Excellent Superhydrophobicity Research Articles

Construction of Durable, Colored, Superhydrophobic Wood-Based Surface Coatings Using the Sand-In Method.

Highly durable color superhydrophobic coatings have attracted much attention in indoor and outdoor decorative applications. In this paper, colorful superhydrophobic coatings with excellent durability were prepared using silane coupling agent-modified iron oxide as the pigment and polydimethylsiloxane-compounded epoxy resin as the base material by the three-step method of "spraying-sanding-spraying". The method is low cost, has a simple preparation process, enables large-area preparation, and has a restorative function. The use of red, yellow, blue, and green four kinds of modified iron oxides through the single color or multicolor into the sand can be obtained by a variety of color coatings, and silica mixed with a variety of colors can be obtained from light to dark coatings. The coating has excellent superhydrophobicity and self-cleaning ability to withstand sandpaper abrasion, water impact, sand impact, UV exposure, and environmental testing. The coating is suitable for interior and exterior decoration and for protection of wooden buildings.

Durable Superhydrophobic Coatings with Attapulgite for Inhibiting 5G Radome Rain Attenuation.

5G radomes are easily wetted and stained by rainfall, which greatly reduces the quality of signal transmission. Superhydrophobic coatings are expected to solve this problem because of their unique wettability, but it is still challenging to develop robust superhydrophobic coatings via simple methods. Here, we report the design of robust superhydrophobic coatings containing oxalic acid-modified attapulgite (MDP) for inhibiting rain attenuation of 5G radomes. First, a homogeneous suspension was prepared by nonsolvent-induced phase separation of a silicone-modified polyester adhesive (SMPA) solution containing fluorinated MDP (F-MDP) nanorods. Superhydrophobic coatings can be easily prepared by spraying the suspension. The effects of phase separation and the SMPA/F-MDP ratio on the surface morphology, superhydrophobicity, and stability of the coatings were systematically investigated. The micro-/nanostructure and low surface energy endow the coatings with excellent static and dynamic superhydrophobicity. Compared with previous studies, the coatings exhibit excellent mechanical stability, flexibility, chemical stability, and pressure resistance due to the combined effects of adhesion by SMPA, self-similar micro-/nanostructures, reinforcement by the MDP nanorods, etc. Consequently, the coatings show good performance in preventing rain attenuation of 5G radomes, an emerging application of Superhydrophobic coatings. We believe that the coatings have great application potential in various fields, including 5G communication.

Photothermal superhydrophobic coating for concrete: Highly effective anti/deicing performance and corrosion resistance

Superhydrophobic concrete is an effective method to prevent corrosion of internal steel bar. However, existing superhydrophobic concrete is difficult to remove the ice on the superhydrophobic concrete surface. Here, we overcame this problem by developing a photothermal superhydrophobic coating for concrete, which obtained from polydimethylsiloxane (PDMS), multi-walled carbon nanotubes (MWCNT) and further superhydrophobicity. This photothermal superhydrophobic coating showed the excellent superhydrophobicity, self-cleaning property, anti-fouling property, and the long anti-icing time. In addition, the ice on the coating would rapidly melt into the water which easily rolled off the surface under the irradiation of infrared light. This coating not only had the good chemical durability and mechanical durability, but also had the corrosion resistance performance. This work will enrich superhydrophobic concrete technology and promote the application of superhydrophobic concrete in practical building.

Hierarchy-constructed superhydrophobic and transparent coating modified intraocular lens by layer-by-layer self-assembly for glistening reduction and antiadhesion

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.

Long-lived superhydrophobic micro/nano-locked fiber membranes for long-lasting oil-water separation effectiveness

Superhydrophobic/superoleophilic oil-water separation membranes have great potential for treating industrial, domestic, and marine oily wastewater. However, the robustness of these membranes remains a challenge that restricts their ability to maintain long-lasting oil-water separation effectiveness. Inspired by the adhesion mechanisms of snail and tree frog, exploiting the synergistic effects of interfacial hydrogen bonding and mechanical interlocking, we herein achieved strong adhesion between hydrophobicized in-situ nanoparticles and textile fibers to fabricate a long-lived superhydrophobic micro/nano-locked fiber membrane (LSMFM). LSMFM maintains excellent superhydrophobicity even when exposed to mechanical and chemical damage, such as continuous sandpaper abrasion, tape-peeling, weight impact, water jet, and acid/alkali/salt erosion. Additionally, LSMFM efficiently separates various light/heavy oil-water mixtures, achieving a remarkable separation flux of >10,000 L·m−2·h−1 and an efficiency >98 %, even after 200 cycles with n-hexane. Importantly, such membranes still maintain a high separation flux >19,000 L·m−2·h−1 and efficiency >97 % after sequentially being subjected to acids, alkalis, freezing, and high temperatures, and even the adsorption bag formed by wrapping LSMFM with superhydrophilic wood pulp cotton can adsorb oil at fixed-point and continuously recover pure oil from oily wastewater. This study paves a new way for the sustainable purification of oily wastewater in extreme environments.

