Superhydrophobic Surfaces Research Articles

A facile preparation of durable superhydrophobic PFA coatings with superior anti-icing, anti-corrosion and self-cleaning performance

The potential of superhydrophobic coatings for various applications has been widely recognized. However, preparing durable superhydrophobic coatings on metal surfaces remains a significant challenge. Perfluoroalkoxy Alkane (PFA), a fluorine-rich material, has recently emerged as a promising candidate for constructing superhydrophobic coatings. In this study, a mechanically stable superhydrophobic PFA coating was prepared using a simple combination of electrodeposition and annealing. The prepared PFA coating displays excellent water repellency, as evidenced by a water contact angle of 171 ± 0.3° and a sliding angle of 1.0 ± 0.4° The water contact angle of the coating only decreases by 0.6°after undergoing 400 tape stripping tests, indicating the remarkable stability. The PFA coating significantly prolongs the freezing time of water droplets on a cool surface at temperatures of -6 °C, -8 °C, and -10 °C, with improvements of 19.4, 72.5, and 47.8 times respectively. The corrosion current density on the coated surface is reduced by four orders of magnitude compared to bare aluminum alloy, and the PFA coating exhibits a high inhibition corrosion efficiency of 99.995 %. Furthermore, the coating possesses exceptional self-cleaning performance by repelling dirt particles and maintaining a clean surface. Consequently, the developed superhydrophobic PFA coating holds significant promise for long-lasting anti-icing, anti-corrosion and self-cleaning applications.

Preparation of Robust Superhydrophobic Coatings Using Hydrophobic and Tough Micro/Nano Particles

Superhydrophobic nanocomposite coatings, prepared using adhesive and fillers, offer advantages including ease of fabrication and suitability for large-scale applications, but compared with other types of artificial superhydrophobic surfaces, poor durability still limits these surfaces from practical applications. The utilization of micro/nanoscale particles with both intrinsic hydrophobicity and robust mechanical properties to prepare coatings should significantly contribute to enhanced durability. Herein, rough and hydrophobic particles with micro/nano hierarchical structures were prepared at first, and robust superhydrophobic surfaces were fabricated using the prepared particles and additional nanoparticles. The initially prepared particles formed a rough framework of the coating, while additional nanoparticles provided inevitable nanoscale structures. A series of mechanical tests were carried out to validate the durability, and the surface with 20 wt.% NPs exhibited the best performance, withstanding 30 tape peeling tests, a 2.47 m sandpaper rubbing test (at a pressure of 5 kPa), the impact of 200 g of grit dropped from a height of 20 cm, and a 2 h acidic immersion. These appealing materials may attract attention for self-cleaning, high-speed water impact resistance, anti-icing, and anti-fouling applications in the coatings industry.

Novel fluorine-functionalized Ti3C2Tx/TiO2 hybrid coatings with enhanced weatherability, antifouling, and interfacial anticorrosion performances

As a valuable symbol of human cultural heritage, bronze inevitably endures varying degrees of corrosion due to environmental change. Thus, developing an efficient protective coating for bronze is crucial to ensure bronze relics receive more protection. Herein, a multifunctional organic-inorganic hybrid composite coating of 1 H,1 H,2 H,2 H-Perfluorodecyltriethoxysilane (PFDTES), Ti3C2Tx nanosheets and TiO2 nanoparticles (PFDTES@Ti3C2Tx/TiO2) are successfully prepared and coated the bronze, which exhibits excellent anti-corrosion, weathering stability and superhydrophobicity. The superhydrophobicity of coating is derived from introducing a low surface energy C-F bond. Furthermore, the corrosion protection ability can be improved by the barrier effect of Ti3C2Tx nanosheets, and TiO2 nanoparticles can enhance the weathering stability of coatings by providing exceptional abrasion resistance and ultraviolet (UV) resistance capabilities. Morphological examination, X-ray photoelectron spectroscopy, an accelerated aging test, and electrochemical measurements, among other methods, were used to research the protective effect and anticorrosion performance of organic-inorganic hybrid coatings. It can be found that the composite coatings have a large water contact angle (153°) and form a superhydrophobic surface. Furthermore, electrochemical results show that the superhydrophobic PFDTES@Ti3C2Tx/TiO2 coating has a higher low-frequency impedance modulus and lower current density than the uncoated substrate, indicating enhanced corrosion resistance. Based on solid and liquid pollutant tests, the PFDTES@Ti3C2Tx/TiO2 coatings also showed good self-cleaning and antifouling properties. And coating maintained good transparency without changing the bronze color and appearance. In conclusion, the superhydrophobic PFDTES@Ti3C2Tx/TiO2 composite coating has potential applications in the field of bronze protection.

