Elham M. Hussien, W. M. Desoky, Magda S. Hanafy, Osiris W. Guirguis, Influence of Oleic Acid (Vegetable Oils) and TiO2 Addition on the Optical Properties and Chromaticity of Chitosan Composite Films, Journal of Engineering and Applied Sciences, Volume 15,Issue 22, 2020, Pages 3660-3667, ISSN 1816-949x, jeasci.2020.3660.3667, (https://makhillpublications.co/view-article.php?doi=jeasci.2020.3660.3667) Abstract: Cs/OA/TiO2 (NPs) composite films were synthesis via conventional solution casting technique. The chromaticity, CIE tristimulus values, color parameters andoptical properties of Chitos an, Cs, films with the addition of TiO2 and Oleic acid were investigated using the transmittance and reflectance measurements of the spectrophotometric. The absorption, α, coefficient of the composite films were estimated. Therefore, the optical band gaps and their type were estimated with effect of additions. The refractive index of the films was estimated. Subsequently, the lattice dielectric constant εL and the ratio of the number carriers concentration to their effective mass, the real (ε1) and imaginary (ε2) parts of the dielectric constants, complex optical conductivity (real, σ1 and imaginary, σ2), The volume energy loss function, VELF and the surface energy loss function were calculated. Moreover, Opto-electrical parameters such as the relaxation time, optical mobility and optical resistivity were extracted using the Drude theory. The developed Chitosan films supporting an optimized amount of TiO2 (NPs) and Oleic acid could be employed in industry and medicine applications. Keywords: Chitosan;TiO2 nanoparticles;Oleic acid;Optical properties and chromaticity