Structural, thermal, optical characterizations of polyaniline/polymethyl methacrylate composite doped by titanium dioxide nanoparticles as an application in optoelectronic devices

Abstract

The casting method was employed for the preparation of polymer blend films doped with TiO2 (0.5, 1, 1.5, and 2.3 wt%). The TiO2 phase formation is anatase, with an average crystal size of 20.25 nm, according to the XRD results. The samples of PANI/PMMA-TiO2 nanocomposite are amorphous nature. Furthermore, as the concentration of TiO2 NPs increases, the amorphousity degree increases. The FTIR technique is used to reveal the nanocomposites' vibrational bands as well as the intermolecular bonding between the blend and the TiO2 NPs. Absorption spectra, reflectance, transmission spectra, extinction coefficient, refractive index, real and imaginary parts of the dielectric constant, third-order susceptibility (χ3), and optical band gaps are among the optical constants studied. As preselected TiO2 NPs are put into thin films (doping ≤1.5 wt%), the optical band gap values (Eg) of the fabricated nanocomposite films decreased. These results are extremely similar to those obtained using the Tauc method. DSC and TGA techniques show that TiO2 NPs help to improve the thermal stability of the polymer blend. The DSC measurement reveals a single Tg of the polymer blend (PANI/PMMA), indicating that the two polymers are miscible. The optical constants revealed noticeable changes with increasing doping concentrations; according to the experimental data. The doped thin films that were developed have a great promise for manufacturing high-efficiency optoelectronic devices.