Development of a Superhydrophobic Protection Mechanism and Coating Materials for Cement Concrete Surfaces.

In order to further enhance the erosion resistance of cement concrete pavement materials, this study constructed an apparent rough hydrophobic structure layer by spraying a micro-nano substrate coating on the surface layer of the cement concrete pavement. This was followed by a secondary spray of a hydroxy-silicone oil-modified epoxy resin and a low surface energy-modified substance paste, which combine to form a superhydrophobic coating. The hydrophobic mechanism of the coating was then analysed. Firstly, the effects of different types and ratios of micro-nano substrates on the apparent morphology and hydrophobic performance of the rough structure layer were explored through contact angle testing and scanning electron microscopy (SEM). Subsequently, Fourier transform infrared spectroscopy and permeation gel chromatography were employed to ascertain the optimal modification ratio, temperature, and reaction mechanism of hydroxy-silicone oil with E51 type epoxy resin. Additionally, the mechanical properties of the modified epoxy resin-low surface energy-modified substance paste were evaluated through tensile tests. Finally, the erosion resistance of the superhydrophobic coating was tested under a range of conditions, including acidic, alkaline, de-icer, UV ageing, freeze-thaw cycles and wet wheel wear. The results demonstrate that relying solely on the rough structure of the concrete surface makes it challenging to achieve superhydrophobic performance. A rough structure layer constructed with diamond micropowder and hydrophobic nano-silica is less prone to cracking and can form more "air chamber" structures on the surface, with better wear resistance and hydrophobic performance. The ring-opening reaction products that occur during the preparation of modified epoxy resin will severely affect its mechanical strength after curing. Controlling the reaction temperature and reactant ratio can effectively push the modification reaction of epoxy resin through dehydration condensation, which produces more grafted polymer. It is noteworthy that the grafted polymer content is positively correlated with the hydrophobicity of the modified epoxy resin. The superhydrophobic coating exhibited enhanced erosion resistance (based on hydrochloric acid), UV ageing resistance, abrasion resistance, and freeze-thaw damage resistance to de-icers by 19.41%, 18.36%, 43.17% and 87.47%, respectively, in comparison to the conventional silane-based surface treatment.

Preparation of Aluminum-Based Superhydrophobic Surfaces for Fog Collection by Bioinspired Sarracenia Microstructures.

Freshwater shortage is a growing problem. Inspired by the Sarracenia trichome fog-trapping and ultrafast water-transport structure, a series of hierarchical textured surfaces with high-low ribs with different wettabilities was prepared based on laser processing combined with dip modification. Through fog-collection performance tests, it was found that the samples with superhydrophobicity and low adhesion had the best fog-collection effect. In addition, it was observed that the fog-collection process of different microstructured samples was significantly different, and it was analysed that the fog-collection process was composed of two aspects: directional condensation and directional transport of droplets, which were affected by the low ribs number and rib height ratio. A design parameter was given to create the Sarracenia trichome-like structure to achieve a fast water transport mode. This study provides a good reference for the development and preparation of fog-collection surfaces.

Dynamics of Snowflakes Impacting Superhydrophobic Surfaces.

