Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

Résumé

Along with advancements in materials and processes in the 20th and the 21st century, the demand for new generations of materials with specific functionalities has emerged. Self-healing ability is striking in the current environmental circumstances as far as the demand for prolonging the service lives of products and reducing waste is irresistible. In this paper, the self-healing ability was introduced into a fluorine-free superhydrophobic coating via the incorporation of microcapsules containing a silicone resin (DMS-S12) and catalyst (dibutyltin dilaurate, DBTL) inside poly (melamine urea formaldehyde) shells. The designed self-healing system is aligned with the chemistry of the superhydrophobic coating from two points of view. First, the silicone nature of the coating remains almost unchanged after the healing action. Second, the free ethoxy groups of the superhydrophobic coating can act as bridges linking healed regions and matrix. Synthesized microcapsules showing mean diameters of 18 and 16 µm were sought-after for application in surface coating. The water contact angle on the coating reached 165°, and the contact angle hysteresis value of 3.6° verified the non-wettability of the coating. The self-healing ability of the coating was visually inspected through microscopy imaging. Electrochemical impedance spectroscopy was utilized in quantifying the self-healing ability of the as-prepared coating. The self-healing efficiency of the coating was calculated using charge transfer resistance (Rct) data. Results indicated self-healing efficiency of up to 90% compared with that of a blank superhydrophobic coating. The required time for the sealing of microcracks through self-healing reactions was obtained to be between 24 and 48 h after crack application.