Tailoring the structural and optical features of (PEO–PVA)/(SrTiO₃–CoO) polymeric nanocomposites for optical and biological applications

The present study focused on the modification of the structural, and optical characteristics of polyethylene oxide and polyviny alcohol blend with different weight percentages of strontium-titanium oxide and cobalt oxide nanoparticles (0, 1%, 2%, 3%, and 4%) wt. prepared by solvent casting technique. All samples were structurally investigated by scanning electron microscope which revealed an association between the polymer matrix and the additive. Optical microscope images show that the additive distribution of NPs in the blend was homogeneous and the nanoparticles create a continuous network inside the polymers. Fourier transform infrared rays showed a shift in the peak position as well as a change in shape and intensity compared with pure (PEO–PVA). Optical examinations showed that the absorbance of (PEO–PVA)/(SrTiO₃–CoO) nanocomposites increased from 50 to 97% when the concentrations of strontium-titanium oxide and cobalt oxide nanoparticles reached 4 wt.%, while the energy gap of (PEO–PVA)/(SrTiO₃–CoO) nanocomposites was dropped from 3.7 to 1.7 eV and from 3.9 to 1.6 eV for allowed and forbidden indirect transition, respectively, with the addition of 4 wt.% of (SrTiO₃–CoO) nanofiller. These results may be as key to employ the (PEO–PVA)/(SrTiO₃–CoO) nanostructures in various photonics fields and optoelectronics nanodevices. The refractive index, extinction coefficient, dielectric constant, and optical conductivity increase with increasing the concentration of (SrTiO₃–CoO) nanoparticles, and this behavior make it may be considered as excellent optical materials for photonics applications. The antibacterial properties of the (PEO–PVA)/(SrTiO₃–CoO) nanocomposites were investigated against Staphylococcus aureus (S. aureus) and (E. coli). Experimental results showed that the nanocomposites have good activity for antibacterial. Finally, the results indicated that the (PEO–PVA)/(SrTiO₃–CoO) nanostructures can be considered as promising materials for optoelectronics nanodevices and antibacterial activity.