Damage Tolerance of Superhydrophobic Coatings with Binary Cooperative Cells for Water Harvesting.

Multifunction superhydrophobic coatings that facilitate water harvesting are attractive for addressing the daunting water crisis, yet, they are caught in a double bind when their durability is considered, as durable coatings will require both tough micro-textures to survive concentrated stress and high-surface-energy chemistry to form chemical bonds within the matrix. To date, a universal bulk-phase coating that combines multifunctionality, ultra-durability, and fabrication feasibility remains challenging. Here, a binary cooperative cell design is reported that can solve the contradiction between the multifunctionality and durability requirements of superhydrophobic coatings. In this strategy, mechanochemically tailored cells with releasable nanoseeds are infused in the common matrix, which serves both as a versatile chemical bridge to achieve strong bonds within the coating building blocks, and as an instantaneous self-repairing generator to improve durability. Such a strategy significantly boosted the wear resistance and outdoor stability of the coatings by over 30-100 and 18 folds, respectively, compared with conventional coatings. The coating is applied to the sustainable application, i.e., enhancing the water collection efficiency by at least 1000% even after harsh abrasion. The strategy will broaden the vision in handling the dilemma properties among functional coatings and promote the application of superhydrophobic coatings in extreme environments.

Underwater Bionic Self-Healing Superhydrophobic Coating with the Synergetic Effect Of Hydrogen Bonds and Self-Formed Bubbles.

The self-healing ability of superhydrophobic surfaces in air has attracted tremendous additions in recent years. Once the superhydrophobic surface is damaged underwater, water seeps into gaps among micro/nano structures. The air film diffuses into water and eventually disappears during immersion without actively replenishing the gas, which results in the impossible of self-healing. Here, an underwater self-healing superhydrophobic coating with the synergetic effect of hydrogen bonds and self-formed bubbles via the spraying method is fabricated. The movement of hydrogen bonds of the prepared polyurethane enables microstructures to reconstruct at room temperature and self-formed bubbles of effervescent materials underwater actively replenish gas before microstructures completely self-healing, achieving the self-healing property of the superhydrophobic coating. Moreover, the hydrophilic effervescent material is sprayed along with unmodified micron-scaled particles because modified nano-scale particles are key factors for the realization of superhydrophobic coating. An underwater stable superhydrophobic surface with pressure resistance (4.9 kPa) is demonstrated. This superhydrophobic coating also shows excellent drag reduction, anti-icing, and anti-corrosion properties. This facile and scalable method offers a new route that an underwater self-healing superhydrophobic coating executes the gas film recovery.

Fast-Crosslinking Enabled Self-Roughed Polydimethylsiloxane Transparent Superhydrophobic Coating and Its Application in Anti-Liquid-Interference Electrothermal Device.

Polydimethylsiloxane (PDMS)-based transparent and superhydrophobic coatings have important applications, such as anti-icing, corrosion resistance, self-cleaning, etc. However, their applications are limited by the inevitable introduction of nanoparticles/high-temperature/segmented PDMS to facilitate a raspy surface. In this study, a self-roughed, neat PDMS superhydrophobic coating with high transparency is developed via a one-step spray-coating technique. PDMS suspensions with various droplet sizes are synthesized and used as building blocks for raspy surface formation by controlled curing on the warm substrate. The optimal coating exhibits a large water contact angle of 155.4° and transparency (T550 = 82.3%). Meanwhile, the employed spray-coating technique is applicable to modify a plethora of substrates. For proof-of-concept demonstrations, the use of the PDMS hydrophobic coating for anti-liquid-interference electrothermal devices and further transparent observation window for long-term operation in a sub-zero environment is shown successful. The proposed facile synthesis method of hydrophobic PDMS coating is expected to have great potential for a broad range of applications in the large-scale fabrication of fluorine-free, eco-friendly superhydrophobic surfaces.

Low-Cost and Scaled-Up Production of Fluorine-Free, Substrate-Independent, Large-Area Superhydrophobic Coatings Based on Hydroxyapatite Nanowire Bundles.

