Numerical analysis and experimental verification of optical scattering from microplastics

Accurate and fast characterization of the micron-sized plastic particles in aqueous media requires an in-depth understanding of light interaction with these particles. Due to the complexity of Mie scattering theory, the features of the scattered light have rarely been related to the physical properties of these tiny objects. To address this problem, we reveal the relation of the wavelength-dependent optical scattering patterns with the size and refractive index of the particles by numerically studying the angular scattering features. We subsequently present a low-cost setup to measure the optical scattering of the particles. Theoretical investigation shows that the angular distribution of the scattered light by microplastics carries distinct signatures of the particle size and the refractive index. The results can be used to develop a portable, low-cost setup to detect microplastics in water.

Automated summary

Accurately characterizing micron-sized plastic particles in water requires understanding their interaction with light. However, the relationship between scattered light features and particle properties has been rarely explored. In this study, we numerically investigate the angular scattering features and reveal the wavelength-dependent optical scattering patterns related to particle size and refractive index. We also propose a low-cost setup to measure the optical scattering of microplastics, which can be used to develop a portable and affordable device for microplastic detection.