Carbon black （CB）/polymer composites with high refractive index （RI） were fabricated from poly（vinyl alcohol） （PVA） and covalently functionalized nano-CB （PVA-es-CB） by simple esterification reaction. Transmission electron microscopy showed that tmifonn aggregates of PVA-es-CB nanoparticles with a size smaller than I00 nm formed in the nanocomposite films. Ellipsometric measurements indicated that the PVA-es-CB/PVA composite films had a RI in the range 1.520-1.598 linearly increased with the PVA-es-CB volume content. Theoretical equation based on Lorentz-Lorenz theory provided reasonably close estimation of the refractive indices to the experimentally observed values. The hybrid films also revealed relatively good surface planarity, thermal stability and optical transparency.