Preparation of superhydrophobic/oleophobic wood coating with fluorinated silica sol by a simple spraying method

The biomimetic construction of superhydrophobic coatings on wood surfaces significantly reduces the water absorption capacity of wood while enhancing its deformation resistance, thereby extending the service life of wooden structures. In this work, a fluorinated silica sol was prepared from alkaline silica sol and 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (PFDMS), and evenly sprayed over the wood surface to effectively produce superhydrophobic/oleophobic wood specimens. The effect of the preparation procedure of fluorinated silica sol on the wettability of the coating was investigated. Acid and alkali corrosion tests were conducted to assess the chemical stability of the superhydrophobic coating, while sandpaper abrasion tests were used to evaluate its mechanical stability. The results showed that with a volume ratio of silica sol to PFDMS of 6:1 and a reaction period of 30 min, the modified wood exhibited excellent superhydrophobicity, with a water contact angle of 157.3° and an oil contact angle of 126.5°. Furthermore, the superhydrophobic coating demonstrated excellent mechanical and chemical durability, along with self-cleaning properties. These findings have significant practical implications for enhancing the performance and longevity of wood.

A durable superhydrophobic surface with bud-particle structure prepared by one-step spray method

Superhydrophobic surfaces play an essential role in numerous applications such as anti-fouling, waterproofing, and drag reduction due to their water-repellent. However, for most fabrication methods, there are high requirements for the preparation process and conditions. Meanwhile, the superhydrophobic surfaces generally have the problem of insufficient durability. In this study, a one-step method to fabricate a stable superhydrophobic surface by spraying is proposed. A new bud-particle structure is obtained by modifying micron and nano Aluminium hydroxide(Al(OH)3) particles, which helps the coated surface to demonstrate excellent superhydrophobicity with the water contact angle ∼157.0° and rolling angle ∼2.0°, and it shows great repellency to water droplet impact. Due to the compatibility of Al(OH)3with the pretreatment substrate and the reinforcing effect of nanoparticles, the coating maintained the superhydrophobicity well in the sandpaper wear and the ultrasonic damage test, which reflects the outstanding robustness of the coating.Moreover,benefiting from the control of the wetting state by micronand nanoparticles doping,the coating showed an excellent underwater drag reduction effect in the rheometer experiment, with a drag reduction rate of ∼67.7 %. The one-step spraying method proposed is a simple and convenient way to create the surface with excellent superhydrophobicity and durability, which has great potential applications in improving metal surface oxidation resistance and underwater reducing drag.

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.

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

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

Development and performance evaluation of green superhydrophobic coating for fouling and corrosion protection

In this paper, a simple and environmentally friendly superhydrophobic stearic acid-modified zinc-nickel-cobalt composite coating (SA@ZNC) is presented. The zinc-nickel-cobalt (ZNC) coating with petal-like micro/nano-rough structure was constructed on the metal surface by combining electrodeposition and chemical substitution techniques. Subsequently, the coating was modified with low surface energy by adding stearic acid, and the SA@ZNC coating with excellent superhydrophobicity (water contact angle of 161.08 ± 0.31° and rolling angle of 3.50 ± 0.54°) was prepared. The coating is self-cleaning against a wide range of simulated contaminants and can remain superhydrophobic in air for over a year. Changes in pH do not significantly affect the superhydrophobicity and at low temperatures, the freezing time of water droplets on the coating was extended by 2.1 times compared to a blank steel sheet. Furthermore, the SA@ZNC coating demonstrated remarkable robustness, withstanding 30 minutes of water impact, a wear mass of 0.2 % after rubbing with weights over 2400 mm and retaining its superhydrophobicity after 80 tape stripping cycles. The results of the corrosion protection tests demonstrated that the SA@ZNC coating provided excellent corrosion protection for N80 steel, exhibiting a current density two orders of magnitude lower than that of the blank sample. Furthermore, the coating exhibited a corrosion inhibition rate of 95.75 ± 0.33 % and excellent charge transfer resistance. The multiple protection mechanisms and homogeneous micro/nanostructure of the coatings resulted in significantly better corrosion resistance than most of the reported zinc-nickel based coatings. The use of low-energy consumption methods and environmentally friendly modifiers positions this coating for large-scale production and potential applications in sectors like food and medicine, with promising implications for corrosion protection in various industries.

