Abstract
In this current study, the polymer nanocomposites films based on chitosan (Cs)/polyvinyl alcohol (PVA)/ with graphene oxide (GO) and titanium dioxide (TiO
2
) as nanofiller have been prepared by casting technique. The prepared polymer nanocomposites are investigated by using various techniques. The XRD patterns of the studied films revealed a clear decrease in the crystallinity degree of the doped Cs/PVA blend films compared with the pure blend. Due to the existence of OH groups in PVA and NH
2
groups in Cs, the interaction between Cs/PVA mix and GO/TiO
2
nanoparticles occurs and was validated by DFT calculations. This interaction was also linked between the experimental and theoretical findings of DFT calculations. Calculations were made to determine optical properties such as the Urbach energy and energy band gap. As the weight proportion of GO/TiO
2
grows, the energy band gap (indirect and direct) reduces from 5.01 to 5.40 eV for pure blend to 4.46 and 3.49 eV for Blend/5%GO/5% TiO
2
, and Urbach energy rises. The ionic conductivity of the polymer nanocomposites films was studied by using the AC-impedance spectroscopy. The greater ionic conductivity ~ 10
–7
S/cm is obtained for the Cs/PVA film, and it was increased to ~ 10
–5
S/cm at room temperature by adding 5% GO/ 5% TiO
2
nanofiller. It was noted from the dielectric characteristics that the polymer blend with 5% GO/5% TiO
2
added had high dielectric constant values at lower frequencies. The non-Debye behavior was indicated by the incomplete semicircles on the argand plot curves at different concentrations. The improved optical, dielectric, and electrical properties of the Cs/PVA-5%GO/5%TiO
2
nanocomposites make it suitable for use in electronic and optoelectronic devices.