Optical, electrical, mechanical, and thermal properties and non-isothermal decomposition behavior of poly(vinyl alcohol)–ZnO nanocomposites

Preparation of Novel Composites of Polyvinyl Alcohol Containing Hesperidin Loaded ZnO Nanoparticles and Determination of Their Biological and Thermal Properties

Hesperidin (HSP) is considered to be the most effective antimicrobial agent against SARS-CoV2 virus. The HSP was loaded onto ZnO nanoparticles that were successfully incorporated, via the hydrothermal method, into polyvinyl alcohol (PVA) for use as food packaging material. The hydrothermal method enabled the bioactive ZnO-HSP to be homogeneously dispersed in the PVA, which significantly increased the thermal stability of the matrix, while decreasing the softening temperature. The water holding capacity and water solubility of the obtained nanocomposites was reduced compared to the PVA. Finally, the ZnO-HSP antimicrobial agent contributed important antibacterial properties to the PVA and increased its antioxidant capacity against Staphylococcus aureus and Escherichia coli pathogens. In addition, the nanocomposites had no cytotoxic/proliferative effects on cancer cells. All results showed promise that the PVA/ZnO-HSP nanocomposites would be an excellent alternative for food packaging applications.

Smart apparel using nano graphitic carbon nitride/PVA in a cotton cloth for military application

An eco-friendly, low-cost smart attire was made of metal-free graphitic carbon nitride (GCN) as a semiconductor material in a biodegradable synthetic polymer (polyvinyl alcohol) and cotton material. Various concentrations such as 0.04, 0.08, 0.12, 0.16, and 0.2 weight percentage of GCN is entrenched in PVA. UV absorption spectra displayed two peaks, one matching PVA (317 nm) and the other excitonic peak of GCN (390 nm).0.2% GCN in PVA showed a low bandgap (2.84 eV) harnessing maximum solar light. Due to the charge transfer mechanism, enhanced blue emission at 450 nm was observed for the higher concentration of graphitic carbon nitride. Due to more defect centers of higher weight percentage of GCN, higher electrical conductivity (7.6462 × 10-3 S/cm) and optical conductivity (0.113 S) were noticed. Due to the higher conductivity of 5GCN, it was embedded with cotton fabric. The fabricated smart apparel can be used to manufacture flexible, lightweight, eco-friendly optoelectronic devices. Further, according to literature, GCN possesses high antibacterial activity, hence it can serve as clothing for the military and medical community.

Effect of ZnO Nanoparticle Content on the Structural and Ionic Transport Parameters of Polyvinyl Alcohol Based Proton-Conducting Polymer Electrolyte Membranes

Proton conducting nanocomposite solid polymer electrolytes (NSPEs) based on polyvinyl alcohol/ammonium nitrate (PVA/NH4NO3) and different contents of zinc oxide nanoparticles (ZnO-NPs) have been prepared using the casting solution method. The XRD analysis revealed that the sample with 2 wt.% ZnO-NPs has a high amorphous content. The ionic conductivity analysis for the prepared membranes has been carried out over a wide range of frequencies at varying temperatures. Impedance analysis shows that sample with 2 wt.% ZnO-NPs has a smaller bulk resistance compared to that of undoped polymer electrolyte. A small amount of ZnO-NPs was found to enhance the proton-conduction significantly; the highest obtainable room-temperature ionic conductivity was 4.71 × 10-4 S/cm. The effect of ZnO-NP content on the transport parameters of the prepared proton-conducting NSPEs was investigated using the Rice-Roth model; the results reveal that the increase in ionic conductivity is due to an increment in the number of proton ions and their mobility.