Fabrication of fluorinated superhydrophobic oil-absorption cabins with controllable movement, elasticity, and wear resistance

Superhydrophobic materials that can withstand harsh environments are critical in oil spills. Here, fluorinated superhydrophobic monoliths were prepared in one step based on a high internal phase emulsion (HIPE) templating method. γ-methacryloyloxypropyltrimethoxysilane (KH570)-modified Fe3O4 nanoparticles were added into the emulsion as co-stabilizers and participated in the composition of micro-nano hierarchical structures. The fluorinated alkyl backbone and rough structure enabled the foam to exhibit excellent superhydrophobicity with a water contact angle (WCA) of 153.5° and a sliding angle (SA) of 5.92°. The unique structure and composition of the foam allowed it to maintain stable superhydrophobicity (153.97°) even after severe sandpaper abrasion tests (Drawn 10 m at 7.1 kPa on P400 grit sandpaper). It also demonstrated exceptional hydrophobicity to strong acids, bases, and UV light. The oil-saturated material can be regenerated through a simple extrusion process, showing outstanding reusability. After ten cycles of oil adsorption, the adsorption capacity remains above 90 % of the initial value. The additional magnetic properties of the material enable it to remove oil in confined or hazardous conditions. More importantly, with the assistance of a vacuum pump, the material permits continuous separation of organic solvents from the water. These excellent properties of the foam make it a potential material for treating wastewater.

Non-fluorinated lignin-based melamine sponges with superhydrophobic and photothermal properties for multi-functional applications

Frequent oil spills and the discharge of oily wastewaters become a significant threat to the environment and ecosystem. Herein, a non-fluorinated lignin-based melamine sponge with superhydrophobic and photothermal properties (labeled as MS@COF/LPs/PDMS) has been achieved by decorating with covalent organic framework (COF), lignin particles (LPs) and PDMS. The MS@COF/LPs/PDMS shows excellent surface superhydrophobicity with a water contact angle of 152.3° and a sliding angle of 6°. The adsorption capacities of the MS@COF/LPs/PDMS range from 38.4 g/g to 100.3 g/g for various oils and organic solvents, and the separation efficiency of the MS@COF/LPs/PDMS for CCl4 reaches 99.7 %. Furthermore, the maximum surface temperature of the MS@COF/LPs/PDMS reaches 61.2 °C because of the thermal vibration of LPs and COF under solar irradiation (1.0 kW/m2). Surprisingly, the MS@COF/LPs/PDMS can rapidly adsorb a droplet of crude oils within 32 s due to the superoleophilicity and excellent photothermal effect. Besides, the melting time of the MS@COF/LPs/PDMS (400 s) reduces by 70 % for an ice droplet under solar irradiation than that of pristine melamine sponge (1330 s). Thus, this study provides new insights into the rational design of low-cost lignin-based melamine sponges for the applications of oil/water separation, crude oil recovery, and de-icing.

Alcohol-gating femtosecond laser-induced micro/nano-structured membranes with reversible switching wettability and breathability.

A reversible liquid gating membrane with the ability to regulate gas/liquid transport is critical for many fields, such as biological applications, multiphase separation, and sewerage treatment. Numerous membranes can respond to external stimuli and dynamically control gas/liquid fluid transport; however, simultaneously achieving regulated gas/liquid transport membranes through simple manufacturing remains a challenge. In this work, we investigated an alcohol-regulation gating membrane via femtosecond laser one-step processing, allowing in situ dynamically controllable gas/liquid transfer. More specifically, the porous membrane, processed by laser, exhibits excellent superhydrophobicity (WCA ∼ 153.4°) and breathability (water-vapor evaporation rates ∼118.3 mg (cm2 h)-1), enabling gas to penetrate but not water. In contrast, it allows the passage of water while preventing the permeation of gas subsequent to the introduction of alcohol. Furthermore, the porous membrane still possesses superbly consistent performance after being placed in air for 90 days or over 100 dropping-drying ethanol cycles test, indicating outstanding durability and reversibility. Significantly, the porous membrane has broad potential applications in medical dressings, providing a new strategy to fabricate next-generation bandages.