Snow and ice accumulation on surfaces presents significant safety and efficiency challenges across various industries, necessitating the development of effective mitigation strategies. In this study, the dynamics and energy dissipation of natural snowflakes impacting superhydrophobic surfaces (SHS) were explored using high-speed imaging and a novel image processing method. The size, velocity (impact and bounce), and contact time of natural wet snowflakes were quantitatively analyzed, identifying two primary impact outcomes: bouncing and fragmentation. The analysis focused on bouncing to study the coefficient of restitution (COR) of snowflakes. It was found that small snowflakes (<1.40 mm in diameter) with low impact velocities (<2.90 m/s) tend to be bounced, whereas larger, faster snowflakes are more likely to be fragmented. For the first time, the contact time of natural snowflakes on SHS was also reported, introducing a dimensionless contact time (DCT) for quantifying energy dissipation during the impact. The results indicate that energy dissipation has a cubic relationship with snowflake size and a quadratic relationship with its impact velocity, demonstrating that larger and faster snowflakes dissipate more energy. It is observed that a reduction in DCT leads to an exponential increase in COR and a decrease in normalized energy dissipation, supporting the theoretical prediction that the COR approaches one and the normalized energy dissipation approaches zero as the DCT approaches zero. These results are significant for enhancing the design and efficiency of anti-icing surfaces, contributing to the development of models that simulate snow accumulation behaviors and inform better design of both active and passive snow mitigation strategies.

Preparation of robust superhydrophobic stainless steel mesh for Oil-Water separation through Mn-Assisted control of one-step electrodeposited Zn growth

Removing oil spills from water presents a significant challenge in environmental remediation. Among various separation materials available, superhydrophobic materials have emerged as promising solutions, notable for their efficiency, cost-effectiveness, and eco-friendliness. The precise control of micro/nanostructure synthesis plays an essential role in creating superhydrophobic surfaces. Herein, the present study demonstrates controlled growth of well-defined hexagonal platelet-like micro/nanostructures of zinc crystals. This is achieved through deliberate manipulation of the electrodeposition crystal growth process, a facet frequently disregarded in previous studies. Notably, the present work, based on the distinctive properties of the Zn hexagonal close-packed structure (hcp), focuses on the effects of incorporating Mn and deposition parameters on the performance of Zn coatings. These findings offer valuable insights into selectively constructing Zn crystal planes for future electrodeposition endeavors. The resulting zinc/manganese stearate (SZM) coating on stainless steel mesh (SSM) shows remarkable water contact angles, reaching an impressive 163.1 ± 2.4°, in accordance with the Cassie-Baxter theory. This feature facilitates highly efficient oil–water separation. Coupled with size sieving of SSM, SZM coatings exhibit an oil–water separation efficiency of up to 99.86 % and a flux as high as 55.58 kL/m2h. Furthermore, the SZM coating exhibits long-lasting superhydrophobicity and exceptional corrosion resistance, even when subjected to challenging conditions such as high temperatures up to 200℃, pressure reaching 7 kg/cm2, or exposure to chemical and mechanical stresses. These enduring properties make SZM coatings suitable for constructing gravity-based and continuous oil–water separation systems, establishing them as a practical solution for diverse oil–water separation applications.

Fabrication and Properties of Superhydrophobic Colored Stainless Steel Surface for Decoration and Anti-Corrosion

A colored superhydrophobic surface on a stainless steel substrate was achieved by means of high temperature oxidation combined with subsequent spraying modification by superhydrophobic nano-silica film. Comprehensive characterizations of the surface were performed in terms of color, morphology, composition, wettability, and corrosion resistance by optical microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), contact angle, potentiodynamic polarization, and electrochemical impedance spectroscopy measurement. At 400 °C, the surface was pale yellow, gradually turning yellow and then red as the temperature increased. At 700 °C and 800 °C, the surface colors were blue and dark brown, respectively. The samples with oxide films demonstrated lower contact angles, specifically 80.5° ± 2.5 at 400 °C, 79.1° ± 2.8 at 500 °C, and 75.6° ± 3.4 at 600 °C. The polarization resistance measured on the oxidized film formed at 600 °C exceeded 7.93 × 104 Ω·cm2. After spraying the treatment, these colorful surfaces exhibited superhydrophobicity, they were self-cleaning, and they satisfied anti-corrosion properties. The treatment performs as an excellent barrier and exhibits a high corrosion resistance of 4.68 × 106 Ω·cm2. The successful preparation of superhydrophobic colored surfaces offers the possibility of providing stainless steel with both decoration value and self-cleaning function simultaneously by our proposed chromium-free fabrication process.

