Search Results (15)

Natural surfaces, such as lotus leaves, springtail cuticles, and pitcher plant peristomes, exhibit extraordinary wetting behaviors due to their unique surface topographies and chemical compositions. These natural architectures have inspired the development of wettability models and the production of artificial surfaces with tailored wettability for advanced applications. Electrodeposited metallic coatings can imitate the wettability behaviors of natural surfaces, showing superhydrophobic, superoleophobic, or slippery characteristics. Such coatings can significantly enhance corrosion resistance by minimizing water–metal contact and promoting self-cleaning effects. This review presents various strategies for fabricating corrosion-resistant metallic coatings, including different electrodeposition techniques in aqueous or non-aqueous baths, followed by post-treatment procedures and surface functionalization methods. However, despite the promising protective properties demonstrated under controlled laboratory conditions, long-term studies under natural exposure conditions are still lacking, which limits the full assessment of the durability and effectiveness of non-wettable electroplated deposits in practical applications. Full article

Superamphiphobic coatings have shown great potential in many fields such as with their anti-corrosion, high-temperature resistance, self-cleaning, and drag reduction properties. However, due to the poor stability of their coatings, it is difficult to apply them on a large scale. In this paper, two kinds of SiO₂ particles and nickel were co-deposited on the surface of steel to construct a micro/nano dual-scale structure by composite electrodeposition. The surface of the coating was then fluorinated with the low-surface-energy material 1H,1H,2H,2H-Perfluorodecyltriethoxysilane (AC-FAS) to prepare a Ni-SiO₂ superamphiphobic coating. The coating has a water contact angle of 159° and an oil contact angle of 151°. The effect of nanoparticle concentration on the wettability and surface morphology of the coating was systematically studied. Comparative experiments revealed that the optimal micro/nanoparticle concentrations were 8 g/L of 20 nm SiO₂ and 2 g/L of 1 μm SiO₂. This preparation method greatly improves the corrosion resistance, wear resistance, chemical stability, and high-temperature resistance of the coating. Full article

In recent years, organic superhydrophobic coatings have emerged as a promising direction for the protection of metal substrates due to their excellent liquid-repelling properties. Nonetheless, these coatings face challenges such as poor mechanical robustness and short service lives, which have limited their development and garnered attention from numerous researchers. Over time, researchers have gained a deeper understanding of superhydrophobic coatings and have published many related articles. Nevertheless, the lack of logical organization and systematic summarization of research focus in this field hinders its advancement. Therefore, the main purpose of this review is to clarify the design principles and working mechanisms of organic superhydrophobic coatings, as well as to summarize and synthesize the latest research on different aspects of superhydrophobic coatings, including liquid-repellent performance, wear resistance, adhesion, antibacterial properties, and self-healing properties. By employing decoupling mechanisms to study each performance aspect separately, this review aims to provide references for extending the service life of organic superhydrophobic coatings. Full article

The application of superamphiphobic coatings improves the surface’s ability to repel fluids, thereby greatly enhancing its various functions, including anti-fouling, anti-corrosion, anti-icing, anti-bacterial, and self-cleaning properties. This maximizes the material’s potential for industrial applications. This work utilized the agglomeration phenomenon exhibited by nano-spherical titanium dioxide (TiO₂) particles to fabricate 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) modified TiO₂ (TiO₂@fluoroPOS) fillers with low surface energy. This was achieved through the in-situ formation of protective armor on the surface of the agglomerates using the sol-gel method and fluorination modification. Polyvinylidene fluoride-tetrafluoropropylene (PVDF-HFP) and TiO₂@fluoroPOS fillers were combined using a spraying technique to prepare P/TiO₂@fluoroPOS coatings with superamphiphobicity. Relying on the abundance of papillae, micropores, and other tiny spaces on the surface, the coating can capture a stable air film and reject a variety of liquids. When the coatings were immersed in solutions of 2 mol/L HCl, NaCl, and NaOH for a duration of 12 h, they retained their exceptional superamphiphobic properties. Owing to the combined influence of the armor structure and the organic binder, the coating exhibited good liquid repellency during water jetting and sandpaper abrasion tests. Furthermore, the coating has shown exceptional efficacy in terms of its ability to be anti-icing, anti-waxing, and self-cleaning. Full article

Superamphiphobic coatings have widespread application potential in various fields, e.g., anti-icing, anti-corrosion and self-cleaning, but are seriously limited by poor mechanical stability. Here, mechanically stable superamphiphobic coatings were fabricated by spraying the suspension composed of phase-separated silicone-modified polyester (SPET) adhesive microspheres with fluorinated silica (FD-POS@SiO₂) on them. The effects of non-solvent and SPET adhesive contents on the superamphiphobicity and mechanical stability of the coatings were studied. Due to the phase separation of SPET and the FD-POS@SiO₂ nanoparticles, the coatings present a multi-scale micro-/nanostructure. Combined with the FD-POS@SiO₂ nanoparticles of low surface energy, the coatings present outstanding static and dynamic superamphiphobicity. Meanwhile, the coatings present outstanding mechanical stability due to the adhesion effect of SPET. In addition, the coatings present outstanding chemical and thermal stability. Moreover, the coatings can obviously delay the water freezing time and decrease the icing adhesion strength. We trust that the superamphiphobic coatings have widespread application potential in the anti-icing field. Full article

