Effective increase in the refractive index of novel transparent silicone hybrid films by introduction of functionalized silicon nanoparticles

Transparent silicone-based polymers have potential and practical applications in many optical devices; however, their chemical structure restricts their refractive indices to a lower value, which cannot meet the demands of the devices. Here, we present an effective and facile method to increase the refractive index of silicone hybrid films by combining novel phenyl-oligosiloxane monomers and vinyl-Si NPs. The refractive index of the films (similar to 0.1 mm, at 632.8 nm) effectively increased from 1.563 to 1.727 with varying content of Si NPs and showed excellent optical transparency (similar to 0.1 mm, >90% at 550 nm). What's more, all of the films exhibited a sufficient pencil hardness (2H-3H). This strategy is reported for the first time for the facile synthesis and effective increase of the refractive index of transparent silicone hybrid films by introduction of functionalized Si NPs. Such silicone films can potentially be used to fabricate multifunctional devices or optical materials with tunable refractive indices.