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Microwave absorption (MA) materials are essential for protecting against harmful electromagnetic radiation. In this study, highly efficient and ultrawide-band microwave-absorbing fabrics with superhydrophobic surface features were developed using a facile dip-coating method involving in situ graphene oxide (GO) reduction, deposition of TiO2 nanoparticles, and subsequent coating of a mixture of polydimethylsiloxane (PDMS) and octadecylamine (ODA) on polyester fabrics. Owing to the presence of hierarchically structured surfaces and low-surface-energy materials, the resultant reduced GO (rGO)/TiO2-ODA/PDMS-coated fabrics demonstrate superhydrophobicity with a water contact angle of 159° and sliding angle of 5°. Under the synergistic effects of conduction loss, interface polarization loss, and surface roughness topography, the optimized fabrics show excellent microwave absorbing performances with a minimum reflection loss (RLmin) of −47.4 dB and a maximum effective absorption bandwidth (EABmax) of 7.7 GHz at a small rGO loading of 6.9 wt%. In addition, the rGO/TiO2-ODA/PDMS coating was robust, and the coated fabrics could withstand repeated washing, soiling, long-term ultraviolet irradiation, and chemical attacks without losing their superhydrophobicity and MA properties. Moreover, the coating imparts self-healing properties to the fabrics. This study provides a promising and effective route for the development of robust and flexible materials with microwave-absorbing properties.

To address the functional failure caused by low-surface-tension liquid wetting and adhesion in superhydrophobic materials, in this study, we constructed a bilayer coating with superamphiphobic properties using an epoxy (Ep) bonding layer and an organosilane-grafted attapulgite (OG-ATP) layer through spray-coating technique. The prepared superamphiphobic bilayer coating exhibited high contact angles (CAs) and low sliding angles (SAs) for cold water (25 °C), hot water (85 °C), glycerol, ethylene glycol, peanut oil, and even n-hexadecane (CA = 150.4 ± 0.3° and SA = 7 ± 2°) with surface tension of 27.5 mN m−1. Surface morphology and elemental analysis confirmed the coating's unique micro-nano hierarchical structure and low surface energy characteristics. Electrochemical impedance spectroscopy (EIS) results showed that the surface charge transfer resistance (Rct) and low-frequency modulus (|Z|0.01Hz) were enhanced by 6–7 orders of magnitude compared to the bare aluminum alloy substrate. The anti-corrosion performance remained stable even after 5 days of 3.5 wt% NaCl immersion. Additionally, icing experiments with water droplets at −10 °C and −15 °C revealed a significant delay in ice formation on the substrate protected by the bilayer coating. The development of this protective material, combining superamphiphobicity, self-cleaning, corrosion resistance, and anti-icing functions, will provide advanced technological reserves in areas such as marine, aviation, transportation, and manufacturing.

Superhydrophobic coatings have aroused great research interest due to their potential applications in aviation, energy, etc. However, the coatings are inclined to lose hydrophobicity when exposed to chemical corrosion, which makes them difficult to play a crucial role in some demanding areas such as road engineering. Self-healing of coatings without external stimulations is challenging but essential for reliable superhydrophobic and anti-ice properties, such an interesting topic has been rarely reported. Here we design a self-healing superhydrophobic CNT@SiO2 coating for anti-ice application. The dodecyl trimethoxysilane modified CNT@SiO2 nanoparticles are mixed with epoxy resin and sprayed to form the robust coating, which exhibits excellent superhydrophobicity (155.1°), self-healing properties and ice resistance. After seven strong alkali corrosion cycles, the self-healing rate recover more than 96% after 48 h. The coating almost doubles the freezing time even at −20 °C. The novel and simple strategy for preparing self-healing and anti-icing multifunctional coating provides a new viewpoint in surface protection.

This study focuses on creating a superhydrophobic, durable, and exceptionally transparent coating with dual-scale roughness by naturally formed raspberry-like particles. This approach facilitates the management of surface roughness at both single and dual scales through variations in surface functionalization temperature. We illustrated that adjusting the temperature of organosilanes functionalization on the surface allows for various reactions, such as the direct grafting of metallic precursors or their polymerization on the surface, resulting in the formation of large raspberry-like particles.We investigated the impact of nanoparticle concentration, functionalization duration, and reaction temperature on surface properties. Our results reveal that a concentration of 1.5 % SiO2 nanoparticles, combined with surface functionalization using TCMS for 4 h at 3 °C, provides the optimal conditions for creating a surface that combines superhydrophobicity, transparency, and acceptable durability. The resulting surface exhibits an impressive contact angle of 158.9°, a sliding angle of 2°, and a transmittance rate of 82 %.Furthermore, the coating demonstrates remarkable resistance to abrasion for up to 35 cycles and can withstand temperatures up to 280 °C. It also offers enhanced protection against UV radiation for 50 h and improved resistance to sand abrasion for up to 30 s, enduring bombardment pressures of up to 6 bars. Moreover, the coating presents several advantages in terms of surface cleaning.

Alkali-activated slag cement (AASC) has shown immense potential for application as a low-carbon and eco-friendly cementitious material. It’s crucial to modify the AASC with superhydrophobic property to obtain excellent durability performance. In this paper, low-cost and non-toxic stearic acid (SA) is selected as a hydrophobic agent to impart integral hydrophobic property to the alkali-activated Portland slag cement mortar (AAPSCM). The SA-modified AAPSCM (M-AAPSCM) shows superhydrophobicity with a contact angle of 150.6° and a sliding angle of 9.5°, even when hammered to reveal its broken inner structure. The characterization analysis indicates that stearic acid not only successfully grafts onto the mortar surface but also forms calcium stearate, which successfully reduces the surface energy of the material. Combined with the porous rough structure constructed by medium sand and ethanol volatilization, the originally hydrophilic material achieves hydrophobic modification under the dual synergistic effect. The M-AAPSCM reached a compressive strength of 20.8 MPa after 28 days of curing, satisfying the requirements for hydraulic engineering applications. And the M-AAPSCM not only exhibits an excellent self-cleaning ability against contaminants like sand particles and chalk powder, but also demonstrates remarkable mechanical robustness, even after being subjected to blade scratching or mechanical fracture. Concurrently, the initial and final setting times of M-AAPSCM were determined to be 32 minutes and 41 minutes respectively, demonstrating its rapid-setting characteristic. Additionally, following the hydrophobic modification, AAPSCM effectively overcomes its inherent issues of severe autogenous shrinkage and poor carbonation resistance. Furthermore, when compared with the ordinary AAPSCM (O-AAPSCM), the durability of the M-AAPSCM against dry-wet cycles, icing, and freeze-thaw cycles is significantly enhanced.

Frequent oil spill accidents caused by transportation, storage and usage may lead to severe damage on aquatic and ecological environments. Effective methods for rapid oil recovery are urgently in demand. Polyvinyl chloride, hydrophobic nano-SiO2, expanded graphite were separately applied to polyurethane and melamine sponge to fabricate superhydrophobic sponge material. The selected superhydrophobic sponge was introduced to establish sponge - covered disc skimmer. Oil recovery tests of the device were conducted to determine the optimum parameters. The examined operating conditions encompassed sponge thickness, immersion depth, rotational speed, oil slick thickness, operation time. The results showed that the melamine sponge modified by both polyvinyl chloride and hydrophobic nano-SiO2 exhibits super-hydrophobicity with a water contact angle of 150.3°. The absorption capacity for diesel oil can reach 53.89 g/g. The absorption capacity can still achieve 90 % of its initial capacity even after 500 extrusion-absorption separation tests. The results indicate the superiority of the superhydrophobic sponge covered surface in oil recovery over the standard steel surface regardless of the operating conditions. The recovery rate of the device can still achieve 96.4 % of its initial capacity with 95 % efficiency even after 85 h operation. The results suggest the superhydrophobic sponge - covered disc skimmer may have great application perspectives in oil spill recovery.

