Femtosecond Laser Treatment for the Design of Electro-insulating Superhydrophobic Coatings with Enhanced Wear Resistance on Glass

Abstract

Femtosecond laser treatment of a glass surface was used to fabricate a multimodal roughness having regular surface ripples with a period of a few micrometers decorated by aggregates of nearly spherical nanoparticles. UV-ozone treatment followed by chemisorption of the appropriate functional fluorosilanes onto the textured surface makes it possible to fabricate a superhydrophobic coating with a specific surface resistance on the order of petaohms on a glass surface. The main advantage of the fabricated coating under severe operating conditions with abrasion loads is the significant durability of its electro-insulating properties. The longevity of the high surface resistivity, even on long-term contact with a water vapor-saturated atmosphere, is directly related to the peculiarities of the surface texture and ripple structure.

Nanosecond laser micro- and nanotexturing for the design of a superhydrophobic coating robust against long-term contact with water, cavitation, and abrasion

“…A quantitative comparison of the mechanical durability of the coating developed in this study with the one presented in our earlier work on fs laser treatment of a glass surface [16] indicates that superhydrophobic textured surfaces of stainless steel are considerably more stable against abrasive wear. The following factors may be responsible for the enhanced abrasive resistance of the superhydrophobic coating fabricated here.…”

“…The above processes could be visualized by The robustness of the developed coating against abrasive wear was studied according to ASTM F735 in an oscillating sand abrasion test. The details of the test procedure were described in our recent study [16]. The complex surface morphology of the fabricated coating does not allow a quantitative estimate of the parameters of damaging loads, such as shear or normal stress acting in the surface.…”

“…1). We note that only a few papers in the literature analyzed abrasive degradation of superhydrophobic coatings with a surface texture fabricated by laser irradiation [16,29]. The textures fabricated by femtosecond laser treatment on titanium [29] and glass [16] were studied in these articles.…”

“…We note that only a few papers in the literature analyzed abrasive degradation of superhydrophobic coatings with a surface texture fabricated by laser irradiation [16,29]. The textures fabricated by femtosecond laser treatment on titanium [29] and glass [16] were studied in these articles. It is difficult to make a quantitative comparison of the stability against abrasion for our coating on steel and for a coating on titanium [29] because the load parameters were very different.…”

“…However, for industrial applications, the resistance to specific mechanical loads must be significant for longterm performance. That is why a lot of effort has been devoted to laboratory studies and the development of industrial techniques to construct superhydrophobic surfaces that are robust against mechanical loads and electrochemical impacts [11][12][13][14][15][16]. Despite considerable progress in this area, long-lived superhydrophobic coatings that are durable in harsh operating conditions are still highly desirable.…”