This study is focused on the preparation, characterization, and multifunctional properties of intelligent hybrid nanopigments. The hybrid nanopigments with excellent environmental stability and antibacterial and antioxidant properties were fabricated based on natural Monascus red, surfactant, and sepiolite via a facile one-step grinding process. The density functional theory calculations demonstrated that the surfactants loaded on sepiolite were in favor of enhancing the electrostatic, coordination, and hydrogen bonding interactions between Monascus red and sepiolite. Thus, the obtained hybrid nanopigments exhibited excellent antibacterial and antioxidant properties, with an inhibition effect on Gram-positive bacteria that was superior to that of Gram-negative bacteria. In addition, the scavenging activity on DPPH and hydroxyl free radicals as well as the reducing power of hybrid nanopigments were higher than those of hybrid nanopigments prepared without the addition of the surfactant. Inspired by nature, gas-sensitive reversible alochroic superamphiphobic coatings with excellent thermal and chemical stability were successfully designed by combining hybrid nanopigments and fluorinated polysiloxane. Therefore, intelligent multifunctional hybrid nanopigments have great application foreground in related fields. Full article

Silane-based materials are used for the protection of heritage and modern buildings. A versatile method is developed to tune the wetting properties of a typical silane-based material from hydrophobicity to superamphiphobicity, thus enhancing the protective efficacy against rainwater and organic pollutants. A commercially available silane product is blended with a fluoropolymer to lower the surface energy and silica (SiO₂) nanoparticles to affect the surface morphologies of the produced coatings on marble. Contact angles of water and oil drops are measured on the coating surfaces which were prepared using 16 different combinations of fluoropolymer and nanoparticle concentrations. It is shown that the synergistic effect of surface structure and chemistry can lead to the production of coatings that possess superamphiphobic properties. The wetting properties of a selected non-wettable coating are further characterised using a custom-made, fully-automated device (Kerberos) which monitors simultaneously the deformation of the liquid interface, spreading and sliding of the drop along the sample surface during tilting. Several tests are carried out to evaluate the durability of the selected superamphiphobic coating, offering overall promising results. The versatile method can be used to impart superamphiphobicity to the surfaces of various materials. The method developed herein can be adopted to tune the wetting properties of other silane-based commercial products which are used for the protection of buildings. Full article

In this work, we report a unique and facile approach to the manufacture of fluorine-free superamphiphobic paper. Based on the principle that Fe₃O₄ nanoparticles (NPs) arranged along the direction of a magnetic field, the mixture of Fe₃O₄ NPs and polydimethylsiloxane (PDMS) was coated on kraft paper through self-assembly and thermal-curing at a high temperature in a magnetic field, fabricating a mushroom-like microstructure on the paper. At an Fe₃O₄ NPs content of 75%, the radius of the mushroom-like pillar caps (R_CAP) and center-to-center spacing between two pillars (S) obtained the optimal size of 37 ± 18 μm and 237 ± 38 μm, respectively. The oil-contact angle and water-contact angle of the fabricated paper were up to 156° and 160.4°, respectively. It also showed excellent oleophobic stability; the oil-contact angle was still maintained at 141.9° after 1 h. In addition, the contact angles of milk, ethylene glycol and castor oil were all above 150°, and the contact angle of diiodomethane was 134.2°. Moreover, the sample showed great oil resistance with a kit rating value of 12/12 and permeability of 1800+ s. Full article

Super-amphiphobic surface with low robustness is not suitable for practical application due to its weak mechanical strength. In this work, an in-site growth of micro-/nanoscale flower-like TiO₂ on the surface of a titanium mesh was successfully fabricated through hydrothermal synthesis, followed by chemical modification with low-surface-energy heptadecafluoro-1,1,2,2-tetrahydrodecyl trichlorosilane. The resultant super-amphiphobic coating was highly repellent to all of the ethanol–water mixtures with surface tensions ranging over 26.0–72.8 mN/m, as well as excellent chemical and mechanical durability. After it was irradiated for 8 h with ultraviolet light, it was used for oil/water and oil/oil mini-separation with the help of its Janus characteristic. This was attributed to its unidirectional penetration for liquid droplets with different surface tension values. This kind of smart super-amphiphobic mesh with photochemical activity could potentially gate and sort liquids via surface tensions. Full article

