Superamphiphobic Properties Research Articles

Highly fluorinated and hierarchical HNTs/SiO2 hybrid particles for substrate-independent superamphiphobic coatings

In this study, superamphiphobic coatings were prepared using a spray-coating method based on highly fluorinated and hierarchical-structure halloysite nanotubes (HNTs)/SiO2 powder. The prepared superamphiphobic coatings could repel liquids with a surface tension as low as 20.1 mN/m (n-heptane). The coating could repel hot water and 68% HNO3, demonstrating excellent superamphiphobic properties. The superamphiphobic HNTs/SiO2 particles were synthesized using a co-condensation reaction and thiol-ene click reaction. These particles possessed a rod-dot micro-/nano-hierarchical structure and a high F content (52.14 at%), which are essential for superamphiphobicity. The spray-coating method was applied to various substrates using a glue and particle system, exhibiting substrate-independent characterization. Moreover, the coatings also showed excellent mechanical, environmental, and chemical durability under harsh conditions. Multiple features, including anti-corrosion, self-cleaning, and antifouling, rendered the coating suitable for applications in numerous fields.

Novel coating system on poly(ethylene terephthalate) fabrics with mechanically durable liquid-repellence: Application as flexible materials with striking loading capacity

Construction of the superamphiphobic materials and their application is of particular interest both in academia and industrial circles for years. Herein, a novel coating system for fabricating superamphiphobic poly(ethylene terephthalate) (PET) fabrics was reported based on both aminopropyltriethoxysilane (APTES) and environment-friendly perfluorooctyltriethoxysilane (FAS) co-modified SiO2 nano-particles, 3-Hydroxytyramine hydrochloride (Dopamine), amino-terminated silicone oils and etched PET fabrics via the one-step Schiff-base reaction and Michael addition reaction. The prepared fabrics displayed superamphiphobic properties, with contact angles of various liquids approaching 150°. In addition, the mechanical durability superamphiphobic fabrics were obtained, which were able to withstand 500 cycles of abrasion test, 20 cycles of sand abrasion test or 20 times standard washing. Furthermore, various liquids, including water and high viscous liquids, can easily slide off the surface of the obtained fabrics in a short time at a small angle. The prepared fabric can not only float on water or oil, but also hold up 25.7 times its own body weight things floated on water or 9 times on sesame oil without sinking. This novel and effective coating system can have more potential applications in the development of soft micro-devices working on liquid surfaces, especially on highly viscous liquid surfaces or under the environment with harsh conditions.

Superamphiphobicity: Bioinspired Surfaces with Superamphiphobic Properties: Concepts, Synthesis, and Applications (Adv. Funct. Mater. 19/2018)

Superamphiphobicity: Bioinspired Surfaces with Superamphiphobic Properties: Concepts, Synthesis, and Applications (Adv. Funct. Mater. 19/2018)

Bioinspired Surfaces with Superamphiphobic Properties: Concepts, Synthesis, and Applications

AbstractAmong diverse wetting phenomena in surface science, superamphiphobicity is regarded as one of the most special super‐antiwetting states. In this paper, a systematic summary is presented to cover the characterization of surface wettability, the construction techniques, and selected functional applications. With respect to fabrication techniques, the following three types of technology routes, viz., “pre‐texturing + post‐modifying,” “pre‐modifying + post‐texturing,” and in situ one‐step construction will be discussed. The merits and demerits of each technology route are discussed. It is vital to rationally design or adopt appropriate construction strategies in diverse conditions. Appropriately constructed superamphiphobic multifunctional surfaces can be applied in many fields, however, most have not been scaled‐up and utilized for practical applications due to some specific difficulties required to be resolved in the future. These challenges and further outlook for super‐antiwetting surfaces are discussed in this review.

Nanotextured Si surfaces derived from block-copolymer self-assembly with superhydrophobic, superhydrophilic, or superamphiphobic properties

We demonstrate the use of wafer-scale nanolithography based on block-copolymer (BCP) self-assembly for the fabrication of surfaces with enhanced wetting properties.

Mussel-Inspired Polyglycerol Coatings with Controlled Wettability: From Superhydrophilic to Superhydrophobic Surface Coatings.