To date, the scaled-up production and large-area applications of superhydrophobic coatings are limited because of complicated procedures, environmentally harmful fluorinated compounds, restrictive substrates, expensive equipment, and raw materials usually involved in the fabrication process. Herein, the facile, low-cost, and green production of superhydrophobic coatings based on hydroxyapatite nanowire bundles (HNBs) is reported. Hydrophobic HNBs are synthesised by using a one-step solvothermal method with oleic acid as the structure-directing and hydrophobic agent. During the reaction process, highly hydrophobic C-H groups of oleic acid molecules can be attached in situ to the surface of HNBs through the chelate interaction between Ca2+ ions and carboxylic groups. This facile synthetic method allows the scaled-up production of HNBs up to about 8 L, which is the largest production scale of superhydrophobic paint based on HNBs ever reported. In addition, the design of the 100 L reaction system is also shown. The HNBs can be coated on any substrate with an arbitrary shape by the spray-coating technique. The self-cleaning ability in air and oil, high-temperature stability, and excellent mechanical durability of the as-prepared superhydrophobic coatings are demonstrated. More importantly, the HNBs are coated on large-sized practical objects to form large-area superhydrophobic coatings.

Composite Superhydrophobic Coating with Transparency and Thermal Insulation for Glass Curtain Walls.

In this paper, the preparation of a transparent superhydrophobic composite coating with a thermal insulation function using antimony-doped tin oxide (ATO) nanoparticles is proposed, which has advantages of being mass-producible and low-cost. In short, nanosilica and ATO are used as raw materials for constructing rough structures, and superhydrophobic coatings are obtained by mixing and adding binders after modification of each, which are then applied to the surface of various substrates by spraying to obtain a transparent superhydrophobic coating with a heat-insulating function. The specific role of each nanoparticle is discussed through comparative experiments that illustrate the mechanism by which the two particles construct rough structures. The coating achieves unique thermal insulation properties while possessing excellent superhydrophobicity (WCA of ∼163° and WSA of ∼3°) and high light transmission (∼70%). Heat-shielding experiments have demonstrated that the composite coating effectively reduces the room temperature by approximately 19% for the same irradiation time. The coating achieves a balanced improvement in visible transmittance, thermal insulation, and superhydrophobicity. In addition, the coating's self-cleaning properties, mechanical properties, chemical weathering resistance, high-temperature resistance, and anti-icing properties were verified through various experiments.

Eco-friendly approach for the fabrication of biо copper based superhydrophobic coating on steel metal and its corrosion resistance evaluation.

This study presents an eco-friendly approach for constructing superhydrophobic (S.H.) coatings on steel surfaces. The biо Сu nanoparticles are synthesized using a biоgenic process. Two types of coatings, Ni-Ѕ.Α and Ni-biо Сu-Ѕ.Α, were developed and characterized. The EDX results confirm the successful fabrication of two distinct coatings on the steel substrate: one involving the modification of nickel with stearic acid, Ni-Ѕ.Α, and the other involving the modification of nickel with both bio-Cu and stearic acid, Ni-biо Сu-Ѕ.Α. The SEM results revealed that the S.H. coats exhibit circular microstructures which contribute to the surface roughness. The contact angles of water droplets on the Ni-Ѕ.Α and Ni-biо Сu-Ѕ.Α coatings were measured at 158° ± 0.9° and 162° ± 1.1°, respectively. Chemical stability tests demonstrated that the Ni-Ѕ.Α coating maintains its S.H. behaviour in a pH range of 3-11, whereas the Ni-biо Сu-Ѕ.Α coating exhibits excellent chemical stability in a broader range of pH (1-13). The coating's mechanical stability was evaluated through abrasion tests. The Ni-Ѕ.Α coating retained its S.H. properties even after an abrasion length equal 1100 mm, while the Ni-biо Сu-Ѕ.Α coating maintained its S.H. behaviour till an abrasion length equal 1900 mm. The corrosion behavior and protective properties of the S.H. coatings were studied via electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques. The PDP and EIS findings demonstrated that both Ni-Ѕ.Α and Ni-biо Сu-Ѕ.Α coatings significantly reduced the corrosion rate compared to uncoated steel.

