Speaker
Description
Antisoiling technologies, based on easy-to-clean and self-cleaning coatings have received significant interest in research and commercial applications. For outdoor uses, easy-to-clean hydrophobic coatings have perhaps bigger potential since the major portion of atmospheric pollution is inorganic. On the other hand, hydrophilic self-cleaning coating usually exhibit strong antistatic functions, although they seem to suffer from poor performance in real-field conditions. It is therefore important to combine within a single coating consistent antisoiling in-field performance with strong anti-static attributes. In this work, a facile chemical preparation mode for the development of transparent, hydrophobic coatings with enhanced anti-static properties, is proposed. These can strongly adhere to various types of substrates, even on non-polar surfaces, that lack hydroxyl groups.
Primary focus is given on the structural design of the coating. More specifically, the coating’s matrix comprises an alkoxysilyl substituted organopolysilazane, which offers increased UV, abrasion, chemical and thermal resistance, as well as excellent adhesion to a variety of substrates. This matrix can exhibit surface energies of the order of 30 mN/m and form a dense Si-O-Si/Si-N-Si network with hydrolysable alkoxysilane groups. Additionally, the covalent grafting of a quaternary ammonium silane (which promotes anti-static behavior) to the siloxane-silazane copolymer though hydrolysis-condensation reactions, is extensively described. The hybrid composition is an organic-inorganic copolymer with alternating silicon and nitrogen atoms –N-S-N-, being modified with quaternary ammonium silanes. Finally, the role of an amphoteric wetting agent, based on an acrylic modified copolymer is also highlighted. On anionic surfaces especially, the latter promotes adhesion through charge interactions with cationic ammonium groups. The coating thus produced, can be easily applied through hand polishing or by HVLP. Curing takes place within 7 days under ambient conditions with the dry film thickness being 1 μm. This innovative methodology may be exploited in various applications offering long-lasting protection to surfaces.
Acknowledgment: This research has been co‐financed by the European Regional Development Fund of the
European Union and Greek national funds through the Operational Program Competitiveness,
Entrepreneurship and Innovation, under the call RESEARCH – CREATE – INNOVATE (project
code:T1EDK-04949).
| Speaker Country | Greece |
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