We present a facile approach to fabricate superamphiphobic surfaces by spray coating silica-fluoropolymer core-shell particles without substrate pretreatment with an additional binder resin. A series of SiO₂@poly(1H,1H,2H,2H-heptadecafluorodecyl methacrylate) (SiO₂@PFMA) core-shell particles with core particles of different sizes were prepared via thiol-lactam initiated radical polymerization (TLIRP). The surface of each SiO₂ particle with an average particle size of 12, 80, 150, and 350 nm was modified with (3-mercaptopropyl) trimethoxysilane and used as a seed for TLIRP. The SiO₂@PFMA particles with various SiO₂ sizes and contents were coated on aluminum substrates by a spray gun and then thermally treated to form a stable, rough composite layer. During the spray coating, the core-shell particles were aggregated by rapid evaporation of the solvent and then irregularly adhered to the substrate resulting in hierarchical structures. In the case of SiO₂@PFMAs with low SiO₂ contents, the roughness created mainly by the polymer shell disappeared during heat treatment. However, the substrates coated with SiO₂@PFMAs with high SiO₂ contents maintained the roughness even after heat treatment. The core-shell particles prepared with 12 nm SiO₂ formed a stable superamphiphobic surface. The water/hexadecane contact and sliding angles on an aluminum plate coated with SiO₂@PFMA, prepared using 12 nm silica at 46 wt% silica content (12 nm-SiO₂(46)@PFMA), were 178.5°/159.2° and 1°/7°, respectively. The cross-cut tape test showed that adhesion between the 12nm-SiO₂(46)@PFMA and the aluminum substrate was classified as 5B. A glass surface spray-coated with the core-shell composite particles exhibited transparent superhydrophobicity and translucent superamphiphobicity by controlling the concentration of the coating solution. Full article

Fabrics treated to repel water, superhydrophobic, and water and oil, superamphiphobic, have numerous industrial and consumer-level benefits. However, the liquid repellency decreases in the course of time. This is largely due to chemical or physical changes of the coating due to prolonged exposure to relatively harsh environments. To develop more durable fabric treatments for specific applications, it is necessary to measure the extent to which the treated fabrics retain their low-wettability after being subjected to controlled aggressive environmental conditions. In this study, plain weave fabrics made from polyester filaments and coated with silicone nanofilaments in-solution were exposed to aerodynamic icing conditions. The coated fabrics showed superhydrophobic behavior, or superamphiphobic for those that were fluorinated. The wettability of the fabrics was progressively evaluated by contact angle and roll-off-angle measurements. The coated fabrics were able to maintain their low-wettability characteristics after exposure to water droplet clouds at airspeeds up to 120 m/s, despite damage to the silicone nanofilaments, visible through scanning electron microscopy. Full article

Understanding the corrosion inhibition behavior of super-amphiphobic coating is important to ensure practicability in the real application. 2 layers system of super-amphiphobic coating was successfully developed using functionalized nano-Al₂O₃ incorporated in polyvinylidene fluoride (PVDF). This study investigates the effect of different amount of functionalizing agent on the coating’s repellency and its relationship toward the corrosion inhibition behavior. We found that a higher amount of fluoroalkylsilane (FAS) led to a decreased in repellency of both water and oil. Electrochemical impedance spectroscopy (EIS) analysis suggests that the synergetic effect between super-hydrophobicity, longer diffusion path, and barrier effect; enhanced the corrosion resistance. Although the coatings demonstrate similar behavior, the most superhydrophobic/amphiphobic coating C1 offers the highest corrosion protection. Full article

Any solid surface with homogenous or varying surface energy can spontaneously show variable wettability to liquid droplets with different or identical surface tensions. Here, we studied a glass slide sprayed with a quasi-superamphiphobic coating consisting of a hexane suspension of perfluorosilane-coated nanoparticles. Four areas on the glass slide with a total length of 7.5 cm were precisely tuned via ultraviolet (UV) irradiation, and droplets with surface tensions of 72.1–33.9 mN m⁻¹ were categorized at a tilting angle of 3°. Then, we fabricated a U-shaped device sprayed with the same coating and used it to sort the droplets more finely by rolling them in the guide groove of the device to measure their total rolling time and distance. We found a correlation between ethanol content/surface tension and rolling time/distance, so we used the same device to estimate the alcoholic strength of Chinese liquors and to predict the surface tension of ethanol aqueous solutions. Full article

Since the discovery of the self-cleaning properties of the lotus effect, the wetting of surfaces were intensively investigated due to their potential application in many industrial sectors. The transparency of flexible liquid repellent coatings are a major industrial problem and their economic consequences are widely known. Hence, a comprehensive understanding of the developments of flexible and transparent superamphiphobic surfaces is required in a number of technological and industrial situations. In this review, we aim to discuss the progress in the design, synthesis, fabrication techniques, and applications of flexible and transparent superamphiphobic surfaces. We start with an introduction, exploring the contact angles and wetting states for superhydrophilic, superhydrophobic, and superoleophobic surfaces, and continue with a review of the wetting transition of such surfaces. Then, we highlight the fabrication techniques involved for the preparation of flexible and transparent superamphiphobic surfaces. This review also discusses the key issues in the fabrication process and surfaces, and their features in improving durability characteristics and self-repellent performance. Then we suggest various recommendations for the improvement of mechanical durability along with potential future directions towards more systematic methods that will also be acceptable for industry. Finally, we conclude with some challenges and potential applications. Full article