Superhydrophobic Coating of European Oak (Quercus robur), European Larch (Larix decidua), and Scots Pine (Pinus sylvestris) Wood Surfaces

Plant surfaces provide an unlimited source of systems for the protection of their surface against the outer environment. These systems have continuously improved over the last 400 million years of evolution. Two of the most fascinating properties of these systems are superhydrophobicity and the self-cleaning ability of several plant species. These properties are most often achieved due to the hierarchical structure of the surface in combination with a deposited blend of epicuticular waxes. In this study, a layer of n-hexatriacontane was deposited on wood surfaces via thermal evaporation, and the self-assembly ability was investigated for various wood species with differently machined surfaces. The behavior of wax crystals was observed using scanning electron microscopy (SEM) and confocal microscopy. The impact on wettability was investigated by measuring contact angles and tilt angles. With wax deposition, a significant change of wettability was achieved, which was represented by the transition from hydrophilic to superhydrophobic surface behavior. The self-assembly ability of n-hexatriacontane resulted in an increased contact angle in all observed samples.