Mechano-Diffusion of Anisotropic Particles in Deformed Polymer Networks

The diffusion of anisotropic particles in polymer networks plays a fundamental role in both biological systems and engineering applications. Existing understanding has been mainly focused on particle size and particle-network interactions, while the role of particle anisotropy remains largely unexplored. In this work, we investigate the impact of mechanical deformation on the diffusion behavior of anisotropic particles in polymer networks. Specifically, in an undeformed isotropic polymer network, anisotropic particles undergo direction-dependent diffusion, favoring pathways with the lowest energy barriers. As the polymer network is subjected to uniaxial tensile loading, the mechanical deformation regulates the diffusion of anisotropic particles via the interplay between strain-induced energy modulation and deformation-driven particle reorientation. We further demonstrate that the aspect ratio of anisotropic particles governs the diffusivity-strain relationship: particles with large aspect ratios exhibit a monotonic increase in diffusivity with strain, whereas those with small aspect ratios show a non-monotonic trend. This work will not only provide insights into anisotropic particle diffusion in biological systems but also lay the foundations for designing polymer composites with controlled particle distribution and orientation.