Fig. 4. Polymer trajectories and distributions for the trapping time and hop length.

a Representative (1D) displacements, Δx_c(t), of polymers with different reversal rates, λ, as a function of time for Pe = 50. Horizontal solid lines indicate the trapping phases for different λ. (Inset) Particle trajectories of the center monomer of a rarely reversing polymer, λτ₀ = 5 · 10⁻⁴ (black ; magnified by a factor of 4), and moderately reversing polymers, λτ₀ = 0.5 and 15 (blue and red, respectively). The trajectories are shown in the xy plane, (Δx_c(t), Δy_c(t)). b Trapping time distribution φ_T(t) and c hop length distribution ${\phi }_{{\ell }_H}\left(\ell \right)$ for Pe = 50 and different reversal rates, λ, extracted from individual trajectories. The inset in b shows the fraction of time spent hopping p = τ_H/(τ_H + τ_T) and the average trapping time τ_T/τ₀ as a function of λτ₀. The black solid line in panel c indicates the chord length distribution of the medium ${\phi }_{L_c}\left(\ell \right)$. The inset in c shows the average hopping length 〈ℓ_H〉 normalized by the average chord length 〈L_c〉 of the porous medium. Source data are provided as a Source Data file.