote the urea oxidation reaction (UOR) is pivotal for the urea-related technologies. Herein a 3D self-supported hierarchical-architectured nanoarray electrode (CC/MnNi@NC) is proposed in which 1D N-doped carbon nanotubes (N-CNTs) with 0D MnNi nanoparticles (NPs) encapsulation are intertwined into 2D nanosheet aligned on the carbon cloth for prominently boosted and sustained UOR electrocatalysis. From combined experimental and theoretical investigations, Mn-alloying can regulate Ni electronic state with downshift of the d-band center, facilitating active Ni3+ species generation and prompting the rate-determining step (*COO intermediate desorption). Meanwhile, the micro/nano-hierarchical nanoarray configuration with N-CNTs encapsulating MnNi NPs can not only endow strong operational durability against metal corrosion/agglomeration and enrich the density of active sites, but also accelerate electron transfer, and more intriguingly, promote mass transfer as a result of desirable superhydrophilic and quasi-superaerophobic characteristics. Therefore, with such elegant integration of 0D, 1D and 2D motifs into 3D micro/nano-hierarchical architecture, the resulting CC/MnNi@NC can deliver admirable UOR performance, favorably comparable to the best-performing UOR electrocatalysts reported thus far. This work opens a fresh prospect in developing advanced electrocatalysts via electronic manipulation coupled with architectural engineering for various energy conversion technologies.

Dropwise Condensate Comb for Enhanced Heat Transfer.

Dropwise condensation on superhydrophobic surfaces could potentially enhance heat transfer by droplet spontaneous departure via coalescence-induced jumping. However, an uncontrolled droplet size could lead to a significant reduction of heat transfer by condensation, due to large droplets that resulted in a flooding phenomenon on the surface. Here, we introduced a dropwise condensate comb, which consisted of U-shaped protruding hydrophilic stripes and hierarchical micro-nanostructured superhydrophobic background, for a better control of condensation droplet size and departure processes. The dropwise condensate comb with a wettability-contrast surface structure induced droplet removal by flank contact rather than three-phase line contact. We showed that dropwise condensation in this structure could be controlled by designing the width of the superhydrophobic region and height of the protruding hydrophilic stripes. In comparison with a superhydrophobic surface, the average droplet radius was decreased to 12 µm, and the maximum droplet departure radius was decreased to 189 µm by a dropwise condensate comb with 500 µm width of a superhydrophobic region and 258 µm height of a protruding hydrophilic stripe. By controlling the droplet size and departure on hierarchical micro-nanostructured superhydrophobic surfaces, it was experimentally demonstrated that both the heat transfer coefficient and heat flux could be enhanced significantly. Moreover, the dropwise condensate comb showed a maximum heat transfer coefficient of 379 kW m-2 K-1 at a low subcooling temperature, which was 85% higher than that of a superhydrophobic surface, and it showed 113% improvement of high heat flux or heat transfer coefficient when it was compared with that of the hierarchical micro-nanostructured superhydrophobic surface at a high subcooling temperature of ∼10.6 K. This work could potentially transform the design and fabrication space for high-performance heat transfer devices by spatial control of condensation droplet size and departure processes.

Single-Cell Enzymatic Screening for Epithelial Mesenchymal Transition with an Ultrasensitive Superwetting Droplet-Array Microchip.

The phenotypic changes of circulating tumor cells (CTCs) during the epithelial-mesenchymal transition (EMT) have been a hot topic in tumor biology and cancer therapeutic development. Here, an integrated platform of single-cell fluorescent enzymatic assays with superwetting droplet-array microchips (SDAM) for ultrasensitive functional screening of epithelial-mesenchymal sub-phenotypes of CTCs is reported. The SDAM can generate high-density, volume well-defined droplet (0.66 nL per droplet) arrays isolating single tumor cells via a discontinuous dewetting effect. It enables sensitive detection of MMP9 enzyme activities secreted by single tumor cells, correlating to their epithelial-mesenchymal sub-phenotypes. In the pilot clinical double-blind tests, the authors have demonstrated that SDAM assays allow for rapid identification and functional screening of CTCs with different epithelial-mesenchymal properties. The consistency with the clinical outcomes validates the usefulness of single-cell secreted MMP9 as a biomarker for selective CTC screening and tumor metastasis monitoring. Convenient addressing and recovery of individual CTCs from SDAM have been demonstrated for gene mutation sequencing, immunostaining, and transcriptome analysis, revealing new understandings of the signaling pathways between MMP9 secretion and the EMT regulation of CTCs. The SDAM approach combined with sequencing technologies promises to explore the dynamic EMT plasticity of tumors at the single-cell level.

