Surface Engineering of Titanium Dioxide Nanoparticles for Silicone-Based Transparent Hybrid Films with Ultrahigh Refractive Indexes.

We report a newly developed surface engineering approach for TiO2 nanoparticles toward transparent TiO2/silicone nanocomposites with high refractive index (RI) values. Zirconate coupling agents are adopted on the TiO2 nanoparticles for surface passivation and to enhance the dispersibility of the nanoparticles in organic substrates. The modified TiO2 nanoparticles can be uniformly dispersed in silicone, forming transparent hybrid films with an ultrahigh RI of 2.01. The preparation technique of colloidal TiO2 and polymer-based nanocomposites is simple and suitable for scalable production, which is promising for expanding the application of TiO2 materials in photonic devices.