Advanced functional coating for self-cleaning and anti-corrosion applications

This thesis is focused on the preparation of organic-inorganic hybrid systems with targeted properties. In particular, thesis presents the synthesis, characterization and application of two types of functional coating, which are hydrophobic / self-cleaning and anticorrosion coatings. Chapter 1 is dedicated to general introduction and the state of art of advanced functional coating. The chapter includes a brief description of the current functional market size and possible applications of functional coatings. Chapter 2 provides a general introduction of superhydrophobic coatings, their possible applications on the glass surface and methods to produce them. In the chapter 3, sol-gel methods has been describe in detail. The sol gel process by employed alkoxysilanes was used in this work to fabricate the functional coatings. Chapters 4, 5 and 6 describes the experimental works of this thesis. In the chapter 4, the solgel process and dip-coating technique were employed for the preparation of hydrophobic self-cleaning hybrid materials. The process has been optimized to obtain transparent and highly hydrophobic sol-gel coatings by using different alkoxysilane. These hybrid sol-gel coatings are a good alternative to provide anti-stick and easy-to-clean properties to glass substrates being quite easy to scale up. In the chapter 5, a method for the preparation of transparent superhydrophobic silica coatings on glass substrates via aerosol‐assisted chemical vapour deposition (AACVD) is described. A multi-layer process to produce dual scale silica nanoparticles films, by using different functional alkoxysilanes was investigated. In this study, a novel strategy to achieve highly transparent superhydrophobic glass surfaces using AACVD of alkoxysilanes, to produce surfaces with excellent durability is described. This shows great potential to obtain silica superhydrophobic films for large–scale applications Finally, in the chapter 6, a preliminary study about the protective barrier coating to protect the integrity of the silver from deleterious chemical degradation in a mirror structure is investigated. Sol-gel hybrid coating has been deposited on mirror to avoid corrosion degradation process of silver layer. Salt spray test was performed on mirror coated with hybrid coating and the results showed a no signs of corrosion on the mirror. The results indicate excellent barrier protection performance of the coating.