Conferring self-healing capability represents an effective approach for extending the lifespan of multifunctional superhydrophobic coatings. Presently, reported self-healing superhydrophobic coatings exhibit scratch-healing capabilities ranging from 5 μm to 40 μm. However, achieving large-scale scratch-healing (>100 μm) remains a significant challenge within this research domain. In this paper, we introduces the design and fabrication of a dual-layer self-healing superhydrophobic anti-corrosion coating using polycaprolactone (PCL), EASTMAN Kristalex 3085 resin (EK), epoxy resin (EP), and 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (PFDTES) modified silica particles via a facile spray-coating approach. The surface morphology, chemical composition, wettability, self-cleaning, damage-healing, and anti-corrosion behaviors of the coating were thoroughly evaluated. Results demonstrate that the coating exhibits self-healing capabilities across multiple scratch-damage scales (45 μm, 55 μm, and 100 μm), particularly exhibiting superior large-scale scratch-healing ability. Furthermore, the coating displays outstanding corrosion resistance, with the charge transfer resistance (Rct) increasing by nearly 8 orders of magnitude compared to the bare Q235 carbon steel substrate. Although the corrosion resistance of the scratch-damaged coatings significantly decreases, the anti-corrosion capability of the scratch-healed coating is effectively restored to its initial state, showcasing excellent anti-corrosion sustainability. Additionally, the coating demonstrates remarkable mechanical stability, withstanding 90 sandpaper abrasion cycles and 70 tape-peeling cycles.

The icing of overhead aluminum conductors is a serious threat to the safe operation of power systems. Various coatings for anti-icing have to face the challenge of durability. Superhydrophobic (SHP) coatings with self-healing properties are gradually showing good anti-icing durability. Herein, SHP self-healing surfaces with composite pore structures were successfully constructed on 1060 aluminum by two-step anodizing and infusion of triethoxy (1H,1H,2H, 2H-perfluoro-1-octyl)silane (POTS). A preparation process of composite pore structure consisting of upper layer of large pores and lower layer of small pores was designed and obtained via two-step anodizing. The impregnated POTS modified the composite pore structure to achieve superhydrophobicity while providing self-healing properties. The SHP surfaces with excellent performance were prepared by optimizing the appropriate current density and oxidation time. The contact and sliding angles were 166.5° and 0.5°, respectively. The frosting time was extended to 175 min, whereas the ice adhesion strength was lowered to 4.3 kPa. Additionally, the SHP surface with composite pore structure demonstrated superior durability and self-healing properties to single pore structure. The composite pore structure could maintain outstanding superhydrophobicity after 12 times of damage/self-healing compared to single pore structure (eight times). The SHP surface with composite pore structure successfully self-healed three times and withstood 135 icing/deicing cycles keeping the ice adhesion strength below 20 kPa, which is preferable to single pore structure (two times). The SHP self-healing aluminum surfaces developed in this work are highly promising for application and can promote the development of SHP coatings for anti-icing on power transmission lines.

Designing suitable surface structures is crucial to achieving long-lasting superhydrophobic properties. In this study, laser marking was utilized to fabricate micron groove arrays, creating the LM sample, which was then coated with a nickel nanocone-shaped structure through electrodeposition, forming the LME sample. Organic modifications were applied to both samples to increase their hydrophobicity. The surface morphology and cross-section structure of the coatings were analyzed in detail, and contact angle measurements indicated the presence of an air layer. A thorough analysis was conducted to compare the hydrophobicity of the laser marked and LME samples, revealing that the LME sample demonstrated exceptional wear-resistant superhydrophobicity. This was validated by various friction wear tests, which were performed using a well-designed testing setup. Moreover, the coating adhesion was assessed through a peeling test, revealing a strong adherence to the substrate. The corrosion resistance of the LME sample was also superior to that of the LM sample, as demonstrated by the results of the corrosion tests. The cost-effective and controllable method of laser marking and electrodeposition used in this study provides a feasible way to develop durable and resistant superhydrophobic coatings on light alloy surfaces.

Aircraft anti-icing and de-icing, aimed at reducing energy consumption, is a compelling technology that enables a plethora of eco-friendly energy applications to overcome long-standing crisis challenges. In this study, we present a tri-conversion strategy, inspired by superhydrophobicity, photothermal conversion, and electrothermal conversion, to develop an all-weather, high-efficiency, and low-energy rotor leading edge anti-icing and de-icing patch. The experimental samples not only possess stable superhydrophobic photothermal conversion capabilities but also achieve a 610-second delay in droplet icing, a 1-second nitrogen blow for frost, and a low ice adhesion strength of 11.6 KPa. Under one sun illumination, it can achieve a stable 54-second static melt and 37-second dynamic melt. With a connection to a 24 V DC stabilized power supply, it showcases an excellent 146-second de-icing capability. The synergistic action of multiple barriers enhances the anti-icing and de-icing performance. This work not only provides rational design principles for high-energy consumption de-icing but also offers insights into harnessing the power of nature for photothermal conversion de-icing.

The morphology of a surface has certain influences on its wettability as reflected by the shape of a sessile droplet thereon. The topological structure of superhydrophobic silicone rubber (MVQ) prepared by template method has the characteristics of simple shape and regular arrangement, but such a structure will lead to unstable contact angle (CA) of superhydrophobic surface. Through this study, it is found that the CA value of the original flat MVQ surface is the same in any direction. However, from 0° to 90°, it is observed that the CA on the MVQ surface, the contact radius between water droplets and MVQ and the projected area of water droplets are different. In different directions, the maximum error of CA is 13.75°, the maximum error of contact radius between water droplets-MVQ is 209.5 μm, and the maximum error of projected area of water droplets is 0.284 mm2. In addition, it is found that the contact radius between water droplets and the surface of silicone rubber decreases with the increase of the projected area of water droplets in the direction of larger CA. In order to explain the error of CA and droplet shape due to directionality, this phenomenon is explained by micro-morphology and three-dimensional morphology combined with contact line density theory. This discovery is beneficial to design super-hydrophobic surface with high directionality and realize the application of micro-channel control technology.