Hierarchical structure on tin bronze hydrostatic bearing surfaces to achieve ultra-high Cassie stability

The hierarchical structure represents a significant approach to enhance the Cassie stability on superhydrophobic hydrostatic bearing surfaces. However, the preparation of a robust hierarchical structure on tin bronze alloy remains unknown. In the present study, a hierarchical structure comprising micro-bulges and nanowires was fabricated on a tin bronze surface, exhibiting excellent superhydrophobicity (water contact angle, WCA = 163°). In contrast to the micro-bulge structure, the hierarchical structure surface exhibited a quasi-reversible trajectory after pressure, with the WCA recovered to 161°. For the same triple-phase contact line (TPCL), a higher Laplace pressure (3640 Pa) is required to destroy the Cassie state of the hierarchical structure. Droplets on the hierarchical structure can rapidly recover to a stable Cassie state after impact. It can be verified the hierarchical structure has higher Cassie stability to resist pressure, thermal exposure, and impact. The slip lengths of the hierarchical structure in water and VG5 lubricant are 18 μm and 27 μm, respectively. The hierarchical structure preparation is straightforward, and its application to hydrostatic bearings can enhance stability.

Superhydrophobic stretchable sensors based on interfacially self-assembled carbon nanotube film for self-sensing drag-reduction shipping.

Multifunctional flexible electronics integrated with superhydrophobicity and flexible sensing can greatly promote broader applications. However, the hierarchical roughness morphology of superhydrophobic surfaces is vulnerable to complex mechanical deformations of stretchable sensors leading to degradation of hydrophobic properties, so constructing robust superhydrophobic stretchable sensors remains challenging. Herein, we propose a facile strategy to fabricate superhydrophobic stretchable sensors based on self-assembled carbon nanotube (CNT) films at the air-water interface. The customizable functions of superhydrophobic stretchable sensors can be achieved by controlling the combination of the CNT film and polydimethylsiloxane (PDMS) through a simple and efficient interfacial transferring strategy. Even under large mechanical deformations, the developed sensors can present excellent robustness and superhydrophobicity with a water contact angle of 150.9° at 80% strain. As a proof-of-concept, this work demonstrates their potential application in self-sensing drag-reduction shipping, which is expected to realize greener, more sustainable and safer aquatic transportation.

One-step fabrication of robust PDMS-MWCNTs composite superhydrophobic coatings with hierarchical micro-nanostructures for anticorrosive applications

Superhydrophobic coatings hold considerable promise for safeguarding metals against corrosion. However, realizing coatings with excellent superhydrophobicity, mechanical strength and corrosion resistance remains a great challenge. In this study, a robust superhydrophobic surface was achieved through the laser processing of multi walled carbon nanotubes (MWCNTs)/polydimethylsiloxane (PDMS) coatings, resulting in a water contact angle (WCA) of approximately 165°. Notably, the coating demonstrated outstanding abrasion resistance in sandpaper abrasion, steel wool abrasion, and falling sand tests. The friction coefficient of the coating is only 0.25. In addition, the robust superhydrophobic coating also has good anti-corrosion. The lowest-frequency impedance value of the composite coatings increases seven orders of magnitude compared with that of carbon steel, and the corrosion inhibition efficiency (η) is 99.83 %. The outstanding corrosion resistance is primarily ascribed to the formation of a dual synergistic barrier by PDMS-MWCNTs, providing effective protection for carbon steel.

Controllable size of graphite nanosheets and functionalized SiO2 microspheres with excellent anti-corrosive/wear function for superhydrophobic coating

The application of superhydrophobic coatings is limited by their complex fabrication process, expensive modification, and lack of durability. This study addresses these issues by proposing a simple and economical method for fabricating strong superhydrophobic coatings by scraping off the fluorinated suspension. This coating comprises epoxy resin (EP), graphene nanosheets, and modified silicon oxide on the Q235 steel substrate. The contact angle and sliding angle of we prepare the coating coating are 152.3° and <10° respectively, exhibiting excellent super-hydrophobicity. After being immersed in 3.5 % sodium chloride solution for 1440 minutes, the coating shows a resistance of 1.14×106 Ω cm2, which is two orders of magnitude higher than that of the coating immersed for 30 minutes (1.08×104 Ω cm2), indicating its excellent corrosion resistance. A 30-day salt spray corrosion test also confirms the good corrosion resistance of the coating. When the coating is polished 100 times under a load pressure of 500 g on 1000-mesh sandpaper, the contact angle is only reduced by 7 times, indicating its good abrasion resistance. In addition, the coating also has good weather resistance and self-repairing ability against ultraviolet radiation. This simple and environmentally friendly manufacturing method has great potential for large-scale practical applications in many fields.