Facile approaches to substrate-independent surface coatings with special wettability properties, such as superhydrophobicity, superhydrophilicity, and superamphiphobicity, have been limited. To address this problem, we combined two separate biomimetic concepts of mussel-inspired adhesion and highly hierarchical lotuslike surface structures to develop a universal fabrication method for various superwetting systems on any kind of material. In this feature article, we summarize our work on mussel-inspired polyglycerol (MI-dPG) and its application in the area of superwetting interfacial materials. MI-dPG mimics not only the functional groups of mfp-5 but also their molecular weight and molecular structure, which results in strong and rapid adhesion to the substrate. Furthermore, the MI-dPG coating process provides precise roughness control. The construction of highly hierarchical and superhydrophilic structures was achieved either directly by pH-controlled aggregation or in combination with nanoparticles. Subsequent postmodification of these highly hierarchical structures with different fluorinated or nonfluorinated hydrophobic molecules yielded a surface with superhydrophobic and even superamphiphobic properties.

Rough Structure of Electrodeposition as a Template for an Ultrarobust Self-Cleaning Surface.

Superhydrophobic surfaces with self-cleaning properties have been developed based on roughness on the micro- and nanometer scales and low-energy surfaces. However, such surfaces are fragile and stop functioning when exposed to oil. Addressing these challenges, here we show an ultrarobust self-cleaning surface fabricated by a process of metal electrodeposition of a rough structure that is subsequently coated with fluorinated metal-oxide nanoparticles. Scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction were employed to characterize the surfaces. The micro- and nanoscale roughness jointly with the low surface energy imparted by the fluorinated nanoparticles yielded surfaces with water contact angle of 164.1° and a sliding angle of 3.2°. Most interestingly, the surface exhibits fascinating mechanical stability after finger-wipe, knife-scratch, sand abrasion, and sandpaper abrasion tests. It is found that the surface with superamphiphobic properties has excellent repellency toward common corrosive liquids and low-surface-energy substances. Amazingly, the surface exhibited excellent self-cleaning ability and remained intact even after its top layer was exposed to 50 abrasion cycles with sandpaper and oil contamination. It is believed that this simple, unique, and practical method can provide new approaches for effectively solving the stability issue of superhydrophobic surfaces and could extend to a variety of metallic materials.

Superamphiphobic Surfaces Prepared by Coating Multifunctional Nanofluids.

Construction of surfaces with the capability of repelling both water and oil is a challenging issue. We report the superamphiphobic properties of mineral surfaces coated with nanofluids based on synthesized Co-doped and Ce-doped Barium Strontium Titanate (CoBST and CeBST) nanoparticles and fluorochemicals of trichloro(1H,1H,2H,2H-perfluorooctyl)silane (PFOS) and polytetrafluoroethylene (PTFE). Coating surfaces with these nanofluids provides both oil (with surface tensions as low as 23 mN/m) and water repellency. Liquids with high surface tension (such as water and ethylene glycol) roll off the coated surface without tilting. A water drop released from 8 mm above the coated surface undergoes first a lateral displacement from its trajectory and shape deformation, striking the surface after 23 ms, bouncing and rolling off freely. These multifunctional coating nanofluids impart properties of self-cleaning. Applications include coating surfaces where cleanliness is paramount such as in hospitals and domestic environments as well as the maintenance of building facades and protection of public monuments from weathering. These superamphiphobic-doped nanofluids have thermal stability up to 180 °C; novel industrial applications include within fracking and the elimination of condensate blockage in gas reservoirs.

Candle-Soot Derived Photoactive and Superamphiphobic Fractal Titania Electrode

Carbon soot is one of the oldest materials known for its hydrophobic properties, robustness, and availability, making it an ideal material for use in various applications. The drawbacks, however, are the loose structural binding between constructing carbon nanoparticles and the amorphous nature of soot itself. In this paper, we present a facile chemical vapor deposition (CVD) method that maintains the soot template structural integrity and enables its modification into a highly photoactive, self-cleaning titania fractal network. The results show that the small air pockets available on the surface combined with the salinization process produces a TiO2 fractal network with superamphiphobic properties. Given the high surface area of the fractal network structure and titania’s well-known photocatalytic activity, the designed surfaces were assessed for their photocatalytic decoloration activities. The results showed that the soot template derived TiO2 films can offer enormous potential in many different applic...

Surface-Independent Hierarchical Coatings with Superamphiphobic Properties.

