In this work, zinc oxide (ZnO) was produced using extracts of Thymus (Z), Hibiscus rosa-sinensis (K), and Daucus carota (G). Furthermore, sodium carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) were combined with ZnO to form three novel nanocomposites. X-ray diffraction (XRD) was used for the structural analysis, where the semicrystalline nature of the (CMC/PVA)/ZnO nanocomposites was confirmed. The characteristics functional groups that arose inside the prepared samples were identified by Fourier transform infrared spectroscopy (FTIR). Evidence for the successful preparation of the pure ZnO particles and their nanocomposites was carried out using a transmission electron microscope (TEM). The ZnO nanoparticles are mostly spherical, irregularly distributed, and have radii ranging from 10 to 40 nm. Their anti-bacterial activity was studied against B. subtilis, E. coli, and Candida albicans. The inhibition zones of all the prepared samples against E. coli were 0, 19, 31, and 23 mm for PVA/CMC blend, PVA/CMC/ZnO (Z) (PCZ-Z), PVA/CMC/ZnO (K) (PCZ-K), and PVA/CMC/ZnO (G) (PCZ-G), respectively, compared to the streptomycin control Gram-positive standard with inhibition zone (34 mm). On the other hand, the inhibition zones of the prepared samples against B. subtilis were equal to 0, 26, 33, and 28 mm for CMC/PVA, PCZ-Z, PCZ-K, and PCZ-G, respectively. Based on these results, the PCZ-K sample is the most effective at resisting E. coli (91.17%) and B. subtilis (94.28%). These nanocomposites do not have harmful chemicals, making them strong candidates for use in biological applications.

In the present work, gold nanoparticles (Au-NPs) were synthesized in two ways: plant extract and laser ablation techniques. Then, Au-NPs were added to (PVP/PVA/CMC) blend (TB) to produce novel nanocomposites using the solution casting technique. X-ray diffraction analysis, Ultraviolet and visible spectroscopy, and transmission electron microscopy provided conclusive evidence for preparing Au-NPs through the above methods. The optical, structural, and dielectric properties of the prepared samples were prudently investigated and confirmed their semicrystalline nature. TEM study concluded that Au-NPs are more uniformly distributed in the TB/AuNPs-biosynthesized (TBAu-B) matrix than in the TB/Au-NPs prepared by laser ablation (TBAu-L) matrix. The decrease in interatomic distances increases the refractive index with an enhancement in optical properties. The change in loss tangent provided a deeper discernment into the relaxation dynamics that arose inside the current films. The electric modulus formalism verified the non-Debye behavior of charge carriers inside the TB-based nanocomposite samples. It also demonstrated a remarkable capacitive feature of the nanocomposite films. The dielectric characteristics of the TBAu-B nanocomposite sample have improved, where AC electrical conductivity reached 1.58 × 10⁻³ S/cm. Because of this favorable enhancement, the TBAu-B nanocomposite has the potential to be utilized in optoelectronic applications such as sensors.