Solute-mediated transport of colloids in disordered media

Solutal gradients due to mixing and reactions in disordered media are ubiquitous. At the scale of a single pore (tens of microns), these gradients generate osmotic flows that can significantly enhance the rate of transport of colloids. Yet, it is not known how solutal gradients can influence the transport on macroscopic length scales. Here, using microfluidic experiments and numerical simulations, we show that solutal gradients can considerably hinder or enhance the transport of colloids through disordered media, and we develop a theoretical model that explains this coupling.