Scalable, fluorine free and hot water repelling superhydrophobic and superoleophobic coating based on functionalized Al2O3 nanoparticles

Abstract

Hot water droplet and oils induced air cushion failure, intensively used fluorine-containing chemicals, tedious preparation process, etc. are the main bottlenecks of the current artificially fabricated superhydrophobic materials, restricting their large-scale production and real-world applications. Herein, a facile, scalable, fluorine-free spray-coating strategy was employed to achieve superhydrophobic and superoleophobic polymerized organosilanes/Al2O3 nanoparticles (POS/Al2O3 NPs) coatings. The POS/Al2O3 NPs coating was achieved through hydrolytic condensation of tetraethyl orthoilicate (TEOS) and hexadecyltrimethoxysilane (HDTMS) in the presence of Al2O3 NPs. A variety of analytical techniques including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray photoelectron spectroscopy (EDS) were used to investigate the fabricated coatings. The POS/Al2O3 NPs coating features high contact angle (>158°) and low sliding angle (<5°) for water, glycerol, and ethylene glycol droplets with different surface tensions, verifying both superhydrophobic and superoleophobic properties. Moreover, the coatings present extremely low surface adhesion force, excellent liquid-driven self-cleaning ability, and hot water repellency. The superamphiphobic POS/Al2O3 NPs coating exhibits promising applications in various fields including self-cleaning, corrosion resistance, and preventing scald as this strategy is applicable on various substrates.