Dynamical coupling of ion adsorption with fluid flow in nanopores

Abstract

AbstractTo describe the commonly existing coupling between adsorption dynamics and fluid flow, a nonequilibrium molecular model is developed, upon which we systematically investigate the dynamical adsorption of ionic components from confined flows onto the charged surfaces of nanoscale pores, and find that a competition relation exists between the adsorption and flow. Promoting flow speed suppresses the adsorption amount, while enhancing adsorption strength reduces the flow speed. With the increase of flow speed, the contact density of co‐ion is enhanced while that of counterion is suppressed, leading to overall enhanced accumulation charge densities at pore surfaces. Besides, the accumulation charge density increases monotonically with the applied voltage in large pores, while displays a nontrivial relation with the applied voltage in small pores of several ion sizes. This work not only extends the theoretical framework of nonequilibrium molecular theories, but also provides novel insights into the regulation of interfacial dynamic processes.