Nickel-titanium (NiTi) is the most ordinarily used shape memory alloy (SMAs), which has important implications in aerospace, medical devices and so on. However, NiTi parts were limited in their application scope and ability due to the difficulty of processing. Until the appearance of laser powder bed fusion (LPBF) technology, it overcame NiTi alloy preparation's multiple challenges and became the preferred method to fabricate NiTi alloy. Nevertheless, the NiTi parts fabricated by LPBF that have a great shortage still exist in corrosion resistance. Therefore, in this paper, a series of micro-nano structures with different characteristics were constructed in LPBF-NiTi by orthogonal experiment for the first time, which wants to explore the degree of influence of various parameters on the wettability of samples. After variance analysis, the nanolaser processing parameters which are most suitable for constructing lotus leaf structures on NiTi alloy surfaces are obtained. The surface morphology and composition were studied by SEM, XRD, EDS, and XPS, respectively. Finally, the corrosion resistance of samples was tested by electrochemical analysis. The results show that the laser power during processing has the greatest influence on the surface morphology of LPBF-NiTi alloy. And the wettability is affected by surface morphology and –CF/-CF2 adsorption. Furthermore, we compared the corrosion resistance of the superhydrophobic samples which was obtained based on the variance analysis with that of the substrate in 3.5 wt% NaCl solution. The result shows that the corrosion resistance and corrosion stability of superhydrophobic samples are brilliantly increased compared with the substrate.

In order to meet the increasing demand for fire prevention and pollution prevention of polyester fiber fabrics (PET) in different scenes, it is imperative to develop surface coatings with superhydrophobic and flame retardant properties. However, how to realize all these functions at the same time is still a big challenge. In this work, fluorinated PDMS was obtained through the cross-linking reaction between fluorosilane and PDMS, which was evenly mixed with the combustion product of silicone rubber (mainly composed of SiO2) and ammonium polyphosphate (APP), and the mixed coating was deposited on the surface of PET fabrics by spraying method to construct a superhydrophobic flame-retardant coating. The coated fabrics shows good superhydrophobicity (water contact angle is 155.61 ± 1.42°, sliding angle is 3.2 ± 0.4°) and self-cleaning performance. In particular, the prepared coated fabrics also has excellent mechanical durability, and it still does not lose its superhydrophobicity after 10 abrasive paper rubbing cycles, 60 min washing and even 300 bending and twisting cycles. In addition, compared with the original fabrics, the coating shows excellent flame retardant performance, which can realize self-extinguishing within 10 s in vertical combustion experiment.

Condensation is the process of changing a substance from a gaseous state into a liquid state, which is a phase-change process and has been widely applied in many fields. Dropwise condensation occurs on hydrophobic and superhydrophobic surfaces, and thus, has a much higher heat-transfer coefficient than film condensation. In this study, four types of micro-structured surfaces including cylinder, cube, cone and pyramid with the same height of 6μmwere made on silicon surfaces. Due to the different surface morphology, the micro-structured surfaces with cylinders and cubes had superhydrophobic properties with the contact angle of 158.4° and 155.5°, respectively; while the micro-structured surfaces with cones and pyramids had hydrophilic properties with the contact angle of 86.4° and 44.4°, respectively. Through the experimentally study of the heat transfer and dynamic characteristics of droplets on the micro-structured surfaces, the results showed that under the same conditions (steam pressure is 0.1MPa, saturated steam temperature is 100 °C and steam flow rate is 0.298 ± 0.02 m3/h), the heat flux increased linearly with the increase of the cooling water temperature difference and the subcooling, respectively. Moreover, condensation heat transfer coefficient decreased as the increase of the subcooling. Because of less sharp edges and bigger contact angles, the cylindrical micro-structured surface had more excellent droplet mobility leading to faster condensation process and heat transfer. Through the comparison of the droplet growth in the horizontal and vertical directions, it was found that the micro-structured surface with more sharp edges had a larger droplets density. However, the sharp edges prevent the coalescence and shedding which slowed down the heat transfer. Therefore, the cylindrical micro-structured surface spent the shortest time in the whole growth process and thus had the best heat transfer performance.

Application of polyfunctional water-repelling coatings for high voltage outdoor power lines wires, insulators, and line supports recently gathered large interest due to their ability to substantially boost performance. Such functionalization can mitigate the accumulation of water precipitates and atmospheric pollutions, decrease leakage current, increase flashover and corona ignition voltage. However, harsh conditions concomitant to a high voltage such as high energy ions and electrons, high ozone concentration, UV radiation impose strict requirements on the durability of applied coatings. In this paper, we focus on the analysis of the durability of superhydrophobic coatings (SHC) and slippery liquid infused porous surfaces (SLIPS) under prolonged exposure to industrial grade alternating current corona discharge. Reported results show that in contrast to previously reported low resilience of polymer-based SHC, proper metal-based SHC withstands many hours of exposure without notable degradation. The obtained data on the stability of SLIPS under corona discharge show notable degradation related to the high rate of infused layer depletion. Overall, reported results broaden the understanding of the effect of corona exposure on functional materials and reinforce the optimistic view on the applicability of SHC and SLIPS coatings in the power transmission industry.

Superhydrophobic surfaces are surfaces which repel water at a certain contact angle (≥150°) and sliding angle (

The oily wastewater has posed a great threat to the environment and human health, and the oil-water mixture is complex and diverse. Therefore, it is crucial to develop a smart and efficient oil/water separation material. In this paper, random polymers containing carboxyl groups were synthesized for surface-modifying hydrophilic SiO2 nanoparticles. Polydimethylsiloxane (PDMS) was then used as the adhesive to fix the modified SiO2 nanoparticles firmly on the fabric surface endowing the fabric with a robust hydrophobic effect. The modified SiO2 nanoparticles not only made the fabric obtain a rough structure but also caused the fabric to have the effect of switchable wettability under the stimulation of pH. In addition, the prepared fabric maintained good mechanical durability and chemical stability after the mechanical abrasion, ultraviolet irradiation, and organic solvent treatment. Interestingly, under the stimulation of pH, the smart fabric could controllably separate different oil/water mixtures (including heavy oil/water and light oil/water) with excellent separation efficiency and high flux even after 20 cycles of separation process. Meanwhile, the pH-responsive fabric material successfully separated light oil/water/heavy oil three-phase oil/water mixture and different kinds of emulsions. Therefore, the prepared pH-responsive superwetting fabric has a broad application prospect in the field of dealing with complex oil/water mixing systems.

In this work, we fabricate a hexagonal array of pillars where each pillar has a “micro-hoodoo” shape, i.e., a reentrant cross section. The shape of the pillars makes them more resilient towards total wetting, i.e., transition from a Cassie-Baxter non-wetting state to a Wenzel wetting state. We show the single-step fabrication of 4 × 4 mm2 arrays by two-photon polymerization direct laser writing of the polydimethylsiloxane (PDMS)-derived commercial resin IP-PDMS. The use of a hydrophobic resin for rapid prototyping of reentrant structures enables the fabrication of surfaces patterns displaying superhydrophobic behavior despite the use of relatively simple structures, i.e. with a single reentrant surface. By changing the size of the micro-hoodoos and the packing density of the arrays, we map wetting behaviors ranging from the pinning of water droplets in Wenzel state to non-wetting Cassie-Baxter states. The measured contact angles follow quite well the theoretical results obtained by minimizing Gibbs free energy using the Wenzel, Cassie-Baxter and partial wetting theories. Among the tested micropatterns, five exhibited superhydrophobic properties, with a static contact angle with water as high as 158.1° ± 7.1°. This is the first demonstration of superhydrophobic surfaces produced by two-photon polymerization direct laser writing of PDMS in a single-step process.

