Stability and Biological Responses of Zinc Oxide Metalworking Nanofluids (ZnO MWnF™) using Dynamic Light Scattering and Zebrafish Assays

Zinc oxide nanoparticles (ZnO NPs) have demonstrated the ability to improve lubrication and thermal conductivity and are promising metalworking lubricant and coolant additives due to their low cost compared to other NPs. Though nano-materials are a focus of research due to their potential to enable advanced technologies, little is known about their effects on the environment and human health. This research investigates two main characteristics of ZnO metalworking nanofluids (MWnF). First, the stability of ZnO NPs (20 nm) is investigated using dynamic light scattering (DLS) for mixtures of a microemulsion (TRIM MicroSol 585XT) and several dispersants, all of which are commercially available. Second, toxicological assessments using a zebrafish assay method are conducted to survey the effect of ZnO NPs on MWnF safety. The research revealed that none of the dispersants enhanced the stability of ZnO NPs more than the prepared microemulsion alone. The work also revealed that ZnO MWnF had a significantly higher toxicity than the prepared microemulsion. This demonstrates the need