Abstract: Through dip-coating technology, a series of composite coatings were fabricated by adjusting the concentration parameters of nano-SiO2 particles (0-10.0 g/L), PMMA, and dichloromethane (CH2Cl2) solvent. Systematic characterization using the contact angle measurements and the UV-Vis spectrophotometry revealed that the material achieved optimal performance balance of superhydrophobicity and transparency at a nanoparticle concentration of 6.25 g/L, exhibiting a static contact angle of 160.8°±1.1°and a transparency exceeding 90% at 550 nm wavelength. Mechanistic analysis revealed that the hierarchical micro-nano structures formed by nanoparticles at this concentration synergistically interacted with the polymer matrix, concurrently generating the surface roughness necessary for the superhydrophobic Cassie-Baxter state while preventing Mie scattering effects to preserve the high transparency typically compromised by excessive particles. This research highlights advantages such as the availability of raw materials, straightforward processing, and low manufacturing costs, demonstrating promising self-cleaning potential and broad application prospects in the protection of optical device surfaces and the self-cleaning of photovoltaic modules.

Key words: Superhydrophobicity, Transparency; SiO₂/PMMA composite coating, Self-cleaning