The superhydrophobic surface of silver metal on Cu-substrate (Cu@Ag-SHS) is successfully fabricated via a chemical etching process having fern leaves-like morphology of the nanoparticles of silver metal. The fabricated product is characterized by PXRD, EDX, SEM, and XPS techniques. Moreover, electrochemical impedance and water contact angle (WCA, using Gonimeter) measurements are carried out. Cu@Ag-SHS contained unique properties such as long-term stability, super buoyancy force (as a drop of water could bounce from the balloon surface, thus presenting superb non-sticking properties), anti-corrosion properties, self-cleaning, anti-abrasion, and durability. Furthermore, photocatalysis properties of Cu@Ag-SHS were tested by the photodegradation of 4-NP into 4-AP.On the other hand, the temple and the low-cost thermal annealing process are persuaded to make coating surfaces homogenous and remove impurities. Moreover, the annealing process executed the sliding angle nearly equal to 2° and the static water contact angle 159 ± 1°. Furthermore, Cu@Ag-SHS revealed fern leaves-likee morphology that is a unique property. Therefore, with the adoption of several characterizing techniques, this has been demonstrated that the developed surfaces of superhydrophobic products and their properties assure that they will be applicable in the fabric and metallic industries.

A highly efficient and versatile method was developed to prepare durable, superhydrophobic surface on various biomass substrates in order to remove organic contaminants from polluted water. This method employed PPy/nanoparticles (TiO2, Ag and SiO2) in combination with HDTMS modification. The coated biomass possessed durable superhydeophobicity with highest WCA of 168.4°, which could collect the oil from oil-water mixtures and water-in-oil emulsion. The collected organic contaminants could also be decomposed by photocatalysis process with TiO2 coated corn stalk. The durable evaluation results proved the outstanding resistance to friction, long-term exposure in environment, high temperature, acidic and basic agents. The method suggested in this work provides a facile and efficient route to synthesize large-scale, durable, and mechanically stable superhydrophobic surface for water pollution control.

In order to remove/collect oils from polluted water, polypyrrole (PPy) nanoparticles have been loaded onto different substrates (cotton, corn stalk, sawdust, metal, fabric and sponge) by in situ polymerization followed by further hydrophobic modification. A wide range of low surface energy reagent could be used, including cetylamine, dodecanethiol, stearic acid and hexadecyltrimethoxysilane (HDTMS). Observations showed that the as prepared superhydrophobic materials could effectively remove oil from water-in-oil emulsion and immiscible oil/water mixtures with separation efficiencies above 99.1%. The coated material exhibited outstanding resistance to abrasion, acids, bases, salt, high temperature water and long-term exposure in environment. The coating method suggested in this work provides a facile and efficient route for superhydrophobic material fabrication, which could be practically used for separation of oil/water mixtures under various harsh conditions.

In this work, a robust epoxy adhesive (EP) @ superhydrophobic SiO2 (SH-SiO2)-based superhydrophobic coating was prepared on the aluminum substrate by a simple one-step spraying strategy. The prepared EP@SH-SiO2 coating exhibits hierarchical micro/nanostructures and is capable of maintaining a contact angle of more than 150° after 1000 cm of abrasion length and 80 tape-peeling repetitions. Molecular dynamics (MD) simulations and quantum mechanics calculations show that the improved mechanical resistance is attributed to the enhanced interfacial interaction between the EP@SH-SiO2 coating and the underlying substrate induced by the epoxy adhesive. Electrochemical measurements in 3.5 wt% NaCl solution show the corrosion inhibition efficiency of the EP@SH-SiO2 coating reaches up to 99.99%, and even after 8 days of immersion, the low frequency impedance modulus of the EP@SH-SiO2 sample is still ∼1 order of magnitude higher than that bare aluminum, demonstrating excellent long-term corrosion protection. The diffusion behavior of the corrosive medium in the EP@SH-SiO2 coating was revealed by MD simulation to support the experimental results. Additionally, the EP@SH-SiO2 coating exhibits good chemical stability and hydrophobic repair properties. This work will provide a new perspective for the preparation and study of robust superhydrophobic aluminum for corrosion protection properties.

Inspired by the biomaterial nacre, we report a versatile and facile strategy to rugged, flame retardant superhydrophobic materials by embedding a nacre-like montmorillonite (MMT) based gas barrier layer into hierarchical epoxy-resins. The well-aligned MMT layer imparted excellent oxygen and water barrier properties that rendered the coating surface water repellent yet protected the substrate materials from fire by suppressing heat and oxygen transfer. The hierarchical epoxy not only provided the robust superhydrophobic structure but offered strong adhesion to MMT layer. After application of this coating to a flammable sponge, it demonstrated superhydrophobicity with a contact angle of ∼153°. Furthermore, the material was rugged, resisting 1200 compression cycles and induced marked flame retardancy. The coated sponge delayed ignition (689% delay in ignition time) and promoted significant flame extinguishing property, compared with the uncoated material (demonstrated by LOI, CONE combustion, and fire scenario tests). Owing to its robustness and multifunctionality, the coated sponge was able to efficiently separate oil from multi-environments including strong corrosive, icy, boiling or vibrating mixtures. Additionally, the versatile application to wood, cotton, textile and other lignocellulosic substrates has been verified. This research opens up a new direction for durable waterproof and fireproof materials.

Recently, engineered surfaces with special wetting behavior such as superhydrophobic and superoleophilic have gained remarkable attention of scientific community for efficiently oil/water separation application. In general, for the fabrication of surfaces with superhydrophobic and superoleophilic behavior, two things are highly essential: (1) Low surface energy, (2) high roughness. Among the utility of various coating materials, polydimethylsiloxane (PDMS) has been explored for the hydrophobic coatings on various types of surfaces because of its several specific properties such as low-surface energy agent, eco-friendly, strong adhesive ability on versatile surfaces, long term thermal and chemical durability, rapid and facile coating formation ability. Therefore, we summarized recent studies on PDMS coatings with special wetting properties (superhydrophobic/superoleophilic) on the surface of various substrates for oil/water separation. The coating fabrication approaches, treatment effects, durability of coating surfaces and oil/water separation efficiency are discussed.

