An OH-PDMS-modified nano-silica/carbon hybrid coating for anti-icing of insulators part I: Fabrication and small-scale testing

Abstract

Super-hydrophobic coatings have recently drawn a lot of attention in research andapplications towards reduction of ice accumulation on insulators. This paper presents a new type of hybrid coating fabricated via self-assembly of a super-hydrophobic layer on a semi-conducting layer. Hydroxy-terminated polydimethylsiloxane (OH-PDMS) modified nano-silica is used for fabrication of the super-hydrophobic layer. Fabrication procedures, hydrophobic characteristics, and flashover performances of the hybrid coating are presented. Experimental results show that the hybrid coating has a dual micro-and nano-scale hierarchical structure and a water contact angle greater than 155˚. Surface resistivity, volume resistivity, temperature rise, and surface flashover voltages of the hybrid coating are also presented. Temperature distribution on the hybrid coating is simulated for further analysis. The results show that the hybrid coating is capable of improving the electrical field and surface temperature along the surface of the coating.Index Terms-Super-hydrophobic and semi-conducting coating, anti-icing, insulator, flashover voltage, electro-thermal effect.

A review on mechanism and application of functional coatings for overhead transmission lines

“…It is a better choice to apply the semiconductor coating on the lower surface and the outer edge of the upper surface of the insulator with a 5-8 cm exposed area. Li et al (2016) and Yan et al (2016) prepared carbon/nano-silica/ PDMS coatings with both semiconducting and superhydrophobic properties on insulators via dip coating and self-assembly techniques. The SEM image is shown in Figure 8A.…”

“…The SEM image of the carbon/nano-silica/PDMS coating (Li et al, 2016). (B) Typical leakage current waveforms of insulators with carbon/ nano-silica/PDMS coating (Yan et al, 2016).…”

Direct laser etching of hierarchical nanospheres on silicon rubber surface with robust dynamic superhydrophobic stability

“…Recently, hydrophobic silicone rubbers have been fabricated using various methods, such as laser processing, surface coating, injection molding, and so on. 3,[12][13][14][15][16][17] As a basic approach to produce surface micro/nanostructures, laser processing is a useful technique in preparing superhydrophobic surfaces with a wide range of materials. [18][19][20] Although previous researches have demonstrated that the wettability of the silicone rubber can be tuned by a femtosecond laser, 21,22 the reliable dynamic superhydrophobic stability still needs to be taken into consideration for the application associated with industrial and practical applications, such as high voltage transmission lines.…”

“…Recently, hydrophobic silicone rubbers have been fabricated using various methods, such as laser processing, surface coating, injection molding, and so on 3,12–17 . As a basic approach to produce surface micro/nanostructures, laser processing is a useful technique in preparing superhydrophobic surfaces with a wide range of materials 18–20 .…”