Diffusioosmotic flows with surface reactions

Diffusioosmosis is the deterministic fluid motion induced by a concentration gradient of solutes. Here we develop a mathematical model to compute the diffusioosmotic flow velocity of an electrolyte solution in a charged parallel-plate channel. We employ the Poisson-Nernst-Planck equation to determine the electric potential due to channel surface reactions. The electric potential is used to compute the diffusioosmotic flow velocity. We report that the surface reactions can vary the surface charges and the diffusioosmotic flow in an intricate manner. The model developed from this work can be utilized to understand and predict diffusioosmosis in natural phenomena such as metamorphism, in addition to that in applications such as enhanced oil recovery, nanoparticle drug delivery, and colloidal species mixing and separation.