Heterogeneous Nucleation of Supersaturated Water Vapor onto Sub-10 nm Nanoplastic Particles

Nanoplastic pollution by atmospheric transport processes is a recently discovered environmental problem on a global scale that is attributed to the dispersion of aerosolized nanoplastics. However, knowledge about the basic physicochemical properties of aerosol nanoplastic particles is scarce. Here, we present experiments on the heterogeneous nucleation of supersaturated water vapor onto sub-10 nm polyethylene terephthalate (PET) seeds. We determined onset saturation ratios for the activation of PET seeds in comparison to the well-documented reference system of silver particles, resulting in lower onset saturation ratios of the PET seeds compared to silver seeds. By using different PET bulk materials for the generation of nanoparticles, we report a strong material dependence of the onset saturation ratios, pointing to a strong effect of additives from commodity plastics in heterogeneous nucleation. Moreover, our results show a strong dependence on nucleation temperature that might be of immediate atmospheric relevance. Our work can be considered as an initial step in airborne nanoplastic detection by condensation techniques, and we anticipate our study to serve as a basis for further research that will eventually allow assessing the impact of nanoplastic dispersion on atmospheric processes.

Automated summary

Nanoplastic pollution is a global environmental problem caused by the dispersion of aerosolized nanoplastics through atmospheric transport. However, there is limited knowledge about the physicochemical properties of aerosol nanoplastic particles. This study investigates the heterogeneous nucleation of supersaturated water vapor on sub-10 nm polyethylene terephthalate (PET) seeds and finds a material dependence of nucleation behavior, as well as a strong dependence on nucleation temperature. These findings contribute to the understanding of airborne nanoplastic detection and assessing the impact of nanoplastic dispersion on atmospheric processes.