From patterned to continuous hydrophilic surface lubrication as strategies to obtain durable low ice adhesion coatings

Abstract

In aviation, ice removal from surfaces primarily relies on energy-intensive active de-icing systems and anti-icing fluids with significant operational and environmental impact. Alternatively, passive low-icing or low-ice-adhesion surfaces may be used. However, existing passive anti-icing and low-ice adhering materials often lack durability, rely on complex fabrication methods, or cannot be integrated into certified coating systems. Similar challenges are faced in other fields such as communications, ships, and cryogenic preservation. In this work, we introduce and compare several scalable PFAS-free surface-modification strategies based on surface lubrication to obtain low ice adhesion. A robust home-made multichannel ice adhesion testing device was further developed and used across the study. The strategies, applied to three polymeric substrates (a commercial aircraft polyurethane (PU) topcoat, polyvinyl chloride (PVC), and polypropylene (PP)), were: (i) controlled UV exposure, (ii) silicone-oil microdroplet contamination, (iii) hydrophilic micropatterns based on covalently grafted Poly(2-hydroxyethyl methacrylate) (PHEMA), and (iv) a UV-curable hydrophilic spray coating based on 2-(Methacryloyloxy)ethyltrimethylammonium chloride (DMC). UV degradation showed a minor yet measurable effect on the reduction of ice adhesion. On the other hand, surfaces coated with molecular water layer-forming treatments (PHEMA patterns and DMC) significantly lowered ice adhesion at −10 °C, outperforming oil microdroplets. Together with homogeneous PHEMA-grafts, the DMC coating achieved the lowest adhesion strengths—consistently below 20 kPa in cyclic testing—attributed to the formation of a non-freezing surface water layer. These results demonstrate that PFAS-free water-lubricating hydrophilic coatings offer a promising pathway toward a new generation of effective passive anti-icing materials.