Fabrication of durable polymer-based superhydrophobic surface with silica nanoparticles

Abstract

The superhydrophobic surface is generally made by controlling the surface chemistry and surface roughness, also it has a water contact angle of at least 150 degrees, and a sliding angle (usually) less than 10°. Therefore, researchers have confirmed that the superhydrophobic surface is produced by this combination of nano/microscale surface structures and materials with low surface energy. In recent years, a rapid number of research works have been focused on developing low-cost, simple, and green manufacturing processes for superhydrophobic surfaces fabrication. However, a common drawback of these modern studies is related to the fabrication process, which consists of uses of chemicals process and complex equipment with post process. In other words, it is limited to apply in real-world industrial applications because of their high fabrication cost, toxic materials. To address these problems, we proposed a fabrication method in this dissertation. In order to do it, we developed the durable superhydrophobic coated surface on the thermoplastic materials with nano-scale hydrophobic silica by rough surface using the simple, low-cost, and without chemical methods in this dissertation. Moreover, simple, and green techniques are used for improving superhydrophobic coated surface mechanical durability. As result, hydrophobic silica nanoparticles have been widely used to generate nano-microscale structures on hydrophobic surfaces with low surface energy by various coating processes with binders for the realization of a superhydrophobic surface. Here, the hydrophobic polypropylene surface and flexible hydrophobic polyethylene terephthalate/polydimethylsiloxane surface were coated with a thick-coated layer of hydrophobic silica nanoparticles using a simple method such as compression molding process, hot-roll lamination and peeling assisted by heat treatment. The important barrier for the wide usage of these superhydrophobic coatings with hydrophobic silica nanoparticles is poor mechanical durability. Mechanical contact or abrasion causes the gradual loss of superhydrophobic coating, and a thin coating layer can be easily destroyed thus limiting the superhydrophobicity function. We prepared the superhydrophobic coated films having a thick coating layer with hydrophobic silica nanoparticles that can overcome. The obtained results, the mechanical durability of the superhydrophobic surface was evaluated by the scotch tape test, scratch test with sandpaper, and bending test. The chemical stability of the superhydrophobic surface was tested by the chemical test with medium solutions and, stability in ambient air. Finally, some potential applications were reported as water droplet bouncing, and self-cleaning.