Hydrophobic recovery of femtosecond laser processed silicone rubber insulator surfaces

Abstract

This article demonstrates the loss and recovery in hydrophobicity of silicone rubber insulator surface processed by a femtosecond laser. The two stages of the wettability conversion were investigated. First, a rough micro/nano structure was formed on the original hydrophobic sample surface processed by the femtosecond laser, and the water contact angle on the surface was reduced from 110 to a minimum of 35 . This hydrophilicity loss was due to the increase in the hydrophilic OH groups and the reduction of the hydrophobic CH 3 groups on the surfaces. Second, the roughened samples were stored in a natural ambient environment. Over a certain storage time, the surface hydrophobicity recovered gradually and evolved into a superhydrophobic state. It was found that the migration of low molecular weight cycle and/or linear siloxane oligomers resulted in the recovery of the hydrophobicity property.Coupled with the increase of surface roughness caused by laser irradiation, the further evolution of the hydrophobicity was promoted. Moreover, the higher temperature accelerates the recovery of the surface hydrophobicity. The research on the conversion mechanism of the wettability on the silicone rubber insulator surface processed by femtosecond laser is of great significance for improving its reliability in practical applications.

Superhydrophobic Epoxy/Fluorosilicone/PTFE Coatings Prepared by One-Step Spraying for Enhanced Anti-Icing Performance

“…It is well known that the rough structure has a significant effect on the wetting per formance of the coating [43,44]. The measurements for the apparent contact and sliding angles of the coatings are shown in Figure 3.…”

Capillary performance of vertically grooved wicks on laser-processed aluminum surfaces with different wettability

“…From the perspective of wettability modification of the background surface and preparation of the SHPi grooves, laser processing is a feasible and effective surface technology [22]. It has been successfully applied to various materials for different applications, such as titanium [23], silicone rubber [24,25], and zirconia ceramics [26]. In particular, rapid antigravity transport of water could be realized in the parallel Vshaped microgroove arrays prepared with a femtosecond laser [27].…”