Intraocular lens (IOL) implantation surgery is the most effective treatment for cataract. However, glistening formed by the incoming liquid microvacuoles can significantly damage postoperative visual quality after prolonged implantation, for which there is still lack of effective clinical treatment. In this study, inspired by the amazing water-repellency of natural superhydrophobic surface, a functionalized IOL material modified with the superhydrophobic and transparent coating was prepared using layer-by-layer electrostatic self-assembly technique combined with fluorination. After the alternate deposition of multiple cationic/anionic polyelectrolytes and silica nanoparticles of varying sizes on IOL materials, the constructed multilayered films with special surface roughness were further fluorinated to reduce surface energy. In addition to its excellent superhydrophobicity and transparency, this multilayered coating could efficiently eliminate the glistening formation of IOL under accelerated condition in vitro. Furthermore, the in vitro experiments with water droplets, cells, and bacteria suggested the superior antiadhesion property of such coating modified materials. The biocompatibility evaluation, both in vitro and in vivo, demonstrated the great biocompatibility of the materials modified with superhydrophobic and transparent coating. Therefore, this multilayered coating with excellent superhydrophobic and transparent characteristics can provide an available approach aiming at anti-glistening and antiadhesion of IOL materials. Advances in the fabrication process of surface coating with specific functions will enhance the practical application and clinical success of modified IOLs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Wood is reportedly more difficult to maintain in hygienic condition versus other food contact materials, yet its use in produce packing and retail warrants efforts to reduce the risk of microbial pathogen contamination and attachment. This study characterized antifouling capabilities of fluorinated silanes applied to wood used in fresh edible produce handling to render the wood superhydrophobic and less supportive of bacterial pathogen attachment. Pine and oak cubic coupon surfaces were treated with 1% (w/w) silane or left untreated. Treated and untreated coupons were inoculated with Salmonella enterica or Listeria monocytogenes and held to facilitate pathogen attachment for 1, 4, or 8 h. Silane treatment of wood produced significant reductions in the proportions of strongly attaching cells for both pathogens versus loosely attaching cells (P < 0.01). Salmonella attachment demonstrated a dependency on wood treatment; silane-treated wood supported a lower fraction of strongly adhering cells (1.87 ± 1.24 log CFU/cm 2 ) versus untreated wood (3.72 ± 0.67 log CFU/cm 2 ). L. monocytogenes demonstrated significant declines in strongly attaching cells during extended exposure to silane-treated wood, from 7.59 ± 0.14 to 5.27 ± 0.68 log CFU/cm 2 over 8 h post-inoculation. Microscopic analysis demonstrated silane treatment increased the surface roughness of both woods, leading to superhydrophobic conditions on wood surfaces, consequently decreasing strong attachment of pathogenic bacteria., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Textiles with self-cleaning and anti-icing capabilities in cold climates are essential for outdoor workers and enthusiasts. Superhydrophobic modification of textile surfaces is effective in imparting these characteristics. Although there are numerous methods available for manufacturing superhydrophobic textiles, careful consideration is warranted for environmental concerns over fluorochemicals, stability of superhydrophobic coatings, and fabric breathability. In this work, we utilized biomass resources such as tung oil and behenic acid, along with zeolitic imidazolate framework (ZIF-8), to modify cotton fabrics, thereby creating an innovative behenic acid/tung oil/ZIF-8 modified cotton (BTZC) fabric with anti-icing and self-cleaning features. This material manifests a unique nanoflower-shaped surface morphology, demonstrating exceptional superhydrophobicity with a static water contact angle (CA) of 162° and a sliding angle (SA) of 2°. Moreover, BTZC excels in its thermal stability, breathability, and resistance to icing. Equally impressive is its robust stability, as evidenced through rigorous testing under continuous washing and abrasion, sustained high and low temperatures, extreme pH environments, and immersion in various chemical solvents. BTZC presents as a fluorine-free, durable, economically viable alternative for outdoor textile applications, marking substantial progress in the utilization of biomass and metal-organic framework materials in the textile industry and promising implications for value enhancement., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Fats, oils and grease (FOGs) deposits in sewers have recently become a significant problem, causing financial strain on water companies, damaging sewer lines, and exposing the environment to dirty water through sanitary sewer overflows. Despite the proactive use of grease traps/interceptors for physical oil-water separation, the issue of FOG deposits persists. This study proposes the use of adsorption-based oil-water separation, employing superhydrophobic cotton, as a new alternative method for removing FOGs. Durable superhydrophobic cotton was successfully prepared using a simple two-step sol-gel method, with octadecyltrimethoxysilane (ODTMS) as a modifying silane. The resulting cotton samples demonstrated remarkable superhydrophobicity, evidenced by water contact angle (WCA) above 154°. Additionally, it exhibited exceptional durability and stability when exposed to hot water, harsh acidic and alkaline solutions, as well as during a laundry test. Moreover, the cotton displayed excellent oil-water separation efficiency (> 98 %) and maintained consistent performance throughout 20 reuse cycles, highlighting its high reusability. This approach holds the potential to address the prevailing FOG deposit issues and contribute to more efficient and sustainable wastewater management practices., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

The intrinsic hydrophilicity of sustainable and environmentally friendly biobased materials like starch and its derivatives limits their potential as hydrophobic functional materials. This study presents an eco-friendly and non-toxic method to create coatings with exceptionally high hydrophobicity. Octadecyltrimethoxysilane (ODS) reacts with nano silica (SiO 2 ) through a silane coupling reaction to form superhydrophobic SiO 2 . The Si-OH groups generated from ODS hydrolysis can undergo a condensation reaction with tannic acid (TA), which is rich in phenolic hydroxyl groups. This enables the hydrophobic silane to bind indirectly with cationic starch (CS), resulting in a stable superhydrophobic CS-based coating. The coating demonstrates significant hydrophobicity (contact angle >170°), excellent UV light transmittance (<4.05 %), self-cleaning properties, prolonged shelf life (over eight months), antibacterial activity, and encapsulation capability. It also shows a separation efficiency exceeding 99 % after 25 oil-water separation cycles and is easily recoverable. The study elucidates the mechanism behind the preparation process and the factors enhancing hydrophobic properties. The research findings suggest that the novel, cost-effective CS/TA/ODS/SiO 2 coating offers a scalable solution for superhydrophobic applications and broadens the horizon for green starch use in hydrophobic materials., Competing Interests: Declaration of competing interest There are no conflicts to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)

At present, many oil-water separation membranes are being developed to purify oily wastewater. However, oily wastewater often contains heavy metal, which are often difficult to dispose during separation. Furthermore, most of the oil-water separation membranes cannot be degraded after scrap, producing pollution to environment. Herein, the polyvinyl alcohol/chitosan@carnauba wax (PCGCW) membrane with heavy metal adsorption and biodegradation performance was acquired by electrospinning and spraying process. The acquired PCGCW membrane had excellent mechanical properties after crosslinking glutaraldehyde (GA). Furthermore, the composite membrane had excellent superhydrophobic property (WCA = 154°) with a rolling angle of 2°, due to the introduction of carnauba wax. Exhilaratingly, for emulsions with surfactant, it had a high separation flux with 19,217 L·m -2 ·h -1 ·bar -1 and splendid an oil purity over 99.9 %. Besides, the efficiency of oil purity and separation flux remained stable even after 10 separations. In addition, the PCGCW membrane had the ability to adsorb heavy metals with adsorption capacity of 51-106 mg/g for Cu 2+ , Fe 3+ , Co 2+ ions. Foremost, the superhydrophobic PCGCW membrane was biodegradable, with degrading 29.76 % within 40 days. The prepared composite membrane had the advantages of low cost, high separation flux, great repeatability, adsorbable heavy metals and degradability, which had a vast application prospect., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Smart polymer glue with photoluminescence and water-repellent properties was developed. The luminescent adhesive continues emitting light for up to 120 min after turning the excitation source off. Nanoparticles of lanthanide strontium aluminum oxide (LSAO) (8-13 nm) were consistently immobilized into carboxymethyl cellulose-reinforced gum Arabic (CMC/GA) adhesive. Using various concentrations of LSAO, the generated adhesives showed emission intensity at 519 nm and an excitation band at 365 nm. Depending on LSAO content, both of afterglow and fluorescence emission were monitored. Photochromism was detected as the transparent adhesive film changes color to green under ultraviolet irradiation. A greenish-yellow lightening in a darkened place was also observed. The nanocomposite resistance to scratches and hydrophobicity were found to enhance as the LSAO content was increased in the carboxymethyl cellulose-reinforced gum Arabic matrix. The LSAO@CMC/GA nanocomposite showed high durability and photostability. The present strategy proved the viability of a potential mass production toward photoluminescent adhesives for various smart applications, such as smart packaging, anti-counterfeiting printing, smart windows, and safety signs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Extracting clean water from oily wastewater and seawater is one of the effective strategies to alleviate the freshwater crisis. However, achieving both high separation efficiency and excellent salt resistance remain challenges for materials. Herein, a novel methyltrichlorosilane-modified polyvinyl alcohol/cellulose aerogel (MPCA) was prepared by freeze drying, chemical cross-linking, and chemical vapor deposition (CVD) methods. The superwetting MPCA presented an asymmetric structure, in which the small dense pores at the top surface facilitated the efficient separation of water-in-oil (W/O) emulsions and the large pores on the bottom surface were beneficial for brine exchange. The as-prepared superwetting aerogel was suitable for the separation of various W/O emulsions with excellent separation flux (631.9-2368.7 L·m -2 ·h -1 ) and outstanding separation efficiency (99.5 %). In addition, MPCA achieved a high evaporation efficiency of 1.39 kg·m -2 ·h -1 and a satisfactory energy conversion efficiency of 89.7 %. Moreover, the unique asymmetric structure endowed the evaporator excellent salt resistance and could self-dissolve the accumulated salt in 20 min. The as-prepared MPCA could achieve efficient W/O emulsion separation as well as produce freshwater in seawater, providing a new strategy for oily waste seawater purification., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing fnancial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

