Baklan D. Obtaining of micro- and nanotextured water-repellent organic-mineral surfaces

The dissertation is devoted to the establishment of regularities of obtaining hydrophobic surfaces with high water-repellent properties, comparison and evaluation of the effectiveness of surfaces obtained by the extractive method, which consists in ablation with a femtosecond laser, and the additive method, which consists in pneumatic spraying to obtain an organic-mineral coating in which the texture is formed by filler particles. The work first established that the textures created by femtosecond laser ablation on anodized aluminum of 6063 grade have a flat surface without a nanolayer, but on unanodized aluminum the texture is obtained with a hierarchical structure that allows increasing the wetting angle. The sequence of destruction under the complex action of UV radiation and water flow for surfaces textured with nano- and microparticles of fillers in polymer compositions was first described, where the polymer is the first to be affected, which leads to the formation of polar groups on the surface, followed by the destruction of the organic modifier on the surface of the filler particles, and the water flow causes the particles to detach, which leads to a loss of hydrophobicity due to an increase in the polymer concentration. For the first time, the possibility of combining the extractive method for creating a microtexture with the additive method for creating a nanotexture was demonstrated and the resulting water-repellent properties and stability of the hydrophobic state were evaluated. For the first time, the sequence of destruction of hierarchical coatings using a nanofiller and two fractions of microfiller under conditions of abrasive wear by a stream of quartz particles is shown, where first, the nanosized filler is ablated, which increases the angle of water rolling, and then cracks are formed and enlarged on the surface, which leads to delamination of the composition. The paper proposes methods for obtaining water-repellent surfaces by the extractive method on the surface of anodized and unanodized aluminum. Methods for obtaining hydrophobic organo-mineral surfaces with micro- and nanotexture were demonstrated and tested. The scientific positions and experimental approaches formulated during the work were implemented in the course "Operational reliability of composite materials", educational and professional program of the second (master's) level of higher education "Chemical technologies of inorganic binders, ceramics, glass and polymeric and composite materials" at the Department of Chemical Technology of Igor Sikorsky Kyiv Polytechnic Institute, specialty 161 "Chemical Technology and Engineering". An application for a patent of Ukraine for utility model No. u202301147 was filed.