Bionic Nanocoating of Prosthetic Grafts Significantly Reduces Bacterial Growth.

Prosthetic materials are a source of bacterial infections, with significant morbidity and mortality. Utilizing the bionic "Lotus effect," we generated superhydrophobic vascular prostheses by nanocoating and investigated their resistance to bacterial colonization. Nanoparticles were generated from silicon dioxide (SiO2), and coated vascular prostheses developed a nanoscale roughness with superhydrophobic characteristics. Coated grafts and untreated controls were incubated with different bacterial solutions including heparinized blood under mechanical stress and during artificial perfusion and were analyzed. Bioviability- and toxicity analyses of SiO2 nanoparticles were performed. Diameters of SiO2 nanoparticles ranged between 20 and 180 nm. Coated prostheses showed a water contact angle of > 150° (mean 154 ± 3°) and a mean water roll-off angle of 9° ± 2°. Toxicity and viability experiments demonstrated no toxic effects of SiO2 nanoparticles on human induced pluripotent stem cell-derived cardiomyocytes endothelial cells, fibroblasts, and HEK239T cells. After artificial perfusion with a bacterial solution (Luciferase+ Escherichia coli), bioluminescence imaging measurements showed a significant reduction of bacterial colonization of superhydrophobic material-coated prostheses compared to that of untreated controls. At the final measurement (t = 60 min), a 97% reduction of bacterial colonization was observed with superhydrophobic material-coated prostheses. Superhydrophobic vascular prostheses tremendously reduced bacterial growth. During artificial perfusion, the protective superhydrophobic effects of the vascular grafts could be confirmed using bioluminescence imaging.

Empowering Photovoltaic Panel Anti-Icing: Superhydrophobic Organic Composite Coating with In Situ Photothermal and Transparency.

Solar energy is widely used in photovoltaic power generation as a kind of clean energy. However, the liquid film, frosting, and icing on the photovoltaic module seriously limit the efficiency of photovoltaic power generation. We developed a composite coating (Y6-NanoSH) by combining an in situ photothermal and transparent Y6 organic film with a nanosuperhydrophobic material. The Y6-NanoSH coated glass exhibited excellent optical clarity both indoors and outdoors, indicating that the coating holds great promise in anti-icing applications for photovoltaic panels. The Y6-NanoSH coating absorbs very little visible light but instead absorbs in the near-infrared region, thereby emitting heat. When exposed to sunlight, the Y6-NanoSH coated photovoltaic panel raises its surface temperature, inhibiting the growth and accumulation of ice and frost on its surface. This is achieved through a combination of photothermal emission and superhydrophobic repellency, which promotes the evaporation and rolling away of water droplets. This validates our success in developing a photothermal, transparent, and superhydrophobic coating with excellent anti-icing capabilities, suitable for use on photovoltaic panels, as well as potential applications in car windscreens, transmission lines, curtain walls, and weather radomes.

Conductive and superhydrophobic lignin/carbon nanotube coating with nest-like structure for deicing, oil absorption and wearable piezoresistive sensor.

The development of multifunctional coatings is a trend. Here, a conductive and superhydrophobic coating with nest-like structure was prepared on the wood or polyurethane (PU) sponge by spraying or soaking methods. The coating contains lignin and carboxylated multi-wall carbon nanotubes (MWCNT) as the main materials, both methyl trimethoxysilane (MTMS) and polydimethylsiloxane (PDMS) as the modifiers. And benefiting from the protective effect of the nest-like structure, the coating exhibits excellent abrasion resistance (withstanding 43 abrasion cycles), stability, and UV resistance (little change in water contact angle after 240 h of ultraviolet (UV) irradiation) by optimizing the proportions. Additionally, the coating provides eminent deicing (complete removal after 142.7 s) and self-cleaning on the wood, as well as the superior sensing performance and oil absorption (15.0-49.6 g/g for various oils) on the PU sponge. When assembled into compressible piezoresistive sensor, it could clearly sense the signals of rapid, short, circulation, different speed and deformation, possessing a prosperous wearable device prospect. It is envisaged that the coating supplies a new platform for superhydrophobicity, wearable electronics and oil absorption.