Mixed superoleophilic/superoleophobic hard granular media for coalescence of oil-in-water-emulsion

To enhance the coalescence separation efficiency of oil/water emulsions, the coalescence mechanism of oil droplets between two media of opposite wettability was investigated. A coalescent-bed comprising a mix of superhydrophobic and superoleophilic quartz sand, along with superhydrophilic and underwater superoleophobic quartz sand, was constructed in a coalescer. Single-factor and response surface experiments were used to study the effects of oleophilic/oleophobic sand mixing ratio, apparent velocity, initial oil concentration, bed thickness, sand particle size on coalescence-separation performance, and to determine the optimal experimental conditions. Employing the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, the agglomeration mechanism of oil droplets within the mixed particle bed was analyzed based on interfacial energy dynamics. Results indicate that the mixing ratio of the two sands significantly influences coalescence separation performance. An optimal oleophilic/oleophobic sand mixing ratio of 1:1 yielded a mass factor of 0.69 kPa−1, showcasing superior coalescence separation efficiency and an optimal balance of separation efficiency and pressure drop. Under the optimal conditions of apparent velocity of 2.7 m/h, initial oil concentration of 471.9 mg/L, bed thickness of 12.6 cm and mixed sand particle size of 0.5 mm, the oil/water separation efficiency reached 98.08 % ± 0.87 %, with effluent oil droplet size being 2.5 to 3 times larger than at the inlet. Analysis of the oil droplet coalescence mechanism revealed a synergistic effect between the two quartz sands, enhancing oil removal performance. The strong affinity of oil to the superhydrophobic and superoleophilic sand surface increases oil droplet wetting and coalescence efficiency, while the water attraction on the superhydrophilic and underwater superoleophobic sand surface forms a stable water film, improving the flux of the continuous water phase and reducing pressure drop across the bed. This study demonstrates that combining quartz sands of opposite wettability not only overcomes the limitations of single-wettability surfaces in coalescing oil removal but also achieves high efficiency and low energy consumption in oil removal.

Phase diagram for nanodroplet impact on solid spheres: From hydrophilic to superhydrophobic surfaces

The impact of droplets on solid surfaces is a crucial fluid phenomenon in the additive industry, biotechnology, and chemistry, where controlling impact dynamics and duration is essential. While extensive research has focused on flat substrates, our understanding of impact dynamics on curved surfaces remains limited. This study seeks to establish phase diagrams for the process of droplet impact on solid spheres and further quantitatively describe the effect of curvature through theoretical analysis. It aims to determine the critical conditions between different impact outcomes and also establish a scaling relationship for the contact time. Here, the post-impact outcome regimes occurring for a wide range of Weber numbers (We) from 1.2 to 173.8, diameter ratio (λ) of solid spheres to nanodroplets from 0.25 to 2, and surface wettability (θ) from 21° to 160°, through the molecular dynamics simulation method (MD) and theoretical analysis. The MD simulations reveal that the phase diagrams of droplet impacts on hydrophilic, hydrophobic, and superhydrophobic spheres differ, with specific distinctions focusing on rebound and three different forms of dripping. Furthermore, a theoretical model based on the principle of energy conservation during impact on superhydrophobic surfaces has been developed to predict the critical conditions between rebound and dripping states, showing good agreement with simulation results. Additionally, a new scaling relationship of contact time for droplet impact on superhydrophobic spherical surfaces has also been established by extending and modifying the existing models, which also agrees well with the simulated results. These insights provide a foundational understanding for designing surface structures.

