Robust Superhydrophobic Surfaces Prepared With Epoxy Resin and Silica Nanoparticles

When nanoparticles are incorporated into surfaces to generate roughness, adhesion of the particles is critical to achieve a durable superhydrophobic surface. In this investigation, we explored the use of bis-phenol A based epoxy and silica nanoparticles to form a composite layer on substrates. After an plasma treatment of the surface layer, the epoxy was etched away and silica nanoparticles exposed on the surface, thereby generating roughness. The plasma etching time was examined to correlate the resulting surface morphology and water droplet contact angles after a fluoroalkyl silane treatment. Surface mechanical stability was studied by an abrasion test. Water vapor condensation on the surface was also assessed by investigation of the contact angle, which offers insight into the applicability of the surfaces to use under hot and humid conditions where degradation of the superhydrophobic surfaces may occur.