Nanoscale Coatings Derived from Fluoroalkyl and PDMS Alkoxysilanes on Rough Aluminum Surfaces for Improved Durability and Anti-Icing Properties

Anti-icing aluminum (Al) surfaces with excellent durability and low icing adhesion strength were fabricated by forming hierarchical structures on Al surfaces and coating silanes with low surface energy. The Al plates were chemically etched and subsequently immersed in hot water to realize micro–nano hierarchical roughness on the surface. The rough Al plates were coated with a solution containing a mixture of 1H,1H,2H,2H-heptadecafluorodecyl (FD)-trimethoxysilane and poly(dimethylsiloxane) (PDMS)-triethoxysilane, and the wettability and anti-icing properties of the coated surface were compared according to the various ratios of FD and PDMS. The anti-icing surface with 2.9 wt % of the PDMS functional group exhibited a relatively low ice adhesion strength of 25.3 kPa despite a high relative humidity of 75% (at −20.5 °C). In addition, the ice adhesion strength achieved after 100 icing/melting cycles was 47.2 kPa, which indicated excellent durability of the anti-icing properties. This is attributed to the synergistic effect of PDMS and the low surface energy of FD groups, which exhibit chain flexibility, low glass-transition temperature, and repulsion against water molecules.