We report a method to fabricate micro-pore arrays on a copper sheet by a 355 nm UV nanosecond pulse laser, and investigate the effects of surface microstructures and micro-pore spacing on the wettability of the formed copper micro-mesh. We found that the surface was initially hydrophilic, but changed to superhydrophobic-oleophilic with water contact angle 151° and oil contact angle about 10° after exposed to ambient environment for 14 days. We analysed the surface morphologies of the processed samples with a three-dimensional profilometer, measured the water and oil contact angles, and characterized the surface by a field emission environmental scanning electron microscope (FESEM) and energy dispersive X-ray spectrometer (EDS). The surface chemistry changes were confirmed by X-ray photographic spectroscopy (XPS). Effective oil-water separation performance of the fabricated copper mesh was demonstrated. Learning from the natural change, we designed a coating material containing C8 long C–C (H) chain and coated onto the freshly prepared copper mesh to convert the surface property into a preferred superhydrophobic-oleophilic nature. This study provides a controllable methodology consisting laser processing and surface modification for making micro-pore copper mesh as a simple and effective method for oil-water separation.

Paper mulch has the advantages of simple process, low production cost and strong degradability, but it is still a great challenge to prepare paper mulch with excellent water resistance and light transmittance. In this paper, through a simple physical brushing method, Zinc oxide (ZnO) solution and silica (SiO2) solution were brushed on the surface of paper mulch film respectively, and ZnO/SiO2 composite superhydrophobic paper mulch film (CSPMF) with micro-nano rough structure was constructed. The microstructure of original paper mulch film (OPMF) and ZnO/SiO2 CSPMF was studied by scanning electron microscope (SEM), and the superhydrophobic surface elements were analyzed by energy dispersive spectrometer (EDS). The contact angle (CA) and rolling angle (RA) of two kinds of sample surfaces are measured by contact angle meter. The static CA and RA of ZnO/SiO2 CSPMF were 160 ± 0.4° and 3 ± 0.3°, respectively. The self-cleaning behavior of soil simulated dust environment was tested on the surface of OPMF and ZnO/SiO2 CSPMF respectively. The horizontal bounce performance and tilt bounce performance of the superhydrophobic surface were tested by high-speed camera. In addition, frost experiments and delayed icing experiments were carried out. The results show that ZnO/SiO2 CSPMF has good self-cleaning performance, bouncing performance and delayed icing performance.

Biomimetic superhydrophobicity endows various substrates with amazing multi-functional properties. However, fragile hierarchical structures, fluorine-containing chemicals usage, and strict requirements for substrate scopes remain thorny challenges. Herein, we constructed a mechanical robust superhydrophobic ZnO@STA@PDMS coating with fluorine-free reagents through wide-applicable and substrate-independent spray-coating method. Field-emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and contact angle meter were used to assess the surface micro-nano structures, chemical compositions, thermal stability and wettability variations. The corrosion resistance of the developed superhydrophobic ZnO@STA@PDMS coating was evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements. The corrosion current density (Icorr) of the substrate reduces by two orders of magnitude after being spray-coated with superhydrophobic ZnO@STA@PDMS coating, indicating excellent corrosion resistance in marine submerged zone. In simulated marine atmospheric conditions with high relative humidity, the salt-deliquesce behaviors of single and double NaCl particles on bare and coated Q235 carbon steel surfaces were recorded. In a high humidity atmospheric environment, the instantaneous salt-deliquesce self-coalescence phenomena provides a new type of anti-corrosion mechanism. Furthermore, the prepared superhydrophobic coating can withstand more than 30 tape-peeling cycles and 400 cm abrasion distance, demonstrating good mechanical stability in prospective real-world applications.

Plastic debris and its fragments are carriers of harmful substances in the marine ecosystem, which has called for much-needed attention over the last few years. Expanded polystyrene (EPS) is a major marine pollutant. Herein, we explain the fabrication of novel water-repellent and self-cleaning microfibers via electrospinning of a polymeric solution with 5, 10, and 15 wt% of inclusions to manipulate their surface, thermal, and wetting properties. Surface chemistry, surface morphology, thermal degradation, wettability, and self-cleaning performance of the produced microfibers were investigated. It was observed that microfibers with 15 wt% inclusion exhibited the best thermal stability among all microfibers above 400 °C. Also, the addition of micro/nanoinclusions improved the strength and number of absorption peaks of the Fourier-transform infrared spectroscopy (FTIR) spectra, in turn forming more functional groups. The incorporation of 15 wt% inclusion, after heat treatment at 70 °C for 6 h, produced the most superhydrophobic surface with the best self-cleaning performance with water contact angle of 172.44° ± 3.13°, contact angle hysteresis of 107.67° ± 5.94, and surface roughness of 21442 nm. Heat treatment and the concentration of micro/nanoinclusions significantly affected the self-cleaning capability of the fabricated microfibers. The fabricated microfibers could be used for anti-fogging and antibacterial applications, debris removal, and water–oil​ separation.

Efficiently obtaining ideal superhydrophobic metallic surfaces through traditional laser ablation is still a challenge. Meanwhile, revealing the mechanism of the transition from superhydrophilic to superhydrophobic of laser-ablated metallic surfaces is required. Inspired by the lotus leaf, we fabricated the arrays of micro-protrusions on aluminum substrates by nanosecond laser ablation. A layer of hydrophobic species was formed on the micro-protrusions after organic adsorption process, which promoted the surface to obtain superior superhydrophobic, anti-wetting and self-cleaning properties. The principle of the transition from superhydrophilic to superhydrophobic during heat treatment process was revealed, and how organic adsorption temperature and time affect water contact angle and slide angle was clarified. We found that nano-particles can drastically reduce the solid–liquid fraction of the surface after analysis. The parameters including laser scanning space, organic adsorption time and heat treatment temperature were optimized to realize high-efficient and energy-saving production. Furthermore, superior wetting resistance to various solutions and the self-cleaning property for solid powders were experimentally indicated. Superhydrophobic aluminum surfaces could be efficiently fabricated in several hours without any expensive equipment, complicated process, strict environment and environmentally harmful chemical reagent by the proposed two-step method.

