Enhanced diffusiophoresis in dead-end pores with time-dependent boundary solute concentration

The diffusiophoretic velocity of a particle depends nonlinearly on solute concentration. We examine the implications of this nonlinearity in a dead-end pore, which is a geometry found both in nature and in microfluidic devices. We define the efficiency of injection and withdrawal processes, then describe particle dynamics with a step-like change in solute concentration at the pore inlet (commonly used in experiments) and with time-dependent boundary solute concentration. We show that particle migration becomes linear with slow transitions in solute concentration and demonstrate changes in particle dynamics with oscillatory solute concentration at the pore inlet.