In the first research project, poly(vinyl chloride)/ titania nanocomposites were prepared. The surface modification of TiO 2 nanoparticles with vitamin B 1 as a biodegradable and biocompatible modifier was performed in order to avoid aggregation and increased the dispercity of the nanoparticles in organic solvents. The modified nanoparticles were characterized by FT-IR, XRD, TEM, FE-SEM and TGA techniques. The FT-IR results confirm the presence of the modifier agent on the titania surface. Then, 3, 5 and 7 wt% of the modified nanoparticles were added into the poly(vinyl chloride) as a polymer matrix. This process was performed under ultrasonic irritation as a fast, easy, green and economical method. The resulting nanocomposites were identified by various techniques including FT-IR, XRD, TEM, FE-SEM, TGA, UV-Vis, mechanical testing and measurement of the contact angle. The nanocomposites showed more UV-Vis absorption than the pure polymer. The mechanical testing results showed that with addition the modified nanoparticles into the polymer, the mechanical properties of the nanocomposites enhancement in comparison to the pure polymer. Also, the measurement of the contact angle showed an increase in the hydrophobicity of the nanocomposites in comparison to the pure polymer. In the second project, the various values of the modified nanoparticles (3, 5 and 7 wt%) introduced into the poly(vinyl alcohol) matrix by the ultrasonic irritation. The resulting nanocomposites were studied by FT-IR, XRD, TEM, FE-SEM, TGA, UV-Vis, mechanical testing and measurement of the contact angle. The TGA results showed more thermal stability for the nanocomposites than the pure polymer. Also, the measurement of the contact angle showed more hydrophility of the nanocomposites in comparison to the pure polymer.