Hexadecyltrimethoxysilane-Modified SiO₂ Nanoparticle-Coated Halloysite Nanotubes Embedded in Silicone–Acrylic Polymer Films as Durable Fluorine-Free Superhydrophobic Coatings

Superhydrophobic coatings have received considerable attention owing to their potential applications. There has been an increasing demand for the construction of durable superhydrophobic coatings using cost-effective and fluorine-free chemicals. Herein, we developed a simple, universal, and eco-friendly approach to fabricate durable superhydrophobic coatings. The as-prepared coating was composed of synthesized fluorine-free hexadecyltrimethoxysilane-modified SiO2 nanoparticle-coated halloysite nanotubes (HDTMS-HNTs/SiO2) and a commercial water-based silicone–acrylic emulsion. SiO2 nanoparticles covered the surface of the HNTs to create a hierarchical micro/nanoscale structure. The silicone–acrylic emulsion bonded the HDTMS-HNTs/SiO2 nanoparticles and anchored them onto the substrate. The as-prepared superhydrophobic coatings exhibited high performance, including a water-repellent property and outstanding mechanical durability. The coatings maintained superhydrophobicity after tests for sand impact abrasion, 50 cycles of sandpaper abrasion, finger touch, and 30 cycles of tape-peeling. Additionally, the simple spray-coating method at room temperature also made the coatings substrate independent, making practical application of superhydrophobic coatings in real life more feasible.