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.

A comprehensive review on anticorrosive/antifouling superhydrophobic coatings: Fabrication, assessment, applications, challenges and future perspectives.

Superhydrophobicity (SHP) is an incredible phenomenon of extreme water repellency of surfaces ubiquitous in nature (E.g. lotus leaves, butterfly wings, taro leaves, mosquito eyes, water-strider legs, etc). Historically, surface exhibiting water contact angle (WCA) > 150° and contact angle hysteresis <10° is considered as SHP. The SHP surfaces garnered considerable attention in recent years due to their applications in anti-corrosion, anti-fouling, self-cleaning, oil-water separation, viscous drag reduction, anti-icing, etc. As corrosion and marine biofouling are global problems, there has been focused efforts in combating these issues using innovative environmentally friendly coatings designs taking cues from natural SHP surfaces. Over the last two decades, though significant progress has been made on the fabrication of various SHP surfaces, the practical adaptation of these surfaces for various applications is hampered, mainly because of the high cost, non-scalability, lack of simplicity, non-adaptability for a wide range of substrates, poor mechanical robustness and chemical inertness. Despite the extensive research, the exact mechanism of corrosion/anti-fouling of such coatings also remains elusive. The current focus of research in recent years has been on the development of facile, eco-friendly, cost-effective, mechanically robust chemically inert, and scalable methods to prepare durable SHP coating on a variety of surfaces. Although there are some general reviews on SHP surfaces, there is no comprehensive review focusing on SHP on metallic and alloy surfaces with corrosion-resistant and antifouling properties. This review is aimed at filling this gap. This review provides a pedagogical description with the necessary background, key concepts, genesis, classical models of superhydrophobicity, rational design of SHP, coatings characterization, testing approaches, mechanisms, and novel fabrication approaches currently being explored for anticorrosion and antifouling, both from a fundamental and practical perspective. The review also provides a summary of important experimental studies with key findings, and detailed descriptions of the evaluation of surface morphologies, chemical properties, mechanical, chemical, corrosion, and antifouling properties. The recent developments in the fabrication of SHP -Cr-Mo steel, Ti, and Al are presented, along with the latest understanding of the mechanism of anticorrosion and antifouling properties of the coating also discussed. In addition, different promising applications of SHP surfaces in diverse disciplines are discussed. The last part of the review highlights the challenges and future directions. The review is an ideal material for researchers practicing in the field of coatings and also serves as an excellent reference for freshers who intend to begin research on this topic.

Anti-Condensation Performance of a New Superhydrophobic Coating for Pavements.

Superhydrophobic coating ice suppression is an advanced and durable technology that shows great potential for application on pavements. Although many researchers have conducted experimental and theoretical validations to confirm the effectiveness of superhydrophobic surfaces in actively suppressing ice formation, there are still some who remain skeptical. They argue that the roughness of the surface may increase ice adhesion due to the mechanical interlocking effect of condensation droplets in low-temperature and high-humidity environments. In this study, we present a comprehensive investigation of a novel superhydrophobic coating specifically designed for pavement surfaces, aiming to address the question of its active anti-icing/ice-sparing capabilities in a condensing environment. The changes in contact angle before and after condensation for four material surfaces with varying wettability were investigated, as well as the morphology and ice adhesion of liquid water after it freezes on the material surface. The findings reveal that the proposed superhydrophobic coating for pavements effectively prevents condensate droplets from infiltrating the surface structure, resulting in delaying the surface icing time and reducing the attachment strength of the ice.

Design and Strengthening of Superhydrophobic Coatings: The Influence of Intermediate Layers.

