Insight into the Organic–Inorganic Hybrid and Microstructure Tailor Mechanism of Sol–Gel ORMOSIL Antireflective Coatings

Having a deep insight into the organic–inorganic hybrid (OIH) and microstructure tailor mechanism of sol–gel ORMSOSIL antireflective (AR) coating is of great interest in the field of sol–gel science and technology. VTES/TEOS ORMOSIL sols were prepared via a sol–gel process by using vinyltriethoxysilane (VTES) and tetraethoxysilane (TEOS) as co-precursors. 29Si MAS NMR was applied to deduce the OIH mechanism between VTES and TEOS. The results of N2 adsorption–desorption analysis indicated that OIH could effectively tailor the pore structure. The OIH of VTES and TEOS significantly increased the porosity. With this convenient sol–gel process, the refractive index of VTES/TEOS ORMOSIL AR coatings could be regulated gradually between 1.12 and 1.21 by varying the VTES/TEOS molar ratio. The OIH mechanism and the drying process of these VTES/TEOS ORMOSIL AR coatings were proposed after a detailed discussion on the relationship between microstructure and optical properties.