Single particle tracking of polymer aggregates inside disordered porous media

TL;DR

This study visualized and analyzed the diffusion behavior of polymer aggregates in disordered porous media using single particle tracking, revealing size-dependent diffusion, confinement, and anisotropic motion.

Contribution

It provides detailed insights into the diffusion dynamics of polymer aggregates in porous media, highlighting complex interactions and confinement effects.

Findings

Diffusion coefficients vary with aggregate and pore sizes.

Over 85% of aggregates exhibit confined diffusion.

Diffusions are anisotropic, indicating complex interactions.

Abstract

The diffusion motions of individual polymer aggregates in disordered porous media were visualized using the single particle tracking (SPT) method because the motions inside porous media play important roles in various fields of science and engineering. The aggregates diffused on the surfaces of pores; continuous adsorption and desorption processes were obserbed. The relationship between the size of the aggregates and pore size was analysed based on diffusion coefficients, moment scaling spectrum (MSS) slope, and diffusion anisotropy analyisies. The obtained diffusion coefficients were different for different the aggregate and pore sizes. The MSS Slope analysis indicated that more than 85% of the aggregates were confined diffusion for all the conditions investigated. The diffusion anisotropies analysis suggested that the diffusions of the aggregates were anisotropic. The interactions between the aggregates and the pores were complex and exhibited different motions than surface diffusion of smooth surfaces.