Synthesis and UV-Curing Mechanism of High-Refractive-Index Transparent Nanocomposites Embedded with Surface-Engineered TiO2 Nanoparticles

Flexible nanocomposites that combine a high refractive index (RI) and excellent optical transparency are key to enabling multifunctional applications in soft electronics, wearable photonics, and next-generation optoelectronic systems. However, achieving both high transparency and a large RI enhancement remains challenging due to nanoparticle aggregation and poor interfacial compatibility. In this study, we present a novel surface-modified TiO 2 nanoparticle (NP) (∼13 nm) that exhibits enhanced compatibility with UV-curable resins achieving a RI exceeding 2.0 while maintaining high optical transparency and flexibility. The DFT calculation was used to evaluate the absorption energy of the modifier methoxytriethyleneoxypropyltrimethoxysilane (MTE-TMS) and the 2D FTIR measurement was operated to explain the interaction mechanism between the TiO 2 NPs and the bisphenol A glycidyl methacrylate (Bis-GMA) monomer. In-situ FTIR further revealed that the nanoparticles accelerate the UV-curing process. indicating that the NPs can also accelerate the curing process. Benefiting from these properties, the nanocomposites are compatible with roll-to-roll processing, making them highly promising for the large-scale fabrication of optical coatings, anti-counterfeiting labels, and display technologies. This interfacial compatibility strategy can be extended to other high-RI nanomaterials, offering a versatile platform for advanced photonic and optoelectronic applications.