Bio-inspired and metal-derived superwetting surfaces: Function, stability and applications.

Due to their exceptional anti-icing, anti-corrosion, and anti-drag qualities, biomimetic metal-derived superwetting surfaces, which are widely employed in the aerospace, automotive, electronic, and biomedical industries, have raised significant concern. However, further applications in other domains have been hampered by the poor mechanical and chemical durability of superwetting metallic surfaces, which can result in metal fatigue and corrosion. The potential for anti-corrosion, anti-contamination, anti-icing, oil/water separation, and oil transportation on surfaces with superwettability has increased in recent years due to the advancement of research in biomimetic superwetting interface theory and practice. Recent developments in functionalized biomimetic metal-derived superwetting surfaces were summarized in this paper. Firstly, a detailed presentation of biomimetic metal-derived superwetting surfaces with unique capabilities was made. The problems with the long-term mechanical and chemical stability of biomimetic metal-derived superwetting surfaces were then examined, along with potential solutions. Finally, in an effort to generate fresh concepts for the study of biomimetic metal-derived superwetting surfaces, the applications of superwetting metallic surfaces in various domains were discussed in depth. The future direction of biomimetic metal-derived superwetting surfaces was also addressed.

Water-oil dual-channels enabled exceptional anti-fouling performances for separation of emulsified oil pollutant.

Oil contamination has been an increasingly concerned environmental issue due to the large quantity of oily wastewater discharged by the industry. The extreme wettability-enabled single-channel separation strategy guarantees efficient separation of oil pollutant from wastewater. However, the ultra-high selective permeability forces the intercepted oil pollutant to form a blocking layer, which weakens the separation capability and slows the kinetics of permeable phase. As a consequence, the single-channel separation strategy fails to maintain a stable flux for a long-term separation process. Herein, we reported a brand-new water-oil dual-channels strategy for accomplishing an ultra-stable long-term separation of emulsified oil pollutant from oil-in-water nano-emulsion by engineering two drastically opposite extreme wettabilities (i.e. superhydrophilicity and superhydrophobicity) to build the water-oil dual-channels. The strategy established the superwetting transport channels to permit water and oil pollutant to permeate through their own channel. In this way, the generation of intercepted oil pollutant was prevented, which guaranteed an exceptional long-lasting (20 h) anti-fouling performance for successful achievement of an ultra-stable separation of oil contamination from oil-in-water nano-emulsion with high flux retention and high separation efficiency. Therefore, our investigations provided a new route for realizing ultra-stable long-term separation of emulsified oil pollutant from wastewater.

Effects of surface nanotexturing on the wickability of microtextured metal surfaces.

HYPOTHESIS: Achieving spontaneous, rapid, and long-distance liquid transport is crucial for many practical applications such as phase change heat transfer and reactions at solid-liquid interfaces. Surface nanotexturing has been widely reported to improve the wickability of microtextured metal surfaces. Although surface nanotextures show high capillary pressure, the high fluid flow resistance through nanotextures prevents fluid transport. The underlying mechanisms responsible for the enhanced wickability of nanotextured surfaces are still unclear. EXPERIMENTS: Herein, we prepared a variety of microtextures and nanotextures on copper surfaces by femtosecond laser micromachining and chemical oxidation, respectively. The wickability of these textured surfaces was quantitively compared by measuring wicking coefficient and capillary rise speed. We designed experiments to eliminate any possible effects of surface oxidation and metal composition on wickability. A theoretical model describing the vertical and horizontal capillary flow in V-shaped microgrooves was proposed and utilized to analyze the experimental results. The effects of time-dependent wettability on wickability were also examined. FINDINGS: Surface nanotexturing can enhance surface wettability while altering the micrometer-scale structural characteristics. The greatly enhanced wickability of nanotextured surfaces can only be observed when the surface microtextures have a very small aspect ratio. Otherwise, for metal surfaces with fine microgrooves, the latter effect is more pronounced, and thus the surface wickability may deteriorate after preparing surface nanotextures; for surfaces with wide microgrooves, both effects are minimal, and the surface wickability enhances only marginally after surface nanotexturing. Furthermore, the wickability of microtextured surfaces will decay rapidly due to the adsorption of airborne organics, whereas adding surface nanotextures can significantly inhibit this degradation. The anti-contamination capability of surface nanotextures is considered likely to be a potential mechanism responsible for the greatly enhanced wickability of nanotextured surfaces noted in some studies.

