Interaction, Adhesion and Aggregation of Microplastic/Nanoplastic Particles: Effects of Plastic Polymer Type

Abstract

Microplastics (MP; <5 mm) and nanoplastics (NP; <1000 nm) are now ubiquitous in nature as they have been released into inland water, lakes, rivers, and marine water through direct discharge, runoff from upland watersheds, and other terrestrial environments. To understand the aggregation of MP and NP in the last decade, surveys and analytical efforts were undertaken. The MP and NP particles in the soil and water environments interact with other natural and engineered nanoparticles, which in turn form aggregates. These plastic particles could form homoaggregates and/or heteroaggregates depending on pH, ionic type, ionic valence, salt concentration, shape and size of the plastic particles, and the polymer type of MP. Differences in MP aggregation due to differences in plastic polymer type are not yet well documented. This review is conducted to investigate the effect of polymer type on the aggregation of MP and NP particles in the presence of various aggregation conditions.