One-step sol-gel preparation of hydrophobic antireflective SiO2 coating on poly(methyl methacrylate) substrate

A hydrophobic nanoporous antireflective (AR) SiO2 coating was deposited on poly(methyl methacrylate) (PMMA) substrate by sol-gel process. The average transmittance of PMMA substrate with designed SiO2 coating in the region of 400-1100 nm was higher around 6.3% than that of substrates (92.0%). It was noted that a maximum transmittance of 99.9% was achieved at the wavelength of 550 nm. The poly(methyl hydrogen) siloxane (PMHS) was introduced to replace the hydroxyl (OH) groups and decrease the surface energy of the coating, it increased significantly the hydrophobicity. Consequently, static water contact angle as high as 125.0 ± 1° was obtained. Cross sectional SEM showed that conformal coating was achieved on PMMA substrate. The hydrophobic AR SiO2 coating exhibited excellent performance on PMMA substrate, showing great application potential in optical devices.