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

Résumé

To enhance the anti-icing capabilities of aqueous self-lubricating coatings, we harnessed the synergistic potential of multiple icephobic methods. We adopted a layer-by-layer technique to maximize the icephobicity of a surface using phase change materials (PCMs). We used solid-state nuclear magnetic resonance (NMR) spectroscopy to confirm the presence of a quasi-liquid layer on a coating containing a PEG-PDMS copolymer. NMR spectra of this coating showed non-frozen water retained at the interface, even at subzero temperatures. Differential scanning calorimetry demonstrated that the quasi-liquid layer delayed ice nucleation because of its viscosity. Placing a PCM-containing layer beneath the aqueous self-lubricating coating reduced ice nucleation temperature and extended the complete freezing time of droplets. These enhanced icephobic properties occurred because of the latent heat release by PCMs, which extends the preservation of the liquid-like layer over a longer period. The PCM-containing layer also heightened the self-lubricating properties of the overlying PEG-PDMS-containing coating, further reducing ice adhesion and accumulation. Ice adhesion strength varied minimally among most concentrations of PCM in the underlying layer after repeated icing/de-icing cycles; however, the 50 % PCM sample showed lower durability, reflecting an adverse effect of high PCM concentrations on the mechanical strength of the coating. Employing a hybrid approach provides a new avenue for fabricating icephobic coatings. This methodology can potentially overcome constraints associated with individual anti-icing techniques to produce durable coatings with an improved icephobic performance.