The employment of intermediate layer technology to improve the mechanical stability of superhydrophobic coatings (SHCs) is an acknowledged tool, but the mechanism by which intermediate layers, especially different ones, affect superhydrophobic composite coatings is not clear. In this work, a series of SHCs based on the strengthening of the intermediate layer were fabricated by employing polymers with different elastic moduli such as polydimethylsiloxane (PDMS), polyurethane (PU), epoxy (EP) resin, as well as graphite/SiO2 hydrophobic components. Following that, the effect of different elastic modulus polymers as an intermediate layer on the durability of SHCs was investigated. From the perspective of elastic buffering, the strengthening mechanism of elastic polymer-based SHCs was clarified. Furthermore, from the perspective of self-lubrication, the wear resistance mechanism of self-lubricating hydrophobic components in the SHCs was elucidated. Also, the prepared coatings exhibited excellent acid and alkali resistance, self-cleaning, anti-stain, and corrosion resistance. This work confirms that low-elastic-modulus polymers can also play the role of buffering external impact energy by elastic deformation even as an intermediate layer, and provides theoretical guidance for the development of SHCs with robustness.

Eco-Friendly Approach for the Construction of Superhydrophobic Coating on Stainless Steel Metal Based on Biological Metal-Organic Framework and Its Corrosion Resistance Performance.

In this paper, we present a sustainable approach for the creation of superhydrophobic (SP) coating on a stainless-steel substrate based on a biological metal-organic framework (MOF). The MOF was synthesized using aspartic acid as a linker and copper ions as a core metal. Two SP coatings were well constructed on stainless steel utilizing electrodeposition of nickel (Ni) and nickel altered by MOF (Ni@Bio-MOF) coatings followed by soaking in a solution of stearic acid in ethanol. The results of Fourier transform infrared spectroscopy demonstrate that the stearic acid-grafted nickel coating (Ni@SA) and the stearic acid-grafted Ni@Bio-MOF composite (Ni@Bio-MOF@SA), were effectively deposited on the stainless steel. The wettability findings displayed that the water contact angle of Ni@SA and Ni@Cu-As MOF@SA are 160° ± 1.1°, and 168° ± 1.2°, respectively. The prepared SP coating was also found to be chemically and mechanically stable. The results show that the Ni@SA coating maintains SP characteristics in a pH range of 3-11 while the Ni@Cu-As MOF@SA coating retained SP characteristics in a pH range of 1-13. Additionally, the superhydrophobic Ni@SA coating demonstrated SP characteristics up to a length of abrasion equal to 1300 mm, while the Ni@Cu-As MOF@SA coating exhibited SP characteristics up to a length of abrasion equal to 2700 mm. Furthermore, the Ni@SA and Ni@Cu-As MOF@SA coatings exhibited significantly improved corrosion protection in a 0.5 M NaCl solution compared with bare stainless steel, with protection efficiencies of approximately 94% and 99%, respectively. The results of this study demonstrate that the proposed approach is a promising method for the fabrication of eco-friendly and corrosion-resistant SP coatings on stainless steel substrate.

Multifunctional Integrated Superhydrophobic Coatings with Unique Fluorescence and Micro/Micro/Nano-Hierarchical Structures Enabled by In Situ Self-Assembly.

Conferring versatility to superhydrophobic materials is extremely desirable to advance their utility. Herein, we have developed a superhydrophobic material with montmorillonite as microskeleton supports and in situ grown ZIF-8 nanoparticles and loaded them with newly developed fluorescent carbon dots. In situ growth of the ZIF-8 on OMMT constructs a dense nanoscale rough structure and meanwhile self-assembly generates abundant microporous, thus forming unique hierarchical microporous/microsheet/nanoparticle tri-tier micro and nano structures. Then the multifunctional superhydrophobic coating is fabricated by a facile spraying technique using polydimethylsiloxane (PDMS) as a multifunctional polymer binder. The PDMS/RB-CDs/ZIF-8@OMMT exhibits superhydrophobicity with a water contact angle of 164.7° and a water sliding angle of 1.4°, which also possesses good self-cleaning performance. Moreover, novel carbon dots are developed in this work which can confer unique fluorescent properties and photothermal properties to materials. Fluorescence characterization reveals the multiple emission peaks among 300-800 nm and excitation wavelength dependence and independence. Photothermal experiments unveil an efficient light-to-heat conversion caused by the light traps and absorption wavelengths associated with photothermal heating. Benefiting from the dense microporous/microsheet/nanoparticle structures, the superhydrophobicity is still maintained after 120 cycles of abrasion. Moreover, electrochemical impedance spectroscopy (EIS) reveals a significant increase in impedance, which is associated with excellent corrosion resistance. The superhydrophobic coating also exhibits superior UV resistance and good thermal stability. Multifunctional fluorescent superhydrophobic materials will enable the development of various and potential applications in different fields.