Facile approaches for the fabrication of substrate independent superamphiphobic surfaces that can repel both water and organic liquids have been limited. The design of such super-repellent surfaces is still a major challenge of surface chemistry and physics. Herein, we describe a simple and efficient dip-coating approach for the fabrication of highly hierarchical surface coatings with superamphiphobic properties for a broad range of materials based on a mussel-inspired dendritic polymer (MI-dPG). The MI-dPG coating process provides a precise roughness control, and the construction of highly hierarchical structures was achieved either directly by pH-controlled aggregation or in combination with nanoparticles (NP). Moreover, the fabrication of coatings with a thickness and roughness gradient was possible via simple adjustment of the depth of the coating solution. Subsequent postmodification of these highly hierarchical structures with fluorinated molecules yielded a surface with superamphiphobic properties that successfully prevented the wetting of liquids with a low surface tension down to about 30 mN/m. The generated superamphiphobic coatings exhibit impressive repellency to water, surfactant containing solutions, and biological liquids, such as human serum, and are flexible on soft substrates.

Development of a highly transparent superamphiphobic plastic sheet by nanoparticle and chemical coating

A highly transparent superamphiphobic plastic sheet was developed. The plastic sheet polymethyl methacrylate (PMMA) was spin-coated on a glass substrate. Synthesized silica nanoparticles were sprayed on PMMA, followed by fluorosilane drop-coating. The results of contact angle measurements show that the developed PMMA sheet has superamphiphobic properties with high advancing contact angles for water (154°), toluene (139°), and silicone oil (132.9°). The amphiphobicity of the plastic sheet can be tuned by the surface coverage of the silica nanoparticles distributed on the PMMA surface. The surface coverage of the nanoparticles on our PMMA sheet is about 20%, and it agrees with our contact angle calculations for the sheet with and without nanoparticles.

Fabrication of durable superamphiphobic aluminum alloy surfaces with anisotropic sliding by HS-WEDM and solution immersion processes

The submillimeter-scale structures were fabricated by the high speed wire electrical discharge machining (HS-WEDM) technology on the 5083 aluminum (Al) alloy substrates. The results showed that the V-shaped groove arrays with a hierarchical structure presented the good superamphiphobicity after a solution immersion, in which the contact angles (CAs) achieved 154.70°, 154.55°, and 153.92° for water, glycerol, and ethylene glycol being, respectively. The effect of the sizes of V-shaped groove on wettability was discussed, this result may be useful for the design of controllable surfaces. In addition, a functional surface with the obvious anisotropic (the directions of the parallel and perpendicular for the grooves) sliding property revealed for water/oil may be expected to obtain potential applications in droplet-directional transportation, fluidic control, and so on. After peeling and mechanical tests the Al surfaces still exhibit superamphiphobic properties. Furthermore, the HS-WEDM technique is efficient and large area three-dimensional for building rough surface. Hence, it can be potentially suitable for industrial production of durable superamphiphobic Al surfaces with anisotropic sliding.

A Superamphiphobic Macroporous Silicone Monolith with Marshmallow‐like Flexibility

A monolithic material has marshmallow-like flexibility and superamphiphobic properties on any cutting surface. The two-step synthesis consists of a simple sol–gel process to obtain vinyl-modified superhydrophobic monolithic gels and grafting of perfluoroalkyl groups onto the pore surface to decrease surface energy. These superamphiphobic materials float on water and even on organic liquids with low polarity, such as alkanes.

Fabrication of a transparent superamphiphobic coating with improved stability

We herein provide an effective method to fabricate a transparent superamphiphobic coating with superhydrophobicity and near-superoleophobicity, the finished coating also shows improved stability under various measurements. To do this, a transparent superhydrophobic coating was first prepared with polydimethylsiloxane (PDMS) and hydrophobic silicon dioxide (SiO2) nanoparticles. Then the coating was sintered to degrade the PDMS into SiO2 before it was further oxidized into silanol (Si–OH). Finally, the coating was treated with 1H, 1H, 2H, 2H-Perfluorooctyl-trichlorosilane (PFTS). The PFTS treated coating shows transparency, superhydrophobicity with a water contact angle of 152.7 ± 2.1° and near-superoleophobicity with a diiodomethane contact angle of 140.7 ± 3.2°. The droplets of water and diiodomethane can simultaneously slide off the surface with a sliding angle of less than 6°. Moreover, the PFTS treated coating shows a higher stability than the PDMS/SiO2 coating fabricated by spin coating under various environmental conditions. The PFTS treated coating also shows quite good stability under high temperature environment. The superamphiphobic properties, transparency and improved stability of the PFTS treated coating are systemically discussed and the results show that the finished coating may be appropriate for many outdoor applications.