Sustainable superhydrophobic and self-cleaning wood via wax within Epoxy/PDMS nano-composite coatings: Durability related to surface morphology

The stability of wood materials in harsh environments requires a durable superhydrophobic (SH) coating. In this paper, a sustainable SH coating, suitable for interior and exterior applications of wood, was produced by reinforcing with bio based carnauba-wax two matrices, i.e. Epoxy resin or polydimethylsiloxane (PDMS). Fluorine-free dodecyl-terminated silica nanoparticles (DDT-SiO2), prepared through a chemical procedure, have been used to increase the hydrophobicity of all coating formulations. A novel approach for the wood substrate preparation was proposed and tested. The results showed that long-term water-repellency of the SH coatings can be enhanced by solvent/ultrasonic pre-treatments, controlling the chemical and morphological characteristics of the wood substrate before coating. The formulation containing wax exhibited a contact angle of 172° and a sliding angle