In‐site synthesis of <scp>TiO₂</scp> in (<scp>HEMA</scp>‐<scp>AA</scp>)‐co‐<scp>PDMS</scp> hydrogel: <scp>UV</scp> resistance, optical transparency, and hydrophilicity

Abstract A (HEMA‐AA)‐co‐PDMS hydrogel doped with TiO 2 nanoparticles was prepared by an in‐situ synthesis method. The relationships between the composition and structure and performance of the hydrogel were characterized by SEM, TEM, TGA, FTIR, AFM, XPS, UV–vis, a universal testing machine, and contact angle. The in‐situ synthesized TiO 2 nanoparticles in the hydrogel improved the hydrophilicity and the absorption of UV and blue light significantly. UV‐C and UV‐B in the range of 100–280 nm and 280–315 nm, respectively, were absorbed completely. Absorption of UV‐A light in the range of 315–400 nm was enhanced from 18% to 45% while the absorption of blue light in the range of 400–500 nm was enhanced from 10% to 30%. Visible light transmittance in the range of 500–800 nm was maintained around 90%. The contact angle of the (HEMA‐AA)‐co‐PDMS hydrogel decreased from 79.5° to 41.5°, and the high elongation at break was retained. The oxygen permeability coefficient of the (HEMA‐AA)‐co‐PDMS hydrogel was 12.12 × 10 −11 (cm 2 /s) [mLO 2 /(mL × mmHg)]. This TiO 2 nanoparticle‐doped (HEMA‐AA)‐co‐PDMS hydrogel showed great potential for producing contact lens with UV and blue light protection.