Effect of Zinc Oxide Morphology on the Antimicrobial Activity and UV Absorbance of Nylon 6/Zinc Oxide Composite Filaments

Two zinc oxide (ZnO) morphologies, nanorods and nanoplates, were synthesized using solvothermal synthesis, and the effect of the ZnO morphologies on the UV absorbance and anitmicrobial activity of nylon 6/ZnO composite filaments was investigated. The ZnO nanorods and nanoplates exhibited a hexagonal wurtzite crystal structure. The ZnO nanorods were 50 nm in diameter and 300 nm in length, and the ZnO nanoplates were 150 nm in width and 25 nm in thickness. Photoluminescence (PL) measurements showed that the intensity of the deep level emission of the ZnO plates in the visible light range was lower than that of the ZnO nanorods, indicating that amount of surface defects on the ZnO nanoplates was relatively small compared that of the ZnO nanorods. The strong crystal diffraction peaks of the ZnO nanorods confirmed that they exhibited higher crystallinity than the ZnO nanoplates. Both the nylon 6/ZnO nanorod and nylon 6/ZnO nanoplate composite filaments showed very good antimicrobial activity even when only 0.5 wt% of ZnO particles was added. The specific surface area of the ZnO nanorods and nanoplates were 10.353 and 11.249 m²/g, respectively. UV protection of the nanoplates was higher than that of the nanorods. The larger specific surface area of the ZnO nanoplates led to higher UV absorbance of the nylon 6/ZnO nanoplate composite filaments.