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In this study, different percentages of semiconducting zinc oxide nanoparticles (ZnONPs) are mixed with polyvinyl alcohol (PVA) to create flexible ZnO/PVA polymer nanocomposite films. The characteristics of the prepared films are investigated using differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The XRD pattern shows that the ZnO/PVA composite films were successfully synthesized; while the SEM images show that the ZnONPs are homogeneously dispersed in the PVA polymer chain. Moreover, the DSC indicates an improvement in the thermal stability behavior with increased of ZnONPs concentration. The electrical conductivity, dielectric properties, electric modulus behavior, and the energy density efficiency of the pristine PVA and ZnO/PVA composite films are determined using an LCR meter in the frequency range 10²–10⁶ Hz. The dielectric constant of the composite film increased from 0.185 for pristine PVA to 1.389 for 9%ZnO/PVA, and the conductivity is improved from $1.93\times 10^{-5}$ S/cm to $7.98\times 10^{-5}$ S/cm. This work would open the road for utilizing ZnO/PVA flexible nanocomposite films for wide range of applications such as batteries, super-capacitor and energy storage devices.

Zinc oxide (ZnO) nanopowder samples were prepared by using co-precipitation method, with varying parametric conditions. Rietveld refinement technique is used to study the structural properties of synthesized samples. XRD and UV spectroscopy techniques have been used to characterize the samples which resemble ZnO nanostructures. Observed lattice parameters are $a=b=3.2482$ Å and $c=5.2011$ Å for sample A, $a=b=3.2500$ Å and $c=5.2062$ Å for sample B, $a=b=3.2497$ Å and $c=5.2017$ Å for sample C, $a=b=3.2550$ Å and $c=5.2122$ Å for sample D. The varying unit cell volume and axial ratio for all samples are calculated as 47.52–47.82 Å and 1.6006–1.6019. VESTA software is used to calculate the bond angles and lengths of Rietveld refinement data. UV-Vis spectroscopy analyzed the absorption, transmission, refractive index and band gap of samples for their possible use in different industrial applications.

Zinc oxide nanoparticles (ZnO-NPs) are widely utilized in many applications due to distinct physical and chemical characteristics. There are growing concerns that abundant use of ZnO-NPs can cause harm to humans and the environment. There is a substantial problem with reproducibility in nanotoxicology research due to the inherent properties of nanoparticles. Dispersion media are used for the preparation of nanoparticles. However, the physical and biological behaviors of ZnO-NPs in aqueous dispersion media are poorly understood. In this study, we investigated the effect of ZnO-NPs on the viability of SH-SY5Y cells. Our results showed that ZnO-NPs diluted from water-dispersed stock solution caused significant cell death at a much lower dose compared to their counterpart diluted from the phosphate-buffered saline (PBS)-dispersed stock solution. Electron microscopic data indicated that ZnO-NPs from the PBS-dispersed stock solution form much larger agglomerates compared to the one from the water-dispersed stock solution. From these data, we can conclude that the types of media used for particle dispersion impact the change in the physical property and cytotoxicity of ZnO-NPs.

Metal and metal oxide nanoparticles are active materials used in water treatment technologies. The emergence of these nanomaterials is due to the increasing demand for clean water supply. Among these nanoscale materials, Silver (Ag) and Zinc oxide (ZnO) are famous for having shown good antibacterial properties, essential in water purification technologies. Aside from its pure metal form, its composites have also been explored due to their synergistic effects with some polymeric matrices. Chitosan, for example, is an abundant natural material for its biodegradability, non-toxicity, and water purification properties. In this review, syntheses of Ag and ZnO nanoparticles together with their composites are discussed. Furthermore, its antibacterial properties, along with its water purification efficiencies, are further analyzed. The authors also give an outlook on the possible directions of nanomaterials in water remediation and the inevitable challenges ahead.