Chitosan-based coatings with tunable transparency and superhydrophobicity: A solvent-free and fluorine-free approach by stearoyl derivatization.

One of the current greatest challenges in materials science and technology is the development of safe- and sustainable-by-design coatings with enhanced functionalities, e.g. to substitute fluorinated substances raising concerns for their potential hazard on human health. Bio-based polymeric coatings represent a promising route with a high potential. In this study, we propose an innovative sustainable method for fabricating coatings based on chitosan with modified functionality, with a fine-tuning of coating properties, namely transparency and superhydrophobicity. The process consists in two main steps: i) fluorine-free modification of chitosan functional groups with stearoyl chloride and freeze-drying to obtain a superhydrophobic powder, ii) coating deposition using a novel solvent-free approach through a thermal treatment. The modified chitosan is characterized to assess its chemico-physical properties and confirm the functionality modification with fatty acid tails. The deposition method enables tuning the coating properties of transparency and superhydrophobicity, maintaining good durability.

Robust Superhydrophobicity through Surface Defects from Laser Powder Bed Fusion Additive Manufacturing.

The robustness of superhydrophobic objects conflicts with both the inevitable introduction of fragile micro/nanoscale surfaces and three-dimensional (3D) complex structures. The popular metal 3D printing technology can manufacture robust metal 3D complex components, but the hydrophily and mass surface defects restrict its diverse application. Herein, we proposed a strategy that takes the inherent ridges and grooves' surface defects from laser powder bed fusion additive manufacturing (LPBF-AM), a metal 3D printing process, as storage spaces for hydrophobic silica (HS) nanoparticles to obtain superhydrophobic capacity and superior robustness. The HS nanoparticles stored in the grooves among the laser-melted tracks serve as the hydrophobic guests, while the ridges' metal network provides the mechanical strength, leading to robust superhydrophobic objects with desired 3D structures. Moreover, HS nanoparticles coated on the LPBF-AM-printed surface can inhibit corrosion behavior caused by surface defects. It was found that LPBF-AM-printed objects with HS nanoparticles retained superior hydrophobicity after 150 abrasion cycles (~12.5 KPa) or 50 cycles (~37.5 KPa). Furthermore, LPBF-AM-printed ships with superhydrophobic coating maintained great water repellency even after 10,000 cycles of seawater swashing, preventing dynamic corrosion upon surfaces. Our proposed strategy, therefore, provides a low-cost, highly efficient, and robust superhydrophobic coating, which is applicable to metal 3D architectures toward corrosion-resistant requirements.

Waterproof and Flame-Retardant Fabric Coating with Nail-Tie Structure was Constructed by Janus Particles with Strong Mechanical, Physical, and Chemical Durability.