Blood repellent dressings plays an important role in trauma medicine. However, such dressings have poor hemostatic efficacy, and can cause infection, rendering them unsatisfactory for clinical application. We prepared a durable superhydrophobic coating for blood repellent dressing based on rosin acid and TiO2 with a water contact angle of 155.7° and a sliding angle of 5°. The morphology and chemical composition of the coating were characterized by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and X-ray spectroscopy (XPS), respectively. The superhydrophobic coating can withstand at least thirty sandpaper abrasions and sixteen washing treatments without losing its superhydrophobic properties. Meanwhile, the superhydrophobic coating demonstrated excellent antimicrobial activities against Gram-positive Staphylococcus aureus (S. aureus) (with log reduction = 1.73) and Gram-negative Escherichia coli (E. coli) (with log reduction = 1.74) and effectively prevented biofilm formation. Besides, the excellent biocompatibility of the superhydrophobic coating was verified by hemocompatible and cytotoxic assays. Finally, it was confirmed that the superhydrophobic coating can reduce blood loss and allows for high air permeability in in vitro tests. The superhydrophobic coating based on rosin acid and TiO2 provides a simple way for preparing novel blood repellent dressings, which may have promising applications in wound dressings.

A stable self-cleaning superhydrophobic coating with reliable corrosion resistance was coated on the aluminum alloy 6061. A dense polyvinylidene fluoride (PVDF) layer was first coated by the doctor blade method, and hydrolyzed methyltrimethoxysilane (HMTMS) nanospheres were then deposited on top of the PVDF using ultrasonic spray hydrolysis technique. Superhydrophobic coatings with a contact angle (CA) of 167° and a sliding angle of 7 ​± ​1° were obtained. The superhydrophobic coating exhibited self-cleaning behavior. The corrosion resistance of the layers was investigated in a 3.5 ​wt% NaCl aqueous solution using potentiodynamic polarization measurement and electrochemical impedance spectroscopy techniques, indicating the high corrosion resistance of the flat PVDF barrier and the excellent resistance of the superhydrophobic coating. The charge transfer resistance of the bare aluminum substrate measured as 6.572 ​kΩ ​cm2 increased to 848.463 ​kΩ ​cm2 and 3.411 ​× ​103 ​kΩ ​cm2 with PVDF and HMTMS, respectively. The results showed that a proper superhydrophobic coating with good chemical stability could significantly increase the corrosion resistance of the substrate. We also showed the capability of the novel ultrasonic spray hydrolysis technique in fabricating stable superhydrophobic films for large-scale applications.

In this study, a photothermal superhydrophobic surface based on carbon nanospheres/carbon nanotubes (CNSs/CNTs) composite was fabricated, and the self-healing effect of its superhydrophobicity under solar irradiation was demonstrated. To investigate the chemical composition and elemental distribution of the coatings, infrared spectroscopy (FT-IR), energy dispersive spectroscopy (EDS) mapping analyses were performed. The morphology, roughness and wetting properties of the coatings were characterized using field emission scanning electron microscopy (FESEM), confocal laser scanning microscopy (CLSM) and contact angle measuring instrument, respectively. The results showed that CNSs and CNTs synergically constructed peak-like microstructures and villi-like nanostructures with the assistance of polydopamine (PDA) and epoxy resin (EP), and the obtained superhydrophobic coating had a water contact angle (WCA) of 160.7° and sliding angle (WSA) of 4.0°. The coating can convert light energy into heat energy (T230s = 189 °C) in a short time under the irradiation of simulated sunlight (I = 20 A). The photothermal self-healing mechanism was analyzed by X-ray photoelectron spectroscopy (XPS). When the coating became superhydrophilic under the treatment of O2 plasma, the hydrophobic long chain provided by dodecyltrimethoxysilane (DTMS) migrated to the upper layer of the coating under the thermodynamic drive, thus realizing the self-healing of superhydrophobic properties.

Superhydrophobic composite strain sensors have attracted extensive attention due to their excellent waterproof, anti-icing, flexible and conductive properties, but there are still challenges to prepare it with broad sensing range, superior sensitivity, stable superhydrophobicity, and excellent long-term stability. In this study, we developed a multifunctional superhydrophobic silicone rubber (SR)/multi-walled carbon nanotubes (MWCNTs)/laser-induced graphene (LIG)/SR composite strain sensor using laser direct writing. A highly stable MWCNTs/LIG crosslinked conductive network layer, high-performance superhydrophobic layer, and stretchable SR layer were integrated to fabricate the sensor by tuning the laser parameters. The SR/MWCNTs/LIG/SR composite strain sensor possessed a high gauge factor of 667, large strain detection range of 0–230%, and a stable sensing response over 2500 cycles due to the MWCNTs/LIG crosslinked conductive network. Moreover, the SR/MWCNTs/LIG/SR composite strain sensor could effectively prevent icing owing to its anti-icing (36 min@-5 °C) and photothermal deicing (88 s@1 W/cm2@NIL) properties and hinder acid and alkaline (pH = 1–14) corrosion attributed to the laser-induced superhydrophobicity, thereby expanding its applications to acid, alkaline, and low-temperature environments. Consequently, the multifunctional superhydrophobic SR/MWCNTs/LIG/SR composite strain sensor is demonstrated to be suitable for human body motion detection in complex and severe environments.

Self-propelling phenomenon that the corresponding device can move on water surface without external energy input has prospective applications in different fields including cell and bacterial control, medical transportation and drug delivery. However, the current strategies to propel the microdevices have many problems which extremely limit their promotion. Here, we reported a self-propelling miniboat composed of a superhydrophobic plate and a superhydrophilic wedge-shaped pattern on its surface to realize the conversion of the surface energy of the water droplet to the kinetic energy of the miniboat. A water droplet dropped on the wedge-shaped pattern easily transported and immersed in water, providing enough force to propel the miniboat. Moreover, the displacement and velocity of the miniboat can be controlled by adjusting the water droplet volume. This study has an important scientific significance and value for promoting the practical application of the self-propelling phenomenon on water surface.

This paper reveals the role of microstructures formed on the surface of aluminum substrates created by acid etching. A wettability study showed that using a fluorinated silica polymer (PF) and the essential oil of eucalyptus (ECA) with adequate surface texture promoted antibacterial activity. Scanning electron microscope (SEM) images showed that the micro-nanostructure enhanced the possibility of loading the ECA as an antibacterial agent. Fourier Transform Infrared (FTIR) spectroscopy analysis confirmed the chemical linkage between the different components of the surface. Antibacterial tests carried out using inhibition discs displayed the antibacterial behavior of the surface's components against Bacillus cereus and Escherichia coli bacteria. The direct tests on the surface confirmed its capacity to limit bacterial adherence when exposed to bacteria contamination, 99.19% and 97.28% in the case of B. cereus with (PF) and ECA:PF-based coatings. In the case of E. coli these were 94.65% and 98.69% with PF and ECA:PF respectively.

