Effect of modified nano zinc oxide on physico-chemical and antimicrobial properties of gamma-irradiated sawdust/epoxy composites

The present study aims to investigate the influence of modified zinc oxide nanoparticles content on the physico-chemical properties of sawdust/epoxy composite specimens. The results show an improvement in the mechanical properties in terms of flexural strength, impact strength, and hardness with increasing the modified zinc oxide nanoparticles content up to 5%, while the physical properties such as water absorption and thickness swelling percentages are decreased directly with increasing the content of modified zinc oxide. In addition, the behavior of irradiated composite specimens containing 5% modified zinc oxide nanoparticles at different gamma-irradiation doses, 10, 30, and 50 kGy, has been studied. The results indicate that the irradiated composite specimens at 10 kGy have better physico-chemical properties as compared to the unirradiated specimens. Furthermore, the antimicrobial properties of composite specimens containing 5% modified zinc oxide at 0 kGy and 10 kGy against different plant pathogenic fungi and bacteria are also discussed. The results demonstrate that the growth activity of fungi and bacteria on the composite specimens are reduced to a great extent as compared to the control composite specimens (0% of zinc oxide nanoparticles). Thermal behavior and morphology of the prepared specimens are detected using thermogravimetric analysis and scanning electron microscopy technique.