Diffusiophoretic Effects on Particle Dispersion in 2D Channel Flow

Chemical concentration gradients—pervasive in aquifers, soil cores, and engineered filters—mobilise suspended colloids through diffusiophoresis, thereby reshaping their dispersion in porous media. To isolate this mechanism at the pore scale, we analyse colloid transport in a long two‑dimensional channel idealising a single transmitting pore. Neglecting Brownian diffusion over the early–to‑mid breakthrough period, we combine an asymptotic Taylor‑dispersion solution for the solute field with a quasi‑stationary description of the diffusiophoretic drift. The resulting theory provides closed‑form trajectories and density fields for both attractive (c_f>c_i) and repulsive (c_f