Highly Transparent and Zirconia-Enhanced Sol-Gel Hybrid Coating on Polycarbonate Substrates for Self-Cleaning Applications

Abstract

To improve the efficacy of polymer-based substrate hybrid coatings, it is essential to simultaneously optimize mechanical strength and preserve the optical properties. In this study, a mixture of zirconium oxide (ZrO2) sol and methyltriethoxysilane modified silica (SiO2) sol-gel was dip-coated onto polycarbonate (PC) substrates to form zirconia-enhanced SiO2 hybrid coatings. Additionally, a solution containing 1H, 1H, 2H, and 2H-perfluorooctyl trichlorosilane (PFTS) was employed for surface modification. The results show that the ZrO2-SiO2 hybrid coating enhanced the mechanical strength and transmittance. The average transmittance of the coated PC reached up to 93.9% (400–800 nm), while the peak transmittance reached up to 95.1% at 700 nm. SEM images and AFM morphologies demonstrate that the ZrO2 and SiO2 nanoparticles were evenly distributed, and a flat coating was observed on the PC substrate. The PFTS-modified ZrO2-SiO2 hybrid coating also exhibited good hydrophobicity (WCA, 113°). As an antireflective coating on PC, with self-cleaning capability, the proposed coating has application prospects in optical lenses and automotive windows.