Stearic Acid Modified Nano-ZnO Superhydrophobic Coating for Steel Mesh

Abstract To mitigate the detrimental effects of water on metal textiles, hydrophobic modification of such materials has garnered significant attention. However, traditional approaches often rely on complex procedures or costly materials, limiting their widespread application. Herein, we present a facile method for fabricating a superhydrophobic coating on steel mesh, and characterize the properties of the modified material. Initially, the surface of the dry steel mesh is uniformly coated with nano-ZnO crystals using a liquid deposition technique at room temperature. Subsequently, stearic acid is employed to hydrophobically modify the ZnO crystals, yielding a ZnO-based superhydrophobic coating. The influence of ZnO concentration and deposition duration on the surface crystal structure, hydrophobicity, and abrasion resistance is investigated. X-ray diffraction (XRD) analysis is performed to study the surface groups before and after hydrophobic modification, while static contact angle measurements are used to assess the hydrophobic properties of the coated surface. Remarkably, even after abrasion with 1000-mesh sandpaper, the superhydrophobic properties of the steel mesh with an optimized ZnO concentration decrease by only 4%. This simple, cost-effective, and highly efficient preparation method holds promising potential for applications in related fields.

Water droplet transport on superhydrophobic surfaces induced by the dual synthetic jets

Droplet transport is very essential in many industrial applications. This article proposed the concept of employing dual synthetic jets in conjunction with superhydrophobic materials to facilitate the long-distance directional transport of water droplets. Experiments showed that the droplet transport speed could reach approximately 90 mm/s. In addition to linear transport, dual synthetic jets were also capable of achieving curved transport of droplets on superhydrophobic surfaces. High-speed photography captured the details of the droplet transport process. Additionally, simulations analyzed the water droplet's aerodynamic forces and the deformation and breakup mechanisms at the actuator's outlet. The research in this paper was anticipated to contribute to new methods for directed droplet transport on superhydrophobic surfaces. It is eliminated the need for pre-processing the surface to create a path, and there was also no need to incorporate conductive or magnetic substances within the droplets.

Fabrication of superhydrophobic titanium surfaces: impact of different micropatterns

ABSTRACT Offshore and nuclear power plants use titanium condensers to cool exhaust steam from turbines. Preparation of robust superhydrophobic Titanium surfaces is necessary to protect these condensers from fouling and pitting phenomena. This study investigates the impact of various laser-textured Titanium grade 2 surface configurations followed by silicone oil heat treatment on enhancing its wettability and tribological properties. Seven distinct micropatterns were fabricated using a fiber laser with a laser power of 7.5 W, a scanning speed of 300 mm/s, a scan loop of 10, and a pulse frequency of 20 kHz. Patterned surfaces were characterized using different techniques, namely, micro-hardness, surface morphology, wettability, elemental analysis and wear. Improvement in wetting property was observed in laser textured samples after heating with silicone oil due to the adsorption of nonpolar groups (C=O, –CH3) resulting in a low energy surface. The grid pattern surface exhibited the highest water contact angle (WCA) of 151.01° due to a dense microstructure.

Anti-corrosion superhydrophobic micro-TiB2/nano-SiO2 based coating with “multi-scale hard particles-embedding-soft membrane” structure fabricated by spray deposition

