Transparent and\nHigh-Refractive-Index Titanium Dioxide/Thermoplastic\nPolyurethane Nanocomposites

Abstract

Transparent nanocomposite films made of surface-modified\ntitanium\ndioxide nanoparticles and thermoplastic polyurethane are prepared\nvia film casting approach showing enhanced refractive indexes and\nmechanical properties. Two different sets of composites were prepared\nup to 37.5 wt % of inorganic nanoparticles with a diameter <15\nnm, one set using particles capped only with oleic acid and a second\none with a bimodal system layer made of oleic acid and mPEO-5000 as\ncoating agents. All of the composites show significantly enhanced\nrefractive index and mechanical properties than the neat polymeric\nmatrix. The transparency of nanocomposite films shows the excellent\ndispersion of the inorganic nanoparticles in the polymeric matrix\navoiding aggregation and precipitation phenomena. Our study provides\na facile and feasible route to produce transparent nanocomposite films\nwith tunable mechanical properties and high refractive indices for\nvarious applications.