Phoretic transport of emulsions through disordered media

Transport of emulsions in disordered environments is important in a myriad of applications, from subsurface flows to targeted drug delivery. Here, we investigate the influence of solute gradients on the transport and dispersion of emulsions in 2D microfluidic chips patterned with an array of obstacles. We observe that emulsion drops migrate in the presence of solute gradients due to the combination of solutal Marangoni flows and diffusiophoresis. Our work sheds light on the interplay between background fluid flows, solute mixing, and phoretic migration of emulsions from the pore-scale to the medium-scale by combining experimental observations and numerical simulations.