Oil spills are one of the most dangerous sources that cause serious environmental pollution and fire and explosion. In this work, multifunctional separator silica@polydivinylbenzene/poly 2,6-dimethyl-1, 4-phenyl ether (silica@PDVB/PPE) Janus particles were fabricated via seed emulsion polymerization, causing phase segregation as well as selective modification. The epoxy modified silica is partially covalently bonded to the fabric substrate surface by simple spraying to achieve a strong composite coating. The low surface energy PDVB/PPE forms a micronano rough layered surface, which can achieve a super hydrophobic and lipophile surface (WCA = 155°) and obtain a high flux separation of water and oil at 32,700 L·m-2·h-1. At the same time, the Janus composite fabric coating has the advantages of high heat resistance and flame retardant, which is realized by halogen-free flame-retardant unsaturated polyphosphate (PPE), making Janus fabric have potential value in separating oil-water mixtures and fire protection applications. In addition, the coating shows excellent chemical durability. After soaking in various aqueous solvents and organic solvents for 30 h, it can still maintain superhydrophobicity and flame retardant. The coating still has water repellency and flame retardant after 50 washings and mechanical wear and has good mechanical durability.

Enhancing Textile Water Repellency with Octadecyltrichlorosilane (OTS) and Hollow Silica Nanoparticles.

Superhydrophobic coatings have attracted substantial attention owing to their potential application in various industries. Conventional textiles used in daily life are prone to staining with water and household liquids, necessitating the development of water-repellent and stain-resistant coatings. In this study, we fabricated a highly water-repellent superhydrophobic PET fabric by using an eco-friendly water-based coating process. Fluorine-free octadecyltrichlorosilane (OTS) solutions with various wt.% of hollow silica (HS) nanoparticles were used to produce a superhydrophobic surface via a facile dip coating method. Our findings revealed that the incorporation of HS nanoparticles substantially increased the water contact angle, with higher concentrations resulting in enhanced water repellency and increased surface roughness. The treated fabrics had a remarkable water contact angle of 152.4° ± 0.8°, demonstrating their superhydrophobic fiber surface. In addition, the durability of these superhydrophobic properties was investigated via a laundry procedure, which showed that the fabrics maintained their water repellency even after 20 laundering cycles. EDX and XRD analyses confirmed that the morphological evaluations did not reveal any substantial structural alterations. Significantly, the fibers maintained their strength and durability throughout the testing, enduring only minor hollow SiO2 nanoparticle loss. This eco-friendly and cost-effective method holds great potential for application in apparel and other industries, offering an effective solution to resist water stains and improve performance in various contexts.

Mussel-Inspired Fabrication of an Environment-Friendly and Self-Adhesive Superhydrophobic Polydopamine Coating with Excellent Mechanical Durability, Anti-Icing and Self-Cleaning Performances.

Superhydrophobic coatings play a crucial role in self-cleaning and anti-icing infrastructure areas under harsh service environments such as very low temperature, strong wind, and sand impact. In the present study, an environment-friendly and self-adhesive superhydrophobic polydopamine coating inspired by mussels had been successfully developed and its growth process was accurately regulated by formula and reaction ratio optimization. The preparation characteristic and reaction mechanism, surface wetting behavior, multi-angle mechanical stability, anti-icing, and self-cleaning tests were systematically investigated. The results showed that the superhydrophobic coating achieved an ideal static contact angle of 162.7° and a roll-off angle of 5.5° through the proposed self-assembly technique in an ethanol-water solvent. This was due to the coupling effect of constructing a hierarchical roughness structure on the coating surface and reducing its surface energy, which had been well documented by the surface morphology characteristic and chemical structure analysis. The as-prepared coating's self-mechanical performances (tensile strength/shear holding power) and surface wear resistance (sand impact/sandpaper abrasion) behaviors were tested, and results showed tight internal compactness and excellent mechanical robustness, respectively. Furthermore, the 180° tape-peeling on 100 cycles and pull-off adhesion tests indicated that the above coating had significant mechanical stability and an increased percentage (57.4%) of interface bonding strength (27.4 MPa) with steel substrate compared to pure epoxy/steel. This was attributed to the metal chelating capacity between polydopamine catechol moieties and steel. Finally, the superhydrophobic coating had obvious self-cleaning properties by using graphite powder as a contaminant. Additionally, the coating had a higher supercool pressure and displayed much-reduced icing temperature, a longer icing delay time, and an extremely low and stable ice adhesion strength (0.115 MPa) owing to the extreme water-repellence and mechanical durability.