Separation and trapping of nanoparticles using pressure-driven flow and electrokinetic transport in micro- and nanochannels

Recently, detection and separation techniques of micro- and nanoparticles using micro- and nanofluidic channels have been developed. Especially, micro- and nanoplastics have attracted significant attention as pollutants of the water environment. On the other hand, it is known that the separation and recovery of nanoobjects that widely disperse in water are quite difficult. In this study, we investigate the behavior of nanoparticles in nanochannels where nanoparticle transport driven by pressure-driven flow is modified by electrostatic force and electroosmotic flow. Furthermore, nanoparticles are effectively separated by size and captured in the nanochannel by the balance between the Stokes drag and the electrostatic forces acting on particles passing through the nanochannel. The present methods are expected to be one of effective methods for separation, condensation, and recovery of nanoplastics from wastewater as well as transport velocity control for single particle analysis.