A simple and effective way to fabricate mechanical robust superhydrophobic surfaces

Abstract

A simple, inexpensive and effective method is developed to fabricate mechanical robust superhydrophobic (SH) surfaces based on particle-filled silicone rubber (SR) composites. A large variety of particles with different features, such as copper, SiO₂, BaTiO₃ (BT), carbon black (CB), and polyvinylidene fluoride (PVDF) can be used to prepare the SH surfaces based on SR composites. The particles were spread on the un-cured SR solution (in n-hexane) surface using a sieve. The excessive particles were removed using ultrasonic washing after the SR matrix was completely cured. Surface roughness is formed due to the accumulation of particles, and the SR matrix provides the required low surface energy. Various SH surfaces based on particle-filled SR composites are obtained with high water contact angle (CA, >160°) and low water sliding angle (SA, <10°). In addition, besides the superhydrophobicity, the surface color, transparence, electric conductivity and other properties can also be achieved by carefully selecting appropriate particles. All of the particles are commercial and used as received without any modification. Furthermore, the mechanical stabilities of the SH surfaces are systematically studied using various possible mechanical actions. The results indicate that the SH surface is mechanically robust against sandpaper abrasion (32.5 kPa, 50 cycles), finger touch, brushing and scratching, as well as high-pressure water impacting (0.12 MPa). The SH surfaces based on particle-filled SR composites can be fabricated at large scale without using any expensive materials and special equipment. Therefore, the SH surface could provide a candidate for practical self-cleaning applications.