The discharge of oily wastewater and offshore oil spills contaminates the biotic and aquatic environment and ultimately result in the destruction of the ecosystem. Recently, the application of ceramic membranes has gained prodigious attention due to its efficiency in oil-water separation process. Ceramic membranes developed from inorganic materials are considered as the most promising technology for the treatment of industrial wastewater. Besides, different types superhydrophobic-superoleophilic substrates are being developed using various substrate materials to tailor its purpose for higher efficiency. Nonetheless, fouling and clogging phenomena restrict the performance of ceramic membrane in oil-water separation. This review emphasizes the recent innovation on superhydrophobic methods for the modification of ceramic membranes for oil-water recovery. It comprises of an overview of the preparation technique of ceramic membrane using various techniques. Moreover, the different types of hydrophobic ceramic membrane modification using chemical agents and consequent effects on oil-water separation were discussed in detail. Furthermore, the technical challenges and issues associated with the applications of superhydrophobic-superoleophilic ceramic membrane for oil-water separation were discussed. Finally, future direction in the research of cost-efficient approach to produce superhydrophobic ceramic membranes for oil-water filtration process is enumerated.

Silica (SiO2) powder and physical deposition technique were performed to fabricate superhydrophobic silicone rubber (SR) surfaces, and the contact angle and the rolling angle were 160.3 ± 1.0° and 2.8 ± 0.3°, respectively (the contact angle and the rolling angle of the original surface of the SR were 130 ± 1.8° and 36.7 ± 0.8°, respectively). The surface roughness of the sample was measured by interferometric three-dimensional topography profiler, and the results showed that the surface roughness increased after being treated by SiO2. A self-cleaning test was designed to verify the self-cleaning effect of the sample surface. Besides, a scanning electron microscope (SEM) was employed to observe the microstructure of the sample surface and the dispersion of SiO2, and energy dispersive spectroscopy (EDS) was utilized to determine the element composition and content of the sample surface. In order to further demonstrate the superhydrophobic property of the surface of the sample, the horizontal bouncing test at room temperature (25 °C) and the tilted bouncing test at an angle of 10° with the horizontal plane were carried out, and it was found that the sample had remarkable bouncing performance. Moreover, high temperature bounce tests were performed to investigate the stability of the surface superhydrophobic property of the sample, indicating that the sample had significant high temperature resistance.

Poor wear resistance and the use of toxic chemicals restrict the marketization of most traditional superhydrophobic surfaces. The present work provides a method to prepare a durable and non-toxic superhydrophobic coating on the surface of a cotton fabric. Thermal polymerization of spray drying was used to obtain uniform structure of TEMPO-oxidized cellulose (TOC) with nano silica (SiO2), for achieving well-combined rough sphere-like micron particles with hierarchical dimensions, which were then immersed into isocyanate (IPDI) and polydimethylsiloxane (PDMS) respectively along with cotton fabric to construct a superhydrophobic coating on the fabric surface. The surface morphology, chemical structure, roughness and wettability of TOC-SiO2/PDMS surface were studied by adjusting the mass ratios of SiO2 to TOC. The optimal superhydrophobicity was obtained while the mass ratio of SiO2 to TOC was 1:1, displaying a water contact angle (CA) of 158.6°. The introduction of the intertwined TOC-SiO2 blends can construct a hierarchical micro-nano structure to enhance the hydrophobicity, simultaneously improve the mechanical durability of the superhydrophobic surface to prevent multiple peeling and friction damage, as well as outstanding chemical stability in a variety of harsh conditions.

The preparation of superhydrophobic (SH) surface on stainless steel by chemical etching method is challenging due to the good corrosion resistance of the material. In this work, SH surface with water contact angle (WCA) as high as 163.21° was accomplished on 304 stainless steel surface by a rapid ultrasonic-assisted chemical etching method within 7 min and a low-cost fluorine-free modification treatment. The mechanism of ultrasonic field on the etching process was explored by detecting the cavitation and oscillation energy in the reactor. It is the first time to found that the ultrasonic cavitation effect enhanced the etching process by both chemical and physical facilitation resulting in hierarchical lamellar micro-structures, “mountain-like” micro-structure clusters and “coral-reef-like” nano-scale structures on the surface. With the ultrasonic power increasing, the ultrasonic cavitation effect not only enhanced the superhydrophobicity of sample surface, but also improved the uniformity of surface wettability. The samples also showed excellent performance of oil/water separation for various organics (all separation efficiencies up to 96%) and remarkable mechanical stability.

The environmental pollution caused by plastic films urgently requires the development of non-toxic, biodegradable, and renewable biopolymer films. However, the poor waterproof and UV resistance properties of biopolymer films have limited their application in fruit packaging. In this work, a novel tannic acid cross-linked chitosan/gelatin film with hydrophobic silica coating (CGTS) was prepared. Relying on the adhesion of tannic acid and gelatin to silica, the coating endows CGTS film with excellent superhydrophobic properties. Especially, the contact angle reaches a maximum value 152.6°. Meanwhile, tannic acid enhanced the mechanical strength (about 36.1 %) through the forming of hydrogen bonding and the network structure. The prepared CGTS films showed almost zero transmittance to ultraviolet light and exhibited excellent radical scavenging ability (∼76.5 %, DPPH). Hence, CGTS film is suitable as a novel multifunctional packaging material for the agriculture to protect premature fruits, or the food industry used in environments exposed to ultraviolet radiation and rainwater., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The present study aims to combat the problem of oil in water pollution via its separation using a superhydrophobic copper mesh. An ecofriendly superhydrophobic copper mesh with a water contact angle of 166 ± 2° is developed by a facile two-step process (electrodeposition followed by coating). The coated mesh with mechanical robustness, chemical endurance and thermal stability is a promising choice for real-world conditions. Additionally, its resistance to corrosion in harsh chemical environments ensures its long-term durability. With a separation efficiency of 99.9 %, the coated mesh serves as an efficient medium for oil-water separation. It can be used as a reusable filtering medium with high separation efficiency in alkali and neutral environments. Besides, it is also competent for continuous oil-water separation and collection of oil from wastewater. Thus, the above study clearly manifests that the coated mesh holds tremendous potential for large-scale oil spill cleanup., Competing Interests: Declaration of competing interest We confirm that there is no conflict to declare., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Hemostatic materials play a crucial role in trauma medicine. However, existing materials have poor hemostatic efficacy and a tendency to adhere to the wound surface, limiting their clinical effectiveness. Herein, a drug-loaded, superhydrophilic/superhydrophobic laminated material (DSLM), consisting of a superhydrophobic inner layer with a micropore array, a superhydrophilic chitosan-based sponge layer loaded with hemostatic/antimicrobial drugs, and a superhydrophobic outer layer, was developed. Furthermore, the DSLM allows unidirectional flow of blood and exudates from the wound bed through the superhydrophobic inner layer while facilitating efficient drug delivery. In addition, it possesses excellent biocompatibility and antiadhesion properties, as confirmed by in vivo and in vitro experiments. Compared with traditional hemostatic materials, the DSLM remarkably increased the survival time by over threefold in the acute femoral transaction wound bleeding model, and simultaneously prevented secondary wound damage by reducing peeling force to one-eighth incomparison to pristine gauze. The DSLM holds promise as a versatile clinical biomaterial for prehospital acute trauma treatment, with its simple structure facilitating manufacturing and expanding applications in biomedicine., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)