To investigate the superhydrophobic properties of different surface textures, nine designs of textures with micro-nanostructures were produced successfully using the laser engraving technique on the surfaces of composite insulator umbrella skirt samples made of silicon rubber. The optimal parameters of the texture designs to give rise to the best hydrophobicity were determined. The surface morphology, abrasion resistance, corrosion resistance, self-cleaning and antifouling property of the different textured surfaces as well as water droplets rolling on the textured surfaces were studied experimentally using a contact angle meter, scanning electron microscope, three-dimensional topography meter and high-speed camera system. It was found that the diamond column design with optimal parameters has the best superhydrophobicity and overall performance. The most remarkable advantage of the optimal diamond column design is its robustness and long-term superhydrophobicity after repeated de-icing in harsh conditions. The reported work is an important step towards achieving superhydrophobic surface without coating for outdoor composite insulator in practical applications.

It is an undisputable fact that surface texture has a profound influence on the functional behavior of products. A method is proposed for manufacturing an anti-icing surface on silicone rubber composite material. Using a multi-function laser engraving machine, cylindrical micro-textures with different size and depth parameters are processed on the umbrella skirt surface of composite insulator samples. The optimal dimensional parameter of the surface micro-texture was determined by the best superhydrophobic property. By analyzing the freezing time of droplets, the influence of texture depth parameters on the anti-icing performance of the silicone rubber surface was investigated, which clearly confirmed that the contact angle affected anti-icing performance. Studying on adhesion of the ice on the sample surface and changing of the water contact angle after ice coating demonstrated the influence of texture-depth parameter on the deicing performance of silicone rubber surface. Thus, the characteristics and optimality of the texture specimen were obtained.

Based on the reaction of AgNO₃ and dopamine-hydrochloride in the weak alkaline conditions, carbon–silver microspheres with layered structure were produced, which subsequently were surface-modified with 1H,1H,2H,2H-perfluorodecyltriethoxysilane to produce a superhydrophobic carbon–silver powder. By using the advantage of high viscosity epoxy resin, this powder can be used to various nonmetal substrates to form robust superhydrophobic coatings. The hydrophobicity, surface morphology, chemical composition, mechanical stability, chemical durability, self-cleaning, antifouling and thermal stability are studied by means of the contact angle metre, scanning electron microscope, X-ray photoelectron spectroscope measurements, three-dimensional topography metre and thermal gravimetric analyses. The results indicate that the prepared powder can be applied to most nonmetal substrates to form excellent superhydrophobic coatings with very good comprehensive performance.

The collector ring/carbon brush assembly of a hydrogenerator set is a critical component for transmitting excitation current into the self-exciting winding. Its operating environment necessitates excellent corrosion resistance and current-carrying frictional properties. The surface condition and material composition of the collector ring are key factors influencing the performance of the brush/ring interface. Coatings have proven effective in enhancing both tribological and corrosion-resistant characteristics. In this study, copper/graphene composite coatings were fabricated via electroplating, and the effects of graphene deposition rate on current-carrying friction characteristics were systematically investigated to optimize electroplating parameters. The results showed that the composite coating reduced contact resistance by 32.58% and friction coefficient by 37.59%. Electrochemical and immersion tests were conducted to evaluate the corrosion behavior under varying pressure and current density conditions. The results revealed that the optimal corrosion resistance was achieved under 1 N pressure and 12 A/cm² current density. The copper/graphene composite coating demonstrated superior corrosion resistance compared to uncoated samples. In summary, the electroplated copper/graphene composite coatings exhibit excellent current-carrying frictional performance and corrosion resistance, offering a promising solution for enhancing the durability and efficiency of hydrogenerator collector rings.