Fabrication of SiO2/PDMS/EP superhydrophobic coating for anti-icing

In low-temperature environments, the condensation and icing phenomena of water molecules on material surfaces may adversely affect the functionality and durability of various products, so it is critical to improve the anti-icing properties of material surfaces. In this study, the anti-icing mechanism of superhydrophobic coatings was analyzed based on the surface wettability theory, and SiO2/PDMS/EP superhydrophobic coating was fabricated by the spraying method. The surface wettability, surface micro-morphology, and surface chemical composition of the coating was characterized, and the stability of the coating as well as the anti-icing properties were investigated. The results show that the SiO2/PDMS/EP superhydrophobic coating sprayed on the Al-based surface has a contact angle of 163.3° and a sliding angle of 4°, and the coating maintains excellent superhydrophobicity at a low temperature of -15°. This coating can significantly delay the freezing time and temperature of droplets on its surface, reduce the shear force and natural deicing time required to remove surface ice, and exhibit excellent anti-icing performance. The excellent anti-icing durability of the coating was demonstrated by the icing-deicing cycle experiment. Subsequently, the anti-frosting performance was further investigated, and the results showed that it effectively slowed down the speed of frost formation. Therefore, the superhydrophobic coating fabricated in this study is suitable for a wide range of working conditions and has potential practicality. It also provides experimental guidance for the application of anti-icing coatings on Al surfaces.

Fabrication of superamphiphobic micro-reentrant structures by inverted electrochemical deposition

Due to excellent oil resistance and shortened liquid-solid contact time, superamphiphobic surfaces have promising application prospects in oil transportation, and petroleum pollution control. Although superamphiphobic surfaces have been constructed on various substrates, there is still a lack of high-efficient methods for fabricating micro-reentrant structures on engineering metal substrates. This paper proposes a new method combining laser processing and inverted electrochemical deposition techniques to achieve high-efficient and large-scale fabrication of superamphiphobic surfaces on copper substrates. Firstly, micropillar array structures are constructed by laser processing, and the structures exhibit excellent superhydrophobicity after low surface energy modification. Then, inverted electrochemical deposition is performed after polishing the top of the array, and local angle of the gas/liquid interface can be controlled by adjusting the distance between the top of the micropillar and the electrolyte level, thus regulating micro-morphology of the roof structure. The influences of electrochemical deposition parameters on characteristics of the micro-reentrant structures are systematically investigated. Finally, superamphiphobic micro-reentrant structures (roof diameter > 190 μm, micropillar spacing <250 μm) with water and oil contact angles exceeding 150° are prepared after lowering the surface energy of the deposited structures. After anti-fouling, blowing, ultrasonic vibration, and tape adhesion tests, the prepared superamphiphobic micro-reentrant structures maintained good water and oil repellency, showing excellent chemical stability and durability. The research may provide a simple, efficient, and low-cost method for high-efficient constructing superamphiphobic surfaces on engineering metal substrates, enriching the fabrication techniques of micro-reentrant structures and facilitating their practical applications.

Polyphosphazene with excellent superhydrophobicity, electrical insulation, flame-retardancy, and mechanical durability for composite insulators

Composite insulator is an important component of the power system which has high requirements for insulating properties, hydrophobicity, long-term reliability, and safety. Aiming to improve the comprehensive performance of composite insulators, we propose a novel composite based on polyphosphazene matrix and inorganic fillers including h-BN, SiO2 and aramid pulp (AF-p). By the synergistic effect of the optimized chemical structure of polyphosphazene and modification by multi-scale hydrophobic electrical insulation fillers, the poly(difluoroalkoxy)phosphazenes (PDFP) composite presents enhanced hydrophobicity with the static water contact angle (WCA) up to 154° and rolling angle (RA) as low as 8°. Benefiting from the multiscale roughness constructed by multi-fillers, the PDFP composite exhibits superior mechanical durability. The contact angle of the sample still exceeds 150° after abrasion by sandpaper (800#) for 1000 cm. Meanwhile, with the addition of hybrid insulation fillers, the Weibull breakdown strength of PDFP/30h-BN/10SiO2-200/6AF-p is improved by 76 % compared to PDFP. Besides, the unique elemental composition of PDFP endows the PDFP composite with excellent flame retardancy with a 55 % limiting oxygen index and V-0 of the UL-94 grade, which guarantees safety for insulator applications. The results confirm the great potential of polyphosphazene for composite insulators.