Superhydrophobic surfaces with multifunctional merits show growing demands in real-world applications. However, the micro-nano textures make them highly susceptible to mechanical wear. Herein, a “multi-scale hard particles-embedding-soft membrane” strategy was proposed to fabricate a composite coating by embedding micro-TiB2/nano-SiO2 particles into polydimethylsiloxane (PDMS)@polyurethane (PU) via a single-step spraying method. The addition of micro-nano particles exerts two effects including “hard” micro-skeletons to overcome ductile issue of “soft” organic membrane and creation of wear-resistant bearing points. Simultaneously, “soft” membrane can absorb stress caused by external mechanical force. Furthermore, PDMS acts as a modifier to decrease surface energy and PU serves as an adhesive to enhance interfacial bonding strength. As a consequence, the proposed hybrid coating could achieve synergistic improvements in mechanical durability and versatility, breaking the undesirable “trade-off” restriction. The optimized superhydrophobic coating exhibits the highest water contact angle (WCA) of 163.21° ± 3.49°, the lowest sliding angle (SA) of 5.75° ± 0.90°, corrosion protection efficiency of 95.5 % in 3.5 wt% NaCl solution, with outstanding multifunctionalities, among the top-level performances. The inherent properties of micro-TiB2/nano-SiO2 ceramics and their highly ordered arrangement in the superhydrophobic coating are expected to provide a reliable and convenient design proposal in corrosion protection engineering.

Durable microstructure-based superhydrophobic composite with photothermal performance for multifunctional application

Nowadays, multifunctional superhydrophobic coating has drawn widespread attention by virtue of its great water-repellent property, whereas the fragile mechanical and chemical durability of superhydrophobic coating greatly limits its practical application. Herein, a robust and multifunctional superhydrophobic composite coating (CFRE-SP@Fe3O4) with anti-corrosion, delay-icing and self-deicing performance is constructed via simple imprinting-demolding process on the carbon fiber reinforced epoxy resin (CFRE) surface and post-deposition modification with polydimethylsiloxane (PDMS) and epoxy resin modified Fe3O4 nanoparticles. The obtained CFRE-SP@Fe3O4 coating displays a superhydrophobic property with a WCA of 155° ± 1.2°. By virtue of the protection effect of the robust micro-grid structures for the inner superhydrophobic Fe3O4 nanoparticles (SP@Fe3O4), the CFRE-SP@Fe3O4 coating still maintains great superhydrophobicity after linear friction for 100 times. Additionally, compared with the carbon steel treated with CFRE, the impedance modulus at lowest frequency of CFRE-SP@Fe3O4 coating treated group further increase with a value of 107 Ω·cm2, confirming the excellent anti-corrosion performance. Owing to the air pocket captured by the micro-/nanostructure on the superhydrophobic surface, the icing time of the CFRE-SP@Fe3O4 surfaces extends from 60 s to 2130 s. Moreover, combined with the photothermal conversion performance of carbon fiber and Fe3O4 nanoparticles, the ice on the CFRE and CFRE-SP@Fe3O4 coatings surfaces begin to melt 137 s, displaying the excellent self-deicing performance.

Numerical analysis of hydrophobic surface effects on cavitation inception and evolution in high-speed centrifugal pumps for thermal energy storage and transfer systems

This study explores the influence of wettability surfaces on cavitation inception and evolution in high-speed centrifugal pumps used for thermal energy storage and transfer systems through numerical simulations. The simulations were conducted using the Kunz mass transfer model implemented in Fluent, combined with the Eulerian multiphase flow approach and the shear stress transport k–ω turbulence model. The cavitation dynamics were analyzed across contact angles ranging from superhydrophilic to superhydrophobic conditions. The results demonstrate that superhydrophobic surfaces delay cavitation onset compared to hydrophilic ones, reducing the critical cavitation coefficient by at least 28%. At flow rates of 1.11 Q0 and 0.89 Q0, cavitation numbers show distinct trends, with superhydrophobic surfaces enhancing cavitation stability and reducing the frequency of cavitation shedding. The reentrant jet dynamics are also affected, with increased hydrophobicity weakening the jets and stabilizing cavitation zones. This research aims to advance the understanding of using surface wettability to manage cavitation in high-speed centrifugal pumps, thereby improving the performance and reliability of thermal energy storage and transfer systems.

