Nanoplastic from mechanically degraded primary and secondary microplastics for environmental assessments

Degradation of plastic waste in the environment leads to the formation of microplastics and nanoplastics. To better understand the fate, behavior and reactivity of nanoplastics, it is essential to conduct experiments with representative and well-characterized nanoplastics. In the present study, we provided a top down method based on mechanical degradation to obtain nanoplastics from both primary and secondary microplastics. These nanoplastics were then characterized in terms of size distribution, morphology and surface charge. It was found that they are highly polydisperse with different shapes and negatively charged surfaces and therefore very close to natural colloid characteristics. These nanoplastics may share similarities with environmental nanoplastics as referred to their chemical nature and morphology. Their physicochemical properties have been studied vs. salinity, pH and temperature.