Laser-Heat Surface Treatment of Superwetting Copper Foam for Efficient Oil-Water Separation.

Oil pollution in the ocean has been a great threaten to human health and the ecological environment, which has raised global concern. Therefore, it is of vital importance to develop simple and efficient techniques for oil-water separation. In this work, a facile and low-cost laser-heat surface treatment method was employed to fabricate superwetting copper (Cu) foam. Nanosecond laser surface texturing was first utilized to generate micro/nanostructures on the skeleton of Cu foam, which would exhibit superhydrophilicity/superoleophilicity. Subsequently, a post-process heat treatment would reduce the surface energy, thus altering the surface chemistry and the surface wettability would be converted to superhydrophobicity/superoleophilicity. With the opposite extreme wetting scenarios in terms of water and oil, the laser-heat treated Cu foam can be applied for oil-water separation and showed high separation efficiency and repeatability. This method can provide a simple and convenient avenue for oil-water separation.

Water harvesting on biomimetic material inspired by bettles.

Many organisms in nature such as beetles and cacti can survive in arid places by their own surface structures that are still able to collect mist. These surfaces have micro-nano structures that maintain a very low adhesion, allowing them to continuously collect and transport water. Here, we used a light curing three dimensional molding process to create a template for a water harvesting system inspired by the back of a beetle, a hydrogel-like beetle back surface for water transport. By changing the curvature structure of the water evacuation channels and altering the hydrophilic and hydrophobic properties of the surface, the designed large-scale artificial water harvesting study was made possible. The results show that if the surface has a proper curvature structure and hydrophobic density, the water collection on the super-impregnated surface is much higher than that on an ordinary hydrophobic surface. Based on this, a new efficient and environmentally friendly water collection scheme is proposed. The data show that the triangular tip structure imitating beetle-backed hydrogel surface collects the highest amount of water with a water weight of 16 g in 2 h. This study offers interesting prospects for designing a new generation of structural materials with a bionic structure distribution for high-efficiency water harvesting. The results of the study are useful for pushing the improvement of environmental-friendly water collection, transport and separation devices. Abbreviations: The dorsal shape of the beetle's back is critical for water collection. In this work, while redesigning the shape of the back of the beetle, the method of 3D printing the beetle back template was used to prepare the beetle back made of hydrogel, which greatly improved the water collection performance and has certain engineering application prospects.

Super-Slippery Poly(Dimethylsiloxane) Brush Surfaces: From Fabrication to Practical Application.

Superwetting surfaces with special slippery performances have been the focus of practical applications and basic research for decades. Compared to superhydrophobic/superoleophobic and slippery liquid-infused porous surfaces (SLIPS), liquid-like covalently attached poly(dimethylsiloxane) (PDMS) brush surfaces have no trouble in constructing the micro/nanostructure and the loss of infused lubricant, meanwhile, it can also provide lots of new advantages, such as smooth, transparent, pressure- and temperature-resistant, and low contact angle hysteresis (CAH) to diverse liquids. This paper focuses on the relationship between the wetting performance and practical functional application of PDMS brush surfaces. Recent progress of the preparation of PDMS brush surfaces and their super-slippery performances, with a special focus on diverse functional applications were summarized. Finally, perspectives on future research directions are also discussed.

A Review of Smart Superwetting Surfaces Based on Shape-Memory Micro/Nanostructures.

Bioinspired smart superwetting surfaces with special wettability have aroused great attention from fundamental research to technological applications including self-cleaning, oil-water separation, anti-icing/corrosion/fogging, drag reduction, cell engineering, liquid manipulation, and so on. However, most of the reported smart superwetting surfaces switch their wettability by reversibly changing surface chemistry rather than surface microstructure. Compared with surface chemistry, the regulation of surface microstructure is more difficult and can bring novel functions to the surfaces. As a kind of stimulus-responsive material, shape-memory polymer (SMP) has become an excellent candidate for preparing smart superwetting surfaces owing to its unique shape transformation property. This review systematically summarizes the recent progress of smart superwetting SMP surfaces including fabrication methods, smart superwetting phenomena, and related application fields. The smart superwettabilities, such as superhydrophobicity/superomniphobicity with tunable adhesion, reversible switching between superhydrophobicity and superhydrophilicity, switchable isotropic/anisotropic wetting, slippery surface with tunable wettability, and underwater superaerophobicity/superoleophobicity with tunable adhesion, can be obtained on SMP micro/nanostructures by regulating the surface morphology. Finally, the challenges and future prospects of smart superwetting SMP surfaces are discussed.