Polymer nanocomposites comprising PMMA matrix and ZnO, SnO2, and TiO2 nanofillers: A comparative study of structural, optical, and dielectric properties for multifunctional technological applications

Polymer nanocomposite (PNC) films consisted of poly (methyl methacrylate) (PMMA) matrix and wide energy bandgap semiconductor nanocrystallite fillers viz. zinc oxide (ZnO), tin oxide (SnO2), and titanium dioxide (TiO2) were prepared by a sonicated suspension of nanoparticles in polymeric solutions followed by the casting method. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) characterization revealed successful nanocomposite formation of these hybrids. The ultraviolet-visible (UV-Vis) spectroscopic study explained that the absorbance and energy bandgap of these PNC films largely differed with the type of metal oxide nanofillers and their concentrations (i.e., 1-5 wt%). The UV-absorbance was found relatively high for the PMMA/TiO2 films and low for the PMMA/SnO2 films at the same concentration of the fillers. The film thickness dependent study confirmed that the increase of film thicknesses significantly enhanced the UV-Vis absorbance and reduced the energy bandgaps of the same composition PMMA/TiO2 composites. The dielectric permittivity of the ZnO and SnO2 containing PNC films was found to be appreciably increased with the increase of concentration of these nanocrystallite fillers, whereas the films bearing TiO2 nanoparticles exhibited a decrease in permittivity as compared to that of the host PMMA matrix film at the temperature of 30 degrees C. Further, a gradual decrease in the permittivity of these nanocomposite materials was noted with the increase of experimental electric field frequency from 20 Hz to 1 MHz range. The electric modulus spectra exhibited a single relaxation process in the lower frequency region which attribute to the ester group rotations of the PMMA chain repeat units and it was found to be largely influenced by the fillers and their concentrations in these nanocomposites. The AC electrical conductivities of all these PNC films were observed slightly increased and showed a linear behaviour with the frequency variation. The wide range tailorable behaviour of the optical and dielectric parameters with the change of nanofillers and their concentrations evidence that these PNCs could be promising multifunctional materials for UV-shielders, optical sensors, and bandgap tuners in developing various advanced optoelectronic and organoelectronic devices, and also their use as low permittivity nanodielectric insulators and substrates to architect the next-generation flexible-type electronic devices.

Automated summary

PNC films consisting of PMMA matrix and wide energy bandgap semiconductor nanocrystallite fillers were prepared by a sonicated suspension of nanoparticles in polymeric solutions followed by the casting method. The UV-Vis study revealed significant differences in absorbance and energy bandgap among the PNC films with various metal oxide nanofillers and concentrations. The films exhibited potential applications in UV-shielding, optical sensing, and bandgap tuning in advanced optoelectronic and organoelectronic devices.