Tunable Wettability and Performance of Coatings Based on Multidimensional SiO2/Silicone Rubber Composite Microspheres

Abstract This paper reports triple-scale raspberry-like composite microspheres synthesized via hydrosilylation, achieving tunable surface roughness. Hierarchical assembly of Dual-Particle-Size SiO2 particles (220 and 84 nm) on silicone rubber microspheres enabled systematic investigation of SiO2 size ratio effects on the wettability of composite. Composite coatings were characterized by FTIR, SEM and contact angle measurements. When the 80 : 20 ratio of 220 nm SiO2 and 84 nm SiO2, the surface of composite achieved maximum water contact angle (157° ± 1°) with robust Cassie–Baxter stability, showing promise for self-cleaning, anti-icing and related applications.