Green and Sustainable Superhydrophobic Phosphogypsum Mortar Coating with Self-Cleaning Properties and Water Resistance

Green and Sustainable Superhydrophobic Phosphogypsum Mortar Coating with Self-Cleaning Properties and Water Resistance

Fast fabrication of superhydrophobic Ti-6Al-4V surface using Q-switched nanosecond pulsed laser at 1064 nm and cyclohexane

Superhydrophobic and superhydrophilic surfaces are attracting significant attention in fundamental and applied research. This study fabricated the micro/nanostructure with a Q-switched nanosecond pulsed laser on the Ti-6Al-4V surface. Three laser-generated surface topographies on titanium were produced based on three different pitch sizes (51 μm, 34 μm, and 29 μm). The laser textured surfaces (LTS) were studied in terms of both structure evolution and chemical composition using Field Emission Scanning Electron Microscopy (FE-SEM), Optical Microscopy (OM), Confocal Laser Scanning Microscopy (CLSM), Raman Spectroscopy, and X-ray Diffractometer (XRD). 29 μm pitch displayed the lowest water contact angle of 18.5° and surface roughness of 0.5 μm. This structure was further treated with cyclohexane at different temperatures. The best sample reached superhydrophobicity with a maximum water contact angle of 155.1° immediately after being treated with cyclohexane at the low temperature of 70 °C for 2 h, while the raw surface, for comparison, showed no change in hydrophobicity after being treated with cyclohexane under the same condition. Thus showing clear evidence of a combined effect between LTS and post-treatment. The surface features were assessed to explain the underlying process.

Eco-friendly bionic superwetting Janus membranes prepared from paper-based laser-induced graphene for photothermal anti-icing and on-demand oil–water separation

Laser-induced graphene (LIG) from carbon precursors is used in the manufacture of semiconductors, energy and biomedical devices. To expand its field of applications, there is a strong need to explore LIG conversion of eco-friendly precursors. An approach combining bionic structures and surface modification on paper-based LIG was investigated for producing asymmetric superwetting Janus membranes. Molecular dynamic simulation illustrates the paper-based LIG conversion mechanism. The Octadecanethiol-modified bionic crescent-shaped LIG surface exhibited superhydrophobic performance, the water contact angle (WCA) is 157° and the water sliding angle (WSA) is 3.5°. The plasma-modified LIG surface was superhydrophilic with the WCA of 0°. The Janus membranes were demonstrated for high-efficient separation of light oil–water and heavy oil–water mixtures. Furthermore, the superhydrophobic surface of the Janus membranes with excellent photothermal properties exhibited superior anti-icing capability. The proposed approach for fabrication of bionic Janus membranes would provide an eco-friendly solution to LIG applications.

Facile fabrication of robust, multi-functional and superhydrophobic coatings with corrosion resistance and anti-icing performance

In this paper, a series of superhydrophobic coatings with varying n-SiO2 content were prepared using a simple one-step spray method. The coatings were characterized with SEM, XPS, electrochemical workstation, AFM, etc. The influence of n-SiO2 content on the micro-nanostructure of the coatings was investigated, as well as the elemental composition, the wettability, mechanical stability, chemical stability, and anti-icing performance. The results showed that as the n-SiO2 content increased, the wettability and anti-icing time of the coatings initially increased and then decreased. The optimal performance was achieved at an n-SiO2 content of 4.16 wt%, with a contact angle of 162.62°, a sliding angle of 4.17°, and an anti-icing time of 1095 s. Mechanical stability was improved with increasing n-SiO2 content, and the coatings lasted for 40 sandpaper abrasion cycles, 55 tape peeling cycles, and 31 icing/deicing cycles at 4.88 wt% of n-SiO2. The coatings demonstrated good chemical stability in neutral and acidic environments but failed in strongly alkaline conditions. Electrochemical tests revealed that the superhydrophobic coatings provided excellent protection, with the corrosion inhibition efficiency (η) of Q235 carbon steel reaching 99.99 % after coating compared to uncoated Q235 carbon steel.